JP2013048284A - Manufacturing method of resin sealing type semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method which achieves high versatility of a resin sheet, enables a uniform shape of obtained package end surfaces, and downsizes a semiconductor device in a sealing method of the semiconductor device which uses the resin sheet for reducing the costs and improving the quality.SOLUTION: A manufacturing method of a semiconductor device includes the steps of: preparing a circuit board 10 on which multiple semiconductor chips 11 are mounted; burying a sealing resin layer 3 of a resin sheet for semiconductor sealing into irregularities and gaps of a semiconductor chip mounting surface of the circuit board 10 with the resin sheet for the semiconductor sealing 1 stretched on a frame body 4 having an opening slightly larger than a planar shape of the circuit board, and thereby causing a sealing resin layer surface to contact with a circuit board surface; and cutting the circuit board with the sealing resin layer for each semiconductor chip. The manufacturing method includes a step where the sealing resin layer is subject to thermal hardening after the step where the sealing resin layer surface is placed in contact with the circuit board surface.

Description

  The present invention relates to a method for manufacturing a resin-encapsulated semiconductor device.

Many semiconductor devices are used as a package form in which a semiconductor element mounted on a circuit board is sealed with a resin.
As a packaging method of a semiconductor element, a method is generally used in which a lead frame (sheet metal, TAB tape, etc.) on which a device is mounted is set in a mold, and a molten resin is filled and solidified in the mold for sealing. It was. However, this method has a limit in reducing the package thickness. The reason for this is that it is difficult to create a mold with high thickness accuracy, and even if such a mold can be created, the micro structure of the device (circuitry) is caused by the flow pressure of the resin that is pressed into the narrow space. This is because there is a possibility that the wire, etc.) may be damaged. In addition, resin sealing using a mold requires the same mold for both small lot products and mass-produced products, and the cost of mold production becomes a problem for small lot products.

For this reason, a semiconductor element sealing method using a resin sheet instead of a mold has been proposed.
For example, in Patent Document 1, “In a semiconductor device manufacturing method in which a semiconductor element mounted on a circuit board having a wiring pattern and a connection portion between the semiconductor element and the wiring pattern is sealed with resin, the size of the semiconductor element is disclosed. An amount of resin corresponding to the shape of the semiconductor element is formed on the surface of the base tape in a pattern corresponding to the shape of the semiconductor element, the resin is melted according to the mechanical strength of the semiconductor element and the connection portion, and the circuit board and The semiconductor element and the molten resin are aligned by adjusting the position of the base tape, and a predetermined pressure is applied to the aligned resin and the semiconductor element to melt the resin. Disclosed is a method for manufacturing a semiconductor package, wherein the semiconductor element is buried without damaging the semiconductor element and the connection portion " It has been.

However, the following problems have been found in the above method.
(1) In the above method, it is necessary to previously form an amount of resin corresponding to the size of the semiconductor element to be sealed on the surface of the base tape in a pattern corresponding to the shape of the semiconductor element. For this reason, it is necessary to prepare various tapes according to the shape of the semiconductor element to be sealed, resulting in poor versatility.
(2) The resin layer formed in a predetermined shape on the substrate is applied with pressure in a molten state, and the semiconductor element is buried. At this time, since the end surface of the resin layer is also melted and fluidized, the side end surface of the obtained package may be irregularly deformed. If the shape of the end face on the package side is irregular, the package is likely to be damaged due to thermal history, mechanical shock, or the like.
(3) Further, according to the above method, the package structure has a structure in which the end portion of the circuit board protrudes from the sealing resin layer as shown in FIG. Therefore, it is disadvantageous in reducing the size of the semiconductor device.

Japanese Patent Laid-Open No. 11-251347

  The present invention has been made in view of the prior art as described above. In a semiconductor element sealing method using a resin sheet, the versatility of the resin sheet is high, and the shape of the package end surface obtained is constant. It is an object of the present invention to provide a method capable of reducing the size of the device, and to reduce the cost and improve the quality in manufacturing the semiconductor device.

The gist of the present invention for solving such problems is as follows.
(1) preparing a circuit board on which a plurality of semiconductor chips are mounted;
For semiconductor encapsulation, comprising a support sheet and a thermosetting sealing resin layer that is detachably laminated on the entire surface of one side of the support sheet on a frame having a slightly larger opening than the planar shape of the circuit board A step of embedding the sealing resin layer of the resin sheet for semiconductor sealing in the unevenness and gaps of the semiconductor chip mounting surface of the circuit board and bringing the sealing resin layer surface into contact with the circuit board surface with the resin sheet stretched And cutting the circuit board together with the sealing resin layer for each semiconductor chip,
A method of manufacturing a semiconductor device including a step of thermally curing the sealing resin layer after the step of bringing the sealing resin layer surface into contact with the circuit board surface and / or after the step of cutting the circuit substrate together with the sealing resin layer for each semiconductor chip .
(2) In the step of bringing the sealing resin layer surface into contact with the circuit board surface, pressurizing locally only in the vicinity of the uppermost surface of the semiconductor chip using a pressing iron having substantially the same size as the semiconductor chip. A method for manufacturing a semiconductor device.
(3) Circuit board fixing formed by stretching a resin sheet for semiconductor encapsulation comprising a support sheet and a thermosetting encapsulating resin layer that is detachably laminated on the entire surface of one side of the support sheet. jig.
(4) A semiconductor device manufactured by the manufacturing method of (1) or (2) above.

  According to the present invention, in a semiconductor element sealing method using a resin sheet, there is provided a method in which the resin sheet is highly versatile, the shape of the obtained package end surface is constant, and the apparatus can be miniaturized. In the manufacture of semiconductor devices, cost reduction and quality improvement are achieved.

2 shows an example of a circuit board on which a semiconductor chip is mounted. XX sectional drawing of FIG. 1-A is shown. 2 shows an example of a circuit board on which a semiconductor chip is mounted. FIG. 2A is a sectional view taken along line YY in FIG. Sectional drawing of the resin sheet for semiconductor sealing is shown. The sealing process of the manufacturing method which concerns on this invention is shown. The dicing process of the manufacturing method which concerns on this invention is shown.

Hereinafter, embodiments (examples) of the present invention will be described more specifically with reference to the drawings.
In the manufacturing method of the present invention, first, a circuit board 10 on which a semiconductor chip 11 is mounted is prepared. As the circuit board, for example, a hard lead frame obtained by punching a copper or copper alloy plate material into a predetermined pattern may be used. However, when considering easy handling by reel winding, a flexible material such as polyimide is used. It is preferable to use a flexible circuit board in which a predetermined wiring pattern is formed by attaching a copper foil to the surface of the conductive film and photoetching the copper foil.

  1-A and 1-B show examples of wire-bonded devices, and FIGS. 2-A and 2-B show examples of flip-chip bonded devices. 1-B is a cross-sectional view taken along line XX of FIG. 1-A, and FIG. 2-B is a cross-sectional view taken along line YY of FIG. 2-A.

  In the wire-bonded device, an electrode terminal on the semiconductor chip 11 and an outer lead (not shown) on the circuit board 10 are electrically connected via the wire 12. The wire 12 is usually composed of a gold wire or the like. The circuit board 10 and the semiconductor chip 11 are bonded (die-bonded) via an adhesive resin 13 such as a normal thermosetting adhesive such as an epoxy adhesive. Also. A film-like die bond material may be used as the adhesive resin.

  In the flip-chip bonded device, the semiconductor chip 11 and a pad-like electrode (not shown) on the circuit board 10 are electrically connected via a solder ball 14 formed on the lower surface of the semiconductor chip 11. The space between the lower surface of the chip formed by the solder balls 14 and the circuit board 10 may be filled with an adhesive resin 15 that is usually called underfill (see FIG. 2).

  The circuit board 10 on which the semiconductor chip 11 having the above configuration is mounted can be obtained by various known methods. 1A and 2A show a state in which a long and wide circuit board 10 is used and semiconductor chips are two-dimensionally arranged. The semiconductor chips may be arranged at regular intervals in the longitudinal direction.

Further, the circuit board 10 may have a structure having an opening depending on the design specifications.
In the present invention, the chip mounting surface of the circuit board 10 on which the plurality of semiconductor chips 11 are mounted is sealed with the semiconductor sealing resin sheet 1. Hereinafter, this process is called a sealing process.

  As shown in FIG. 3, a semiconductor sealing resin sheet 1 (hereinafter sometimes referred to as a resin sheet) used in the sealing process is peeled and laminated on the entire surface of one side of the supporting sheet 2. And a thermosetting sealing resin layer 3. Suitable examples of the support sheet 2 and the sealing resin layer 3 will be described later. The resin sheet 1 is preferably used with its outer peripheral part fixed to a frame 4 having an opening slightly larger than the circuit board 10. By using the frame body 4, transfer between processes can be performed easily. Further, the resin sheet 1 is stretched on the frame 4 and the circuit board 10 is fixed to the resin sheet 1, so that it can be used as a jig for holding the circuit board 10 in the dicing process. The material of the frame 4 is not particularly limited, and may be made of metal, resin, or the like. When the resin sheet 1 is fixed to the frame body 4, the resin sheet 1 is laminated on the frame body 4, and the frame body 4 is heated to heat the thermosetting sealing resin layer 3 on the outer periphery of the resin sheet 1. Then, the frame 4 and the resin sheet 1 are firmly bonded to each other and the resin leakage from the end of the resin sheet 1 is prevented.

  In the sealing step, the sealing resin layer 3 of the resin sheet 1 is embedded in the irregularities and gaps on the semiconductor chip mounting surface of the circuit board 10, the sealing resin layer surface is brought into contact with the circuit board surface, and the semiconductor chip 11 is completely formed. The resin sheet 1 is covered so as to cover it. At this time, the sealing process is preferably performed by the following two processes as shown in FIG. In FIG. 4 and subsequent figures, wire-bonded devices are shown as an example, but the same applies to flip-chip bonded devices.

First, the sealing resin layer 3 of the semiconductor sealing resin sheet 1 is brought into close contact with the top surface of the semiconductor chip while heating only the semiconductor chip 11 mounted on the circuit board 10.
In the wire-bonded chip, the wire 12 is also heated by heating the chip 11. When the resin sheet 1 is pressed vertically on the heated chip 11 and the wire 12, the sealing resin layer 3 first comes into contact with the wire 12, and only the sealing resin layer 3 in the vicinity of the wire locally decreases in viscosity. For this reason, the wire 12 is quickly embedded in the sealing resin layer 3, and damage to the wire 12 is reduced. However, the resin far from the heated wire or chip is delayed in heat conduction, and no substantial decrease in viscosity occurs until a sufficient time has elapsed after the sealing resin layer 3 contacts the chip 11. When the resin sheet 1 is brought into contact with the upper surface of the chip 11, it is preferable to pressurize locally only in the vicinity of the uppermost surface of the chip using a pressing iron 5 having approximately the same size as the chip.

  Similarly, in the flip-chip bonded device, when only the chip 11 is heated and the resin sheet 1 is pressed vertically to the heated chip 11, the sealing resin layer 3 adheres to the top surface of the chip without any gap.

  Next, the sealing resin layer 3 is embedded in the irregularities and gaps on the semiconductor chip mounting surface of the circuit board 10 while heating the entire circuit board 10. By heating the entire circuit board 10, the entire sealing resin layer is also softened. By pressing the resin sheet 1 against the circuit board 10, the sealing resin is sufficiently embedded in the side surface of the chip 11, the base, and the circuit board 10 body. Since the wire 12 has already been filled with resin, a large force that breaks the wire by the flow of the resin is not applied. As a result, the sealing resin is sufficiently filled up to the unevenness and gaps of the circuit board 10 and the chip 11 is resin-sealed, so that the quality of the semiconductor device can be improved.

  At this time, in order to press the resin sheet 1 against the circuit board 10, a flat plate press that presses the entire surface of the resin sheet 1 may be used. However, when the resin sheet 1 is fixed to the frame body 4, Since the frame body 4 is lowered in the direction of the circuit board and the resin sheet 1 can be pressed against the circuit board 10 by the roller 6, the process and the apparatus are simplified. Further, it is preferable to perform deaeration when the resin sheet 1 is pressed against the circuit board 10. Deaeration can reduce the occurrence of air accumulation between the sealing resin layer 3 and the circuit board 10, and the adhesion between the sealing resin layer 3 and the circuit board 10 is improved.

  In the above process, the semiconductor chip 11 and the circuit board surface are heated to a temperature at which the sealing resin layer 3 can be sufficiently softened and to a temperature at which the thickening of the sealing resin layer 3 does not start by curing. . At this time, if the sealing resin layer 3 is excessively softened, the resin is unnecessarily fluidized, and the resin is diffused to a portion other than the necessary portion, which may cause device contamination and appearance defects.

  In addition, when the circuit board 10 is composed of a lead frame and the board surface has an opening like a QFN (Quad Flatpack Non-leaded Package) type device, the circuit board back surface is provided prior to the sealing step. A pressure-sensitive adhesive sheet such as a masking tape is affixed in advance to the surface opposite to the chip mounting surface. The opening is closed with a masking tape to prevent the sealing resin from flowing out from the opening.

After the sealing step, the circuit board 10 is diced for each semiconductor chip to obtain a desired semiconductor device. Hereinafter, this process is called a dicing process.
In the present invention, the sealing resin layer 3 is thermoset after the sealing step, after the dicing step, or after both steps. The thermosetting conditions may be any conditions as long as the thermosetting resin constituting the sealing resin layer 3 is completely cured. In the case where the heat curing is performed twice after the sealing step and after the dicing step, precuring is performed in the previous stage to form a B stage, and complete curing is performed in the subsequent stage.

In the dicing process, the circuit board 10 and the sealing resin layer 3 are cut into individual pieces along the shape of the individual circuit board to obtain a resin-sealed semiconductor device.
The dicing method is not particularly limited, and may be a method using a dicing blade or laser dicing using a laser beam.

  Although not limited at all, several examples of the dicing method will be described below. During normal dicing, an object to be cut is attached to an adhesive sheet (dicing sheet) and the outer peripheral portion of the adhesive sheet is fixed with a ring frame in order to prevent scattering of the cut chips.

  However, when the resin sheet 1 is used while being fixed to the frame 4, the resin sheet 1 itself can be used as a dicing sheet and the frame 4 can be used as a ring frame. That is, as shown in FIG. 5, with the outer periphery of the resin sheet 1 fixed by the frame body 4, the resin sheet 1 is introduced into the dicing apparatus, the circuit board 10 and the sealing resin layer 3 are cut, and the support sheet 2 is completely removed. Dicing so as not to cut. Then, the resin sheet is obtained by peeling the support sheet. As described above, by using the circuit board holding jig in which the resin sheet 1 is fixed to the frame body 4, it is not necessary to use a dicing sheet, so that the process can be simplified and the cost can be reduced.

Further, the dicing step in the present invention may be a step using a normal dicing sheet.
A desired resin-sealed semiconductor device can be obtained by sticking a dicing sheet to the laminate of the resin sheet 1 and the circuit board 10 and cutting it by a normal dicing method. At this time, the dicing sheet may be adhered to the support sheet surface of the resin sheet, or the dicing sheet may be adhered to the circuit board surface. In this case, the support sheet is peeled and removed at an arbitrary stage after the dicing process. Moreover, you may stick a dicing sheet to the sealing resin layer surface or circuit board surface exposed after peeling a support sheet.

  When a circuit board having an opening is used, a masking tape is affixed to the back side of the circuit board (the opposite side of the chip mounting surface), but the masking tape is peeled off at any step after the sealing process. Is done.

  Next, the suitable example of the resin sheet 1 for semiconductor sealing used by this invention is demonstrated. As shown in FIG. 3, the semiconductor sealing resin sheet 1 includes a support sheet 2 and a thermosetting sealing resin layer 3 that is detachably laminated on the entire surface of one side of the support sheet 2.

  Examples of the support sheet 2 include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, and polybutylene terephthalate film. , Polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene / (meth) acrylic acid copolymer film, ethylene / (meth) acrylic acid ester copolymer film, polystyrene film, polycarbonate film, polyimide film, fluororesin film, etc. The film is used. These crosslinked films are also used. Furthermore, these laminated films may be sufficient. Furthermore, these films may be transparent films, colored films or opaque films.

  In the method for manufacturing a semiconductor device according to the present invention, since the sealing resin layer 3 on the support sheet 2 is transferred to the chip mounting surface of the circuit board, the support sheet 2 and the sealing resin layer 3 can be peeled off. Are stacked. For this reason, the surface tension of the surface in contact with the sealing resin layer 3 of the support sheet 2 is preferably 40 mN / m or less, more preferably 37 mN / m or less, and particularly preferably 35 mN / m or less. Such a film having a low surface tension can be obtained by appropriately selecting the material, and by applying a release agent such as a silicone resin or an alkyd resin to the surface of the film and performing a release treatment. It can also be obtained. Further, the support sheet 2 and the sealing resin layer 3 are detachably laminated by interposing a weak adhesive layer or an energy ray curable adhesive layer between the support sheet 2 and the sealing resin layer 3. You can also. The sealing resin layer 3 is finally cured by heat to become a cured resin. Therefore, it can peel easily from a weak adhesive layer after hardening. In addition, the energy ray-curable pressure-sensitive adhesive layer is cured when irradiated with energy rays and loses or drastically reduces the adhesive force. For this reason, peeling of the hardened sealing resin layer 3 can be performed more easily.

  The film thickness of such a support sheet 2 is usually about 10 to 500 μm, preferably about 15 to 300 μm, and particularly preferably about 20 to 250 μm. When a weak pressure-sensitive adhesive layer or an energy ray curable pressure-sensitive adhesive layer is used, the thickness of the pressure-sensitive adhesive layer is usually 1 to 1000 μm, preferably about 3 to 300 μm.

It is preferable that the sealing resin layer 3 has thermosetting properties and exhibits unique flow characteristics under a heating environment.
As described above, the sealing resin layer 3 of the resin sheet 1 is transferred to the chip mounting surface of the circuit board 10 and finally cured to seal the chip and the circuit. That is, in the present invention, the sealing resin layer 3 of the resin sheet 1 is embedded in the irregularities and gaps of the chip mounting surface, the sealing resin surface is brought into contact with the circuit board surface, and finally the sealing resin layer 3 is formed. Harden. The thickness accuracy of the sealing resin layer 3 affects the thickness accuracy of the finally formed package. For this reason, the thing with little fluctuation | variation in thickness accuracy in storage and a transfer condition is preferable.

Therefore, the elastic modulus of the sealing resin layer 3 before thermosetting is preferably 1.0 × 10 ^{3 to} 1.0 × 10 ⁴ Pa, and more preferably 1.0 × 10 ^{3 to} 5.0 × 10 ³ Pa. In addition, the elasticity modulus of the sealing resin layer 3 is measured at a measurement frequency of 1 Hz by a dynamic viscoelasticity measuring apparatus at 100 ° C. When the elastic modulus of the encapsulating resin layer 3 before thermosetting is in such a range, the encapsulating resin layer 3 is hardly deformed under the storage and transportation environment of the resin sheet, and the thickness accuracy of the encapsulating resin layer 3 is improved. Kept.

  In addition, if the sealing resin layer 3 is too hard at the time of pressure contact with the chip mounting surface, there is a possibility that the resin is not sufficiently filled in the flip chip bonded device and the air is trapped. May be crushed or broken. On the other hand, if the sealing resin layer 3 is too soft, the sealing resin is excessively fluidized, and the resin diffuses to a portion other than the necessary portion, which may cause device contamination and poor appearance. Therefore, the sealing resin layer 3 at the time of pressure contact with the chip mounting surface, that is, the sealing resin layer 3 before thermosetting is required to have appropriate heat fluidity.

  For this reason, the melt viscosity at 120 ° C. of the sealing resin layer 3 before thermosetting is preferably 100 to 200 Pa · sec, more preferably 110 to 190 Pa · sec. The melt viscosity at 120 ° C. of the encapsulating resin layer 3 before thermosetting is measured with a dynamic viscoelasticity measuring device at a measurement frequency of 1 Hz.

  Further, when the temperature of the sealing resin layer 3 before thermosetting is constant at 120 ° C., the time until the melt viscosity reaches the minimum value is preferably 60 seconds or less, more preferably 50 seconds or less, and particularly preferably 40 Less than a second. The encapsulating resin containing a polymer in the composition takes time until the whole shows a uniform viscosity even at high temperatures. Accordingly, when the sealing resin is heated to a constant temperature, the viscosity gradually decreases. However, since the sealing resin has thermosetting properties, the viscosity increases due to thermosetting over time. The time for the melt viscosity at 120 ° C. of the sealing resin layer 3 to reach the minimum value is measured by a dynamic viscoelasticity measuring device at a measurement frequency of 1 Hz.

The sealing resin layer 3 basically includes a binder component (A) and a thermosetting component (B) as essential components, and other additives (C) are blended as necessary.
Hereinafter, the components (A) to (C) will be described.

"Binder component (A)"
As the binder component (A), any polymer having adhesiveness can be used without particular limitation, but usually an acrylic polymer is preferably used. Examples of the repeating unit of the acrylic polymer include a repeating unit derived from a (meth) acrylic acid ester monomer and a (meth) acrylic acid derivative. Here, as the (meth) acrylic acid ester monomer, (meth) acrylic acid cycloalkyl ester, (meth) acrylic acid benzyl ester, and (meth) acrylic acid alkyl ester having 1 to 18 carbon atoms in the alkyl group are used. . Among these, (meth) acrylic acid alkyl esters in which the alkyl group has 1 to 18 carbon atoms are particularly preferable, such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, and propyl methacrylate. Butyl acrylate, butyl methacrylate and the like are used. Examples of (meth) acrylic acid derivatives include glycidyl (meth) acrylate.

In particular, it preferably includes a glycidyl (meth) acrylate unit and at least one alkyl (meth) acrylate unit. In this case, the content of the component unit derived from glycidyl (meth) acrylate in the copolymer is usually 0 to 80% by mass, preferably 5 to 50% by mass. By introducing a glycidyl group, compatibility with an epoxy resin as a thermosetting component described later is improved, and Tg after curing is increased, thereby improving heat resistance. As the (meth) acrylic acid alkyl ester, it is preferable to use methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, or the like. Further, by introducing a hydroxyl group-containing monomer such as hydroxyethyl acrylate, it becomes easy to control the adhesion to the adherend and the physical properties of the adhesive.
The weight average molecular weight of the acrylic polymer is preferably 100,000 or more, more preferably 150,000 to 1,000,000.

"Thermosetting component (B)"
The thermosetting component (B) has a property of forming a three-dimensional network when heated and bonding the adherend firmly. Such a thermosetting component (B) is generally formed from a thermosetting resin such as epoxy, phenol, resorcinol, urea, melamine, furan, unsaturated polyester, and silicone, and an appropriate curing accelerator. ing. Various such thermosetting components are known, and various conventionally known thermosetting components can be used in the present invention without particular limitation. As an example of such a thermosetting component, an adhesive component composed of (B-1) an epoxy resin and (B-2) a thermally activated latent epoxy resin curing agent can be exemplified.

  As the epoxy resin (B-1), conventionally known various epoxy resins are used. Usually, those having a weight average molecular weight of about 300 to 2,000 are preferred, particularly 300 to 500, preferably 330 to 400. It is desirable to use a liquid epoxy resin blended with a normal solid epoxy resin having a weight average molecular weight of 400 to 2000, preferably 500 to 1500. Moreover, the epoxy equivalent of the epoxy resin preferably used in the present invention is usually 50 to 5000 g / eq. Specific examples of such epoxy resins include glycidyl ethers of phenols such as bisphenol A, bisphenol F, resorcinol, phenyl novolac, and cresol novolac; glycidyl ethers of alcohols such as butanediol, polyethylene glycol, and polypropylene glycol; Glycidyl ethers of carboxylic acids such as phthalic acid, isophthalic acid and tetrahydrophthalic acid; glycidyl type or alkyl glycidyl type epoxy resins in which active hydrogen bonded to a nitrogen atom such as aniline isocyanurate is substituted with a glycidyl group; vinylcyclohexane diepoxide; 3,4-epoxycyclohexylmethyl-3,4-dicyclohexanecarboxylate, 2- (3,4-epoxy) cyclohexyl-5,5-spiro (3,4- Such as in the epoxy) cyclohexane -m- dioxane, carbon in the molecule - epoxy is introduced by for example oxidation to carbon double bond include a so-called alicyclic epoxides. Further, a dicyclopentadiene skeleton-containing epoxy resin having a dicyclopentadiene skeleton and a reactive epoxy group in the molecule may be used.

  Among these, in the present invention, bisphenol glycidyl type epoxy resin, o-cresol novolak type epoxy resin and phenol novolak type epoxy resin are preferably used.

These epoxy resins can be used alone or in combination of two or more.
The thermally activated latent epoxy resin curing agent (B-2) is a type of curing agent that does not react with the epoxy resin at room temperature but is activated by heating at a certain temperature or more and reacts with the epoxy resin.

  The activation method of the thermally activated latent epoxy resin curing agent (B-2) includes a method in which an active species (anion, cation) is generated by a chemical reaction by heating; A method in which a dispersion is stably dispersed and dissolved with an epoxy resin at a high temperature to start a curing reaction; a method in which a molecular sieve encapsulated type curing agent is eluted at a high temperature to start a curing reaction; a method using a microcapsule, etc. Exists.

  These thermally activated latent epoxy resin curing agents can be used singly or in combination of two or more. Of these, dicyandiamide, an imidazole compound or a mixture thereof is particularly preferable.

  The thermally activated latent epoxy resin curing agent (B-2) as described above is usually 0.1 to 20 parts by mass, preferably 0.5 to 15 parts by mass with respect to 100 parts by mass of the epoxy resin (B-1). Parts, particularly preferably 1 to 10 parts by weight.

"Other ingredients (C)"
The sealing resin layer 3 may be blended with a coupling agent (C1). It is desirable that the coupling agent (C1) has a group that reacts with the functional group of the component (A) or (B), preferably the component (B).

  The coupling agent (C1) is considered to react with the thermosetting component (B) (particularly preferably an epoxy resin) during the curing reaction, and without impairing the heat resistance of the cured product. Adhesion and adhesion can be improved, and water resistance (moisture heat resistance) is also improved.

  The coupling agent (C1) is preferably a silane (silane coupling agent) because of its versatility and cost merit. The coupling agent (C1) as described above is usually 0.1 to 20 parts by mass, preferably 0.3 to 15 parts by mass, particularly preferably 100 parts by mass of the thermosetting component (B). It is used at a ratio of 0.5 to 10 parts by mass.

  A crosslinking agent (C2) such as an organic polyvalent isocyanate compound or an organic polyvalent imine compound can be added to the sealing resin layer 3 in order to adjust initial adhesiveness and aggregation before curing.

  Examples of the organic polyvalent isocyanate compounds include aromatic polyvalent isocyanate compounds, aliphatic polyvalent isocyanate compounds, alicyclic polyvalent isocyanate compounds, trimers of these polyvalent isocyanate compounds, Examples thereof include terminal isocyanate urethane prepolymers obtained by reacting a polyvalent isocyanate compound and a polyol compound. Specific examples of the organic polyvalent isocyanate compound include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, and 1,4-xylene diisocyanate. Narate, diphenylmethane-4,4′-diisocyanate, diphenylmethane-2,4′-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4 ′ -Diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, lysine isocyanate and the like.

  Specific examples of the organic polyvalent imine compound include N, N′-diphenylmethane-4,4′-bis (1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, tetramethylol. Examples thereof include methane-tri-β-aziridinylpropionate, N, N′-toluene-2,4-bis (1-aziridinecarboxamide) triethylenemelamine, and the like. The crosslinking agent (C2) as described above is usually blended in an amount of 0.1 to 20 parts by mass, preferably 0.2 to 10 parts by mass with respect to 100 parts by mass of the binder component (A).

  Further, the sealing resin layer 3 may further contain a filler such as silica, alumina, glass, mica, chromium oxide, titanium oxide, and pigment. These fillers may be blended at a ratio of about 0 to 400 parts by mass with respect to a total of 100 parts by mass of components (excluding fillers) constituting the sealing resin layer 3.

  Moreover, in order to control the thermal responsiveness (heating fluidity | liquidity) of the sealing resin layer 3, you may mix | blend the thermoplastic resin which has a glass transition point at 60-150 degreeC. Examples of the thermoplastic resin include polyester resin, polyvinyl alcohol resin, polyvinyl butyral, polyvinyl chloride, polystyrene, polyamide resin, cellulose, polyethylene, polyisobutylene, polyvinyl ether, polyimide resin, phenoxy resin, polymethyl methacrylate, styrene-isoprene- Examples thereof include a styrene block copolymer and a styrene-butadiene-styrene block copolymer. Among these, a phenoxy resin is particularly preferable because of excellent compatibility with other components of the sealing resin layer.

  The blending ratio of the thermoplastic resin in the sealing resin layer 3 is preferably 1 to 50 parts by mass, more preferably 2 to 40 parts by mass, per 100 parts by mass in total of the binder component (A) and the thermosetting component (B). Particularly preferably, it is used in a proportion of 3 to 30 parts by mass. When an acrylic polymer is used as the binder component (A), the weight ratio of the acrylic polymer to the thermoplastic resin (acrylic polymer / thermoplastic resin) is 9/1 to 3/7. Preferably it is.

"Sealing resin"
The sealing resin layer 3 preferably has the heat fluidity described above. As a 1st factor which influences the heat fluidity of the sealing resin layer 3, the ratio of the binder component (A) and thermosetting component (B) in the said compound is mention | raise | lifted. Since the binder component (A) is a high molecular weight substance, the fluidity during heating is inhibited as the amount added is increased, and the fluidity is exhibited when the amount added is small. On the other hand, the thermosetting component (B) has a low molecular weight and exhibits fluidity before curing. Therefore, the blending amount of the binder component (A) with respect to the thermosetting component (B) is important in order to have appropriate fluidity and fluidity that does not bleed. The preferable blending ratio of the thermosetting component (B) is preferably 10 to 99 mass in 100 parts by mass of the total of the binder component (A) and the thermosetting component (B) ((A) + (B)). Parts, more preferably 50 to 97 parts by mass, particularly preferably 83 to 95 parts by mass.

  Moreover, when sealing resin contains a thermoplastic resin in large quantities, fluidity | liquidity becomes excessive and desired elastic modulus and melt viscosity may not be obtained. Accordingly, when the thermoplastic component is blended, the blending ratio is appropriately selected within the above-described range so as to meet the desired elastic modulus and heat fluidity.

  The thickness of the sealing resin layer 3 composed of the above components depends on the size of the device to be sealed, particularly the height from the circuit board to the top of the chip (the top of the wire) and the chip size and the area ratio of the circuit board. The preferable range differs, for example, the preferable thickness of the sealing resin layer 3 is about 40-2000 micrometers, More preferably, it is about 50-1000 micrometers. When the sealing resin layer 3 is thin, the chip portion can be sealed in a shape higher than the surroundings by the pressure contact method. However, when the sealing resin layer 3 is sufficiently thicker than the chip, all the chips are sealed. The sealing resin layer 3 may be embedded and the upper surface of the sealing resin layer 3 may be pressed into an average to form a flat surface.

  Moreover, the sealing resin layer 3 may have two or more constituent layers. For example, the constituent layer on the circuit board side of the sealing resin layer is formed of the resin having the heat fluidity, and the upper layer thereof, that is, the outermost layer in the final package, the impact resistance, the scratch resistance, etc. It is preferable that the resin layer forms a very hard cured layer. Further, a resin layer capable of displaying information by means such as laser marking may be provided on the outermost layer.

  The semiconductor sealing resin sheet 1 has a configuration in which a sealing resin layer 3 is detachably laminated on a support sheet 2 and is protected on the exposed surface of the sealing resin layer in order to protect the sealing resin layer 3. A film may be laminated. As a protective film. A film similar to the support sheet 2 described above can be used.

  The manufacturing method of such a resin sheet 1 for semiconductor encapsulation is not particularly limited, and may be produced by applying and drying a composition constituting the sealing resin layer 3 on the support sheet 2. You may manufacture by providing a sealing resin layer on another peelable sheet | seat, and transferring this to the said support sheet 2. FIG. When the sealing resin layer 3 cannot be formed with a film thickness required in one coating and drying step, the same composition may be further applied and dried on the sealing resin layer a plurality of times, or a resin formed thinly A sealing resin layer obtained by coating and drying separately on a sheet may be laminated to obtain a sealing resin layer 3 having a required film thickness.

  According to the present invention, in a semiconductor element sealing method using a resin sheet, there is provided a method in which the resin sheet is highly versatile, the shape of the obtained package end surface is constant, and the apparatus can be miniaturized. Is done. This reduces costs and improves quality in the manufacture of semiconductor devices such as area array type packages such as LGA (Land Grid Array) and BGA (Ball Grid Array) and QFN (Quad Flatpack Non-leaded Package). It is done.

DESCRIPTION OF SYMBOLS 1 ... Semiconductor sealing resin sheet 2 ... Support sheet 3 ... Sealing resin layer 4 ... Frame 5 ... Pressing iron 10 ... Circuit board 10
DESCRIPTION OF SYMBOLS 11 ... Semiconductor chip 12 ... Wire 13 ... Adhesive resin 14 ... Solder ball 15 ... Adhesive resin

Claims (4)

Preparing a circuit board on which a plurality of semiconductor chips are mounted;
For semiconductor encapsulation, comprising a support sheet and a thermosetting sealing resin layer that is detachably laminated on the entire surface of one side of the support sheet on a frame having a slightly larger opening than the planar shape of the circuit board A step of embedding the sealing resin layer of the resin sheet for semiconductor sealing in the unevenness and gaps of the semiconductor chip mounting surface of the circuit board and bringing the sealing resin layer surface into contact with the circuit board surface with the resin sheet stretched And cutting the circuit board together with the sealing resin layer for each semiconductor chip,
A method of manufacturing a semiconductor device including a step of thermally curing the sealing resin layer after the step of bringing the sealing resin layer surface into contact with the circuit board surface and / or after the step of cutting the circuit substrate together with the sealing resin layer for each semiconductor chip .   2. The manufacturing of a semiconductor device according to claim 1, wherein in the step of bringing the sealing resin layer surface into contact with the circuit board surface, a pressure iron having substantially the same size as the semiconductor chip is used to pressurize locally only in the vicinity of the uppermost surface of the semiconductor chip. Method.   A circuit board fixing treatment in which a semiconductor sealing resin sheet comprising a support sheet and a thermosetting sealing resin layer that is detachably laminated on the entire surface of one side of the support sheet is stretched over the entire frame. Ingredients.   A semiconductor device manufactured by the manufacturing method according to claim 1.

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