JP2003213086A - Resin paste for semiconductor and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin paste for semiconductors causing neither decline in hot adhesive strength nor debonding of resin paste layer when subjected to soldering crack resistance test after undergoing moisture absorption treatment, thus highly reliable. <P>SOLUTION: This resin paste for semiconductors essentially comprises (A) an epoxy resin, (B) a curing agent, (C) a compound of the general formula (1) and (D) a filler; wherein the amount of the component C is 0.1-50 pt(s).wt. based on 100 pts.wt. of the component A. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin paste for adhering a semiconductor element such as IC or LSI to a metal frame or the like.

[0002]

2. Description of the Related Art Conventionally, a resin paste for semiconductors has been generally used as a method for adhering a semiconductor element such as an IC to a lead frame. In response to the trend toward smaller and lighter electronic devices and higher functionality in recent years, semiconductor devices are becoming smaller, thinner, and narrower in pitch. There has been a strong demand for improvement in solder crack resistance after moisture absorption of a device. In order to improve resistance to solder cracking, it is important that the semiconductor element and the lead frame are in close contact with each other and that stress during soldering is relaxed. Among them, it was particularly important to improve the adhesion after the moisture absorption treatment, but in the conventional semiconductor resin paste, the adhesion between the lead frame or the semiconductor element and the semiconductor resin paste after the moisture absorption treatment is deteriorated, and the semiconductor There was a problem that the reliability of the device did not improve as expected.

[0003]

DISCLOSURE OF THE INVENTION The present invention is for a semiconductor having excellent reliability in which adhesion is not deteriorated by moisture absorption treatment and peeling of a resin paste layer for semiconductor does not occur in a solder crack resistance test after moisture absorption treatment. A resin paste and a semiconductor device using the same are provided.

[0004]

The present invention comprises (A) an epoxy resin, (B) a curing agent, (C) a compound represented by the general formula (1), and (D) a filler as essential components, and (C) ) A resin paste for semiconductors, wherein the compound represented by the general formula (1) is 0.1 to 50 parts by weight per 100 parts by weight of the epoxy resin.

[Chemical 4] (R1 is a hydrogen atom, or an alkyl group having 1 to 6 carbon atoms or an allyl group, which may be the same or different.
4 integer)

In a further preferred embodiment, (C) is a resin paste for semiconductors in which the compound represented by the general formula (1) is at least one selected from the compounds represented by the formula (2) or the formula (3). is there.

[Chemical 5]

[Chemical 6] Further, it is a semiconductor device manufactured by using the above resin paste for a semiconductor.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The (A) epoxy resin used in the present invention is a monomer or oligomer having an epoxy group,
Refers to all polymers. For example, bisphenol A, bisphenol F, phenol novolac, polyglycidyl ether obtained by reaction of cresol novolacs with epichlorohydrin, crystalline epoxy resin such as biphenyl type epoxy resin, stilbene type epoxy resin, hydroquinone type epoxy resin, butanedioldiene Aliphatic epoxy resins such as glycidyl ether and neopentyl glycol diglycidyl ether, heterocyclic epoxy resins such as diglycidyl hydantoin, alicyclic compounds such as vinylcyclohexenedioxide, dicyclopentadienedioxide and alicyclic diepoxy adipate Epoxy resin, dicyclopentadiene modified phenol type epoxy resin, triphenol methane type epoxy resin, naphthol type epoxy resin, phenol Examples thereof include hydrogenated epoxy resins such as rutile type epoxy resin, biphenylaralkyl type epoxy resin, glycidyl amine, and 2,2-bis (4-hydroxycyclohexyl) propane diglycidyl ether. These may be used alone or in combination. Can be used. Although there are various types of epoxy resins depending on the molecular weight, those having a small molecular weight and being liquid at room temperature are preferable from the viewpoint of workability in compounding and viscosity after compounding.

When the epoxy resin is solid or semi-solid, or when it is liquid and has a high viscosity, it is preferable to use a reactive diluent having an epoxy group in combination. Examples of the reactive diluents include n-butyl glycidyl ether, versatic acid glycidyl ester, styrene oxide,
Examples thereof include ethylhexyl glycidyl ether, phenyl glycidyl ether, cresyl glycidyl ether, butyl phenyl glycidyl ether, and these may be used alone or in combination of two or more.

Examples of the curing agent (B) used in the present invention include phenol resins, dicarboxylic acid dihydrazide compounds, imidazole compounds, aliphatic amines, aromatic amines, dicyandiamide, etc., and these may be used alone or in combination. It is possible to use together.

The phenol resin preferably has two or more active hydrogen groups per molecule which react with the epoxy groups and participate in crosslinking. Examples of such a phenol resin include bisphenol A, bisphenol F,
Bisphenol S, tetramethylbisphenol A, tetramethylbisphenol F, tetramethylbisphenol S, dihydroxydiphenyl ether, dihydroxybenzophenone, o-hydroxyphenol, m-hydroxyphenol, p-hydroxyphenol, biphenol, tetramethylbiphenol, ethylidene bisphenol, methylethylidene Phenol novolac resins and monohydric phenols obtained by reacting bis (methylphenol), cyclohexylidene bisphenol, monohydric phenols such as phenol, cresol and xylenol with formaldehyde in dilute aqueous solution under strong acidity Initial condensation products with polyfunctional aldehydes such as acrolein and glyoxal under acidic conditions, resorcin, catechol, hydroquino Initial condensate and the like of the acidic conditions of polyhydric phenols with formaldehyde etc., these can be used in combination of one or more.

Examples of the dicarboxylic acid dihydrazide compound include carboxylic acid dihydrazides such as adipic acid dihydrazide, dodecanoic acid dihydrazide, isophthalic acid dihydrazide, p-oxybenzoic acid dihydrazide, and the like. These may be used alone or in combination. Can be used.

Examples of the imidazole compound include 2
-Methylimidazole, 2-ethylimidazole, 2-
Phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxy methyl imidazole, 2-C ₁₁ H ₂₃ - General such as imidazole 2,4-diamino-which has been added storage stability by adding imidazole, triazine and isocyanuric acid
6- {2-methylimidazole- (1)}-ethyl-S
-Triazine, its isocyanate adduct, etc. are mentioned, and these can be used alone or in combination of two or more. The compounding amount of the (B) curing agent is not particularly limited, but is 0.1 to 100 parts by weight of the epoxy resin.
200 parts by weight is preferred. If it is less than the lower limit, the adhesive strength may decrease, and if it exceeds the upper limit, the viscosity becomes high and the workability may decrease.

Specific examples of the compound represented by the general formula (1) (C) used in the present invention are shown in the formulas (2) and (3), but the invention is not limited thereto and these are not limited thereto. 1
It is possible to use types or a combination of multiple types.
Among them, at least one selected from the compounds represented by the formulas (2) and (3) is particularly preferable because a high-purity compound is easily available.

The compound represented by the general formula (1) is characterized by containing benzoxazole and thiophene in one molecule. Since nitrogen in benzoxazole and sulfur in thiophene are bonded to the metal, the adhesive strength between the lead frame and the organic substrate and the gold-plated portion is improved, and the strength is less decreased even after the moisture absorption treatment. The compounding amount of the compound represented by the general formula (1) is preferably 0.1 to 50 parts by weight, more preferably 0.3 to 20 parts by weight, based on 100 parts by weight of the epoxy resin. If it is less than the lower limit value, there is no effect of preventing the adhesive strength after moisture absorption from being lowered by blending the compound represented by the general formula (1), and if it is more than the upper limit value, the adhesive strength decrease after moisture absorption treatment is small. However, it is not preferable because the initial adhesive strength is lowered and the viscosity is increased.

Examples of the (D) filler used in the present invention include inorganic fillers and organic fillers. Examples of the inorganic filler include metal powder such as gold powder, silver powder, copper powder, and aluminum powder, fused silica, crystalline silica, silicon nitride, alumina, aluminum nitride, talc, and the like. Among these, the metal powder is mainly used for imparting electrical conductivity and thermal conductivity. As an organic filler,
Examples thereof include silicone resins, fluororesins such as polytetrafluoroethylene, acrylic resins such as polymethylmethacrylate, and crosslinked products of benzoguanamine or melamine with formaldehyde. These fillers preferably have a content of ionic impurities such as halogen ions and alkali metal ions of 10 ppm or less.

As the shape of the filler, for example, a flake shape, a scale shape, a resin shape, a spherical shape, or the like is used. Depending on the required viscosity of the resin paste for semiconductors,
Although the fillers used have different particle diameters, it is usually preferable that the average particle diameter is 0.3 to 20 μm and the maximum particle diameter is about 50 μm. If the average particle diameter is less than the lower limit value, the viscosity becomes high, and if it exceeds the upper limit value, bleeding may occur because the resin component flows out during coating or curing. Maximum particle size is 50μ
If it exceeds m, when the resin paste for semiconductor is applied by the dispenser, the outlet of the needle is blocked and it cannot be used continuously for a long time. Further, a relatively coarse filler and a fine filler may be mixed and used, and various types and shapes may be appropriately mixed. Further, in order to impart required characteristics, a filler other than the above may be used. For example, a nanoscale filler having a particle size of about 1 to 100 nm, a composite material of silica and acrylic, a composite filler of an organic compound and an inorganic compound such as a material obtained by applying a metal coating to the surface of an organic filler, and the like can be mentioned. . The filler of the present invention may be one whose surface is previously treated with a silane coupling agent such as alkoxysilane, acyloxysilane, silazane or organoaminosilane. The amount of the (D) filler compounded is not particularly limited, but is preferably 1 to 95 parts by weight per 100 parts by weight of the resin paste. If it is less than the lower limit value, the viscosity may be too low to cause sagging of the paste, or the reinforcing strength due to the filler may not be obtained, which may lower the adhesive strength or solder resistance, and if it exceeds the upper limit value, the viscosity may be high. Therefore, the workability is deteriorated and the cured product of the paste becomes brittle, so that the solder resistance may be deteriorated.

The resin paste for semiconductors of the present invention is (A)-
The component (D) is an essential component, but in addition to these, additives such as a curing accelerator, a silane coupling agent, a titanate coupling agent, a pigment, a dye, a defoaming agent, a surfactant, a solvent, etc. may be added if necessary. Can be appropriately mixed. The resin paste for a semiconductor of the present invention is obtained by a manufacturing method in which components (A) to (D), other additives and the like are premixed, kneaded using a roll or the like, and then defoamed under vacuum. . A known method can be used to manufacture a semiconductor device using the resin paste for a semiconductor of the present invention.

[0017]

EXAMPLES The present invention will be specifically described with reference to Examples. The mixing ratio of each component is parts by weight. <Examples 1 to 13> Each component was kneaded with a roll according to the formulation of Table 1 and defoamed using a vacuum chamber to obtain a resin paste for semiconductors. The obtained resin paste for semiconductors was evaluated by the following methods. The results are shown in Table 1.

<Materials used> Epoxy resin: Bisphenol A type epoxy resin (viscosity 4000 mPas)
・ S / 25 ° C, epoxy equivalent 170) (hereinafter BPAE
P) 2,2-bis (4-hydroxycyclohexyl) propane diglycidyl ether (viscosity 1700 mPa · s / 2
5 ° C, epoxy equivalent 190) (hereinafter referred to as HBPADGE) -Curing agent: phenol novolac resin (hydroxyl equivalent 104), dicyandiamide-compound represented by general formula (1): compound represented by formula (2), formula (3) Compounds / inorganic fillers shown: Silver powder: Particle size 0.1 to 50 μm, average particle size 3 μm, flakes. Silica: average particle size 3 μm, maximum particle size 20 μm, spherical

<Evaluation Method> Viscosity: Using an E-type viscometer (3 ° cone), 25 ° C,
The value at 2.5 rpm was measured. -Adhesive strength: A 5 mm x 5 mm silicon chip was mounted on a copper frame using a resin paste for semiconductors, and cured at 200 ° C for 60 minutes using an oven. After curing, the die shear strength during heating at 260 ° C. was measured. -Adhesive strength after moisture absorption treatment: A sample was prepared in the same manner as the adhesive strength, and the sample was allowed to stand for 72 hours in an environment of 85 ° C and relative humidity of 85% for moisture absorption treatment. 260 after moisture absorption
The die shear strength during heating at ℃ was measured. -Soldering resistance (peeling rate): Silicon chip (size 9.0)
(mm × 9.0 mm) was mounted on a lead frame (made of copper) using a resin paste for semiconductors, and cured at 200 ° C. for 60 minutes under an atmosphere of nitrogen in an oven. An 80-pin QFP (package size 14 × 20 mm, thickness 2.
0 mm), the mold temperature is 175 ° C., the injection pressure is 7.5 MPa,
Transfer molding with a curing time of 60 seconds, 175 ° C,
It was post-cured in 8 hours. The obtained package is 85 ℃,
Leave for 168 hours in an environment of 85% relative humidity, then 2
It was immersed in a solder bath at 60 ° C. for 10 seconds. The total value of the peeling area inside the package was measured using a transmission type ultrasonic flaw detector, and the peeling area between the chip and the epoxy resin encapsulant and the lead frame and epoxy were measured using a reflection type ultrasonic flaw detector. The total value of the peeled area from the resin sealing material was measured.
(Peeling area of die attach layer) = [(total value of peeling area in transmission)-(total value of peeling area in reflection)]
The peeling rate of the resin paste for semiconductors is calculated as (peeling rate) = [(peeling area of die attach layer) / (chip area)] × 100.
The average value of 5 packages was calculated and expressed as%.

<Comparative Examples 1 to 12> Resin pastes for semiconductors were obtained in the same manner as in Examples according to the formulations shown in Table 2 and evaluated in the same manner as in Examples. The results are shown in Table 2.

[0021]

[Table 1]

[0022]

[Table 2]

[0023]

According to the present invention, there is no reduction in adhesive strength under heat, and a highly reliable resin paste for semiconductors in which peeling of the resin paste layer for semiconductors does not occur in the solder crack resistance test after moisture absorption treatment, and A semiconductor device using this is obtained.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 4J002 BD123 BG043 CC042 CC183                       CD001 CP033 DA078 DA098                       DE148 DF008 DJ008 DJ018                       DJ048 EN016 EN056 EQ026                       ET006 EU116 EV307 FA018                       FB098 FD013 FD018 FD142                       FD146 FD207 GQ05                 5F047 AA11 BA34

Claims (3)

[Claims] 1. An epoxy resin (A), a curing agent (B),
(C) The compound represented by the general formula (1) and the (D) filler are essential components, and the compound represented by the (C) general formula (1) is 0.1 to 50 parts by weight per 100 parts by weight of the epoxy resin. A resin paste for semiconductors characterized by being present. [Chemical 1] (R1 is a hydrogen atom, or an alkyl group having 1 to 6 carbon atoms or an allyl group, which may be the same or different.
4 integer) 2. The resin paste for semiconductors according to claim 1, wherein the compound represented by the general formula (1) (C) is at least one selected from the compounds represented by the formula (2) or the formula (3). . [Chemical 2] [Chemical 3] 3. A semiconductor device manufactured by using the semiconductor resin paste according to claim 1.