TWI624914B - Resin sheet for electronic component sealing, resin sealed semiconductor device, and method for manufacturing resin sealed semiconductor device - Google Patents

Abstract

A resin sheet for sealing an electronic component, which is used for producing a resin-sealed semiconductor device, and contains 70 to 93% by weight of an inorganic filler as a whole of the resin sheet for electronic component sealing, and has a thickness of 250 μm. The moisture permeability after the heat hardening is 300 g/m ² ‧ 24 hours or less under the conditions of a temperature of 85 ° C, a humidity of 85%, and 168 hours.

Description

Resin sheet for electronic component sealing, resin sealed semiconductor device, and method for manufacturing resin sealed semiconductor device

The present invention relates to a resin sheet for electronic component sealing, a resin sealing type semiconductor device, and a method of manufacturing a resin sealing type semiconductor device.

Conventionally, in the manufacture of a semiconductor device, a semiconductor wafer is mounted on various substrates such as a lead frame or a circuit board, and then resin sealing is performed so as to cover electronic components such as semiconductor wafers. In the resin-sealed semiconductor device manufactured as described above, there is a problem that reliability is lowered if the water absorbing property of the sealing resin is high. Therefore, the reliability of the resin-sealed type semiconductor device has been improved by using a sealing resin having a low water absorbability.

On the other hand, a polypropylene resin sheet having moisture permeability resistance has been known (for example, see Patent Document 1). The polypropylene resin sheet described in Patent Document 1 can be used in various packages or containers.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 07-148853

However, in the production of a resin-sealed semiconductor device, there is a problem that reliability is not improved even when a sealing resin having low water absorbability is used.

The present invention has been made in view of the above problems, and an object thereof is to provide an A resin sheet for electronic component sealing and a highly reliable resin-sealed semiconductor device having improved reliability of a resin-sealed semiconductor device.

In order to solve the above-mentioned problems, the inventors of the present invention have found that the moisture permeability of the sealing resin is related to the reliability in the resin-sealed semiconductor device, and the present invention has been completed.

In other words, the resin sheet for electronic component sealing of the present invention is characterized in that it is used for producing a resin-sealed semiconductor device, and contains 70 to 93% by weight of an inorganic filler for the entire resin sheet for electronic component sealing. The moisture permeability after heat hardening at a thickness of 250 μm was 300 g/m ² ‧ 24 hours or less under the conditions of a temperature of 85 ° C, a humidity of 85%, and a 168 hour.

Previously, it has been considered that the reliability of the resin-sealed type semiconductor device depends on the water absorption of the sealing resin, and the moisture permeability is not investigated. Therefore, although the water absorbing property of the sealing resin is low, the reliability of the resin-sealed type semiconductor device cannot be ensured. As a result of intensive studies, the inventors of the present invention have found that the reliability of the resin-sealed semiconductor device is improved if the moisture permeability of the sealing resin is low. For this reason, the inventors of the present invention have estimated that if the moisture permeability of the sealing resin is low, it is difficult for water to reach the electronic component from the outside. In other words, it is presumed that when a sealing resin having a low water absorption property but a high moisture permeability is used, since the water finally reaches the electronic component, the reliability of the resin sealing type semiconductor device is lowered.

According to the above configuration, 70 to 93% by weight of the inorganic filler is contained in the entire resin sheet for electronic component sealing, and the moisture permeability after thermal curing at a thickness of 250 μm is 85 ° C, 85%, and 168 hours in humidity. Under the conditions of 300 g / m ² ‧ 24 hours or less, so water is not easy to reach the electronic parts from the outside. As a result, the reliability of the resin-sealed type semiconductor device can be improved. Further, the evaluation condition of the moisture permeability is set to a temperature of 85 ° C, a humidity of 85%, and a 168 hour, which is the most stringent in the solder resistance reliability test (MSL (moisture sensitivity level) test) of the semiconductor package. The moisture absorption condition is the Level 1 condition.

In the case where the thickness is not 250 μm, the conversion is carried out by the following formula 1 to obtain a moisture permeability at a temperature of 85 ° C, a humidity of 85%, and a thickness of 168 hours, which is 250 μm.

(Formula 1) A-(250-D)×0.101

(A: moisture permeability, D: sample thickness (μm))

In the above configuration, the moisture permeability after the heat curing at a thickness of 250 μm is preferably 100 g/m ² ‧ 24 hours or less at a temperature of 60 ° C, a humidity of 90%, or 168 hours. When the moisture permeability after thermal curing at a thickness of 250 μm is 100 g/m ² ‧ 24 hours or less under the conditions of a temperature of 60 ° C, a humidity of 90%, and a 168 hour, the reliability of the resin-sealed semiconductor device can be further improved. Further, the evaluation conditions of the moisture permeability were set to a temperature of 60 ° C, a humidity of 90%, and 168 hours, which is one of the most stringent conditions in the high-temperature and high-humidity placement test of the semiconductor package.

In the case where the thickness is not 250 μm, the conversion is performed by the following formula 2 to obtain a moisture permeability at a temperature of 60 ° C, a humidity of 90%, and a thickness of 168 hours, which is 250 μm.

(Formula 2) A-(250-D)×0.010

(A: moisture permeability, D: sample thickness (μm))

In the above configuration, it is preferably produced by kneading and pressing. Since the resin sheet for electronic component sealing of the present invention contains 70 to 93% by weight of an inorganic filler with respect to the entire resin sheet for electronic component sealing, it is difficult to form into a sheet shape. Therefore, it is manufactured by kneading extrusion, whereby a less uniform sheet such as a void (bubble) can be produced. As a result, low moisture permeability can be further achieved.

Moreover, the resin-sealed semiconductor device of the present invention is characterized in that it includes a semiconductor wafer to which an adherend is bonded to the adherend, and a resin sheet for sealing an electronic component for sealing the semiconductor wafer, and the resin for sealing an electronic component. The sheet contains 70 to 93% by weight of an inorganic filler based on the entire resin sheet for electronic component sealing, and the moisture permeability after thermal curing at a thickness of 250 μm is at a temperature of 85 ° C, a humidity of 85%, and 168 hours. A gap of 300 g/m ² ‧ 24 hours or less is formed between the adherend and the semiconductor wafer.

In MEMS (Micro Electro Mechanical Systems) or surface acoustic wave filters (SAW filters) such as acceleration sensors, pressure sensors, and gyro sensors, there is a structural necessity to be A gap is formed between the adhesive and the semiconductor wafer. However, once water permeates into such a space from the outside, it is difficult to eliminate, and the reliability of the resin-sealed type semiconductor device is lowered by the water.

According to the above configuration, the resin sheet for electronic component sealing contains 70 to 93% by weight of an inorganic filler with respect to the entire resin sheet for electronic component sealing, and the moisture permeability after heat curing at a thickness of 250 μm is 85 ° C. When the humidity is 85% or 168 hours, it is 300 g/m ² ‧ 24 hours or less, so that it is difficult for water to penetrate into the gap between the adherend and the semiconductor wafer from the outside. As a result, the reliability of the resin-sealed type semiconductor device can be improved.

Moreover, the resin-sealed semiconductor device of the present invention is characterized by comprising the resin sheet for electronic component sealing described above.

According to the above configuration, the resin sheet for electronic component sealing contains 70 to 93% by weight of an inorganic filler with respect to the entire resin sheet for electronic component sealing, and the moisture permeability after heat curing at a thickness of 250 μm is 85 ° C. At a humidity of 85% or 168 hours, it is 300g/m ² ‧24 hours or less, so water does not easily reach the electronic parts from the outside. As a result, the reliability of the resin-sealed type semiconductor device can be improved.

Moreover, the method for producing a resin-sealed semiconductor device according to the present invention includes the step of laminating a resin sheet for electronic component sealing from the side of the semiconductor wafer so as to cover the semiconductor wafer to which the flip chip is bonded to the adherend, and the electron The resin sheet for sealing a part contains 70 to 93% by weight of an inorganic filler with respect to the entire resin sheet for electronic component sealing, and the moisture permeability after heat curing at a thickness of 250 μm is at a temperature of 85 ° C, a humidity of 85%, and 168. Under the condition of hour, it is 300g/m ² ‧24 hours or less.

According to the above configuration, the resin sheet for electronic component sealing contains 70 to 93% by weight of an inorganic filler with respect to the entire resin sheet for electronic component sealing, and the moisture permeability after heat hardening at a temperature of 250 μm is at a temperature of 85 Since the temperature is 85 g/m ^{2 and} ‧ 24 hours or less under the conditions of ° C, humidity of 85%, and 168 hours, water in the resin-sealed type semiconductor device manufactured is not easily reached from the outside to the electronic component. As a result, the reliability of the resin-sealed type semiconductor device can be improved.

2‧‧‧Resin sheet for electronic parts sealing

3‧‧‧ cutting protective tape

31‧‧‧Substrate

32‧‧‧Adhesive layer

4‧‧‧Semiconductor wafer

5‧‧‧Semiconductor wafer

51‧‧‧Bumps formed on the circuit side of the semiconductor wafer 5

52‧‧‧ gap

6‧‧‧Adhesive body

61‧‧‧Conductive conductive material covered by the bonding pad of the adherend 6

Fig. 1 is a schematic cross-sectional view showing an example of a resin sheet for sealing an electronic component according to the embodiment.

Fig. 2 is a cross-sectional schematic view for explaining a method of manufacturing the resin-sealed semiconductor device of the embodiment.

3 is a cross-sectional schematic view for explaining a method of manufacturing the resin-sealed semiconductor device of the embodiment.

4 is a cross-sectional schematic view for explaining a method of manufacturing the resin-sealed semiconductor device of the embodiment.

Fig. 5 is a cross-sectional schematic view for explaining a method of manufacturing the resin-sealed semiconductor device of the embodiment.

Fig. 6 is a cross-sectional schematic view for explaining a method of manufacturing the resin-sealed semiconductor device of the embodiment.

The embodiment of the present invention will be described with reference to the drawings, but the present invention is not limited to the examples. Fig. 1 is a schematic cross-sectional view showing an example of a resin sheet for sealing an electronic component according to the embodiment. Furthermore, in this specification, the parts that need not be explained are omitted in the figure. In addition, there are parts which are illustrated for enlargement or reduction, etc., for easy explanation.

(Resin sheet for electronic parts sealing)

As shown in FIG. 1, the resin sheet 2 for electronic component sealing has a sheet form. The resin sheet 2 for electronic component sealing is used to manufacture a resin-sealed semiconductor device (for example, the resin-sealed semiconductor device 50 shown in FIG. 6).

When the thickness of the resin sheet 2 for electronic component sealing is 250 μm, the moisture permeability after heat curing is 300 g/m ² ‧24 hours or less under conditions of a temperature of 85 ° C, a humidity of 85%, and 168 hours, preferably 200 g / m ² ‧ 24 hours or less, more preferably 100 g / m ² ‧ 24 hours or less Further, although the above-mentioned moisture permeability is preferably as small as possible, it is, for example, 1 g/m ^{2 for} ‧ 24 hours or longer. Since the moisture permeability after thermal hardening at a thickness of 250 μm is 300 g/m ² ‧ 24 hours or less under the conditions of a temperature of 85 ° C, a humidity of 85%, and a 168 hour, water does not easily reach the electronic component from the outside. As a result, the reliability of the resin-sealed type semiconductor device including the resin sheet 2 for electronic component sealing can be improved.

Further, when the thickness of the resin sheet 2 for electronic component sealing is 250 μm, the moisture permeability after heat curing is preferably 100 g/m ² ‧ 24 hours or less under the conditions of a temperature of 60 ° C, a humidity of 90%, and a 168 hour period. More preferably, it is 50 g/m ² ‧24 hours or less, and further preferably 20 g/m ² ‧24 hours or less. Further, although the above-mentioned moisture permeability is preferably as small as possible, it is, for example, 0.5 g/m ^{2 for} ‧ 24 hours or longer. When the moisture permeability after thermal curing at a thickness of 250 μm is 100 g/m ² ‧ 24 hours or less under the conditions of a temperature of 60° C., a humidity of 90%, and a 168 hours, the resin sheet for electronic component sealing can be further improved. The reliability of the resin sealed semiconductor device.

The resin composition for forming the electronic component sealing resin sheet 2 is not particularly limited as long as it can be used for sealing electronic parts (for example, the semiconductor wafer 5), and examples thereof include a resin combination containing the following components A to E. The object is preferred.

Component A: Epoxy

B component: phenolic resin

Component C: Elastomer

D component: inorganic filler

Component E: Hardening accelerator

(component A)

The epoxy resin (component A) is not particularly limited. For example, a triphenylmethane type epoxy resin, a cresol novolac type epoxy resin, a biphenyl type epoxy resin, a modified bisphenol A type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type can be used. Various epoxy resins such as epoxy resin, modified bisphenol F epoxy resin, dicyclopentadiene epoxy resin, phenol novolak epoxy resin, and phenoxy resin. These epoxy resins may be used singly or in combination of two or more.

From the viewpoint of ensuring the toughness after curing of the epoxy resin and the reactivity of the epoxy resin, it is preferably a solid having an epoxy equivalent of 150 to 250, a softening point or a melting point of 50 to 130 ° C at a normal temperature, wherein From the viewpoint of reliability, a triphenylmethane type epoxy resin, a cresol novolak type epoxy resin, and a biphenyl type epoxy resin are preferable.

Further, from the viewpoint of low stress, a modified bisphenol A type epoxy resin having a soft skeleton such as an acetal group or a polyoxyalkylene group is preferred, and the modified bisphenol A having an acetal group is preferred. Since the epoxy resin is liquid and works well, it can be preferably used.

The content of the epoxy resin (component A) is preferably from 1 to 10% by weight, more preferably from 2 to 5% by weight, based on the total of the resin sheet for electronic component sealing.

(B component)

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

As the phenolic resin, from the viewpoint of reactivity with the epoxy resin (component A), it is preferred to use a hydroxyl group equivalent of 70 to 250 and a softening point of 50 to 110 ° C. From the viewpoint of high reactivity, a phenol novolak resin can be preferably used. Further, from the viewpoint of reliability, a low hygroscopic property such as a phenol aralkyl resin or a biphenyl aralkyl resin can also be preferably used.

The blending ratio of the epoxy resin (component A) to the phenol resin (component B) is preferably 1 equivalent to the epoxy group in the epoxy resin (component A), and the phenol system is used. The total amount of the hydroxyl groups in the resin (component B) is adjusted to be 0.7 to 1.5 equivalents, more preferably 0.9 to 1.2 equivalents.

(C component)

The elastomer (C component) used together with the epoxy resin (component A) and the phenol resin (component B) is a semiconductor wafer in the case where the resin sheet for electronic component sealing is formed into a sheet shape. The flexibility required for the sealing of 5 is not particularly limited as long as it exhibits such an effect. For example, various acrylic copolymers such as polyacrylate, styrene acrylate copolymer, butadiene rubber, styrene-butadiene rubber (SBR), ethylene-vinyl acetate copolymer (EVA), and the like can be used. A rubbery polymer such as pentadiene rubber or acrylonitrile rubber. In particular, since it is easily dispersed in the epoxy resin (component A) and has high reactivity with the epoxy resin (component A), the heat resistance or strength of the obtained resin sheet for electronic component sealing can be further improved. From the viewpoint, it is preferred to use an acrylic copolymer. These may be used alone or in combination of two or more.

Further, the acrylic copolymer can be synthesized by, for example, radically polymerizing an acrylic monomer mixture having a specific mixing ratio. As a method of radical polymerization, a solution polymerization method using an organic solvent as a solvent or a suspension polymerization method in which a raw material monomer is dispersed while being dispersed in water can be used. As the polymerization initiator used at this time, for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis-(2,4-dimethylvaleronitrile), 2, can be used. 2'-Azobis-4-methoxy-2,4-dimethylvaleronitrile, other azo or diazo polymerization initiators, benzamidine peroxide and methyl ethyl ketone peroxide A peroxide-based polymerization initiator or the like. Furthermore, in the case of suspension polymerization, it is preferred to add, for example, polypropylene. A dispersing agent of guanamine and polyvinyl alcohol.

The content of the elastomer (component C) is preferably from 1 to 10% by weight, more preferably from 2 to 5% by weight, based on the entire resin sheet for electronic component sealing. By setting the content of the elastomer (component C) to 1% by weight or more, flexibility and toughness can be imparted to the sheet. Moreover, by setting the content of the elastomer (component C) to 10% by weight or less, the strength of the molded article required for packaging can be exhibited.

Further, the weight ratio of the elastomer (component C) to the epoxy resin (component A) (weight of the component C/weight of the component A) is preferably 0.3 to 2, more preferably 0.7 to 1.5. By setting the above weight ratio to 0.3 or more, toughness and flexibility can be imparted to the sheet. On the other hand, by setting the above weight ratio to 2 or less, the reliability of the package after curing can be maintained.

(D component)

The inorganic filler (component D) is not particularly limited, and various conventionally known fillers can be used, and examples thereof include quartz glass, talc, cerium oxide (melted cerium oxide or crystalline cerium oxide), and alumina. A powder such as aluminum nitride or tantalum nitride. These may be used alone or in combination of two or more.

Among them, in terms of a low moisture permeability, it is preferred to use a cerium oxide powder, and more preferably a cerium oxide powder in a cerium oxide powder. Examples of the molten cerium oxide powder include spherical molten cerium oxide powder and crushed molten cerium oxide powder. From the viewpoint of fluidity, it is particularly preferable to use spherical molten cerium oxide powder. Among them, those having an average particle diameter of 0.1 to 50 μm are preferably used, and those having a range of 0.3 to 25 μm are particularly preferably used.

Further, the average particle diameter can be derived, for example, by using a sample taken from a parent group and measuring by a laser diffraction scattering type particle size distribution measuring apparatus.

The content of the inorganic filler (component D) is preferably 70 to 93% by weight, more preferably 75 to 90% by weight, even more preferably 80 to 88%, based on the entire resin sheet for electronic component sealing. weight%. Since the inorganic filler has a low moisture permeability, the moisture permeability of the resin sheet 2 for electronic component sealing can be reduced by setting the content to 70% by weight or more. On the other hand, when the content of the inorganic filler is 93% by weight or less, the resin sheet 2 for electronic component sealing can be easily formed into a sheet shape.

(E component)

The curing accelerator (component E) is not particularly limited as long as it is cured by an epoxy resin or a phenol resin, and triphenylphosphine or tetraphenyl is preferably used from the viewpoint of curability and preservability. An organic phosphorus compound such as tetraphenylphosphonium borate or an imidazole compound. These hardening accelerators may be used singly or in combination with other hardening accelerators.

The content of the curing accelerator (component E) is preferably 0.1 to 5 parts by weight based on 100 parts by weight of the total of the epoxy resin (component A) and the phenol resin (component B).

(other ingredients)

Further, in addition to the components A to E in the resin composition, a flame retardant component may be added. As the flame retardant component, for example, an organic phosphorus-based flame retardant such as phosphazene, or various metal hydroxides such as aluminum hydroxide, magnesium hydroxide, iron hydroxide, calcium hydroxide, tin hydroxide, or a composite metal hydroxide can be used. Things and so on. From the viewpoint of dispersibility in the resin composition, an organic phosphorus-based flame retardant is preferred, but a viewpoint of exhibiting flame retardancy with a relatively small amount of addition or a viewpoint of cost may be adopted as the case may be. In the case of aluminum hydroxide or magnesium hydroxide, there are also cases. These may be used alone or in combination.

Further, in addition to the above respective components, the resin composition may be appropriately blended with other additives such as carbon black-based pigments as needed.

(Method of manufacturing resin sheet for electronic component sealing)

The procedure for producing the resin sheet 2 for electronic component sealing will be described below in the case where the resin sheet 2 for electronic component sealing is a sheet-like thermosetting resin layer.

First, a resin composition is prepared by mixing the above components. The mixing method is not particularly limited as long as it is a method of uniformly dispersing and mixing the respective components. Thereafter, for example, A varnish obtained by dissolving or dispersing each component in an organic solvent or the like is applied to form a sheet. Alternatively, the kneaded material may be directly kneaded by a kneading machine or the like to prepare a kneaded product, and the kneaded material obtained in the above manner may be extruded to form a kneaded product.

As a specific production procedure for using the varnish, the above-mentioned components A to E and other additives as necessary are appropriately mixed according to a usual method, and uniformly dissolved or dispersed in an organic solvent to prepare a varnish. Then, the varnish is applied onto a support such as polyester and dried to obtain a resin sheet 2 for electronic component sealing. Then, if necessary, in order to protect the surface of the resin sheet for electronic component sealing, a release sheet such as a polyester film may be bonded. The release sheet was peeled off at the time of sealing.

The organic solvent is not particularly limited, and various conventionally known organic solvents such as methyl ethyl ketone, acetone, cyclohexanone, and the like can be used. Alkane, diethyl ketone, toluene, ethyl acetate, and the like. These may be used alone or in combination of two or more. Further, it is generally preferred to use an organic solvent in such a manner that the concentration of the solid content of the varnish reaches 30 to 60% by weight.

The thickness of the sheet after the organic solvent is dried is not particularly limited, and is usually preferably from 5 to 100 μm, more preferably from 20 to 70 μm, from the viewpoint of uniformity of thickness and amount of residual solvent.

On the other hand, in the case of using kneading, the components of the above-mentioned components A to E and optionally other additives are mixed by a known method such as a stirrer, and then kneaded and kneaded to prepare a kneaded product. The method of the melt-kneading is not particularly limited, and examples thereof include a method of performing melt-kneading by a known kneading machine such as a kneading roll, a pressure kneader, or an extruder. The kneading condition is not particularly limited as long as it is at least the softening point of each of the above components, and is, for example, 30 to 150 ° C, and preferably 40 to 140 ° C in consideration of thermosetting properties of the epoxy resin, and further preferably It is 60 to 120 ° C, and the time is, for example, 1 to 30 minutes, preferably 5 to 15 minutes. Thereby, a kneaded product can be prepared.

The electronic component seal can be obtained by forming the obtained kneaded material by extrusion molding A resin sheet 2 was used. Specifically, the resin sheet 2 for electronic component sealing can be formed by directly performing extrusion molding at a high temperature without cooling the kneaded material after melt-kneading. The extrusion method is not particularly limited, and examples thereof include a T-die extrusion method, a rolling method, a roll kneading method, a co-extrusion method, and a calender molding method. The extrusion temperature is not particularly limited as long as it is at least the softening point of each of the above components, and is, for example, 40 to 150 ° C, preferably 50 to 140 ° C, in consideration of thermosetting properties and moldability of the epoxy resin. Further preferably, it is 70 to 120 °C. According to the above aspect, the resin sheet 2 for electronic component sealing can be formed.

In particular, since 70 to 93% by weight of the inorganic filler is contained in the entire electronic component sealing resin sheet 2, it is preferably produced by kneading extrusion from the viewpoint of sheet form moldability. By using kneading extrusion, it is possible to produce a less uniform sheet such as pores (bubbles). As a result, low moisture permeability can be achieved.

The resin sheet 2 for electronic component sealing obtained in the above manner can also be used by laminating to a desired thickness as needed. In other words, the sheet-like resin composition can be used in a single layer structure, or can be used as a laminate in which a multilayer structure of two or more layers is laminated.

(Method of Manufacturing Resin-Sealed Semiconductor Device)

Next, a method of manufacturing the resin-sealed semiconductor device of the present embodiment will be described below with reference to FIGS. 2 to 6 . 2 to 6 are schematic cross-sectional views for explaining a method of manufacturing the resin-sealed semiconductor device of the embodiment.

In the method of manufacturing a semiconductor device described above, at least a step of laminating a resin sheet for electronic component sealing from the side of the semiconductor wafer so as to cover the semiconductor wafer on which the flip chip is bonded to the adherend is provided.

[installation steps]

First, as shown in FIG. 2, the semiconductor wafer 4 is bonded to the adhesive layer 32 of the dicing protective tape 3 formed by laminating the adhesive layer 32 on the substrate 31, and then held and fixed (mounting step). The adhesive layer 32 is bonded to the back surface of the semiconductor wafer 4. The back surface of the semiconductor wafer 4 refers to the surface opposite to the circuit surface (also referred to as non-circuit surface, non-electrode formation). Face, etc.). The bonding method is not particularly limited, and a method of press-bonding is preferred. The press-bonding is usually carried out by pressing one side by a pressing method such as a press roll. Further, as the cut protection tape 3, a conventionally known one can be used.

As the substrate 31, for example, low density polyethylene, linear polyethylene, medium density polyethylene, high density polyethylene, ultra low density polyethylene, random copolymer polypropylene, block copolymer polypropylene, or the like may be used. Polyolefins such as homopolypropylene, polybutene, polymethylpentene, ethylene-vinyl acetate copolymer, ionic polymer resin, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylate ( Random, alternating) copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, polyurethane, polyethylene terephthalate, polyethylene naphthalate and other polyester, poly Carbonate, polyimide, polyetheretherketone, polyimide, polyetherimine, polyamine, fully aromatic polyamine, polyphenylene sulfide, aromatic polyamine (paper), glass , glass cloth, fluororesin, polyvinyl chloride, polyvinylidene chloride, cellulose resin, polyoxyn resin, metal (foil), paper, and the like.

As the adhesive for forming the adhesive layer 32, for example, a usual pressure-sensitive adhesive such as an acrylic adhesive or a rubber-based adhesive can be used. Further, the adhesive layer 32 can be formed by an ultraviolet curable adhesive. The ultraviolet curable adhesive can increase the degree of crosslinking by irradiation with ultraviolet rays, and the adhesion is easily lowered, and the pickup can be easily performed by ultraviolet irradiation after the cutting step.

[Cutting step]

Then, as shown in FIG. 3, the dicing of the semiconductor wafer 4 is performed. Thereby, the semiconductor wafer 4 is cut into a specific size and singulated (small pieces) to manufacture the semiconductor wafer 5. The dicing can be performed, for example, from the circuit surface side of the semiconductor wafer 4 according to the convention. The cutting device used in this step is not particularly limited, and a conventionally known one can be used.

Further, in the case of performing the extension of the cut protection tape 3, the extension can be carried out using a previously known stretching device. The extension device has an annular outer ring that can press the cutting protection tape 3 downward through the cleavage ring, and has a smaller diameter than the outer ring and supports the cutting protection tape 3 Inner ring. By this stretching step, in the pickup step described later, it is possible to prevent adjacent semiconductor wafers from coming into contact with each other and being damaged.

[pickup step]

In order to recover the semiconductor wafer 5 which is then fixed to the dicing protective tape 3, as shown in FIG. 4, the semiconductor wafer 5 is picked up, and the semiconductor wafer 5 is peeled off from the dicing protective tape 3. The method of picking up is not particularly limited, and various methods previously known can be employed. For example, a method in which each semiconductor wafer 5 is ejected from the side of the substrate 31 by a needle, and the semiconductor wafer 5 that is ejected by the pickup device is picked up can be cited.

[Crystalline connection step]

As shown in FIG. 5, the picked-up semiconductor wafer 5 is fixed to an adherend such as a substrate by a flip chip bonding method (flip-chip mounting method). Specifically, the semiconductor wafer 5 is fixed to the adherend 6 in a form in which the circuit surface (also referred to as a surface, a circuit pattern forming surface, an electrode forming surface, and the like) of the semiconductor wafer 5 is opposed to the adherend 6 by convention. . For example, the bump 51 formed on the circuit surface side of the semiconductor wafer 5 is brought into contact with the bonding conductive material (solder or the like) 61 covered by the connection pad of the adherend 6, and the conductive material is melted while being pressed. The electrical connection between the semiconductor wafer 5 and the adherend 6 is ensured, and the semiconductor wafer 5 can be fixed to the adherend 6 (the flip chip bonding step). At this time, a gap is formed between the semiconductor wafer 5 and the adherend 6, and the distance between the gaps is usually about 15 μm to 300 μm. Further, after the semiconductor wafer 5 is flip-chip bonded (flip-chip bonded) to the adherend 6, the opposite faces or gaps of the semiconductor wafer 5 and the adherend 6 can be cleaned. Further, the void may be filled with a sealing material (sealing resin or the like) according to the use of the semiconductor device, or may be retained in the form of a void. Among them, in a MEMS or surface acoustic wave filter (SAW filter) such as an acceleration sensor, a pressure sensor, a gyro sensor, etc., since it is structurally necessary to form a gap between the adherend and the semiconductor wafer, For such use, it is retained in the form of voids.

As the adherend 6, various substrates such as a lead frame or a circuit board (such as a printed circuit board) can be used. The material of such a substrate is not particularly limited, and examples thereof include a ceramic substrate or a plastic substrate. Examples of the plastic substrate include an epoxy substrate and a bismaleimide III. A substrate, a polyimide substrate, or the like.

In the flip chip bonding step, the material of the bump or the conductive material is not particularly limited, and examples thereof include a tin-lead metal material, a tin-silver metal material, a tin-silver-copper metal material, and a tin-zinc system. Solder (alloy) such as metal, tin-zinc-bismuth metal, or gold-based metal or copper-based metal.

Further, in the flip chip bonding step, the conductive material is melted to connect the bump on the circuit surface side of the semiconductor wafer 5 to the conductive material on the surface of the adherend 6, and the temperature at the time of melting of the conductive material is usually It is about 260 ° C (for example, 250 ° C ~ 300 ° C).

Then, a sealing step for sealing the gap between the flip chip bonded semiconductor wafer 5 and the adherend 6 is performed as needed. The sealing step is carried out using a sealing resin for underfill. The sealing condition at this time is not particularly limited, and the sealing resin can be thermally cured by heating at 175 ° C for 60 seconds to 90 seconds. However, the present invention is not limited thereto, and for example, it can be carried out at 165 ° C to 185 ° C. Cured in a few minutes.

The sealing resin for underfill is not particularly limited as long as it is an insulating resin (insulating resin), and can be appropriately selected from known sealing materials such as sealing resins, and more preferably an insulating resin having elasticity. The sealing resin for underfilling is, for example, a resin composition containing an epoxy resin. Examples of the epoxy resin include the epoxy resins exemplified above. In addition, as the resin component, the sealing resin for underfill which is formed of a resin composition containing an epoxy resin may contain, in addition to the epoxy resin, a thermosetting resin (such as a phenol resin) other than the epoxy resin, or Thermoplastic resin, etc. In addition, the phenolic resin can also be used as a curing agent for an epoxy resin, and examples of such a phenolic resin include the above-exemplified phenolic resins.

[Step of Laminating Resin Sheet for Electronic Parts Sealing]

In the lamination step of the resin sheet for electronic component sealing, to cover the semiconductor wafer 5 In this manner, the resin sheet 2 for electronic component sealing is laminated on the adherend 6 from the side of the semiconductor wafer 5 (see FIG. 6). The resin sheet 2 for electronic component sealing functions as a sealing resin for protecting the semiconductor wafer 5 and its accompanying elements from external environmental interference.

The method of laminating the resin sheet 2 for electronic component sealing is not particularly limited, and a method of extruding a melt-kneaded product of a resin composition for forming a resin sheet for electronic component sealing by extrusion molding is described. The semiconductor wafer 5 is placed on the adherend 6 and pressed, whereby the resin sheet for electronic component sealing is formed and laminated at one time; and the resin composition for forming the resin sheet for electronic component sealing is used from the semiconductor. The wafer 5 is coated on the adherend 6 and then dried. The resin composition is applied onto a release-treated sheet, and the coated film is dried to form a resin sheet 2 for electronic component sealing. The electronic component sealing resin sheet 2 is transferred from the semiconductor wafer 5 side to the adherend 6;

Since the resin sheet 2 for electronic component sealing has a sheet shape, when the semiconductor wafer 5 is coated, the semiconductor wafer 5 can be embedded only by adhering to the adherend 6 from the side of the semiconductor wafer 5, thereby improving the production efficiency of the semiconductor device. . In this case, the resin sheet 2 for electronic component sealing can be laminated on the adherend 6 by a known method such as hot pressing or laminating. The temperature is, for example, 40 to 120 ° C, preferably 50 to 100 ° C, and the pressure is, for example, 50 to 2500 kPa, preferably 100 to 2000 kPa, and the time is, for example, 0.3 to 10 minutes, preferably 0.5 to 5 minutes. . In addition, in consideration of improvement in adhesion and followability of the resin sheet 2 for electronic component sealing to the semiconductor wafer 5, it is preferable to perform pressing under reduced pressure conditions (for example, 10 to 2000 Pa).

After the resin sheet 2 for electronic component sealing is laminated on the adherend 6 from the semiconductor wafer 5 side as described above, the resin sheet 2 for electronic component sealing is cured. The curing of the resin sheet 2 for electronic component sealing is carried out at a temperature ranging from 120 ° C to 190 ° C, a heating time of from 1 minute to 60 minutes, and a pressure of from 0.1 MPa to 10 MPa. According to the above, the resin-sealed semiconductor device 50 can be obtained. Especially unused between the adherend 6 and the semiconductor wafer 5 In the case of the underfill sealing resin, the resin-sealed semiconductor device 50 in which the voids 52 are formed between the adherend 6 and the semiconductor wafer 5 can be manufactured.

In the above embodiment, a case where the resin sheet for electronic component sealing is used for manufacturing a flip chip type semiconductor device will be described. However, the resin sheet for electronic component sealing of the present invention is not limited to this example, and may be used for manufacturing a semiconductor device in which the back surface of a semiconductor wafer is attached to an adherend.

In the above embodiment, the case where no article is attached to the back surface of the semiconductor wafer has been described. However, the present invention is not limited to this example, and the film for flip chip type semiconductor back surface may be attached to the back surface of the semiconductor wafer. The film for flip chip type semiconductor back surface is used to protect the back surface of the semiconductor wafer (the exposed back surface) when the semiconductor wafer is mounted on the substrate by flip chip bonding, and a conventionally known one can be used.

In the above-described embodiment, the resin sheet for electronic component sealing is laminated from the semiconductor wafer side so as to cover the semiconductor wafer on which the flip chip is bonded to the adherend, but the resin sheet for electronic component sealing of the present invention is It is not limited to a semiconductor wafer, and it may be laminated by covering other electronic components (for example, capacitors, resistors, etc.). In other words, the resin sheet for electronic component sealing of the present invention is not limited to the embedding of a semiconductor wafer, and can be used for embedding other electronic components.

[Examples]

Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited to the following examples as long as the present invention is not exceeded. In addition, in each case, unless otherwise indicated, a part is a weight basis.

<Production of kneaded material for resin sheet for electronic component sealing>

(Example 1)

The kneaded material was prepared by kneading the following components at 120 ° C for 5 minutes by a biaxial kneading machine.

A component (epoxy resin): bisphenol F type epoxy resin (made by Dongdu Chemical Co., Ltd.) Made, YSLV-80XY) 3.38 parts

Component B (phenolic resin): a phenolic resin having a biphenyl aralkyl skeleton (manufactured by Megumi Chemical Co., Ltd., MEH7851SS) 3.58 parts

Component C (elastomer): Thermoplastic elastomer (manufactured by Kaneka Co., Ltd., product name: SIBSTER 072T) 3.04 parts

Component D (inorganic filler): spherical cerium oxide (manufactured by Electric Chemical Industry Co., Ltd., product name FB-9454FC, average particle size 20 μm) 88 parts

Component E (hardening accelerator): an imidazole-based catalyst as a curing catalyst (2PHZ-PW manufactured by Shikoku Chemical Industry Co., Ltd.) 0.119 parts

Other Ingredients 1: Carbon Black (manufactured by Mitsubishi Chemical Corporation, #3030B) 0.3 parts

Other Ingredients 2: Flame Retardant (Phenoxyphosphazene oligomer, product name: FP-100, manufactured by Fushimi Pharmaceutical Co., Ltd.) 1.58 parts

Then, the kneaded product was extrusion-molded, and the extruded product was brought into a constant thickness by vacuum pressing (250 μm in the present Example 1). The vacuum pressing was carried out in a vacuum state in a chamber heated to 90 degrees, and was carried out under the conditions of pressing for 5 minutes (pressing pressure: 2 MPa). Thereby, the resin sheet for electronic component sealing of Example 1 was obtained. Thereafter, it was heated at 150 ° C for 1 hour to be hardened.

(Examples 2 to 6 and Comparative Example 1)

The resin sheets for electronic component sealing of Examples 2 to 6 and Comparative Example 1 were obtained in the same manner as in Example 1 except that the amount of the formulation was changed to that shown in Table 1. Thereafter, it was heated at 150 ° C for 1 hour to be hardened.

(Example 7)

The following components were dissolved in 400 parts by weight of methyl ethyl ketone, and formulated by means of a homogenizer to become uniform.

A component 1 (epoxy resin 1): (manufactured by DIC Corporation, EXA-4850-150) 3.62 parts

A component 2 (epoxy resin 2): novolac type epoxy resin (manufactured by Dainippon Ink Co., Ltd., EPPN501HY) 1.53 parts

Component B (phenolic resin): (manufactured by Qun Rong Chemical, GS-200) 1.84 parts

Component C (elastomer): 17.02 parts of an acrylic copolymer containing 86 parts of butyl acrylate, 7 parts of acrylonitrile, 7 parts of glycidyl methacrylate, and a weight average molecular weight of 750,000.

Component D (inorganic filler): spherical cerium oxide (manufactured by Admatechs, SO-E2, average particle diameter 0.5 μm) 75 parts

E component (hardening accelerator): an imidazole-based catalyst as a curing catalyst (2PHZ-PW manufactured by Shikoku Chemical Industry Co., Ltd.) 0.25 parts

Other Ingredients: Carbon Black (Made by Mitsubishi Chemical Corporation, #20) 0.74 parts

Then, the above formulation was applied using a comma coater, and a resin sheet having a thickness of 50 μm was obtained by solvent drying. Then, five sheets of the above resin sheet were laminated by a roll laminator heated to 70 ° C to obtain a resin sheet for electronic component sealing of Example 7 having a thickness of 250 μm. Thereafter, it was heated at 150 ° C for 1 hour for moisture permeability measurement to be hardened.

(Comparative Example 2 and Comparative Example 3)

The resin sheets for electronic component sealing of Comparative Example 2 and Comparative Example 3 were obtained in the same manner as in Example 7 except that the blending amount was changed to that shown in Table 2. Thereafter, it was heated at 150 ° C for 1 hour to be hardened.

<Transparency measurement>

The moisture permeability of the resin sheet for electronic component sealing (after heat curing) produced in the examples and the comparative examples was measured in accordance with JIS Z 0208 (cup method). The measurement conditions are as follows. The results are shown in Tables 1 and 2.

(Measurement condition 1)

Temperature 85 ° C, humidity 85%, 168 hours, thickness of resin sheet for electronic parts sealing Degree: 250μm

(Measurement condition 2)

Temperature 60 ° C, humidity 90%, 168 hours, thickness of resin sheet for electronic parts sealing: 250 μm

<Reliability evaluation result>

Prepare 25 1mm × 1mm × 0.2mmt size Si wafers (5 rows × 5 rows, wafer spacing is set to 0.5mm). Ultrasonic waves are connected to the 0.5mm thick alumina substrate by gold bumps. The gap between the lower surface and the substrate: 20 μm).

Then, using the resin sheet for electronic component sealing produced in the examples and the comparative examples, the Si wafer was sealed by vacuum pressing (sealing conditions: 50 ° C, 1 MPa, 1 minute, vacuum degree: 1000 Pa) at 150 ° C. Hardened for 1 hour. Thereby, a cured product in a state in which a void is formed in the lower portion of each wafer is obtained. Thereafter, it is divided into individual packages by cutting. The moisture absorption was carried out at 85 ° C, 85%, and 168 hours by the method of MSL1 (Moisture Sensitivity Level) according to JEDEC (Joint Electron Device Engineering Council). Thereafter, a 260 ° C × 3 times moisture absorption reflow test was performed by an IR reflow (infrared reflow) apparatus. The package after the test was observed by an ultrasonic microscope, and the peeling was observed to be × between the substrate and the resin, and the unobserved was set to ○. The results are shown in Tables 1 and 2.

Claims (6)

A resin sheet for sealing an electronic component, which is used for producing a resin-sealed semiconductor device, and contains 70 to 93% by weight of an inorganic filler for the entire resin sheet for electronic component sealing, and further One or two or more kinds of phenol-based resins selected from the group consisting of phenolic novolak resins, phenol aralkyl resins, and biphenyl aralkyl resins, and having a thickness of 250 μm, the moisture permeability after heat curing is at a temperature It is 300 g/m ² ‧24 hours or less at 85 ° C, humidity 85%, and 168 hours. The resin sheet for electronic component sealing according to claim 1 has a moisture permeability after heat curing at a thickness of 250 μm at a temperature of 60 ° C, a humidity of 90%, and a condition of 168 hours, and is 100 g/m ^{2 for} ‧ 24 hours or less. The resin sheet for electronic component sealing according to claim 1 or 2, which is produced by kneading extrusion. A resin-sealed semiconductor device comprising: a semiconductor wafer bonded to the adherend by an adherend; and a resin sheet for sealing an electronic component that seals the semiconductor wafer; and the resin for sealing an electronic component The sheet contains 70 to 93% by weight of an inorganic filler based on the entire resin sheet for electronic component sealing, and further contains a group selected from the group consisting of a phenol novolak resin, a phenol aralkyl resin, and a biphenyl aralkyl resin. One or two or more kinds of phenolic resins having a thickness of 250 μm and a moisture permeability after heat curing at a temperature of 85 ° C, a humidity of 85%, and a condition of 168 hours are 300 g/m ^{2 for} ‧ 24 hours or less A gap is formed between the adherend and the semiconductor wafer. A resin-sealed type semiconductor device comprising the one of claims 1 to 3 Resin sheet for electronic parts sealing. A method of manufacturing a resin-sealed semiconductor device, comprising the step of laminating a resin sheet for electronic component sealing from a side of a semiconductor wafer so as to cover a semiconductor wafer that is bonded to an adherend, and the electronic component The resin sheet for sealing contains 70 to 93% by weight of an inorganic filler based on the entire resin sheet for electronic component sealing, and further contains a phenol novolak resin, a phenol aralkyl resin, and a biphenyl aralkyl group. One or two or more kinds of phenolic resins in the group of resins, the moisture permeability after heat curing at a thickness of 250 μm is 300 g/m ² ‧24 hours under the conditions of a temperature of 85 ° C, a humidity of 85%, and a 168 hour the following.