JP6484061B2 - Manufacturing method of electronic component package - Google Patents

Description

  The present invention relates to a method for manufacturing an electronic component package.

  For the production of electronic component packages such as semiconductor chips, typically, one or more electronic components fixed to an adherend such as a substrate or a temporary fixing material are sealed with a sealing resin, and if necessary Then, a procedure of dicing the encapsulated material so as to form a package in units of electronic components is employed. As such a sealing resin, a sheet-shaped sealing resin having a good handling property has been proposed (Patent Document 1).

JP 2006-19714 A

  However, when an electronic component is sealed by pressure molding with a flat plate press using such a sealing resin sheet, a void is formed around the electronic component at the outer peripheral portion as compared with the central portion of the molded product (sealed product). It was found that (bubbles) are likely to occur. If the molded product is subjected to a thermosetting process while containing voids, the voids expand due to heating in this process, and in some cases, appearance defects and package cracks may occur, which may significantly reduce the reliability of the electronic component package. . Such a tendency becomes conspicuous when a large sealing resin sheet is used in order to increase the number of electronic components per unit process.

  An object of the present invention is to provide an electronic component package manufacturing method capable of manufacturing a highly reliable electronic component package with a high yield by preventing generation of voids after the electronic component is sealed with a resin.

  The present inventors have examined the above problems, and the void in the molded product after sealing is not due to the fact that the pressure at the time of pressure sealing is not evenly applied between the central portion and the outer peripheral portion of the molded product. I got the knowledge of heels. As a result of further intensive studies, the inventors have found that the above-described problems can be solved by the following configuration, and have completed the present invention.

That is, the present invention includes a step A for preparing an adherend on which a plurality of electronic components are arranged, and a step B for laminating a sealing resin sheet on the adherend under pressure so as to embed the electronic components. Including
In the step B, the electronic component package is produced by pressurizing the sealing resin sheet through a pressure dispersion material.

  In the manufacturing method, when a sealing resin sheet is laminated on an adherend under pressure and an electronic component is resin-sealed (hereinafter also referred to as “pressure sealing”), a pressure dispersion material is interposed. Therefore, the pressure applied to the sealing resin sheet is more uniform, in other words, the pressure difference between the central portion and the outer peripheral portion of the sealing resin sheet can be reduced. A highly reliable electronic component package can be manufactured by suppressing the generation of voids later. In addition, although the generation | occurrence | production mechanism of the pressure difference of the center part of a sealing resin sheet and an outer peripheral part is not certain, it estimates as follows. That is, since the side surface of the sealing resin sheet is generally an open system in a flat plate press, if the sealing resin sheet is softened by heating during pressure sealing, the sealing resin sheet faces outward at the outer periphery. Will be extended. As a result, the thickness of the sealing resin sheet becomes thin and it is difficult for the pressure to be applied. As a result, it is assumed that the pressure difference is generated. In addition, since it is only necessary to interpose a pressure dispersion material at the time of pressure sealing, a highly reliable electronic component package can be manufactured with a high yield while using an existing process as it is.

  The pressure dispersion material is preferably larger than the sealing resin sheet in plan view. Thereby, a pressure dispersion material can go around to the side of a sealing resin sheet with the pressure at the time of pressure sealing, and the pressurization state from a side will be achieved. As a result, the pressure on the outer peripheral portion of the sealing resin sheet where voids are likely to be generated can be supplemented from the side surface, and the uniformity of the pressure load can be further improved.

  The pressure dispersion material is preferably porous. By making it porous, the pressure dispersibility can be improved, and the uniformity of the pressure load on the sealing resin sheet during pressure sealing can be further enhanced.

  The pressure dispersion material is preferably made of a fluorine sponge or a silicone sponge. Since these materials have moderate elasticity, they are excellent in pressure dispersibility. Moreover, since it also has releasability, it can peel easily from the sealing resin sheet or the press plate for pressure sealing.

  It is preferable to perform the step B with a release film interposed between the sealing resin sheet and the pressure dispersion material. Thereby, peeling between a sealing resin sheet and a pressure dispersion material can be performed easily, and the production efficiency of an electronic component can be improved.

  The shape of the sealing resin sheet in plan view may be a circle with a diameter of 300 mm or more or a rectangle with a side length of 300 mm or more. In order to increase the yield of electronic component packages obtained by a single sealing process, the number of electronic components to be sealed is increased and the size of the sealing resin sheet in plan view is increased (that is, the area is increased). do it. However, when the area of the encapsulating resin sheet is increased, the pressure distribution on the encapsulating resin sheet is biased and the void generation rate is increased. In the manufacturing method, even when such a large-area sealing resin sheet is used, the uniformity of the pressure load on the sealing resin sheet by the pressure dispersion material can be improved, so the void after sealing Can be prevented, and as a result, the manufacturing efficiency of the electronic component package can be improved.

  The pressing is preferably performed by a flat plate press. Although the flat plate press is preferable from the simplicity of operation and availability, since the side surface of the sealing resin sheet is an open system at the time of resin sealing as described above, the center portion of the sealing resin sheet A pressure difference is likely to occur between the outer periphery and the outer periphery. However, since the manufacturing method uses a pressure dispersion material at the time of pressure sealing, the pressure difference can be reduced even by pressing with such a flat plate press, and a highly reliable package is manufactured. be able to.

It is sectional drawing which shows typically 1 process of the manufacturing method of the electronic component package which concerns on one Embodiment of this invention. It is sectional drawing which shows typically 1 process of the manufacturing method of the electronic component package which concerns on one Embodiment of this invention. It is sectional drawing which shows typically 1 process of the manufacturing method of the electronic component package which concerns on one Embodiment of this invention. It is sectional drawing which shows typically 1 process of the manufacturing method of the electronic component package which concerns on one Embodiment of this invention. It is sectional drawing which shows typically 1 process of the manufacturing method of the electronic component package which concerns on one Embodiment of this invention. It is sectional drawing which shows typically 1 process of the manufacturing method of the electronic component package which concerns on one Embodiment of this invention. It is sectional drawing which shows typically 1 process of the manufacturing method of the electronic component package which concerns on one Embodiment of this invention. It is sectional drawing which shows typically 1 process of the manufacturing method of the electronic component package which concerns on one Embodiment of this invention. It is sectional drawing which shows typically the electronic component and to-be-adhered body which concern on another one Embodiment of this invention. 3 is a photograph of a chip exposed surface of the sealing body of Example 1. 6 is a photograph of a chip exposed surface of a sealing body of Comparative Example 1.

  An embodiment of a method for manufacturing an electronic component package of the present invention will be described below with reference to the drawings. However, in some or all of the drawings, parts unnecessary for the description are omitted, and there are parts shown enlarged or reduced for easy explanation.

<< First Embodiment >>
[Electronic component package manufacturing method]
A method for manufacturing an electronic component package according to this embodiment using a sealing resin sheet will be described with reference to FIGS. 1A to 1H. 1A to 1H are cross-sectional views schematically showing one process of a method for manufacturing an electronic component package according to an embodiment of the present invention. In the first embodiment, a semiconductor chip is manufactured by using a semiconductor chip as an electronic component and a temporary fixing material as an adherend, and sealing the semiconductor chip mounted on the temporary fixing material with a sealing resin sheet. To do.

[Step A1: Temporary fixing material preparation step]
In the temporary fixing material preparing step, the temporary fixing material 1 in which the thermally expandable pressure-sensitive adhesive layer 1a is laminated on the support 1b is prepared as an adherend (see FIG. 1A). In addition, it can replace with a thermally expansible adhesive layer, and can also use a radiation curing type adhesive layer.

(Thermal expansion adhesive layer)
The heat-expandable pressure-sensitive adhesive layer 1a can be formed of a pressure-sensitive adhesive composition containing a polymer component and a foaming agent. Examples of the polymer component (particularly the base polymer) include known resins used in pressure-sensitive adhesive compositions, such as polyimide resins, silicone resins, aliphatic olefin resins, hydrogenated styrene thermoplastic elastomers, and acrylic resins. Can do. Of these, acrylic resins are preferred.

  In addition, an external cross-linking agent can be appropriately used for the heat-expandable pressure-sensitive adhesive in order to adjust the pressure-sensitive adhesive force. Specific examples of the external crosslinking method include a method of adding a so-called crosslinking agent such as a polyisocyanate compound, an epoxy compound, an aziridine compound, a melamine crosslinking agent, and reacting them. When using an external crosslinking agent, the amount used is 20 parts by weight or less (preferably 0.1 parts by weight to 10 parts by weight) with respect to 100 parts by weight of the base polymer.

(Foaming agent)
The foaming agent used in the heat-expandable pressure-sensitive adhesive layer 1a is not particularly limited, and can be appropriately selected from known foaming agents. A foaming agent can be used individually or in combination of 2 or more types. As the foaming agent, thermally expandable microspheres can be suitably used. Examples of the heat-expandable microsphere include a microsphere in which a substance that expands easily by gasification by heating, such as isobutane, propane, or pentane, is encapsulated in an elastic shell. Examples thereof include vinylidene chloride-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyacrylonitrile, polyvinylidene chloride, and polysulfone.

  Examples of thermally expandable microspheres include a series of “Matsumoto Microsphere F30”, “Matsumoto Microsphere F30D”, “Matsumoto Microsphere F301D”, “Matsumoto Microsphere F50D”, “Matsumoto Microsphere F501D”, “Matsumoto Microsphere F80SD”, “Matsumoto Microsphere F80VSD”, etc.) , "053DU", "551DU", "551-20DU", and "551-80DU" can be used.

  When thermally expandable microspheres are used as the foaming agent, the particle size (average particle diameter) of the thermally expandable microspheres can be appropriately selected according to the thickness of the thermally expandable pressure-sensitive adhesive layer. . The average particle diameter of the heat-expandable microspheres can be selected from a range of, for example, 100 μm or less (preferably 80 μm or less, more preferably 1 μm to 50 μm, particularly 1 μm to 30 μm).

  The amount of foaming agent (thermally expandable microspheres, etc.) can be set as appropriate depending on the expansion ratio of the thermally expandable pressure-sensitive adhesive layer and the ability to lower the adhesive strength, but generally a thermally expandable pressure-sensitive adhesive layer is formed. The amount is, for example, 1 part by weight to 150 parts by weight (preferably 10 parts by weight to 130 parts by weight, more preferably 25 parts by weight to 100 parts by weight) with respect to 100 parts by weight of the base polymer.

In the present embodiment, the foaming start temperature (thermal expansion start temperature) (T ₀ ) of the foaming agent is preferably 80 ° C. to 210 ° C., more preferably 90 ° C. to 200 ° C. If the foaming start temperature of the foaming agent is too low, the foaming agent may inadvertently foam. On the other hand, if the foaming start temperature of the foaming agent is too high, excessive heat resistance is required for the support of the temporary fixing material and the sealing resin, which is not preferable in terms of handleability, productivity, and cost. Foaming starting temperature of the foaming agent (T ₀₎ corresponds to the foaming starting temperature of the heat-expandable pressure-sensitive adhesive layer (T _0).

  The thickness of the heat-expandable pressure-sensitive adhesive layer is not particularly limited, and can be appropriately selected depending on the reduction in adhesive strength, and is, for example, about 5 μm to 300 μm (preferably 20 μm to 150 μm).

  The thermally expandable pressure-sensitive adhesive layer may be either a single layer or multiple layers.

  In the present embodiment, the heat-expandable pressure-sensitive adhesive layer has various additives (for example, a colorant, a thickener, a bulking agent, a filler, a tackifier, a plasticizer, an anti-aging agent, an antioxidant, and a surfactant. Agent, cross-linking agent, etc.).

(Support)
The support 1 b is a thin plate member that serves as a strength matrix of the temporary fixing material 1. The material of the support 1b may be appropriately selected in consideration of handling properties, heat resistance, and the like. For example, metal materials such as SUS, plastic materials such as polyimide, polyamideimide, polyether ether ketone, and polyether sulfone, glass Etc. can be used. Among these, a SUS plate is preferable from the viewpoints of heat resistance, strength, reusability, and the like.

  The thickness of the support 1b can be appropriately selected in consideration of the intended strength and handleability, and is preferably 100 to 5000 μm, more preferably 300 to 2000 μm.

(Middle layer)
In the present embodiment, an intermediate layer may be provided between the heat-expandable pressure-sensitive adhesive layer 1a and the support 1b for the purpose of improving adhesion and improving peelability after heating (not shown). ) Among them, it is preferable that a rubbery organic elastic intermediate layer is provided as the intermediate layer. The rubber-like organic elastic intermediate layer is preferably formed of natural rubber, synthetic rubber, or synthetic resin having rubber elasticity having a D-type Sure D-type hardness of 50 or less, particularly 40 or less based on ASTM D-2240. The thickness of the intermediate layer is, for example, about 5 μm to 300 μm, preferably about 20 μm to 150 μm.

(Method for forming temporary fixing material)
The temporary fixing material 1 is obtained by forming the thermally expandable pressure-sensitive adhesive layer 1a on the support 1b. The heat-expandable pressure-sensitive adhesive layer is, for example, a sheet obtained by mixing a pressure-sensitive adhesive (pressure-sensitive adhesive), a foaming agent (heat-expandable microspheres, etc.) and, if necessary, a solvent or other additives. It can be formed using a conventional method for forming a layer. Specifically, for example, a method of applying a mixture containing a pressure-sensitive adhesive, a foaming agent (such as thermally expandable microspheres), and a solvent and other additives as necessary onto the support 1b, an appropriate separator ( The heat-expandable pressure-sensitive adhesive layer may be formed by applying the mixture on a release paper or the like to form a heat-expandable pressure-sensitive adhesive layer, and transferring (transferring) the mixture onto the support 1b. it can.

[Step A2: Semiconductor Chip Placement Step]
In the semiconductor chip arrangement step, a plurality of semiconductor chips 13 are arranged on the temporary fixing material 1 such that the active surface A1 faces the temporary fixing material 1 (see FIG. 1A). A known device such as a flip chip bonder or a die bonder can be used to arrange the semiconductor chip 13.

  The layout and the number of arrangement of the semiconductor chips 13 can be appropriately set according to the shape and size of the temporary fixing material 1, the number of target packages produced, and the like, for example, a matrix of a plurality of rows and a plurality of columns. Can be arranged in a line.

[Process B: Sealing process]
In the sealing step, the sealing resin sheet 11 is laminated on the temporary fixing material 1 so that the semiconductor chip 13 is embedded in the sealing resin sheet 11, and the semiconductor chip 13 is resin-sealed with the sealing resin sheet (FIG. 1B). And FIG. 1C). The sealing resin sheet 11 functions as a sealing resin for protecting the semiconductor chip 13 and its accompanying elements from the external environment.

  First, the sealing resin sheet 11 is prepared. The sealing resin sheet 11 (see FIG. 1B) may be prepared in a state of being laminated on a separator (not shown) such as a polyethylene terephthalate (PET) film. In this case, the separator may be subjected to a release treatment in order to easily peel off the sealing resin sheet 11. Details of the resin composition and the manufacturing method for forming the sealing sheet 11 will be described later.

  After preparing the sealing resin sheet, as shown in FIG. 1B, the temporary fixing material 1 in which the semiconductor chip 13 is fixed on the lower heating plate 101 is disposed with the surface on which the semiconductor chip 13 is mounted facing upward. The sealing resin sheet 11 is disposed on the surface of the temporary fixing material 1 on which the semiconductor chip 13 is mounted. In this step, the temporary fixing material 1 may be first disposed on the lower heating plate 101, and then the sealing resin sheet 11 may be disposed on the temporary fixing material 1. The sheet 11 may be laminated first, and then a laminate in which the temporary fixing material 1 and the sealing resin sheet 11 are laminated may be disposed on the lower heating plate 101.

(Pressure dispersion material)
In the present embodiment, the pressure dispersion material 2 is disposed between the sealing resin sheet 11 and the upper heating plate 102. Thereby, the pressurization with respect to the sealing resin sheet 11 is performed through the pressure dispersion material. The pressure dispersion member 2 disperses the pressure applied to the sealing resin sheet 11 during hot pressing by the lower heating plate 101 and the upper heating plate 102, so that the central portion and the outer peripheral portion of the sealing resin sheet 11 are dispersed. Has the effect of reducing the pressure difference.

  The size of the pressure dispersion material 2 in plan view may be smaller than the sealing resin sheet 11, may be the same, or may be larger. The pressure dispersion material 2 is preferably larger than the sealing resin sheet 11 in plan view. Thereby, it becomes easy for the pressure dispersion material 2 to wrap around the side surface of the sealing resin sheet 11 due to the pressure at the time of pressure sealing, and not only the upper surface of the sealing resin sheet 11 but also the pressure state from the side surface is achieved. It will be. As a result, the pressure on the outer peripheral portion of the sealing resin sheet where voids are likely to be generated can be compensated from the side surface, and the uniformity of the pressure load can be further increased to suppress the generation of voids. In addition, when the planar view size of the pressure dispersion material 2 is equal to or less than that of the sealing resin sheet 11, a flexible forming material is used to enhance the spreadability of the sealing resin sheet 11, and the pressure during sealing is increased. What is necessary is just to make it reach to the side surface of the sealing resin sheet 11.

  If the pressure dispersion material 2 is too soft, the pressure load or transmission to the sealing resin sheet is not sufficient, and if it is too hard, it is difficult to follow the shape of the sealing resin sheet. Therefore, the material for forming the pressure dispersion material 2 is moderate enough to disperse the load pressure on the sealing resin sheet 11 and moderate flexibility enough to follow the sealing resin sheet 11 (and the temporary fixing material 1). It is not particularly limited as long as it has a good resilience. Suitable forming materials include polyimide, fluororesin, silicone resin, urethane resin, natural rubber, synthetic rubber (chloroprene rubber, ethylene propylene rubber, nitrile rubber, etc.) and the like. Of these, fluororesins and silicone resins are preferred from the viewpoint of heat resistance.

  The pressure dispersion material 2 is preferably porous. By making it porous, the pressure dispersibility can be improved, and the uniformity of the pressure load on the sealing resin sheet during pressure sealing can be further enhanced. In particular, the pressure dispersion material 2 is preferably formed of a fluorine sponge or a silicone sponge. Since these materials have moderate elasticity, they are excellent in pressure dispersibility. Moreover, since it also has releasability, it can peel easily from the sealing resin sheet or the press plate for pressure sealing.

  The Shore E hardness of the pressure dispersion material 2 is preferably 10 or more and 70 or less, and more preferably 15 or more and 50 or less. If the Shore E hardness is too low, the pressure dispersion material itself is crushed by pressurization, making it difficult to properly apply pressure to the sealing resin sheet. On the other hand, if the Shore E hardness is too high, the spreadability of the pressure dispersion material is lowered, and the followability to the shape of the sealing resin sheet is lowered, so that a sufficient pressure dispersion action may not be exhibited. is there.

  The apparent density of the pressure dispersion material 2 is not particularly limited, but if the apparent density is too large, the flexibility is often lowered, and the followability to the sealing resin sheet 11 may be lowered. On the other hand, if the apparent density is too small, the mechanical strength of the pressure dispersion material itself is lowered, the resilience is lowered, and the pressure dispersion action may be impaired. The apparent density can be measured according to JIS K 7222: 2005.

  Although the thickness in the case where the pressure dispersion material 2 is in a sheet form can be appropriately set according to the thickness of the laminate of the adherend and the sealing resin sheet, the pressure dispersion material is thicker than the laminate. It is preferable. This is because the laminate can be embedded in the pressure dispersion material, and a pressure load from the upper surface and the side surface of the sealing resin sheet becomes possible.

  In this embodiment, as shown in FIGS. 1B and 1C, it is preferable to perform pressure sealing by further interposing a release film 3 between the sealing resin sheet 11 and the pressure dispersion material 2. Thereby, peeling after sealing between the sealing resin sheet 11 and the pressure dispersion material 2 can be performed easily, and the production efficiency of electronic components can be improved. The material for forming the release film 3 is preferably a so-called non-stiff (low rigidity) material from the viewpoint of followability to the laminate of the sealing resin sheet 11 and the temporary fixing material 1, and is preferably an olefin film or fluororesin. A system film or the like is preferable. Although the thickness of the release film 3 is not particularly limited, it is preferably 10 μm or more and 100 μm or less, and more preferably 20 μm or more and 50 μm or less, from the viewpoint of the followability and handling properties.

  Next, as illustrated in FIG. 1C, the sealing resin sheet 11 is temporarily pressed 1 while the semiconductor chip 13 is embedded in the sealing resin sheet 11 by hot pressing with the lower heating plate 101 and the upper heating plate 102. Laminate on top. Thereby, the sealing body (refer FIG. 1D) by which the semiconductor chip 13 currently fixed on the temporary fixing material 1 was embedded in the sealing resin sheet 11 is obtained. In this embodiment, since pressure is applied by hot pressing through the pressure dispersion material 2, as shown in FIG. 1C, the pressure dispersion material spread by pressure covers the upper surface and side surfaces of the sealing resin sheet. It will be. As a result, pressure load from the side surface as well as the upper surface of the sealing resin sheet is possible, thereby reducing the pressure difference between the central portion and the outer peripheral portion of the sealing resin sheet, and the semiconductor chip of the sealing resin sheet and Generation of voids due to insufficient adhesion to the temporary fixing material can be suitably suppressed. A spacer (not shown) may be interposed between the lower heating plate 101 and the upper heating plate 102 so that the thickness of the sealing resin sheet 11 after hot pressing becomes a predetermined value.

  As hot press conditions, the temperature is, for example, 40 to 130 ° C., preferably 60 to 120 ° C., the pressure is, for example, 50 to 2500 kPa, preferably 100 to 2000 kPa, and the time is, for example, 0 .3 to 10 minutes, preferably 0.5 to 5 minutes. In consideration of improvement in the adhesion and followability of the sealing resin sheet 11 to the semiconductor chip 13 and the temporary fixing material 1, it is preferable to press under reduced pressure conditions (for example, 10 to 2000 Pa). In the present embodiment, by employing the sealing resin sheet 11 and the pressure dispersion material 2, the semiconductor chip 13 can be embedded simply by pasting the semiconductor chip 13 on the temporary fixing material 1 and the reliability of the semiconductor package. And production efficiency can be improved.

  After hot pressing, the sealing body 15 is taken out from the hot pressing apparatus, and when the separator is laminated on the sealing resin sheet 11, the separator is peeled off before the sealing body 15 is sent to the thermosetting process.

[Process C: Thermosetting process]
In the thermosetting step, the sealing body 15 is formed by applying a thermosetting process to the sealing resin sheet 11 (see FIG. 1D). The conditions of the thermosetting treatment of the sealing resin sheet 11 are preferably 100 to 200 ° C., more preferably 110 to 180 ° C. as the heating temperature, and preferably 3 to 200 minutes, more preferably 30 to 120 minutes as the heating time. In the meantime, you may pressurize as needed. In the pressurization, preferably 0.1 MPa to 10 MPa, more preferably 0.5 MPa to 5 MPa can be employed.

[Step D: Thermally expandable pressure-sensitive adhesive layer peeling step]
In the heat-expandable pressure-sensitive adhesive layer peeling step, the temporary fixing material 1 is heated to thermally expand the heat-expandable pressure-sensitive adhesive layer 1a, thereby peeling between the heat-expandable pressure-sensitive adhesive layer 1a and the sealing body 15. (See FIG. 1E). Alternatively, a procedure of performing peeling at the interface between the support 1b and the thermally expandable pressure-sensitive adhesive layer 1a and then performing peeling by thermal expansion at the interface between the thermally expandable pressure-sensitive adhesive layer 1a and the sealing body 15 is also preferable. Can be adopted. In either case, peeling at the interface between the thermally expandable pressure-sensitive adhesive layer 1a and the sealing body 15 is facilitated by heating and thermally expanding the heat-expandable pressure-sensitive adhesive layer 1a to reduce its adhesive strength. Can be done. As the conditions for thermal expansion, the conditions for the foaming start temperature of the foaming agent in the above-mentioned thermally expandable pressure-sensitive adhesive layer can be suitably employed.

  In this step, the surface of the sealing body 15 may be cleaned by plasma treatment or the like prior to the rewiring forming step with the semiconductor chip 13 exposed.

[Process E: Rewiring process]
In the present embodiment, it is preferable to further include a rewiring forming step of forming the rewiring 19 on the surface of the sealing body 15 on the active surface A1 side of the semiconductor chip 13. In the rewiring forming step, after the thermally expandable pressure-sensitive adhesive layer 1a is peeled off, a rewiring 19 connected to the exposed semiconductor chip 13 is formed on the sealing body 15 (see FIG. 1F).

  As a method of forming the rewiring, for example, a metal seed layer is formed on the exposed semiconductor chip 13 using a known method such as a vacuum film forming method, and then re-reformed by a known method such as a semi-additive method. The wiring 19 can be formed.

  Thereafter, an insulating layer such as polyimide or PBO may be formed on the rewiring 19 and the sealing body 15.

[Process F: Bump formation process]
Next, a bumping process for forming bumps 17 on the formed rewiring 19 may be performed (see FIG. 1G). The bumping process can be performed by a known method such as a solder ball or solder plating. The material of the bump is not particularly limited. For example, a tin-lead metal material, a tin-silver metal material, a tin-silver-copper metal material, a tin-zinc metal material, a tin-zinc-bismuth metal material, etc. Solders (alloys), gold-based metal materials, copper-based metal materials, and the like.

[Process G: Dicing process]
Finally, dicing is performed on the laminate including elements such as the semiconductor chip 13, the sealing resin sheet 11, and the rewiring 19 (see FIG. 1H). As a result, the semiconductor package 18 in which the wiring is drawn outside the chip region can be obtained for each semiconductor chip. In FIG. 1H, dicing is performed corresponding to one semiconductor chip, but dicing may be performed with two or more semiconductor chips as a unit. Dicing is usually performed after fixing the sealing body 15 with a conventionally known dicing sheet. The alignment of the cut portion may be performed by image recognition using direct illumination or indirect illumination.

  In this step, for example, a cutting method called full cut for cutting up to a dicing sheet can be adopted. It does not specifically limit as a dicing apparatus used at this process, A conventionally well-known thing can be used.

  In addition, when expanding a sealing body following a dicing process, this expansion can be performed using a conventionally well-known expanding apparatus. The expanding device includes a donut-shaped outer ring that can push down the dicing sheet through the dicing ring, and an inner ring that has a smaller diameter than the outer ring and supports the dicing sheet. By this expanding process, it is possible to prevent the adjacent semiconductor packages 18 from coming into contact with each other and being damaged.

(Process H: Board mounting process)
If necessary, a substrate mounting step of mounting the semiconductor package 18 obtained above on a separate substrate (not shown) can be performed. For mounting the semiconductor package 18 on the substrate, a known device such as a flip chip bonder or a die bonder can be used.

[Sealing resin sheet]
Hereinafter, the suitable aspect of the resin composition which forms a sealing resin sheet is demonstrated. The resin composition preferably further includes a thermosetting resin from the viewpoint of improving heat resistance and stability after curing the sealing resin sheet. As specific components, epoxy resin compositions containing the following components A to E are preferred.
A component: Epoxy resin B component: Phenol resin C component: Elastomer D component: Inorganic filler E component: Curing accelerator

(A component)
It does not specifically limit as an epoxy resin (A component) as a thermosetting resin. For example, triphenylmethane type epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, modified bisphenol A type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, modified bisphenol F type epoxy resin, dicyclopentadiene type Various epoxy resins such as an epoxy resin, a phenol novolac type epoxy resin, and a phenoxy resin can be used. These epoxy resins may be used alone or in combination of two or more.

  From the viewpoint of ensuring the toughness after curing of the epoxy resin and the reactivity of the epoxy resin, those having an epoxy equivalent of 150 to 250 and a softening point or melting point of 50 to 130 ° C. are preferably solid, and in particular, from the viewpoint of reliability. Therefore, triphenylmethane type epoxy resin, cresol novolac type epoxy resin, and biphenyl type epoxy resin are preferable.

  Also, from the viewpoint of low stress, a modified bisphenol A type epoxy resin having a flexible skeleton such as an acetal group or a polyoxyalkylene group is preferable, and a modified bisphenol A type epoxy resin having an acetal group is in a liquid state and is easy to handle. Therefore, it can be particularly preferably used.

  The content of the epoxy resin (component A) is preferably set in the range of 1 to 10% by weight with respect to the entire epoxy resin composition.

(B component)
The phenol resin (component B) is not particularly limited as long as it can be used as a thermosetting resin and causes a curing reaction with the epoxy resin (component A). For example, a phenol novolak resin, a phenol aralkyl resin, a biphenyl aralkyl resin, a dicyclopentadiene type phenol resin, a cresol novolak resin, a resole resin, or the like is used. These phenolic resins may be used alone or in combination of two or more.

  From the viewpoint of reactivity with the epoxy resin (component A), it is preferable to use a phenolic resin having a hydroxyl equivalent weight of 70 to 250 and a softening point of 50 to 110 ° C., among which the curing reactivity is high. A phenol novolac resin can be preferably used. From the viewpoint of reliability, low hygroscopic materials such as phenol aralkyl resins and biphenyl aralkyl resins can also be suitably used.

  From the viewpoint of curing reactivity, the blending ratio of the epoxy resin (component A) and the phenol resin (component B) is a hydroxyl group in the phenol resin (component B) with respect to 1 equivalent of the epoxy group in the epoxy resin (component A). It is preferable to mix | blend so that it may become 0.7-1.5 equivalent, More preferably, it is 0.9-1.2 equivalent.

(C component)
The elastomer (C component) used together with the epoxy resin (A component) and the phenol resin (B component) is not particularly limited, and for example, various acrylic copolymers and rubber components can be used. A rubber component is preferably included from the viewpoint that the dispersibility in the epoxy resin (component A) and the heat resistance, flexibility, and strength of the obtained sealing resin sheet can be improved. Such a rubber component is preferably at least one selected from the group consisting of butadiene rubber, styrene rubber, acrylic rubber, and silicone rubber. These may be used alone or in combination of two or more.

  The content of the elastomer (component C) is preferably 1.0 to 3.5% by weight, more preferably 1.0 to 3.0% by weight, based on the entire epoxy resin composition. If the content of the elastomer (component C) is less than 1.0% by weight, it becomes difficult to obtain the flexibility and flexibility of the sealing resin sheet 11, and further the resin sealing that suppresses the warping of the sealing resin sheet It will also be difficult. On the other hand, when the content exceeds 3.5% by weight, the melt viscosity of the sealing resin sheet 11 is increased and the embedding property of the electronic component is lowered, and the strength and heat resistance of the cured body of the sealing resin sheet 11 are reduced. Tend to decrease.

(D component)
The inorganic filler (component D) is not particularly limited, and various conventionally known fillers can be used. For example, quartz glass, talc, silica (fused silica, crystalline silica, etc.), alumina, nitriding Examples thereof include aluminum, silicon nitride, and boron nitride powders. These may be used alone or in combination of two or more.

  Among these, silica powder is used in that the internal stress is reduced by reducing the coefficient of thermal expansion of the cured product of the epoxy resin composition, and as a result, warpage of the sealing resin sheet 11 after sealing of the electronic component can be suppressed. It is preferable to use a fused silica powder among the silica powders. Examples of the fused silica powder include spherical fused silica powder and crushed fused silica powder. From the viewpoint of fluidity, it is particularly preferable to use a spherical fused silica powder. Among them, those having an average particle size in the range of 55 μm or less are preferably used, those in the range of 0.1 to 30 μm are more preferable, and those in the range of 0.5 to 20 μm are particularly preferable.

  The average particle diameter can be derived by using a sample arbitrarily extracted from the population and measuring it using a laser diffraction / scattering particle size distribution measuring apparatus.

The content of the inorganic filler (component D) is preferably 70 to 90% by volume of the entire epoxy resin composition (81 to 94% by weight because the specific gravity is 2.2 g / cm ³ in the case of silica particles). More preferably, it is 74 to 85% by volume (84 to 91% by weight in the case of silica particles), and still more preferably 76 to 83% by volume (85 to 90% by weight in the case of silica particles). When the content of the inorganic filler (D component) is less than 70% by volume, the linear expansion coefficient of the cured product of the epoxy resin composition increases, and thus the warpage of the sealing resin sheet 11 tends to increase. On the other hand, since the softness | flexibility and fluidity | liquidity of the sealing resin sheet 11 will worsen when the said content exceeds 90 volume%, the tendency for adhesiveness with an electronic component to fall is seen.

(E component)
The curing accelerator (component E) is not particularly limited as long as it allows curing of the epoxy resin and the phenol resin, but from the viewpoint of curability and storage stability, triphenylphosphine or tetraphenylphosphonium tetraphenyl. Organic phosphorus compounds such as borates and imidazole compounds are preferably used. These curing accelerators may be used alone or in combination with other curing accelerators.

  It is preferable that content of a hardening accelerator (E component) is 0.1-5 weight part with respect to a total of 100 weight part of an epoxy resin (A component) and a phenol resin (B component).

(Other ingredients)
In addition to the A component to the E component, a flame retardant component may be added to the epoxy resin composition. As the flame retardant composition, various metal hydroxides such as aluminum hydroxide, magnesium hydroxide, iron hydroxide, calcium hydroxide, tin hydroxide, and complex metal hydroxide can be used. As the flame retardant component, a phosphazene compound can be used in addition to the metal hydroxide. As phosphazene compounds, for example, SPR-100, SA-100, SP-100 (above, Otsuka Chemical Co., Ltd.), FP-100, FP-110 (above, Fushimi Pharmaceutical Co., Ltd.) and the like are available as commercial products. is there. As the cyclic phosphazene oligomer, for example, FP-100, FP-110 (above, Fushimi Pharmaceutical Co., Ltd.) and the like are commercially available. From the viewpoint of exhibiting a flame retardant effect even in a small amount, the content of the phosphorus element contained in the phosphazene compound is preferably 12% by weight or more.

  In addition to the above components, the epoxy resin composition can be appropriately mixed with other additives such as a pigment including carbon black as necessary.

  The planar view shape of the sealing resin sheet 11 is not particularly limited, and may be a circle having a diameter of 300 mm or more or a rectangle having a side length of 300 mm or more. By enlarging the sealing resin sheet 11 as described above, the number of electronic components to be sealed in one sealing process can be increased, and the yield of the obtained electronic component package can be increased. Can do. Further, when the sealing resin sheet is increased in area, the generation ratio of voids in the outer peripheral portion also increases, but the pressure is applied to the sealing resin sheet 11 via a pressure dispersion material during pressure sealing. Therefore, the pressure difference between the central portion and the outer peripheral portion can be reduced to prevent the generation of voids, thereby improving the reliability and manufacturing efficiency of the electronic component package.

  The storage elastic modulus of the sealing resin sheet at 55 ° C. before thermosetting is preferably 10 Pa or more and 200000 Pa or less, and more preferably 100 Pa or more and 150,000 Pa or less. By setting the storage elastic modulus before thermosetting to the above range, the handling property of the sealing resin sheet and the embedding property of the electronic component are improved.

(Method for producing sealing resin sheet)
A method for producing the sealing resin sheet will be described below. The manufacturing method of the sealing resin sheet of this embodiment includes a kneading step of preparing a kneaded product, and a molding step of forming the kneaded product into a sheet shape to obtain a sealing resin sheet.

(Kneading process)
First, an epoxy resin composition is prepared by mixing the above-described components. The mixing method is not particularly limited as long as each component is uniformly dispersed and mixed. Thereafter, a kneaded product is prepared by directly kneading each compounding component with a kneader or the like.

  Specifically, the above components A to E and, if necessary, each component of other additives are mixed using a known method such as a mixer, and then kneaded to prepare a kneaded product. The method of melt kneading is not particularly limited, and examples thereof include a method of melt kneading with a known kneader such as a mixing roll, a pressure kneader, or an extruder. As such a kneader, for example, a kneading screw having a portion in which the protruding amount of the screw blade from the screw shaft in a part of the axial direction is smaller than the protruding amount of the screw blade of the other portion or the shaft A kneader equipped with a kneading screw having no screw blades in a part of the direction can be suitably used. Low shear force and low agitation in the part where the protruding amount of the screw wing is small or where there is no screw wing increases the compression rate of the kneaded product, and it is possible to eliminate the trapped air and generate pores in the obtained kneaded product Can be suppressed.

  The kneading conditions are not particularly limited as long as the temperature is equal to or higher than the softening point of each component described above. For example, when considering the thermosetting property of 30 to 150 ° C. and the epoxy resin, preferably 40 to 140 ° C., more preferably It is 60-120 degreeC, and time is 1 to 30 minutes, for example, Preferably it is 5 to 15 minutes. Thereby, a kneaded material can be prepared.

(Molding process)
The sealing resin sheet 11 can be obtained by forming the obtained kneaded material into a sheet shape by extrusion molding. Specifically, the encapsulating resin sheet 11 can be formed by extrusion molding without cooling the kneaded product after melt-kneading while maintaining a high temperature state. Such an extrusion method is not particularly limited, and examples thereof include a T-die extrusion method, a roll rolling method, a roll kneading method, a co-extrusion method, and a calendar molding method. The extrusion temperature is not particularly limited as long as it is equal to or higher than the softening point of each component described above, but considering the thermosetting property and moldability of the epoxy resin, for example, 40 to 150 ° C, preferably 50 to 140 ° C, Preferably it is 70-120 degreeC. As described above, the sealing resin sheet 11 can be formed.

  Although the thickness of the sealing resin sheet 11 is not specifically limited, It is preferable that it is 100-2000 micrometers. Within the above range, the electronic component can be satisfactorily sealed. Further, by making the resin sheet thin, the amount of heat generation can be reduced, and curing shrinkage hardly occurs. As a result, the amount of package warpage can be reduced, and a more reliable electronic component package can be obtained.

  The encapsulating resin sheet thus obtained may be used by being laminated so as to have a desired thickness if necessary. That is, the sealing resin sheet may be used in a single layer structure, or may be used as a laminate formed by laminating two or more multilayer structures.

<< Second Embodiment >>
A second embodiment which is an embodiment of the present invention will be described. FIG. 2 is a cross-sectional view schematically showing an electronic component and an adherend according to another embodiment of the present invention. In the first embodiment, the resin sealing is performed in a state where the semiconductor chip is temporarily fixed to the temporary fixing material. In the second embodiment, a semiconductor wafer is used as an adherend, and the semiconductor wafer is flip-chip connected to the semiconductor wafer. The semiconductor chip is sealed with a sealing resin sheet to produce a semiconductor package. Hereinafter, differences from the first embodiment will be mainly described.

(Process A: Chip mounting wafer preparation process)
In the chip mounting wafer preparation step, a semiconductor wafer 22A in which a plurality of semiconductor chips 23 are flip-chip connected is prepared (see FIG. 2). The semiconductor chip 23 can be formed by dicing a semiconductor wafer on which a predetermined circuit is formed by a known method. For mounting the semiconductor chip 23 on the semiconductor wafer 22A, a known device such as a flip chip bonder can be used. In the present embodiment, flip chip connection is employed in which the active surface A2 on which the protruding electrode 23a of the semiconductor chip 23 is formed faces the semiconductor wafer 22A. The semiconductor chip 23 and the semiconductor wafer 22A are electrically connected to each other through bump electrodes 23a formed on the semiconductor chip 23 and through electrodes 22a provided on the semiconductor wafer 22A. As the through electrode 22a, an electrode of the TSV (Through Silicon Via) type can be suitably used.

  Also, an underfill material 24 is filled between the semiconductor chip 23 and the semiconductor wafer 22A in order to alleviate the difference in thermal expansion coefficient between them and prevent the occurrence of cracks and the like particularly at the connection site. A known material may be used as the underfill material 24. The underfill material 24 may be disposed by injecting a liquid underfill material 24 between the semiconductor chips 23 after mounting the semiconductor chip 23 on the semiconductor wafer 22A, or a semiconductor chip with a sheet-like underfill material 24. 23 or the semiconductor wafer 22A may be prepared and then the semiconductor chip 23 and the semiconductor wafer 22A may be connected.

  The subsequent sealing process to substrate mounting process can be performed under the same conditions as in the first embodiment. In the second embodiment, since the semiconductor wafer is used as the adherend, the thermally expandable pressure-sensitive adhesive layer peeling step is omitted, and in the rewiring forming step, the semiconductor wafer 22A is connected to the through electrode 22a. Rewiring is formed on the semiconductor wafer 22A. Furthermore, after the sealing resin sheet laminated on the semiconductor wafer 22A is thermally cured, a grinding process for grinding the semiconductor wafer 22A to a desired thickness may be provided. Grinding may be performed using a known grinding apparatus for fixing the sealing body by bonding the back surface grinding tape to the cured sealing resin sheet, and fixing the semiconductor wafer 22A of the fixed sealing body. A well-known thing can be used for the tape for back surface grinding.

<< Third Embodiment >>
In the first embodiment, each compounding component is kneaded with a kneader or the like to prepare a kneaded product, and the kneaded product is extruded to form a sheet. On the other hand, in this embodiment, the varnish which melt | dissolved or disperse | distributed each component in the organic solvent etc. is applied, and it forms in a sheet form.

  As a specific production procedure using a varnish, the above components A to E and, if necessary, other additives are appropriately mixed according to a conventional method, and uniformly dissolved or dispersed in an organic solvent to prepare a varnish. Subsequently, the sealing sheet can be obtained by applying the varnish on a support such as polyester and drying it. If necessary, a release sheet such as a polyester film may be bonded to protect the surface of the sealing sheet.

  The organic solvent is not particularly limited, and various conventionally known organic solvents such as methyl ethyl ketone, acetone, cyclohexanone, dioxane, diethyl ketone, toluene, ethyl acetate and the like can be used. These may be used alone or in combination of two or more. In general, it is preferable to use an organic solvent so that the solid content concentration of the varnish is in the range of 30 to 95% by weight.

  Although the thickness of the sheet after drying the organic solvent is not particularly limited, it is usually preferably set to 5 to 100 μm, more preferably 20 to 70 μm, from the viewpoint of uniformity of thickness and the amount of residual solvent. is there. Alternatively, a plurality of dried sheets may be laminated to obtain a desired thickness.

<< Other embodiments >>
In the first and second embodiments, a semiconductor chip is used as the electronic component, and in the second embodiment, a semiconductor wafer is used as the adherend. However, other elements may be used. Examples of electronic components include SAW (Surface Acoustic Wave) filter sensors, MEMS (Micro Electro Mechanical Systems) and other hollow electronic devices (hollow electronic devices); ICs (integrated circuits), transistors, etc. Semiconductors, capacitors, resistors, light-emitting elements, and the like can be used. Moreover, a printed wiring board, a lead frame, a tape carrier, etc. can be used as an adherend. Note that an electronic device having a hollow structure may be sealed in a hollow state, or may be solidly sealed using an underfill material or the like so as not to include a hollow portion depending on a sealing target.

  Hereinafter, preferred embodiments of the present invention will be described in detail by way of example. However, the materials, blending amounts, and the like described in this example are not intended to limit the scope of the present invention only to those unless otherwise specified. The term “parts” means parts by weight.

<Production of workpiece>
A thermally expandable pressure-sensitive adhesive layer (product name “Riva Alpha No. 3195V” manufactured by Nitto Denko Corporation) was laminated on a SUS carrier to make a temporary fixing material, and a chip was placed on the thermally expandable pressure-sensitive adhesive layer with a flip chip bonder. Things were used as work.

Carrier size: 300mm diameter x 1.1mm thickness
Carrier material: SUS
Chip size: 7mm □ × 0.3mm thickness Number of chips: 482

<Preparation of sealing resin sheet>
A sealing resin sheet was produced by the following procedure. In Production Example 1, a sheet was formed by a kneading method, and in Production Example 2, a sheet was formed by a coating method.

(component)
The components used in Production Examples 1 and 2 were as follows.

Epoxy resin: YSLV-80XY manufactured by Nippon Steel Chemical Co., Ltd. (bisphenol F type epoxy resin, epkin equivalent 200 g / eq. Softening point 80 ° C.)
Phenol resin: MEH-7851-SS manufactured by Meiwa Kasei Co., Ltd. (phenol resin having a biphenylaralkyl skeleton, hydroxyl group equivalent 203 g / eq. Softening point 67 ° C.)
Silane coupling agent: KBM-403 (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd.
Curing accelerator: 2PHZ-PW (2-phenyl-4,5-dihydroxymethylimidazole) manufactured by Shikoku Kasei Kogyo Co., Ltd.
Thermoplastic resin: J-5800 (acrylic rubber) manufactured by Mitsubishi Rayon Co., Ltd.
Filler: FB-9454FC manufactured by Denki Kagaku Kogyo Co., Ltd. (fused spherical silica powder, average particle size 17.6 μm)
Carbon black: # 20 (particle size 50 nm) manufactured by Mitsubishi Chemical Corporation

(Mixing ratio)
(1) It compounded so that the hydroxyl group in a phenol resin might become 1 equivalent with respect to 1 equivalent of epoxy groups in an epoxy resin (The total amount of an epoxy resin and a phenol resin in 100 weight% of all compounding components: 9.3 weight%).
(2) A curing accelerator was blended so as to be 1.0 part by weight with respect to 100 parts by weight of the total of epoxy resin and phenol resin.
(3) A thermoplastic resin was blended so as to be 30% by weight in 100% by weight of organic components (all components excluding filler).
(4) A filler was blended so as to be 88% by weight in 100% by weight of all blended components (79.5% by volume in the resin sheet).
(5) 0.1 part by weight of a silane coupling agent was blended with 100 parts by weight of the filler.
(6) Carbon black was blended so as to be 0.3% by weight in 100% by weight of all blended components.

(Production Example 1)
Each component was blended according to the above blending ratio, and melt-kneaded under reduced pressure conditions (0.01 kg / cm ² ) at 60 to 120 ° C. for 10 minutes using a roll kneader to prepare a kneaded product. Subsequently, the obtained kneaded material was molded into a sheet having a thickness of 500 μm by a flat plate pressing method, and a sealing resin sheet A was obtained.

(Production Example 2)
According to the above blending ratio, an epoxy resin, a phenol resin, a thermoplastic resin, a filler, and a silane coupling agent were added to methyl ethyl ketone (MEK) so as to have a solid content concentration of 95%, followed by stirring. Stirring was performed for 5 minutes at 800 rpm rotation using a rotation and revolution mixer (manufactured by Sinky Co., Ltd.). Thereafter, according to the above blending ratio, a curing accelerator and carbon black are further added, MEK is added so that the solid content concentration becomes 90%, and further stirred at 800 rpm for 3 minutes to obtain a coating liquid (varnish). Obtained.

  Thereafter, the coating solution was applied onto MRA-50 that had been subjected to silicone release treatment, and dried at 120 ° C. for 3 minutes to prepare a sheet having a thickness of 100 μm. Further, a plurality of the produced sheets were bonded at 90 ° C. with a roll laminator to obtain a sealing resin sheet B having a thickness of 500 μm.

[Examples 1 to 4]
The produced sealing resin sheet was cut into a circular shape having a diameter of 12 inches in plan view. The cut sealing resin sheet was laminated while embedding chips on the workpiece by vacuum hot pressing under the following heating and pressing conditions. At the time of lamination, a pressure dispersion material having a length of 400 mm × width of 400 mm and a thickness of 2000 μm was placed on the sealing resin sheet, and then heating and pressing were performed. The sealing resin sheet and pressure dispersion material used in each example are shown in Table 1.

(Paste conditions)
Temperature: 90 ° C
Applied pressure: 0.5 MPa
Degree of vacuum: 2000Pa
Press time: 5 minutes

  In all the examples, after releasing all the portions of the sealing resin sheet protruding from the workpiece, the sealing resin sheet is thermally cured in a hot air dryer at 150 ° C. for 1 hour. Thus, a sealed body was produced.

[Comparative Examples 1 and 2]
A sealing body was produced in the same manner as in Example 1 except that the sealing resin sheets were laminated without arranging the pressure dispersion material.

<Evaluation>
(Appearance evaluation)
The external appearance of the sealing body was confirmed visually. If a void exists in the sealing body, the void expands due to heating during thermosetting, and the surface of the sealing resin sheet rises due to the expanded void. The case where there was no unevenness (protrusion) to the extent that it could be visually confirmed on the surface of the sealing resin sheet was evaluated as “◯”, and the case where the unevenness was present was evaluated as “x”. The results are shown in Table 1.

(Flatness evaluation)
The thickness of one sealing body was measured at a plurality of locations, and the difference between the maximum value and the minimum value of the thickness was determined and evaluated as TTV (Total Thickness Value). The thickness was measured at 25 points in the plane using a dial gauge, and the difference between the maximum value and the minimum value was used as the TTV value. The case where the TTV was 40 μm or less was evaluated as “◯”, and the case where it exceeded 40 μm was evaluated as “X”. The results are shown in Table 1.

(Evaluation of chip embedding)
Each sealing body is placed on a hot plate heated to 180 ° C. with the temporary fixing material side down, heated for 3 minutes to foam the thermally expandable pressure-sensitive adhesive layer, and a sealing resin sheet in which chips are embedded ( In addition, the sealing body) was separated from the workpiece. Thereafter, Riva Alpha attached to the sealing body was peeled off on a hot plate at 100 ° C., and the chip exposed surface side was visually observed. Check the presence or absence of air entrapment traces (dents from the surface) in the peripheral area of the chip, and the ratio of chips with no entrapment trace to the total number of chips (N = 482) is 98% or more The case where “◯” was less than 98% was evaluated as “x”. The results are shown in Table 1.

  Moreover, the photograph of the chip | tip exposed surface of the sealing body of Example 1 is shown in FIG. 3, and the photograph of the chip | tip exposed surface of the sealing body of the comparative example 1 is shown in FIG. 4, respectively.

  As is clear from Table 1, in Examples 1 to 4, all evaluations were good, and generation of voids was not confirmed. On the other hand, in Comparative Examples 1 and 2, the trace of air in the chip embedding property was confirmed together with the unevenness in the appearance evaluation, and voids were generated. In FIG. 4, white portions indicated by arrows in the photograph correspond to void traces. In addition, the TTV was increased due to the generation of voids, and the thickness was not uniform.

[Examples 5 to 7 and Comparative Examples 3 to 5]
In this example, a SAW chip, which is a hollow electronic device, was used as an electronic component, and the chip embedding property and the hollow sealing uniformity when this was pressure-sealed with a sealing resin sheet were evaluated.

(Preparation of sealing resin sheet)
The following components and blending amounts were used for forming the sealing resin sheets of Examples 5 to 7 and Comparative Examples 3 to 5.
Epoxy resin: YSLV-80XY manufactured by Nippon Steel Chemical Co., Ltd. (bisphenol F type epoxy resin, Epokin equivalent: 200 g / eq., Softening point: 80 ° C.)
6.3 parts Phenolic resin: LVR8210DL (Novolak type phenolic resin, hydroxyl group equivalent: 104 g / eq., Softening point: 60 ° C.) manufactured by Gunei Chemical Co., Ltd.
3.4 parts Thermoplastic resin: ME-2000M manufactured by Negami Kogyo Co., Ltd. (carboxyl group-containing acrylate polymer, weight average molecular weight: about 600,000, Tg: −35 ° C., acid value: 20 mgKOH / g)
1.7 parts Filler 1: FB-5SDC (spherical silica, average particle size 5 μm) manufactured by Denki Kagaku Kogyo Co., Ltd.
61.6 parts Filler 2: SC-220G-SMJ (manufactured by Admatechs) (spherical silica, average particle size 0.5 μm; surface treatment with silane coupling agent (“KBM503” manufactured by Shin-Etsu Chemical Co., Ltd.))
26.4 parts carbon black: # 20 manufactured by Mitsubishi Chemical Corporation
0.36 parts Curing accelerator: 2PHZ-PW (2-phenyl-4,5-dihydroxymethylimidazole) manufactured by Shikoku Kasei Kogyo Co., Ltd.
0.24 parts

  According to the above blending ratio, each component was dissolved and dispersed in methyl ethyl ketone as a solvent to obtain a varnish having a solid concentration of 90% by weight. This varnish was applied on a release treatment film made of a polyethylene terephthalate film having a thickness of 38 μm after the release treatment with silicone, and then dried at 110 ° C. for 5 minutes. As a result, a sheet having a thickness of 50 μm was obtained. Four layers of this sheet were laminated to obtain a sealing resin sheet having a thickness of 200 μm.

(Evaluation of chip embedding and hollow sealing uniformity)
A SAW chip with the following specifications on which aluminum comb-shaped electrodes are formed is mounted on a 30 mm × 30 mm square ceramic substrate under the following bonding conditions to produce a SAW chip mounting substrate including the ceramic substrate and the SAW chip mounted on the ceramic substrate. did. The gap width between the SAW chip and the ceramic substrate was 20 μm.

<SAW chip>
Chip size: 1.2 mm square (thickness 150 μm)
Bump material: Au (height 20 μm)
Number of bumps: 6 bumps Number of chips: 100 (10 x 10)

<Bonding conditions>
Equipment: manufactured by Panasonic Electric Works Co., Ltd. Bonding conditions: 200 ° C., 3N, 1 sec, ultrasonic output 2W

  A 200 μm-thick sealing resin sheet (28 mm × 28 mm square) is placed on the SAW chip mounting substrate, and a fluorine sponge sheet having a length of 40 mm × width of 40 mm and a thickness of 2000 μm is used as a pressure dispersion material on the sealing resin sheet. Arranged. Under the heating and pressing conditions shown below, vacuum pressing was performed by a parallel plate method to obtain a laminate.

<Vacuum press conditions>
Temperature: 70 ° C
Applied pressure: 1 to 5 kgf / cm ² (see Table 2)
Degree of vacuum: 1.6 kPa
Press time: 1 minute

  After opening to atmospheric pressure, the laminate was heated in a hot air dryer at 150 ° C. for 1 hour to obtain a sealed body. Cleavage the interface between the substrate of the obtained sealing body and the sealing resin, and the periphery of the chip because the sealing resin does not reach the lower part of the chip with the product name “Digital Microscope” (200 times) manufactured by KEYENCE The presence or absence of air entrainment traces (ie, voids) in the region was confirmed. Of the total number of chips (N = 100), the case where 98 or more chips without biting marks were evaluated was evaluated as “◯”, and the case where the number was 97 or less was evaluated as “X”. The results are shown in Table 2.

  Further, for each chip, the amount of resin entering the hollow portion between the SAW chip and the ceramic substrate was measured. The resin penetration amount was determined by measuring the maximum value and the minimum value of the reach distance of the resin that entered the hollow portion from the end of the SAW chip, and set the maximum penetration amount and the minimum penetration amount, respectively. When a void is generated, the resin does not reach the hollow portion and remains in the region outside the chip in a plan view, and therefore the resin entry amount is a negative value. “○” when the maximum entry amount is 20 μm or less and the minimum entry amount is −20 μm or more, “X” when the maximum entry amount exceeds 20 μm or the minimum entry amount is less than −20 μm. As evaluated.

  As can be seen from Table 2, in Examples 5 to 7 using a fluorine sponge sheet at the time of pressure sealing, both the chip embedding property and the hollow sealing uniformity were good. On the other hand, in any of Comparative Examples 3 to 5 in which no pressure dispersion material was used, voids were generated, resulting in poor chip embedding. In Comparative Example 5 where the pressure applied during pressure sealing is relatively large, the uniformity of hollow sealing was good, but there was a large variation in the amount of resin entering during hollow sealing throughout Comparative Examples 3-5. It was.

DESCRIPTION OF SYMBOLS 1 Temporary fixing material 1a Thermal expansion adhesive layer 1b Support body 2 Pressure dispersion material 3 Release film 11 Sealing resin sheet 13, 23 Semiconductor chip 15 Sealing body 18 Semiconductor package 19 Rewiring 22A Semiconductor wafer

Claims (6)

Including a step A of preparing an adherend on which a plurality of electronic components are arranged, and a step B of laminating a sealing resin sheet on the adherend under pressure so as to embed the electronic components,
In the step B, have lines through the pressure distribution member the pressure applied to the sealing resin sheet,
The pressure dispersion material is a manufacturing method of an electronic component package larger than the sealing resin sheet in a plan view . The method of manufacturing an electronic component package according to claim 1, wherein the pressure dispersion material is porous. Method of manufacturing an electronic component package according to claim 1 or 2 is formed by the pressure variance member fluorine sponge or silicone sponge. The manufacturing method of the electronic component package of any one of Claims 1-3 which perform the said process B by interposing a peeling film between the said sealing resin sheet and the said pressure dispersion material. Planar shape of the sealing resin sheet, a method for producing an electronic component package according to any one of claims 1-4 lengths of more than a circular or side diameter 300mm is more rectangular 300mm. Method of manufacturing an electronic component package according to any one of claims 1 to 5 for the by pressurized flat press.