KR20190111911A - Adhesive sheet for semiconductor device manufacture and manufacturing method of semiconductor device using same - Google Patents

Abstract

This invention relates to the adhesive sheet for semiconductor device manufacture, This adhesive sheet for semiconductor device manufacture is equipped with a base material and the thermosetting adhesive bond layer provided in one surface of the said base material, and peels to the lead frame or wiring board of a semiconductor device. In the adhesive sheet for semiconductor device manufacture possibly stuck, the said adhesive layer is a carboxyl group-containing acrylonitrile- butadiene copolymer (a), the epoxy resin (b) which has following structural formula (1), and two or more maleimide groups Compound (c) to contain and reactive siloxane compound (d) are contained. Moreover, this invention provides the manufacturing method of the semiconductor device used for this.

Description

Adhesive sheet for semiconductor device manufacture and manufacturing method of semiconductor device using same

The present invention relates to an adhesive sheet suitably used as a mask tape when assembling a semiconductor device by a quad flat non-lead (QFN) method, and a method of manufacturing a semiconductor device using the same.

This application claims priority based on Japanese Patent Application No. 2017-017490 for which it applied to Japan on February 2, 2017, and uses the content here.

In recent years, in response to the demand for miniaturization, thinning, and multifunction of IT devices including mobile phones, the need for additional high-density packaging technology in semiconductor devices (semiconductor packages) is increasing.

As a CSP (Chip Size Package) technology that meets this demand, the QFN method has been noted (see Patent Documents 1 and 2). In particular, it is widely employed in the small pin type of 100 pins or less.

Here, as a method of assembling a general QFN package by the QFN method, the following method is known. First, in an adhering process, an adhesive sheet is affixed to one surface of a lead frame, and then, in a die attach process, a semiconductor element, such as an IC chip, in the semiconductor element mounting part (die pad part) formed in multiple in the lead frame. Mount each one. Next, in the wire bonding step, the plurality of leads and the semiconductor elements disposed along the outer circumference of each semiconductor element mounting portion of the lead frame are electrically connected by the bonding wires. Next, at the sealing process, the semiconductor element mounted in the lead frame is sealed with sealing resin.

Then, in a peeling process, by peeling an adhesive sheet from a lead frame, the QFN unit in which the some QFN package was arranged can be formed. Finally, in the dicing step, by dicing this QFN unit along the outer periphery of each QFN package, a plurality of QFN packages can be manufactured.

The adhesive sheet used in such a use is sufficiently and stably adhered to the adhesive sheet used without such peeling from the back surface of the lead frame and the back surface of the sealing resin until the peeling process, and can be easily peeled off in the peeling process. It is desired that there is no problem such as residual adhesive or residual adhesive on the back of the frame or the back of the sealing resin.

Especially in recent years, the lead frame which consists of copper alloys is used for cost reduction of a semiconductor device. The lead frame made of such a copper alloy also has a catalytic action of oxidative deterioration with respect to the polymer material of copper, which is a transition metal, and the adhesive is liable to oxidatively deteriorate due to the thermal history accompanying the QFN package assembly after the taping process. It becomes easy to become heavy peeling and an adhesive remainder in the process.

However, the adhesive sheet used conventionally did not fully satisfy the practical level which can be used for the lead frame which consists of copper alloys.

For example, although the adhesive sheet containing the acrylonitrile butadiene copolymer and bismaleimide resin laminated | stacked on the base material which consists of a heat resistant film in the conventional adhesive sheet (refer patent document 3), this When used, the acrylonitrile-butadiene copolymer is likely to deteriorate due to the heat applied in the die attach cure treatment, the wire bonding step, and the resin encapsulation step after the taping step, and in the peeling step, it becomes difficult to peel off or the adhesive sheet breaks. In addition, there existed a problem that adhesive residue remained.

Japanese Patent Laid-Open No. 2003-165961 Japanese Patent Laid-Open No. 2005-142401 Japanese Patent Laid-Open No. 2008-095014

This invention is made | formed in view of the said situation, Until it peels from the back surface of a lead frame and the back surface of sealing resin, even if it receives the heat history accompanying QFN assembly until a peeling process, it adheres to these sufficiently and stably and encapsulates. An object of the present invention is to provide an adhesive sheet which does not leak resin and can be easily peeled off in the peeling step, and does not cause or break the residual adhesive due to the adhesive, and a method of manufacturing a semiconductor device using the same.

The adhesive sheet for semiconductor device manufacture of this invention is equipped with the base material and the thermosetting adhesive bond layer provided in one surface of the said base material, and is attached to the adhesive sheet for semiconductor device manufacture which is peelable and stuck to the lead frame or wiring board of a semiconductor device. The adhesive layer includes a carboxyl group-containing acrylonitrile-butadiene copolymer (a), an epoxy resin (b) having the following structural formula (1), a compound (c) containing two or more maleimide groups, and a reactive siloxane. It is characterized by containing a compound (d).

[Tue 1]

Moreover, it is preferable that the said (a) component is a carboxyl group-containing acrylonitrile-butadiene copolymer whose acrylonitrile content is 5-50 mass%, and the carboxyl group equivalent computed from a number average molecular weight is 100-20000.

It is preferable that the sum total of the said (b) component, the said (c) component, and the said (d) component is 30-300 mass parts with respect to 100 mass parts of said (a) component.

Moreover, it is preferable that the mass ratio ((c) / (b)) of (c) component with respect to said (b) component is the range of 0.1-10.

Moreover, it is preferable that ratio of the reactor number of (d) component with respect to the sum of the number of epoxy groups of the said (b) component and the number of maleimide groups of (c) component is 0.05-1.2.

Moreover, the manufacturing method of the semiconductor device of this invention is a manufacturing method of the semiconductor device using the adhesive sheet for semiconductor device manufacture of the said base material,

An adhering step of adhering the adhesive sheet for semiconductor device production to a lead frame or a wiring board;

A die attach step of mounting a semiconductor element on the lead frame or a wiring board;

A wire bonding step of conducting the semiconductor element and an external connection terminal with each other;

A sealing step of sealing the semiconductor element with a sealing resin;

After the said sealing process, the peeling process of peeling the adhesive sheet for semiconductor device manufacture from a lead frame or a wiring board is provided.

According to the present invention, even before the peeling step, even if the heat history accompanying QFN assembly is received, it is not peeled off from the back side of the lead frame and the back side of the encapsulating resin, and it adheres to them sufficiently and stably, and there is no leakage of the encapsulating resin, Furthermore, in the peeling process, it can peel easily, and the adhesive sheet which does not produce the adhesive residue which an adhesive remains or breaks can be provided, and the manufacturing method of the semiconductor device using the same can be provided.

1 is a plan view illustrating an example of a lead frame used in a method of manufacturing a semiconductor device of the present invention.
2 is a flowchart for explaining a method for manufacturing a semiconductor device of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

[Adhesive sheet for semiconductor device manufacture]

The adhesive sheet (henceforth an adhesive sheet) for semiconductor device manufacture of this invention is equipped with a base material and the thermosetting adhesive layer provided in one surface of the said base material, and is peelable to the lead frame or wiring board of a semiconductor device. In the adhesive sheet to be stuck, the adhesive layer contains a carboxyl group-containing acrylonitrile-butadiene copolymer (a), an epoxy resin (b) having the following structural formula (1), and two or more maleimide groups (c): ) And a reactive siloxane compound (d), which are used as a mask tape when assembling a semiconductor device by the QFN method.

[Tue 2]

The carboxyl group-containing acrylonitrile-butadiene copolymer (a) has a role of appropriately maintaining the melt viscosity of the adhesive layer in the initial stage of heating, and imparts good flexibility and adhesion to the cured adhesive layer. Thereby, adhesiveness with respect to the base material which consists of a heat resistant film etc. is good, and the adhesive bond layer which is not cracked can be formed. As a carboxyl group-containing acrylonitrile-butadiene copolymer (a), although a well-known thing can be used without a restriction | limiting, it is preferable that it is 5-50 mass%, and, as for an acrylonitrile content, it is more preferable that it is 10-40 mass%. When acrylonitrile content is less than the said range, since the solubility to a solvent and compatibility with another component fall, there exists a tendency for the uniformity of the adhesive bond layer obtained to fall. On the other hand, when an acrylonitrile content exceeds the said range, the adhesive layer obtained will become adhesiveness with respect to a lead frame or sealing resin, and when this is used for an adhesive sheet, peeling in a peeling process will become difficult or an adhesive sheet will break There is a possibility.

It is preferable that it is the range of 100-20000, and, as for the carboxyl group equivalent computed from the number average molecular weight in a carboxyl group-containing acrylonitrile- butadiene copolymer, it is more preferable that it is 200-10000. When the carboxyl group equivalent is less than the above range, the reactivity with other components is too high, and the storage stability of the adhesive layer obtained tends to be lowered. On the other hand, when the carboxyl group equivalent exceeds the above range, since the reactivity with other components is insufficient, the adhesive layer obtained tends to be a low B stage. As a result, when it is used for an adhesive sheet, when an adhesive sheet is heated in the initial stage of heating, ie, the sticking process of an adhesive sheet, die-attach treatment, etc., an adhesive layer becomes low viscosity, and foaming arises in an adhesive layer, It tends to flow out, and there exists a tendency for thermal stability to fall.

The carboxyl group equivalent calculated from the number average molecular weight is obtained by dividing the number average molecular weight (Mn) by the number of carboxyl groups (number of functional groups) per molecule and represented by the following formula.

Carboxyl Equivalent = Mn / Function

The epoxy resin (b) and the compound (c) containing two or more maleimide groups are responsible for the thermosetting property of the adhesive layer, and by using them in combination, the thermal stability is excellent, and in the peeling step, the compound can be easily peeled off, The adhesive layer which does not produce adhesive residue or breakage can be formed. In particular, the epoxy resin (b) imparts toughness to the adhesive layer, and by containing it, it is possible to suppress the adhesive residue due to cracking of the adhesive layer in the peeling step.

The compound (c) containing two or more maleimide groups exhibits the function of adjusting the adhesiveness of the adhesive layer while providing thermal stability to the adhesive layer, and by containing this, the adhesiveness is appropriately controlled and in the peeling step The adhesive layer which can be peeled easily can be formed.

As a specific example of the compound (c) containing 2 or more maleimide groups, the compound which comprises bismaleimide resin is used preferably, The thing of following formula (2-1)-(2-3), etc. are mentioned, Especially, the compound represented by following formula (2-1) or (2-3) is useful at the point of solubility to a solvent.

[Tue 3]

The reactive siloxane compound (d) is for improving the peelability from the encapsulating resin of the adhesive layer while increasing the compatibility of each component constituting the adhesive layer. A uniform adhesive layer can be formed without problems of separation and precipitation. As a result, an adhesive bond layer becomes uniform, and it can suppress problems, such as peeling fall and adhesive residue which arise in part because adhesive strength is high.

As the reactive siloxane compound (d), a siloxane compound imparted with reactivity by a reactor such as amino modification, epoxy modification, carboxy modification, mercapto modification, or the like can be used without limitation. Among these, 1,3-bis (3-aminopropyl) tetramethyldisiloxane, dimethylsiloxane tetramer or tetramer of the aminopropyl terminal, bis (3-aminophenoxymethyl) tetramethyldisiloxane (b) component, It is suitable in that reaction with (c) component advances rapidly. As the reactive siloxane compound (d), it is preferable to use the one in which the reactor is bound to the sock end of the siloxane structure in view of the reactivity. However, the silane coupling agent having one end or one end reactive and the other non-reactive is also used. Can be used.

Moreover, as each component of (a)-(d) mentioned above, the thing comprised from all 1 type of compounds may be used, and the mixture of 2 or more types of compounds may be used.

It is preferable that the sum total of (b) component, (c) component, and (d) component is 30-300 mass parts with respect to 100 mass parts of (a) component, and, as for the ratio of each component, 30-200 mass parts is more preferable. . When the sum total of (b) component, (c) component, and (d) component is less than the said range, the reactivity of an adhesive bond layer will fall, it will become difficult for insoluble infusible to advance even by heating, and adhesive force will become low as thermal stability falls. Tends to be strong. On the other hand, when the said range is exceeded, the melt viscosity of the adhesive bond layer in a heating initial stage will become inadequate, and in the adhesive sheet using this adhesive bond layer, there exists a possibility that an adhesive bond layer may flow out or foam | bubble in die-attach curing process etc. after a taping process. .

Moreover, the range of 0.1-10 is preferable, and, as for the mass ratio ((c) / (b)) of (c) component with respect to (b) component, the range of 1-7 is more preferable. If it is less than the said range, the adhesive layer obtained will be easy to advance hardening reaction at normal temperature, the storage stability will run out, adhesive strength will become strong too much, and the adhesive sheet using this will become incapable of peeling or fracture | rupture in a peeling process. There is. On the other hand, when it exceeds the said range, at the time of manufacture of an adhesive sheet, when the adhesiveness of this adhesive bond layer and the base material which consists of a heat resistant film falls, an adhesive bond layer will foam, or the obtained adhesive sheet will become easy to become adhesive residue. There is a tendency.

Furthermore, it is preferable that ratio of the reactor number of (d) component with respect to the sum of the number of epoxy groups of (b) component and the number of maleimide groups of (c) component is 0.05-1.2, More preferably, it is 0.1-0.8. . If it is less than the said range, the reactivity to the adhesive bond layer whole may fall, and hardening reaction may become difficult to advance by die attach curing process etc., and as a result, adhesive force may become strong too much. On the other hand, when it exceeds the said range, reaction will progress too much, a problem, such as gelation, will arise easily at the time of preparation of an adhesive bond layer, and adhesive force will become weak easily.

In addition to each essential component of (a)-(d), you may add reaction promoters, such as organic peroxide, imidazole, and triphenylphosphine, to an adhesive bond layer. By these addition, it is also possible to control the state in normal temperature of an adhesive bond layer to a favorable B stage.

In addition, for the purpose of controlling melt viscosity, improving thermal conductivity, imparting flame retardancy, a filler having an average particle diameter of 1 μm or less may be added. Examples of the filler include inorganic fillers such as silica, alumina, magnesia, aluminum nitride, boron nitride, titanium oxide, calcium carbonate and aluminum hydroxide, and organic fillers such as silicone resins and fluorine resins. When using a filler, it is preferable to make the content into 1-40 mass% in an adhesive bond layer.

The adhesive bond layer of this invention is provided with the adhesive bond layer mentioned above in the one surface of the heat resistant film which is a base material.

When manufacturing such an adhesive sheet, first, the compound containing at least 2 or more of the above-mentioned carboxyl group-containing acrylonitrile-butadiene copolymer (a), the epoxy resin (b) which has the said structural formula (1), and maleimide group (c) and the adhesive coating material which consists of a reactive siloxane compound (d) and a solvent are prepared. Then, this coating material may be applied to one surface of the heat resistant film so that the thickness of the adhesive layer after drying is preferably 1 to 50 µm, more preferably 3 to 20 µm, and may be dried. Moreover, in order to protect an adhesive bond layer, it is preferable to provide a peelable protective film further on the formed adhesive bond layer, In that case, a coating material is apply | coated and dried on a protective film, an adhesive bond layer is formed, and a heat resistant film thereon You may manufacture an adhesive sheet by the method of providing this. In addition, a protective film peels at the time of use of an adhesive sheet.

As the heat resistant film, a composite such as polyimide, polyphenylene sulfide, polyether sulfone, polyether ether ketone, liquid crystal polymer, polyethylene terephthalate, polyethylene naphthalate or the like, a heat resistant plastic film, epoxy resin-cloth, etc. Although a heat resistant film etc. are mentioned, A polyimide film is especially preferable.

As for the thickness of a polyimide film, 12.5-125 micrometers is preferable, More preferably, it is 25-50 micrometers. If it is less than the above range, the elasticity of the adhesive sheet becomes insufficient, and it tends to be difficult to handle. If it exceeds the above range, there is a tendency that the work in the taping step and the peeling step at the time of QFN assembly becomes difficult.

As a solvent used for an adhesive paint, 1 or more types of organic solvents, such as hydrocarbons, alcohol, ketones, ethers (tetrahydrofuran, etc.), water, etc. can be used preferably, The usage-amount has suitable viscosity as a coating material. It may adjust as appropriate. Moreover, any of a solution, an emulsion, and suspension may be sufficient as the property of a coating material, and what is necessary is just to select suitably according to the coating apparatus, environmental conditions, etc. to be used.

Examples of the peelable protective film include plastic films such as polyethylene, polypropylene, vinyl chloride, fluorine resin, silicone, and the like that have been provided with peelability by silicone coating or the like on polyethylene terephthalate, polyethylene naphthalate, paper, or the like.

[Manufacturing Method of Semiconductor Device]

The manufacturing method of the semiconductor device using the adhesive sheet of this invention includes the sticking process of sticking an adhesive sheet to a lead frame or a wiring board, the die attach process of mounting a semiconductor element in a lead frame or a wiring board, a semiconductor element, and The wire bonding process which electrically connects an external connection terminal, the sealing process of sealing a semiconductor element with sealing resin, and the peeling process of peeling an adhesive sheet from a lead frame or a wiring board after a sealing process are provided.

Hereinafter, an example of the manufacturing method of the semiconductor device using the adhesive sheet of this invention is demonstrated with reference to FIGS. 1 is a plan view of a lead frame seen from a side on which a semiconductor element is mounted, and FIGS. 2A to 2F are process drawings showing a method of manufacturing a QFN package using the lead frame shown in FIG. AA sectional drawing of a lead frame.

First, the lead frame 20 of schematic structure 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 plurality of leads are formed along the outer periphery of each semiconductor element mounting portion 21. 22) (external connection terminal) is formed.

As a material of the lead frame 20, a conventionally well-known thing is mentioned, For example, a copper plate and a copper alloy plate, or what provided strike plating to these, or the surface of a copper alloy plate, a nickel plating layer, a palladium plating layer, and a gold plating layer are The thing provided in this order is mentioned.

As shown to Fig.2 (a), the adhesive sheet 10 is stuck to one surface (lower surface) of the lead frame 20 so that an adhesive bond layer (not shown) may contact the lead frame 20 (adhesion) fair). As a method of sticking the adhesive sheet 10 to the lead frame 20, there are a lamination method and a press method, but from the viewpoint of productivity, a lamination method capable of continuously performing a taping process is suitable. The temperature of the adhesive sheet 10 in this process is 150 degreeC from normal temperature (5-35 degreeC), for example, and 60-120 degreeC is more preferable. When sticking at temperature higher than 150 degreeC, curvature will arise easily in a lead frame.

If the lead frame 20 is warped in this step, positioning in the die attach step or the wire bonding step becomes difficult, conveyance to the heating furnace becomes difficult, and there is a fear of lowering the productivity of the QFN package. have.

As shown in FIG.2 (b), an IC chip etc. are connected through the die attach agent (not shown) to the side in which the adhesive sheet 10 in the semiconductor element mounting part 21 of the lead frame 20 is not stuck. The semiconductor element 30 is mounted. At this time, since the curvature is suppressed, the lead frame 20 is easily positioned. And the semiconductor element 30 is mounted correctly in a predetermined position. Then, it heats about 100-200 degreeC, hardens a die attach agent, and fixes the semiconductor element 30 to the semiconductor element mounting part 21, and mounts it (hardening process of a die attach. Above, a die attach process.) . At this time, the adhesive sheet 10 is cured by the adhesive layer and adhered to the lead frame.

If the outgas component which arises from the adhesive sheet 10, the die attach agent, etc. is affixed to the lead frame 20 or the semiconductor element 30, it will be easy to produce the yield fall by the wire bonding process with respect to a wire bonding process. Here, the plasma treatment is applied to the lead frame 20 or the semiconductor element 30 after the die attach step and before the wire bonding step (plasma cleaning step). As the plasma treatment, for example, the lead frame 20 (hereinafter sometimes referred to as work in progress) on which the adhesive sheet 10 is attached and on which the semiconductor element 30 is mounted may be used as argon gas or argon gas and hydrogen gas. And a method of plasma irradiation in an atmosphere such as mixed gas. The irradiation output of the plasma in the plasma processing is 150 to 600 W, for example. Moreover, the time of plasma processing is 0.1 to 15 minutes, for example.

As shown in FIG. 2 (c), the bonding wire 31 such as a gold wire, a copper wire, or a copper wire coated with palladium is coated on the lead 22 (external connection terminal) of the semiconductor element 30 and the lead frame 20. Is electrically conducted (wire bonding step). This process is performed, heating a work in progress on the heater block about 150-250 degreeC. The heating time in this process is 5 to 60 minutes, for example.

When the work is heated in the wire bonding step, when the fluorine additive is contained in the adhesive layer, the fluorine additive moves to the surface of the adhesive layer. Therefore, in the peeling step described later, the adhesive sheet 10 includes the lead frame 20 and It becomes easy to peel from the sealing resin 40.

As shown in FIG.2 (d), the workpiece shown in FIG.2 (c) is mounted in a metal mold | die, and it injects and fills in a metal mold | die by using sealing resin (mold material). After filling an arbitrary amount in a metal mold | die, the semiconductor element 30 is sealed by the sealing resin 40 by maintaining the inside of metal mold | die at arbitrary pressure (sealing process). Conventionally well-known things are used as sealing resin, For example, mixtures, such as an epoxy resin and an inorganic filler, are mentioned.

As shown in FIG.2 (e), the adhesive sheet 10 is peeled from the sealing resin 40 and the lead frame 20, and the QFN unit 60 in which the some QFN package 50 was arranged is obtained (peeling off). fair).

As shown in FIG.2 (f), the several QFN package 50 is obtained by dicing the QFN unit 60 along the outer periphery of each QFN package 50 (dicing process).

In addition, although the above-mentioned embodiment demonstrated the manufacturing method of the QFN package using a lead frame as an example, this invention is not limited to this, The manufacturing method of semiconductor devices other than the QFN package using a lead frame, and the semiconductor using a wiring board It is also applicable to the manufacturing method of an apparatus.

The adhesive layer in the adhesive sheet of the present invention is obtained by crosslinking the carboxyl group of the carboxyl group-containing acrylonitrile-butadiene copolymer (a) with the glycidyl group of the epoxy resin (b) to take a B stage state (semicured state). It can be set as glass transition temperature (10 degreeC-50 degreeC). An adhesive sheet having an adhesive layer having a low glass transition temperature is excellent in productivity capable of continuously performing a taping process by a roll laminate or the like at relatively low heating conditions, specifically, 60 to 150 ° C.

Moreover, when the adhesive bond layer of the low glass transition temperature (10 degreeC-50 degreeC) in the adhesive sheet of this invention is heated, the characteristic of high elastic modulus is obtained. In recent years, for the purpose of cost reduction in the wire bonding process, it has begun to spread the product which bonded with the low cost copper wire or the palladium coated copper wire instead of the conventional gold wire. Since copper wire or palladium-coated copper wire is a metal of higher elasticity than gold, processing at the load higher than the conventional gold wire is required in order to make a stable shape.

When such a large load is applied to the lead frame, the adhesive layer is deformed and the resin is encapsulated in the state of the deformed adhesive layer if the adhesive layer in the adhesive sheet adhered to the lead frame is low in elastic modulus. Doing so causes leakage of the sealing resin from the deformed adhesive layer portion. Moreover, when peeling an adhesive sheet from a lead frame, the adhesive layer breaks from the said modified adhesive bond layer part, and the problem also arises that an adhesive agent remains on the lead frame surface. In addition, when an adhesive agent is a low elastic modulus at the time of wire bonding, when an adhesive agent deform | transforms, a wire load will hardly be transmitted and a wire bonding defect will also occur easily. Since the adhesive bond layer in the adhesive sheet of this invention has the characteristic of high elastic modulus as mentioned above, even if it wire-bonds using copper wire or a palladium-coated copper wire, the wire bonding defect, the leakage of sealing resin, or an adhesive bond layer It is difficult to cause the problem of residual.

Moreover, since the adhesive bond layer in the adhesive sheet of this invention has the compound (c) containing 2 or more maleimide groups, it is possible to suitably control hardening of an adhesive bond layer in the drying process at the time of manufacture of an adhesive sheet, The adhesive layer can be in a high B-stage state, thereby suppressing the increase in the adhesive strength to the lead frame, and as a result, leakage of the encapsulating resin, retention of the adhesive to the lead frame, and breakage of the adhesive layer during peeling. Can be suppressed.

Example

EMBODIMENT OF THE INVENTION Hereinafter, an Example is shown and this invention is demonstrated concretely.

[Examples 1-6 and Comparative Examples 1-4]

(Composition of adhesive paint)

In the mass ratio shown in Table 1, (a)-(d) component, other components, and tetrahydrofuran (THF) which is a solvent were mixed, and the adhesive coating material was prepared.

Next, this adhesive paint was applied to one surface of a polyimide film (trade name Kapton 100EN manufactured by Toray DuPont, manufactured by Toray DuPont) so as to have a thickness of 5 μm after drying, and then set to 180 ° C. in a hot air circulation type oven. It dried in the middle and obtained the adhesive sheet.

In addition, the detail of each used component is as follows.

Carboxyl group-containing acrylonitrile-butadiene copolymer: Carboxyl group equivalent 1500 computed from a number average molecular weight, and acrylonitrile content 27 mass%

Acrylonitrile-butadiene copolymer: Acrylonitrile content 27 mass%

Epoxy resin having the structural formula (1): molecular weight 630, functional group equivalent 210 g / eq

Bisphenol A diphenyl ether bismaleimide: Molecular weight 570, functional group equivalent 285 g / eq

1,3-bis (3-aminopropyl) tetramethyldisiloxane: Molecular weight 248, functional group equivalent 62 g / eq

About the adhesive sheet of each example obtained as mentioned above, (1) peeling strength with respect to a lead frame material, (2) thermal characteristics after a die attach process, and (3) peeling with respect to the sealing resin material The presence or absence of the adhesive residue after strength and sheet peeling, and (4) the presence or absence of the sealing resin leakage of the test body after the resin sealing process were measured or confirmed.

(1) Peel strength against lead frame material

(i) fabrication of test bodies

The adhesive sheet obtained in each example was cut into a width of 50 mm × 60 mm, and this was tested for a lead frame (surface strike plating, 8 × 8 matrix arrangement, package size 5 mm) made of an outer dimension of 57.5 mm × 53.5 mm copper alloy. 5 mm, 32 pins) was used as a test body by using a roll laminate. Lamination conditions at that time were made into the temperature of 80 degreeC, the pressure of 4 N / cm, and the crimping | compression-rate 1 m / min.

(ii) measurement of peel strength

About the test body mentioned above, 90 degree peeling strength was measured using the universal tensile tester. Moreover, the lead frame was fixed and the adhesive sheet was pulled in the vertical direction and measured. Tensile speed was 50 mm / min. The results are shown in Table 2.

(2) Thermal characteristics after die attach process

In the adhesive sheet obtained by each example, the thing which made the polyimide film of thickness 25 micrometers into the polyethylene terephthalate film (PET film) which gave the release process of thickness 38 micrometers was produced, and assumes a die attach curing process, It heated at 175 degreeC for 1 hour using.

The adhesive bond layer in the adhesive sheet after heating was taken out from PET film, and the tensile storage elastic modulus was measured using DMA (Dynamic Mechanical Analyzer). The measurement was performed at a frequency of 11 Hz, a temperature increase rate of 10 ° C./min, and a load of 1.0 gf using a Vibro measuring instrument (RHEOVIBRON DDV-II-EP manufactured by Orientec Co., Ltd.) as DMA. Table 2 shows the results of the temperature applied when the wire bonding step is assumed and the tensile storage modulus at 180 ° C.

(3) Peel strength to the test body after the resin encapsulation step and the presence or absence of adhesive residue after sheet peeling

(i) Fabrication and Heat Treatment of Test Specimens

The adhesive sheets obtained in each example were assumed a thermal history associated with actual QFN assembly, and the following (a) to (d) were performed in order.

(a) The adhesive sheet obtained in each example was cut into a width of 50 mm x 60 mm, and this was tested for a lead frame (surface strike plating, 8 x 8 matrix arrangement, package) made of an outer dimension of 57.5 mm x 53.5 mm copper alloy. It was affixed using roll lamination to size 5 mm x 5 mm, 32 pins). Lamination conditions at that time were made into the temperature of 80 degreeC, the pressure of 4 N / cm, and the crimping | compression-rate 1 m / min.

(b) The test lead frame made of the copper alloy on which the adhesive sheet was stuck was heated in a ventilation oven at 175 ° C / 1 hour. This is a process that assumes a die attach cure process.

(c) Plasma Irradiation Treatment: Yield Engineering Co., Ltd. 1000P was used for 450 W / 60 seconds using Ar as the gas species.

(d) 200 degreeC / 30-minute heating: It heated using the hotplate as a process which assumed the wire bonding process.

Subsequently, sealing resin on the conditions of 175 degreeC / 3 minutes using a mold press machine on the copper material exposure surface opposite to the surface on which the adhesive sheet of the heat-processed to-be-adhered body of (a)-(d) was bonded together Was laminated (resin sealing step). As sealing resin, the epoxy mold resin (EME-G631BQ) by Sumitomo Bakelite Co., Ltd. was used.

(ii) the measurement of peel strength and the presence or absence of adhesive residue after sheet peeling

About the test body after the resin sealing process mentioned above, 90 degree peeling strength was measured using the universal tensile tester. Moreover, the test body was fixed and the corner part of the adhesive sheet was pulled in the vertical direction, and it measured. Tensile speed was 300 mm / min. Moreover, the presence or absence of the adhesive residue after sheet peeling was confirmed by the magnification of 100 times using the optical microscope (Digital microscope VHX-500 by a Keyence company). The results are shown in Table 2.

(4) Whether the sealing resin leaked out of the test body after the resin sealing step

About the test body after the resin sealing process mentioned above, the presence or absence of the sealing resin leak was confirmed by the magnification of 100 times using the optical microscope (digital microscope VHX-500 by a Keyence company). The results are shown in Table 2.

In addition, the symbol of the judgment column in Table 2 shows the following content.

(1) Measurement of Peel Strength for Lead Frame Material

(Circle): Peeling strength is 10 gf / 50 mm or more.

(Triangle | delta): Peeling strength is 5 gf / 50 mm or more and less than 10 gf / 50 mm.

X: Peeling strength is less than 5 gf / 50 mm.

(2) Thermal characteristics after die attach process

○: Tensile storage modulus at 180 ° C. is 10 MPa or more

(Triangle | delta): The tensile storage elastic modulus in 180 degreeC is 1 MPa or more and less than 10 MPa

X: Tensile storage modulus in 180 degreeC is less than 1 MPa

(3) Peel strength to the test body after the resin encapsulation step and the presence or absence of adhesive residue after sheet peeling

(Circle): Since peeling strength is less than 1000 gf / 50mm, the peeled adhesive sheet is not broken and an adhesive agent does not remain on the lead frame material surface and the sealing resin surface.

(Triangle | delta): Peeling strength is 1000 gf / 50mm or more, the peeled adhesive sheet is not broken, and an adhesive agent does not remain on the lead frame material surface and sealing resin surface.

X: The breakage of an adhesive sheet is confirmed, or the residue of an adhesive agent is confirmed on the lead frame material surface and the sealing resin surface, or it corresponds to at least either.

(4) Whether the sealing resin leaked out of the test body after the resin sealing step

(Circle): The sealing resin did not leak to the surface of the lead frame material for testing of the resin sealing agent after adhesive sheet peeling.

X: The sealing resin leaked on the test lead frame material surface of the resin sealing agent after adhesive sheet peeling.

As apparent from Table 2 above, the adhesive sheets of Examples 1 to 6 had a peel strength of 5 gf / 50 mm or more with respect to the test lead frame made of copper alloy, and had excellent adhesion to the lead frame member. . Moreover, it was confirmed that the adhesive sheets of Examples 1-6 have the tensile storage elastic modulus in 180 degreeC or more, 10MPa or more, and have the characteristic which can fully endure the deformation | transformation of the adhesive bond layer which arises by the load in a wire bonding process. Moreover, the adhesive sheet of Examples 1-6 was the outstanding characteristic that there is no leakage of sealing resin, the base material and adhesive bond layer of an adhesive sheet did not break, and an adhesive agent does not remain on the surface of a lead frame material and the sealing resin surface.

On the other hand, the adhesive sheets of Comparative Example 1, Comparative Example 2, and Comparative Example 4 confirmed that the tensile storage modulus at 180 ° C. was less than 10 MPa, making it difficult to withstand the deformation of the adhesive layer caused by the load in the wire bonding step. It became. Moreover, in the adhesive sheets of Comparative Examples 1-4, the adhesive sheet broke at the time of peeling from the sealing resin material, and the adhesive agent remained in the lead frame material surface and the peeling sealing resin surface also in the place where sheet peeling is possible.

The adhesive sheet according to the present invention is suitably used as a mask tape when assembling a semiconductor device by a QFN (Quad Flat Non-lead) method. According to the adhesive sheet according to the present invention, even before the peeling step, even if the thermal history accompanying QFN assembly is received, the adhesive sheet is sufficiently peeled from the back side of the lead frame and the back side of the encapsulating resin without sufficient peeling and stably attached thereto. There is no leakage and in addition, in a peeling process, it can peel easily, and the adhesive residue which an adhesive remains does not produce or break. Moreover, the adhesive sheet by this invention is applied to manufacture of a semiconductor device.

10 Adhesive sheet for semiconductor device manufacture
20 lead frames
30 semiconductor devices
31 bonding wire
40 bags of resin
50 QFN Package

Claims (6)

In the adhesive sheet for semiconductor device manufacture provided with the base material and the thermosetting adhesive bond layer provided in one surface of the said base material, and sticking so that peeling is possible to the lead frame or wiring board of a semiconductor device,
The adhesive layer includes a carboxyl group-containing acrylonitrile-butadiene copolymer (a), an epoxy resin (b) having the following structural formula (1), a compound (c) containing two or more maleimide groups, and a reactive siloxane compound ( d) containing the adhesive sheet for semiconductor device manufacture characterized by the above-mentioned.
[Tue 1]

The method according to claim 1,
The said (a) component is a carboxyl group-containing acrylonitrile-butadiene copolymer whose acrylonitrile content is 5-50 mass%, and the carboxyl group equivalent computed from a number average molecular weight is 100-20000, The adhesive sheet for semiconductor device manufacture characterized by the above-mentioned. . The method according to claim 1,
The total of the (b) component, the (c) component, and the (d) component is 30-300 mass parts with respect to 100 mass parts of said (a) component, The adhesive sheet for semiconductor device manufacture characterized by the above-mentioned. The method according to claim 1,
Mass ratio ((c) / (b)) of (c) component with respect to said (b) component is the range of 0.1-10, The adhesive sheet for semiconductor device manufacture characterized by the above-mentioned. The method according to claim 1,
The ratio of the number of reactors of (d) component with respect to the sum of the number of epoxy groups of the said (b) component, and the number of maleimide groups of (c) component is 0.05-1.2, The adhesive sheet for semiconductor device manufacture characterized by the above-mentioned. As a manufacturing method of a semiconductor device using the adhesive sheet for semiconductor device manufacture of Claim 1,
An adhering step of adhering the adhesive sheet for semiconductor device production to a lead frame or a wiring board;
A die attach step of mounting a semiconductor element on the lead frame or a wiring board;
A wire bonding step of conducting the semiconductor element and an external connection terminal with each other;
A sealing step of sealing the semiconductor element with a sealing resin;
And a peeling step of peeling the adhesive sheet for semiconductor device production from the lead frame or the wiring board after the sealing step.

Images