JP2021125516A - Adhesive sheet for manufacturing semiconductor device - Google Patents

Abstract

To provide an adhesive sheet for manufacturing a semiconductor device without resin leakage in a resin sealing step.SOLUTION: An adhesive sheet for manufacturing a semiconductor device includes a base material, and an adhesive layer provided on one surface of the base material, and is detachably attached to a lead frame or a wiring board of the semiconductor device, and the adhesive layer includes a silicone adhesive and a silane coupling agent, and the adhesive layer is subjected to plasma treatment for 1 minute under a condition of an output of 450 W, and then a surface contact angle measured with mesitylene of the adhesive layer after heating at 220°C for 30 minutes is 30° or more.SELECTED DRAWING: None

Description

The present invention relates to an adhesive sheet for manufacturing a semiconductor device.

In recent years, with the miniaturization and multi-functionalization of electronic devices such as portable personal computers and mobile phones, in addition to the miniaturization and high integration of electronic components that make up electronic devices, high-density mounting technology for electronic components has become necessary. ing. Against this background, surface-mounted semiconductors such as CSP (Chip Scale Package) that can be mounted at high density instead of peripheral-mounted semiconductor devices such as QFP (Quad Flat Package) and SOP (Small Outline Package). The device is attracting attention. Further, among CSPs, the QFN (Quad Flat Non-led) package is particularly suitable because it can be manufactured by applying the conventional manufacturing technology of a semiconductor device, and is mainly used as a small terminal type semiconductor device having 100 pins or less. ing.

As a method for manufacturing a QFN package, the following methods are generally known. First, in the attachment process, an adhesive sheet is attached to one surface of the lead frame, and then in the die attach process, a semiconductor such as an IC chip is attached to a plurality of semiconductor element mounting portions (die pad portions) formed on the lead frame. Each element is mounted. Next, in the wire bonding step, a plurality of leads arranged along the outer periphery of each semiconductor element mounting portion of the lead frame and the semiconductor element are electrically connected by a bonding wire. Next, in the sealing step, the semiconductor element mounted on the lead frame is sealed with the sealing resin. Then, in the peeling step, the pressure-sensitive adhesive sheet is peeled from the lead frame to form a QFN unit in which a plurality of QFN packages are arranged. Finally, in the dicing step, a plurality of QFN packages can be manufactured by dicing the QFN unit along the outer circumference of each QFN package.

Conventionally, in the method for manufacturing a QFN package, a pressure-sensitive adhesive sheet for manufacturing a semiconductor device using an acrylic adhesive has been used, but when these pressure-sensitive adhesive sheets for manufacturing a semiconductor device are used, resin leakage (mold flash) occurs in the sealing process. ) May occur.
In addition, it has become common to further enhance the wire bonding characteristics by providing a step of performing plasma treatment (plasma cleaning step) before the wire bonding step to remove impurities adhering to the surface of the semiconductor element and, for example, the lead frame. ing. When a conventional pressure-sensitive adhesive sheet for manufacturing semiconductor devices is used, the surface layer of the pressure-sensitive adhesive exposed surface of the pressure-sensitive adhesive sheet for manufacturing semiconductor devices is roughened by plasma cleaning, and when the pressure-sensitive adhesive sheet for semiconductor manufacturing is peeled off, the connection terminals and sealing of the semiconductor device are sealed. Adhesive transfer to the resin surface (hereinafter, may be referred to as "glue residue") may occur. When such adhesive residue occurs, the adhesive adheres to the portion sealed with the sealing resin and the external connection terminal portion of the lead in the vicinity thereof, so that the manufactured semiconductor device is mounted on a wiring board or the like. At that time, a connection failure may occur.
To solve these problems, an adhesive sheet for manufacturing a semiconductor device having an adhesive layer containing a thermosetting resin component and a thermoplastic resin component has been proposed (for example, Patent Document 1). According to the invention of Patent Document 1, since the wire bonding characteristics are excellent even if the plasma treatment is not performed, the adhesive residue due to the plasma treatment can be reduced.

JP-A-2007-123710

However, in the invention of Patent Document 1, although the adhesive residue can be reduced, there is a problem that the adhesive strength to the sealing resin is strong and it is difficult to peel off. In addition, the pressure-sensitive adhesive sheet for manufacturing a semiconductor device is required to have peelability so that it can be peeled off with a smaller peeling force in a manufacturing method provided with a plasma cleaning step.
Therefore, an object of the present invention is to provide a pressure-sensitive adhesive sheet for manufacturing a semiconductor device, which has no adhesive residue and is excellent in peelability.

The pressure-sensitive adhesive sheet for manufacturing a semiconductor device of the present invention includes a base material and an adhesive layer provided on one surface of the base material, and is detachably attached to a lead frame or a wiring substrate of the semiconductor device. In the pressure-sensitive adhesive sheet for manufacturing an apparatus, the pressure-sensitive adhesive layer is characterized by containing a silicone pressure-sensitive adhesive and fluorine oil.
Further, the pressure-sensitive adhesive layer is subjected to plasma treatment for 1 minute under the condition of an output of 450 W, and then the surface contact angle measured by mesitylene of the pressure-sensitive adhesive layer after heating the pressure-sensitive adhesive layer at 220 ° C. for 30 minutes is determined. It is preferably 30 ° or more.

According to the pressure-sensitive adhesive sheet for manufacturing a semiconductor device of the present invention, there is no adhesive residue on the lead frame or the wiring board, and the peelability is excellent.

It is a top view which shows an example of the lead frame used in the manufacturing method of the semiconductor device of this invention. It is a process drawing explaining the manufacturing method of the semiconductor device of this invention.

The pressure-sensitive adhesive sheet for manufacturing a semiconductor device of the present invention (hereinafter, may be simply referred to as a pressure-sensitive adhesive sheet) is peelably attached to a lead frame or a wiring board of a semiconductor device.
A lead frame is a metal plate formed by etching or pressing to form a conductor pattern, and a wiring board is a conductive material having a conductor pattern on the surface (or may include an inner surface) of an electrically insulating substrate. It is the one formed by.

The pressure-sensitive adhesive sheet of the present invention includes a base material and a pressure-sensitive adhesive layer provided on one surface of the base material.
Examples of the base material include heat-resistant materials such as a heat-resistant resin film and a metal foil.
When manufacturing a semiconductor device such as a QFN package using an adhesive sheet, the adhesive sheet is exposed to a high temperature of 150 to 250 ° C. in a die-attaching step, a wire bonding step, and a sealing step. When a heat-resistant resin film is used as the base material, the coefficient of thermal expansion of the heat-resistant film rapidly increases when the temperature exceeds the glass transition temperature (Tg), and the difference in thermal expansion from the metal lead frame becomes large. Therefore, when the temperature is returned to room temperature, the heat-resistant film and the lead frame may be warped. If the heat-resistant film and the lead frame are warped, the lead frame cannot be mounted on the positioning pin of the mold in the sealing process, which may cause misalignment.
Therefore, when a heat-resistant film is used as the base material, it is preferably a heat-resistant film having a glass transition temperature of 150 ° C. or higher, and more preferably 180 ° C. or higher.
Further, the coefficient of thermal expansion of the heat-resistant film at 150 to 250 ° C. is preferably 5 to 50 ppm / ° C., more preferably 10 to 30 ppm / ° C. Examples of the heat-resistant film having such properties include films made of polyimide, polyamide, polyether sulfone, polyphenylene sulfide, polyetherketone, polyetheretherketone, triacetylcellulose, polyetherimide and the like.

Further, even when a metal foil is used as the base material, the coefficient of thermal expansion of the metal foil at 150 to 250 ° C. is preferably 5 to 50 ppm / ° C., and further 10 to 30 ppm for the same reason as the heat-resistant film. More preferably, it is / ° C. Metals include foils made of gold, silver, copper, platinum, aluminum, magnesium, titanium, chromium, manganese, iron, cobalt, nickel, zinc, palladium, indium, and tin, and alloy foils containing these metals as the main components. , Or these plated foils.

When manufacturing a semiconductor device using the pressure-sensitive adhesive sheet of the present invention, in order to prevent adhesive residue in the peeling step described later, the adhesive strength Sa between the base material and the pressure-sensitive adhesive layer, the sealing resin and the lead frame, or The ratio (adhesive strength ratio) Sa / Sb of the adhesive strength Sb between the wiring substrate and the pressure-sensitive adhesive layer is preferably 1.5 or more. When Sa / Sb is less than 1.5, adhesive residue is likely to occur in the pressure-sensitive adhesive sheet peeling step. In order to make the adhesive strength ratio Sa / Sb 1.5 or more, in the case of a heat-resistant film, before forming the pressure-sensitive adhesive layer, on the surface of the heat-resistant film on the side where the pressure-sensitive adhesive layer is formed. , Corona treatment, plasma treatment, primer treatment, sandblasting, etc., which are preferably performed in advance to increase the adhesive strength Sa between the heat-resistant film and the pressure-sensitive adhesive layer. Further, in the case of metal foil, it is classified into rolled metal foil and electrolytic metal foil according to the manufacturing method. In order to make the adhesive strength ratio Sa / Sb 1.5 or more, electrolytic metal foil is used and the surface is roughened. It is preferable to provide an adhesive layer on the surface on the rolled side for adjustment. Further, among the electrolytic metal foils, it is particularly preferable to use an electrolytic copper foil.
The thickness of the base material is determined in consideration of the material and the like, and is, for example, 10 to 100 μm.

The pressure-sensitive adhesive layer contains a silicone pressure-sensitive adhesive and fluorine oil.
As the silicone pressure-sensitive adhesive, an organic peroxide curing type, a type that cures with a platinum-based catalyst, or the like can be used, and the form of the pressure-sensitive adhesive may be a solvent type or a solvent-free type.
Specific examples of the silicone pressure-sensitive adhesive include those containing alkylsiloxane as a main component and those containing polyalkylalkenylsiloxane and polyalkylhydroxanesiloxane as main components.
As the silicone pressure-sensitive adhesive, a silicone pressure-sensitive adhesive containing polyalkylalkenyl siloxane and polyalkyl hydrogen siloxane as main components is particularly preferable.

The content of the silicone pressure-sensitive adhesive in the pressure-sensitive adhesive layer is determined in consideration of the type of the silicone pressure-sensitive adhesive and the like, and is preferably 80 to 98% by mass, more preferably 85 to 95% by mass, for example. If it is less than the above lower limit value, the adhesive strength may be insufficient and the mold flush characteristics may be deteriorated, and if it exceeds the above upper limit value, the content of the fluorine-containing oil may be too small and the peelability may be deteriorated. be.

As the fluorine oil, a fluorine-containing group oligomer, a fluorinated alkene, or the like can be used.
Specific examples of the fluorine oil include low polymers of perfluoroalkane, polytrifluoroethylene, perfluoropolyether, and chlorotrifluoroethylene.
As the fluorine oil, a fluorine oil having a hydroxy group and an alkenyl group is particularly preferable.

The content of fluorine oil in the pressure-sensitive adhesive layer is appropriately determined in consideration of the type of fluorine-containing oil, the type and amount of resin, and the like. For example, 0.5 to 20% by mass is preferable in the pressure-sensitive adhesive layer, and 0 .5 to 10% by mass is more preferable, and 0.5 to 5.0% by mass is further preferable. If it is less than the above lower limit value, the peelability may be lowered, and if it exceeds the above upper limit value, the adhesive strength may be insufficient and the mold flash characteristics may be lowered, or the adhesive strength may be insufficient.

The adhesive strength of the pressure-sensitive adhesive layer to the lead frame or wiring board at 25 ° C. is preferably 0.05 N / 20 mm or more. If the adhesive strength is equal to or higher than the above lower limit, the adhesive strength is appropriate for the lead frame or the wiring board.

Inorganic or organic fillers may be added to the pressure-sensitive adhesive layer in order to adjust the coefficient of thermal expansion, thermal conductivity, surface tack, adhesiveness, etc. of the pressure-sensitive adhesive layer. Inorganic fillers include crushed silica, molten silica, alumina, titanium oxide, beryllium oxide, magnesium oxide, calcium carbonate, titanium nitride, silicon nitride, boron nitride, titanium boborate, tungsten boborate, silicon carbide, titanium carbide, Fillers made of zirconium carbide, molybdenum carbide, mica, zinc oxide, carbon black, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, antimony trioxide, etc., or those with trimethylsiloxyl groups introduced on their surfaces, etc. It can be exemplified. Examples of the organic filler include fillers made of polyimide, polyamideimide, polyetheretherketone, polyetherimide, polyesterimide, nylon, silicone resin and the like.
Further, a cross-linking agent may be added to the pressure-sensitive adhesive layer.
The thickness of the pressure-sensitive adhesive layer is not particularly limited, but is, for example, 2 to 20 μm.

The pressure-sensitive adhesive sheet may have a structure in which a peelable protective film is attached on the pressure-sensitive adhesive layer, and the protective film is peeled off immediately before attachment to a lead frame, a wiring board, or the like. In this case, the pressure-sensitive adhesive layer is prevented from being damaged between the time when the pressure-sensitive adhesive sheet is manufactured and the time when the pressure-sensitive adhesive sheet is used. The protective film may be a film having releasability, and examples thereof include films of polyester, polyethylene, polypropylene, polyethylene terephthalate and the like, and films in which the surface of these films is released with a silicone resin or a fluorine compound. ..

As a method for manufacturing the pressure-sensitive adhesive sheet, a casting method in which an adhesive is applied onto a base material and dried, or a laminating method in which the pressure-sensitive adhesive is once applied on a release film, dried, and then transferred onto the base material. Etc. are suitable. The components constituting the pressure-sensitive adhesive layer include organic solvents such as aromatic solvents such as toluene, xylene and chlorbenzene, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, dimethylformamide, dimethylacetamide and N-methylpyrrolidone. It is preferable to dissolve it in an aproton polar solvent, tetrahydrofuran or the like alone or in a mixture, and use it as a pressure-sensitive adhesive coating solution.

The pressure-sensitive adhesive layer on the pressure-sensitive adhesive sheet was subjected to plasma treatment for 1 minute under the condition of an output of 450 W, and then the pressure-sensitive adhesive layer was heated at 220 ° C. for 30 minutes, and then surface contact measured with mesitylene of the pressure-sensitive adhesive layer. The angle is preferably 30 ° or more. When the surface contact angle of the pressure-sensitive adhesive layer measured under these conditions is 30 ° or more, the pressure-sensitive adhesive sheet is easily peeled off from the lead frame and the sealing resin even after the lead frame or wiring substrate is subjected to plasma treatment. The efficiency can be improved, the productivity of the semiconductor device can be improved, and the defective product of the semiconductor device due to the adhesive residue can be prevented.

The method for manufacturing a semiconductor using the pressure-sensitive adhesive sheet of the present invention includes a sticking step of sticking the pressure-sensitive adhesive sheet to a lead frame or a wiring board, a plasma cleaning step of applying a plasma treatment to the lead frame or the wiring board, and the pressure-sensitive adhesive sheet. It includes a peeling step of peeling from the lead frame or the wiring board.

Hereinafter, an example of a method for manufacturing a semiconductor device using the pressure-sensitive adhesive sheet of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a plan view of a lead frame viewed from the side on which a semiconductor element is mounted, and FIGS. 2 (a) to 2 (f) are steps showing a method of manufacturing a QFN package using the lead frame shown in FIG. FIG. 5 is a cross-sectional view taken along the line AA'of the lead frame of FIG.

The method for manufacturing the semiconductor device of the present embodiment includes a sticking step of sticking an adhesive sheet to a lead frame, a dicing step of mounting a semiconductor element on the lead frame, and a plasma cleaning step of applying plasma treatment to the lead frame. A wire bonding step of electrically connecting the semiconductor element and the lead of the lead frame, a sealing step of sealing the semiconductor element with a sealing resin, and a peeling step of peeling the adhesive sheet from the lead frame to obtain a QFN unit. , A dicing step of dividing a QFN unit to obtain a QFN package is provided.

First, a lead frame 20 having a schematic configuration shown in FIG. 1 is prepared. In the lead frame 20, a plurality of semiconductor element mounting portions (die pad portions) 21 on which semiconductor elements such as IC chips are mounted are formed in a matrix, and a large number of leads 22 are formed along the outer periphery of each semiconductor element mounting portion 21. It is a thing.
Examples of the material of the lead frame 20 include those conventionally known, and examples thereof include those in which a nickel-plated layer, a palladium-plated layer, and a gold-plated layer are provided in this order on the surface of a copper plate.

As shown in FIG. 2A, the adhesive sheet 10 is attached to one surface (lower surface) of the lead frame 20 so that the adhesive layer (not shown) abuts on the lead frame 20 (adhesion step). .. As a method of attaching the adhesive sheet 10 to the lead frame 20, a laminating method or the like is preferable.

As shown in FIG. 2B, a semiconductor element 30 such as an IC chip is attached to the side of the lead frame 20 where the adhesive sheet 10 is not attached in the semiconductor element mounting portion 21 via a die attachant (not shown). Place it. Then, it is heated to about 100 to 200 ° C. to cure the die attach agent, and the semiconductor element 30 is fixedly mounted on the semiconductor element mounting portion 21 (diatouch agent curing process. The above is the die attach step). Here, the fluorine oil in the pressure-sensitive adhesive layer is unevenly distributed on the surface of the pressure-sensitive adhesive layer when heated in the sticking step or the die-attaching step.

If the outgas component generated from the pressure-sensitive adhesive sheet 10 or the die-attaching agent adheres to the lead frame 20 or the semiconductor element 30, the yield tends to decrease due to poor wire bonding in the wire bonding process. Therefore, after the die-attaching step and before the wire bonding step, the lead frame 20 and the semiconductor element 30 are subjected to plasma treatment (plasma cleaning step). As the plasma treatment, for example, the lead frame 20 (hereinafter, may be referred to as a work-in-progress product) on which the adhesive sheet 10 is attached and the semiconductor element 30 is mounted is subjected to argon gas, a mixed gas of argon gas and hydrogen gas, or the like. A method of irradiating plasma in an atmosphere can be mentioned. The irradiation output of plasma in the plasma processing is, for example, 150 to 600 W. The plasma treatment time is, for example, 0.01 to 5 minutes.

As shown in FIG. 2C, the semiconductor element 30 and the lead 22 of the lead frame 20 are electrically connected by a bonding wire 31 such as a gold wire (wire bonding step). This step is performed while heating the work-in-process on the heater block to about 150 to 250 ° C. The heating time in this step is, for example, 5 to 30 minutes.
When the work-in-process is heated in the wire bonding step, the amount of fluorine oil dispersed in the pressure-sensitive adhesive layer is sufficient to migrate to the surface of the pressure-sensitive adhesive layer and improve the peelability. Then, in the peeling step described later, the pressure-sensitive adhesive sheet 10 is easily peeled from the lead frame 20 and the sealing resin 40.

As shown in FIG. 2 (d), the work-in-process shown in FIG. 2 (c) is placed in a mold, and a transfer mold (mold molding) is performed using a sealing resin (molding material) to form a semiconductor. The element 30 is sealed with the sealing resin 40 (sealing step). As the sealing resin, conventionally known ones are used, and examples thereof include a mixture of an epoxy resin and an inorganic filler.

As shown in FIG. 2E, the adhesive sheet 10 is peeled from the sealing resin 40 and the lead frame 20 to obtain a QFN unit 60 in which a plurality of QFN packages 50 are arranged (peeling step). At this time, since a sufficient amount of fluorine oil is present on the surface of the pressure-sensitive adhesive layer, the pressure-sensitive adhesive sheet 10 can be easily peeled off from the lead frame 20 and the sealing resin 40.

As shown in FIG. 2 (f), a plurality of QFN packages 50 are obtained by dicing the QFN unit 60 along the outer circumference of each QFN package 50 (dicing step).

As described above, by manufacturing a semiconductor device such as a QFN package using the pressure-sensitive adhesive sheet 10 of the present embodiment, the pressure-sensitive adhesive sheet 10 can be easily removed from the lead frame 20 and the sealing resin 40 even if a plasma cleaning step is provided. It is peeled off. Therefore, the work efficiency can be improved, the productivity of the semiconductor device can be improved, and the defective product of the semiconductor device due to the adhesive residue can be prevented.

In the above-described embodiment, a method of manufacturing a QFN package using a lead frame has been described as an example, but the present invention is not limited to this, and a method of manufacturing a semiconductor device other than a QFN package using a lead frame, It can also be applied to a method for manufacturing a semiconductor device using a wiring board.

The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

(Raw materials used)
<Silicone adhesive>
Additive-curing silicone pressure-sensitive adhesive A mixture of a raw rubber-like organopolysiloxane having an average of two or more alkenyl groups in one molecule and an organosiloxane resin consisting of 1/2 unit of R3SiO and 4/2 units of SiO.

<Fluorine oil 1>
Fluorine-containing group / hydrophilic group-containing oligomer (trade name: Megafuck F430, manufactured by DIC Corporation)

<Fluorine oil 2>
Fluorine-containing group, hydrophilic group, lipophilic group-containing oligomer (trade name: Megafuck F477, manufactured by DIC Corporation)

<Silane coupling agent>
2- (3,4-Epoxycyclohexyl) ethyltrimethoxysilane

<Crosslinking agent>
Organopolysiloxane having an average of two or more silicon atom-bonded hydrogen atoms in one molecule

<Platinum catalyst>
Made by Toray Dow Corning Co., Ltd. Product name SRX-212

(Examples 1 to 4, Comparative Example 1)
According to the composition shown in Table 1, each raw material was dispersed in an appropriate amount of toluene to prepare a pressure-sensitive adhesive coating solution.
Next, a polyimide resin film (manufactured by Toray DuPont Co., Ltd., trade name: Kapton 100EN, thickness 25 μm, glass transition temperature 300 ° C. or higher, coefficient of thermal expansion 16 ppm / ° C.) was used as a heat-resistant base material, and dried on it. The above-mentioned pressure-sensitive adhesive coating liquid was applied so that the subsequent thickness would be 5 μm. After applying the pressure-sensitive adhesive coating liquid, it was dried at 150 ° C. for 3 minutes to obtain a pressure-sensitive adhesive sheet for each example. The surface contact angle, mold flash and adhesive residue of the obtained adhesive sheet were evaluated as follows.

<Surface contact angle>
The pressure-sensitive adhesive sheet was installed in a plasma cleaner device (YES-G1000, manufactured by YIELDENGINEERING SYSTEM) with the pressure-sensitive adhesive layer facing upward, and the pressure-sensitive adhesive layer was subjected to plasma treatment for 1 minute under the condition of an argon gas atmosphere and an output of 450 W. ..
Next, the plasma-treated adhesive sheet is heated at 220 ° C. for 30 minutes, and the adhesive layer of the heated adhesive sheet is turned upward and placed on a sample table of a contact angle meter (DropMaster DM500, manufactured by Kyowa Interface Science Co., Ltd.). The surface contact angle of the adhesive was measured under the following conditions.
Liquid for measurement: Mesitylene Measurement method: Sessile drop method Liquid volume: 2 μL
Waiting time until measurement: 20 seconds

<Mold flush and adhesive residue>
As the lead frame, three blocks having the following specifications (32LQFNPADSIZE3.0SQMM, 64 pieces / block) in which a nickel-plated layer, a palladium-plated layer, and a gold-plated layer were provided on a copper plate in this order were used. The adhesive sheet of each example was cut into 50 mm × 60 mm using a paper cutter (paper holder NS type, manufactured by Uchida Yoko Co., Ltd.). Using a desktop laminator (MAII-700, manufactured by Taisei Laminator Co., Ltd.), attach the cut adhesive sheet to the lead frame under the conditions of 25 ° C., speed = 1.0 m / min, and pressure = 0.37 N / mm. (Attachment process).
Next, with the adhesive sheet on the lower side, the lead frame to which the adhesive sheet was attached was placed in an oven (Perfect Oven PHH-201, manufactured by ESPEC CORPORATION) and heated at 175 ° C. for 1 hour (diatouch in the die attach process). Equivalent to agent hardening treatment).
Next, the pressure-sensitive adhesive sheet was installed in a plasma cleaner device (YES-G1000, manufactured by YIELDENGINEERING SYSTEM) with the pressure-sensitive adhesive layer facing upward, and the pressure-sensitive adhesive layer was subjected to plasma treatment for 1 minute under the condition of an argon gas atmosphere and an output of 450 W. Performed (plasma cleaning process).
After the plasma cleaning process, the adhesive sheet was placed on the lower side, the lead frame to which the adhesive sheet was attached was placed on a hot plate (EC-1200, manufactured by Seieidou Inuchi), and heated at 220 ° C. for 30 minutes (for the wire bonding process). Equivalent).
After the wire bonding process is completed, a lead frame to which an adhesive sheet is attached is attached using a transfer molding press (TEP12-16, manufactured by Fujiwa Seiki Co., Ltd.) under the conditions of a heating temperature of 175 ° C., a resin pressure of 69 MPa, and a mold pressure of 14 MPa. It was sealed with a sealing resin (EME-G631BQ, manufactured by Sumitomo Bakelite Co., Ltd.) (sealing step). After the sealing step, the adhesive sheet was peeled off, and the presence or absence of mold flush generation and the adhesive residue were confirmed. For the adhesive residue, the area of the pressure-sensitive adhesive remaining on the surface of the sealing resin after peeling was shown as a percentage.

[Lead frame specifications]
External dimensions: 55 mm x 58 mm
Use: For QFN QFN array: 8 x 8 (64 in total) matrix array Package size: 5 mm x 5 mm
Number of pins: 32

As shown in Table 1, in the pressure-sensitive adhesive sheets according to Examples 1 to 4 of the present invention, none of the 192 QFN packages generated mold flush, and there was little adhesive residue. On the other hand, it was confirmed that the pressure-sensitive adhesive sheet according to Comparative Example 1 had a practical problem with 85% of the pressure-sensitive adhesive remaining on the surface of the sealing resin after the pressure-sensitive adhesive sheet was peeled off.

10 Adhesive sheet for manufacturing semiconductor devices 20 Lead frame 30 Semiconductor element 31 Bonding wire 40 Encapsulating resin 50 QFN package

Claims (2)

The pressure-sensitive adhesive layer in a pressure-sensitive adhesive sheet for manufacturing a semiconductor device, which comprises a base material and a pressure-sensitive adhesive layer provided on one surface of the base material and is detachably attached to a lead frame or a wiring substrate of the semiconductor device. Is an adhesive sheet for manufacturing semiconductor devices, which is characterized by containing a silicone adhesive and fluorine oil. The pressure-sensitive adhesive layer was subjected to plasma treatment for 1 minute under the condition of an output of 450 W, and then the pressure-sensitive adhesive layer was heated at 220 ° C. for 30 minutes, and then the surface contact angle of the pressure-sensitive adhesive layer measured with mesitylene was 30 °. The pressure-sensitive adhesive sheet for manufacturing a semiconductor device according to claim 1, wherein the pressure-sensitive adhesive sheet is as described above.

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