JP2006237275A - Process for producing semiconductor device and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process for producing a semiconductor device in which the thickness of resin seal is strictly controlled by a simple method using a simple device, and also to provide a semiconductor device. <P>SOLUTION: A sealing device 10 produces a semiconductor device by pressure sealing a substrate 14 mounting a semiconductor element 12 by means of a die 16 using a sealing resin sheet 24. The die 16 has a concave cavity 18 formed to have predetermined dimensions corresponding to the dimensions of the semiconductor element 12. The die 16 is arranged while spaced apart from the substrate 14 with the semiconductor element 12 mounted thereto and the resin sheet 24 is arranged between the semiconductor element 12 and the die 16 (arranging process), the substrate 14 and the die 16 are superposed and pressed while thermally fusing the resin sheet 24 (fusing process), the fused resin sheet is hardened (hardening process) and released from the die to obtain a semiconductor device. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semiconductor device manufacturing method for sealing a substrate on which a semiconductor element is mounted using a resin sheet, and a semiconductor device manufactured by the manufacturing method.

  A substrate on which an electronic component such as a semiconductor chip (hereinafter, sometimes referred to as a semiconductor element in this specification) is mounted has an electrode of the semiconductor element and an electrode of the substrate electrically connected by an electrical connection means. . As the electrical connection means, for example, in the case of a surface mounting method in which a semiconductor element is directly mounted on an importer or an electronic circuit in an inexpensive manufacturing process, bonding wires are still widely used from the viewpoint of cost.

And in order to protect this electrical connection means from atmospheric gas containing moisture and oxygen when using the semiconductor device, for example, the semiconductor device is widely sealed with a resin.
As a sealing method using a resin, a method using a liquid resin having excellent fluidity has been widely used since the resin can be reliably filled between the bonding wires that require high-density wiring.
This method using a liquid resin is one in which the liquid resin is applied to the surface of the substrate or poured into a cavity of a mold that covers the substrate, and then the liquid resin is cured.

However, with the progress of miniaturization and weight reduction of semiconductor devices, the demand for precise dimensional control technology in the molding and sealing process of chip size packages has increased, and the sealing method using the above liquid resin meets this requirement. It is no longer possible.
Also, in the case of the resin sealing method in which the liquid resin is poured into the mold cavity covering the substrate, if the clearance of the cavity on the chip after clamping is about 0.15 mm or less, the resin to the clearance location There is also a problem that the wraparound is not sufficiently performed and the state of insufficient filling is generated.

  In order to meet the above requirements, a method of using a resin sheet (film-shaped sealing resin) instead of a liquid resin as a sealing resin is also employed.

As a sealing method using such a resin sheet, for example, the following is disclosed.
This resin sealing method includes a step of placing the substrate on one of the opposing mold sets, and a mold surface of a concave cavity provided on the other mold of the mold set. A step of placing the resin sheet on the substrate, a step of generating a molten resin in the cavity by heating the resin sheet, a step of immersing the electronic component in the molten resin by clamping the mold set, and a melting in the cavity A step of forming a molded product by curing the resin, a step of opening the mold set, and a step of taking out the molded product. In this case, preferably, a movable member is provided on the mold on which the resin sheet is placed, and the movable member is moved up and down so that the liquid level of the molten resin and the mating surface of the mold in which the cavity opens are flush with each other. Thus, the sealing height of the resin is adjusted (see Patent Document 1).
And according to this method, when the chip mounted on the substrate is resin-sealed, defects such as voids and wire deformation are reduced, and easy handling and effective use of the resin material are enabled. .
JP 2004-146556 A

However, with the above resin sealing method, it is considered difficult to strictly control the resin sealing thickness in order to realize a precise dimensional control technique for the chip size package.
In the above resin sealing method, it is substantially indispensable to provide a movable member in the mold. In this case, including the step of adjusting the sealing thickness of the resin by the movable member includes a large number of steps. In addition, the apparatus becomes expensive, and furthermore, due to the structure having the movable part, it is difficult to apply a high pressure to the mold during sealing, so there is a possibility that proper molding may not be performed. Alternatively, if the standing time of the resin melted in the mold becomes long, the curing of the resin proceeds in the mold, and there is a concern that the resin does not flow sufficiently during sealing.
Further, in the above resin sealing method, there is a possibility that the resin may flow between the mold for housing the movable member and the movable member. In that case, in order to maintain the smooth operation of the movable member, the apparatus is disassembled. It may be necessary to clean it.

  The present invention has been made in view of the above problems, and provides a method for manufacturing a semiconductor device and a semiconductor device capable of strictly controlling the sealing thickness of a resin by a simple method using a simple device. With the goal.

In order to achieve the above object, a method for manufacturing a semiconductor device according to the present invention includes:
In a method for manufacturing a semiconductor device in which a substrate on which a semiconductor element is mounted is sealed using a resin sheet,
A mold having a concave cavity formed in a predetermined dimension corresponding to the dimension of the semiconductor element is disposed apart from the substrate on which the semiconductor element is mounted, and the mold is disposed between the semiconductor element and the mold. An arrangement step of arranging a resin sheet;
A melting step of superposing and pressing the substrate and the mold while the resin sheet is heated and melted;
A curing step for curing the molten resin sheet;
It is characterized by having.

  In the semiconductor device manufacturing method according to the present invention, the predetermined dimension includes at least a depth dimension of the cavity obtained by adding a value of 0.15 mm or less to a height dimension of the semiconductor element. To do.

  Further, in the method for manufacturing a semiconductor device according to the present invention, the predetermined dimension of the cavity is 1.01 to 1.2 times the volume of the semiconductor element including a melt-cured product of the resin sheet in a sealed state. Including at least a three-dimensional dimension of the cavity forming the volume.

  In the method for manufacturing a semiconductor device according to the present invention, the resin sheet is 10 Pa.s at a temperature of 150 ° C. s to 100 Pa. It has a melt viscosity of s and is cured within a time range of 150 to 250 ° C. within a time of 30 to 180 minutes.

  The method for manufacturing a semiconductor device according to the present invention is characterized in that, in the arranging step, a release resin sheet is further arranged between the resin sheet and the cavity.

  In addition, a semiconductor device according to the present invention is manufactured by the above-described method for manufacturing a semiconductor device, and the thickness dimension of the melt-cured product of the resin sheet on the upper surface of the semiconductor element in a sealed state is 0.15 mm or less. And

  According to the present invention, since the mold has a concave cavity formed in a predetermined size corresponding to the size of the semiconductor element, the sealing thickness of the resin of the semiconductor device can be reduced by a simple method using a simple device. It can be strictly controlled.

  Embodiments of the present invention will be described below with reference to the drawings.

First, a sealing device used in a method for manufacturing a semiconductor device according to the present invention will be described with reference to FIG.
As shown in FIG. 1, the sealing device 10 uses a resin sheet (not shown in FIG. 1; see the resin sheet 24 in FIG. 2) for sealing the substrate 14 on which the semiconductor element 12 is mounted. The semiconductor device is manufactured by press-sealing with a mold 16.
The mold 16 has a concave cavity 18 formed in a predetermined dimension corresponding to the dimension of the semiconductor element 12.

The predetermined dimension of the cavity 18 is set in order to obtain a suitable outer dimension of the semiconductor device in a sealed state, which is useful from the viewpoint of reducing the size and weight of the semiconductor device and reducing the thickness.
As the predetermined dimension of the cavity 18, preferably, the depth dimension D of the cavity 18 is slightly larger than the height dimension H of the semiconductor element, and a value of 0.15 mm or less is added to the height dimension H of the semiconductor element 12. Dimensions.
By adding a value of 0.15 mm or less to the height dimension H of the semiconductor element 12, the sealing thickness of the upper surface of the semiconductor element 12 is set to 0.15 mm or less, and the height dimension of the semiconductor device can be reduced. it can. Incidentally, as described above, when the liquid resin is poured into the mold cavity covering the substrate and sealed with the resin by the transfer molding method, the sealing thickness is set to 0.15 mm or less as described above. , Sealing becomes insufficient. The lower limit of the value added to the height dimension H of the semiconductor element 12 is not particularly limited, but is preferably 0.05 mm or more from the viewpoint of surely sealing.
Note that the dimension obtained by adding a value of 0.15 mm or less to the height dimension H of the semiconductor element 12, that is, the sealing height after sealing, is as follows from the viewpoint of downsizing the height dimension of the semiconductor device. It is preferable that it is 1 mm or less.

  The predetermined dimension of the cavity 18 is preferably a three-dimensional dimension of the cavity 18, that is, a depth dimension D of the cavity 18 and a dimension of two sides forming the opening of the cavity 18. The cavity volume is set to be 1.01 to 1.2 times the volume of the semiconductor element including the melt-cured product. Thereby, the volume of the semiconductor device can be reduced. At this time, the depth dimension D of the cavity 18 is preferably a dimension obtained by adding a value of 0.15 mm or less to the height dimension H of the semiconductor element 12 as described above.

Here, the substrate (printed substrate) 14 on which the semiconductor element 12 is mounted is not particularly limited, and may be a laminated substrate or a substrate composed of a single layer. Similarly, the substrate 14 may be a rigid substrate or may be a flexible substrate.
In this embodiment, the case where a flexible printed circuit board is used as the substrate 14 is taken as an example. Flexible printed circuit board, for example, wiring that has been processed by etching metal such as copper, copper alloy, aluminum, nickel on a heat-resistant insulating resin layer such as polyimide resin, polyamideimide resin, aramid resin, polyester resin Is used for COF, interposer, multilayer wiring board and the like.
Even when a flexible printed circuit board is used as the substrate 14 or a rigid substrate whose rigidity is not sufficiently large is used, and even when a rigid substrate whose rigidity is sufficiently large is used, pressure molding with a mold is performed satisfactorily. For this purpose, a stage 20 on which the substrate 14 is arranged and supported is provided.

  The electrical connection means for electrically connecting the semiconductor element 12 and the substrate 14 is not particularly limited, and may be a multi-chip module (MCM) or a bare chip direct mounting system, and a chip having an interposer. A size package (CSP) connected to the substrate may be used. Further, the connection method of the bare chip electrode and the substrate 14 electrode (all of which are not shown) is not particularly limited, and may be wire bonding, TAB, or Also, an appropriate method such as flip chip can be selected and employed. In the present embodiment, as a method of connecting the bare chip electrode and the substrate 14 electrode (both electrodes are not shown), both electrodes are formed by wires (bonding wires) 22 provided on an interposer substrate (not shown). Taking the case of electrical connection as an example.

  The mold 16 and the stage 20 include appropriate heating means (not shown). In addition, the sealing device 10 includes appropriate lifting means (not shown) that lifts and lowers the mold 16 toward the substrate 14.

  In the sealing device 10 described above, the substrate 14 on which the semiconductor element 12 is mounted is fixedly disposed on the stage 20, the mold 16 is provided above and spaced apart from the substrate 14, and the mold 16 is moved up and down. Resin sealing is performed. However, instead of this, the sealing device 10 is configured so that the substrate 14 and the mold 16 of the sealing device 10 are arranged upside down and the mold 16 is moved up and down toward the substrate 14 disposed above. May be.

  Next, a method for manufacturing a semiconductor device according to the present invention will be described with reference to FIGS.

  In the method for manufacturing a semiconductor device according to the present invention, a mold 16 having a concave cavity 18 formed to have a predetermined dimension corresponding to the dimension of the semiconductor element 12 is disposed apart from the substrate 14 on which the semiconductor element 12 is mounted. In addition, a disposing step of disposing the resin sheet 24 between the semiconductor element 12 and the mold 16, a melting step of superposing and pressing the substrate 14 and the mold 16 while heating and melting the resin sheet 24, and a molten resin A curing step for curing the sheet 24.

Here, as the resin sheet (resin film) 24, what is known as a sheet-like adhesive can be used, but it has a low viscosity that melts during sealing and enters into the gap near the wire. Is required. Examples of the resin as a raw material for such a resin sheet include polyimide resins, epoxy resins, polyester resins, and the like, and those having desired characteristics are selected. That is, preferably, the resin sheet 24 is 10 Pa. At a temperature of 150 ° C. s to 100 Pa. A material having a melt viscosity of s and being cured within a time range of 30 minutes to 180 minutes in a temperature range of 150 ° C. to 250 ° C. is selected. As a result, when the resin sheet 24 is melted, it is possible to reliably fill the resin with a portion where the molten resin is difficult to rotate, such as a cavity having a narrow clearance between the mold and the semiconductor element 12. The molten resin can be efficiently cured at a low temperature that does not give a low temperature.
In addition, these resins may be a resin composition composed of a plurality of resins, or may be a resin composition containing a filler. Moreover, it is preferable that the thickness of the resin sheet 24 is 0.05 mm or more and 1 mm or less in order to supply a sufficient amount of resin for sealing the semiconductor element 12 and to avoid the excessive resin from protruding.

In the arranging step, the resin sheet 24 is arranged between the semiconductor element 12 and the 16 mold 16 as described above.
That is, when the sealing device 10 is used, the resin sheet 24 is disposed on the upper surface of the semiconductor element 12 as shown in FIG. At this time, the resin sheet 24 may be disposed in the cavity 18. The same applies to the case of using a sealing device in which the mold 16 and the substrate 14 are arranged upside down.
The cavity 18 of the mold 16 is sized to accommodate the semiconductor element 12 and the wire 22.

In the melting step, as described above, the substrate 14 and the mold 16 are overlapped and pressed while the resin sheet 24 is heated and melted.
At this time, prior to lowering the mold 16, the temperature of the mold 16 is set to be about 10 ° C. to 80 ° C. higher than the melting start temperature of the resin sheet 24, and the temperature of the stage 20 is set 5 times higher than the temperature of the mold 16. Set to a temperature lower by about 60 ° C to 60 ° C.
Then, as shown in FIG. 3, the mold 16 is moved downward to soften and melt the resin sheet 24 and fill the cavity 18.
Next, in the curing step, the mold 16 and the stage 20 are brought into close contact with the substrate 14 between them, the mold is clamped with a predetermined pressure, and the state is maintained as it is for about 5 seconds to 10 seconds, for example. Further, the mold 16 is moved downward by, for example, 0.005 mm to 0.05 mm and held, for example, for about 5 seconds to 60 seconds.

  Finally, the mold 16 is moved up and cooled to take out the semiconductor device 26 according to the present invention which is a molded product (see FIG. 4).

  As described above, the semiconductor device 26 according to the present invention preferably has a thickness dimension of the melt-cured product of the resin sheet on the upper surface of the semiconductor element in a sealed state of 0.15 mm or less.

In the embodiment described above, only the sealing resin sheet 24 is used, but at this time, more preferably, as shown in FIG. 5, the release resin sheet between the resin sheet 24 and the mold 16. 28 is further arranged.
The release resin sheet 28 may be laminated on the resin sheet 24, or a release resin sheet may be provided on the inner surface of the mold 16 that defines the cavity 18.
Examples of the raw material resin used for the release resin sheet 28 include olefins such as polyethylene and polypropylene and polyesters such as PET. In view of heat resistance and the like, a PET film is more preferable. In this case, the surface of the resin sheet may be treated with a release agent or the like in order to improve the release property.
Due to the presence of the release resin sheet 28, the mold release property between the cured resin sheet (resin) 24 and the mold 16 can be improved, and the resin-encapsulated semiconductor element can be easily removed from the mold. In addition, since the sealing resin and the mold are not in direct contact with each other, the contamination of the mold is improved, and the mold cleaning step is unnecessary or simplified.

It is a figure which shows schematic structure of the sealing device used for the manufacturing method of the semiconductor device which concerns on this invention. It is a figure for demonstrating the arrangement | positioning process of the manufacturing method of the semiconductor device which concerns on this invention. It is a figure for demonstrating the melting process and hardening process of the manufacturing method of the semiconductor device which concerns on this invention. It is a figure which shows the semiconductor device manufactured by the manufacturing method of the semiconductor device which concerns on this invention. It is a figure for demonstrating the method of using the resin sheet for mold release in the manufacturing method of the semiconductor device which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Sealing device 12 Semiconductor element 14 Substrate 16 Mold 20 Stage 22 Wire 24, 28 Resin sheet 26 Semiconductor device

Claims (6)

In a method for manufacturing a semiconductor device in which a substrate on which a semiconductor element is mounted is sealed using a resin sheet,
A mold having a concave cavity formed in a predetermined dimension corresponding to the dimension of the semiconductor element is disposed apart from the substrate on which the semiconductor element is mounted, and the mold is disposed between the semiconductor element and the mold. An arrangement step of arranging a resin sheet;
A melting step of superposing and pressing the substrate and the mold while the resin sheet is heated and melted;
A curing step for curing the molten resin sheet;
A method for manufacturing a semiconductor device, comprising:   2. The method of manufacturing a semiconductor device according to claim 1, wherein the predetermined dimension includes at least a depth dimension of the cavity obtained by adding a value of 0.15 mm or less to a height dimension of the semiconductor element.   The predetermined dimension includes at least a three-dimensional dimension of the cavity that forms a volume of the cavity that is 1.01 to 1.2 times the volume of the semiconductor element including a melt-cured product of the resin sheet in a sealed state. 3. A method of manufacturing a semiconductor device according to claim 1, wherein:   The resin sheet has a pressure of 10 Pa. s to 100 Pa. The semiconductor according to any one of claims 1 to 3, which has a melt viscosity of s and is cured within a time range of 30 minutes to 180 minutes in a temperature range of 150 ° C to 250 ° C. Device manufacturing method.   5. The method of manufacturing a semiconductor device according to claim 1, wherein in the arranging step, a resin sheet for releasing is further arranged between the resin sheet and the cavity.   While manufactured with the manufacturing method of the semiconductor device of any one of Claims 1-5, the thickness dimension of the molten hardened | cured material of the resin sheet of the semiconductor element upper surface in a sealing state is 0.15 mm or less. A featured semiconductor device.

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