JP2003027033A - Heat-resistant adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a heat-resistant adhesive which gives a high bond strength at a low bonding pressure and hence is suitable for die bonding. SOLUTION: This heat-resistant adhesive comprises a bismaleimide compound, a polyquinoline compound and fine metallic particles of any of Al, Ag, Au, Cu and Ni, which are surface-treated with stearic acid, zinc stearate or aluminum stearate. The adhesive gives a high bond strength at a low bonding pressure and hence is suitable for die bonding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat resistant adhesive, and more particularly to a heat resistant adhesive suitable for die bonding of pellets of IC, LSI and the like.

[0002]

2. Description of the Related Art Generally, in a semiconductor device, a semiconductor pellet is adhered to an insulating substrate material or a metal frame serving as a support. Further, it is electrically connected to an external input / output terminal formed on the substrate through, for example, a wire, and is sealed with a metal, a ceramics cap, a mold resin or the like. As a method for adhering semiconductor pellets, Japanese Patent Application Laid-Open No. 54-69065, E.C. Conference, Proceeding, 37
(1987) pp. 96-109 (ECC Proceedings 37th (19
87)) and the like, a method of using an epoxy resin as an adhesive layer, and a heat treatment using Au foil for Au-Si.
A method of forming a eutectic and using it as an adhesive layer, and a method of using glass as an adhesive layer are known. In recent years, there have been many demands for CMOS ceramic package products for large-scale computers,
Its development is in progress. A large chip of 10 mm x 10 mm or more is used for this ceramic package product. However, it has been found that such a large chip has the following problems. That is, (1) concentration of stress in the adhesive phase at the time of pellet bonding, and chipping of the pellet due to mismatch of thermal expansion coefficients, and (2) deterioration of the adhesive layer due to thermal history at the time of glass sealing. (1) is particularly likely to occur when an Au-Si eutectic crystal forming a rigid adhesive layer or a glass layer is used. (2) is likely to occur when an epoxy resin is used as an adhesive layer.

To solve this problem, for example, Japanese Patent Laid-Open No.
No. 1-264023 and Japanese Patent Laid-Open No. 62-199674.
This can be solved by using a polyimide resin having high heat resistance described in Japanese Patent Publication No.

[0004]

However, in order to obtain a desired adhesive force, the polyimide resin is required to be bonded at the time of bonding.
It is necessary to apply a pressure of 20 to 40 kgf / cm ² for pressure bonding. Applying such a large pressing force to the pellet during die bonding has a bad influence on the element such as chipping of the pellet, cracking of the passivation film, and disconnection. Therefore, in order to avoid this, a polyimide resin in a varnish state is used and attached to the pellet by potting. However, in this case, the quality of the device in which the adhesive is used is increased by the varnish protruding to the wire bonding area of the package base and the increase in thermal resistance due to the generation of voids inside the adhesive layer due to solvent evaporation during varnish thermosetting. It has been a problem to have a negative impact on. An object of the present invention is to provide a heat resistant adhesive suitable for die bonding, which can obtain high bonding strength with low pressure at the time of bonding.

[0005]

In order to achieve the above object, the present invention provides a bismaleimide compound and a polyquinoline compound, and Al, A surface-treated with stearic acid, zinc stearate or aluminum stearate.
g, Au, Cu, and / or Ni. With such an adhesive, it becomes suitable for die bonding in which a high bonding strength can be obtained with a low bonding pressure.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to Examples. The present invention is not limited to these examples.

Example 1 (Synthesis of Adhesive Varnish) First, a polyquinoline compound is prepared by the following steps. 6,6'-bis (2- (4-
Fluorophenyl) -4-phenylquinoline) 74.3
g, 4,4 '-(1,1,1,3,3,3-hexafluoro-2,2-propylidene) bisphenol 40.
6 g and 25 g of anhydrous potassium carbonate were added to a 1-liter stainless steel flask, and 450 ml of N-methyl-2-pyrrolidone and 90 ml of toluene were further added as a solvent. A water-cooled cooling tube equipped with a calcium chloride tube and a Dean-Stark tube for removing water, a dry nitrogen introduction tube, a mechanical stirrer, and a thermometer were installed. Water was refluxed for 24 hours using an oil bath, and water in the system was distilled off together with toluene for 24 hours. The solution was initially yellow, then gradually turned brown and became black at this stage. Furthermore, the reaction temperature is 20
The temperature was raised to 0 ° C. and the reaction was performed for 6 hours. The reaction solution changed from black to deep blue as the viscosity increased. The reaction was stopped by adding 650 ml of N-methyl-2-pyrrolidone and diluting and cooling. In order to purify the obtained polymer solution, it was poured into water and precipitated. Subsequently, the mixture was stirred and washed in water at 50 ° C. for 2 hours and washed three times. The polymer was filtered and dried in a vacuum dryer at 60 ° C. for 24 hours to obtain 101.1 g of a polymer of polyquinoline compound.

After dissolving 21 g of the polyquinoline compound obtained above in 70 g of cyclopentanone, 9 g of 2,2-bis [4- (4-maleimidophenoxy) phenyl] propane as a bismaleimide compound was added and dissolved to homogeneity. Got a varnish.

(Evaluation of Adhesive Varnish) As shown in FIG. 1, the varnish obtained in the above process was used to form a ceramic substrate 1 having external input / output terminals 2 and Al wiring 3 and having a thickness of 2 mm and a length and width of 45 mm. A 12 mm square was drawn on the above with a dispenser to form an adhesive layer 4. Then, after drying at 140 ° C for 30 minutes to remove the solvent, the semiconductor pellets 5 are loaded with 720 g (500 kgf
/ Cm ² ), while heating at 300 ° C. for 1 minute while pressure-bonding.

At this time, pellet cracks did not occur. Adhesive strength was measured by sampling 10
A sufficient adhesive strength of 110 kgf / cm ² was obtained.

Example 2 The varnish produced in Example 1 was uniformly applied to a polyimide film using a doctor blade having a gap of 100 μm and dried in a dryer at 100 ° C./10 minutes and 200 ° C./10 minutes. The solvent was removed and the polyimide film was peeled off to obtain an adhesive film having a thickness of 30 μm. The residual solvent amount of this film was measured by a differential thermal balance,
It was about 2% of the total weight.

Adhesion was evaluated in the same manner as in Example 1 except that this film was cut into 11 mm square and used as an adhesive.
No pellet cracking and adhesive strength of 70-110 kg
It showed f / cm ² and sufficient strength.

Example 3 To the varnish of Example 1, scale-like Al powder coated with zinc stearate (average particle size: 2 μm or less) was added so that the solid content ratio was 1/1. It kneaded sufficiently using three roll mills. The suspension obtained by this shows thixotropic property, and about 250 Pa · s at a shear rate of 10 sec ⁻¹ .
It had a viscosity (measured at 25 ° C.) and was suitable for screen printing.

The ceramic substrate 3 described in the first embodiment is used for this suspension by using a screen plate having an 11 mm square opening.
Printed on top. Then, after drying at 140 ° C. for 30 minutes, the semiconductor pellets 5 were pressure-bonded with a load of 500 g (413 kgf / cm ² ) and heated at 350 ° C. for 30 minutes in a nitrogen stream to bond them.

At this time, no pellet crack occurred. Adhesive strength was measured by sampling 10
It showed a sufficient strength of 110 kgf / cm ² . In addition, the heat value of pellets is about 8 ℃ per 1W of power consumption (hereinafter expressed in ° C / W), which improves the thermal conductivity of the adhesive compared to the one without Al powder (11-12 ℃ / W). As a result, a reduction of around 30% was confirmed.

(Example 4) Using the suspension prepared in Example 3, a film was prepared by the method described in Example 2 and the adhesive strength and the calorific value of the pellet were measured. In all cases, good results equivalent to those in Example 3 were obtained. Also,
No pellet cracks occurred.

Example 5 18 g of the polyquinoline compound obtained in Example 1 was dissolved in 70 g of cyclopentanone, and then 2,2-bis [4- (4- (4-
Maleimidophenoxy) phenyl] -1,1,1,3
12 g of 3,3-hexafluoropropane was added and dissolved to obtain a uniform varnish of the polyquinoline compound. The resulting varnish is evenly applied to a polyimide film and dried in a dryer at 100 ° C / 10 minutes and 170 ° C / 10 minutes to remove the solvent,
The polyimide film was peeled off to obtain an adhesive film having a thickness of 30 μm.

The same evaluation as in Example 2 was carried out using this film, and as a result, no pellet cracks were generated,
The adhesive strength was 50 kgf / cm ² or more, which was a good result.

(Embodiment 6) 6,6'-bis (2- (4 "
-Fluorophenyl) -4-phenylquinoline) 11
4.75 g, 9,9-bis (4-hydroxyphenyl)
Fluorene 66.0472g and anhydrous potassium carbonate 39.1g
Was added to a 2 l stainless steel flask, and 705 ml of N-methyl-2-pyrrolidone and 421 ml of toluene were further added as a solvent. A water-cooled cooling tube equipped with a calcium chloride tube and a Dean-Stark tube for removing water, a dry nitrogen introduction tube, a mechanical stirrer, and a thermometer were installed. Water was refluxed for 15 hours using an oil bath, and water in the system was distilled off together with toluene. Furthermore, it heated at 200 degreeC for 12 hours. The reaction mixture was then diluted with N-methyl-2-pyrrolidone and the resulting polymer was slowly poured into 3 volumes of acetone to condense the polymer. The polymer is collected by filtration, N
Dissolved in -methyl-2-pyrrolidone and condensed with 3 volumes of water. Further, the polymer obtained by filtration was subjected to a vacuum treatment under a vacuum of 130
After drying at ℃ for 12 hours, polymer 1 of polyquinoline compound
70 g was obtained.

Polyquinoline compound 2 thus obtained
After dissolving 1 g in 70 g of N-methyl-2-pyrrolidone, 9 g of bis (4-maleimidophenyl) methane, which is a bismaleimide compound, was added and dissolved to obtain a uniform varnish. The obtained varnish is uniformly applied to a polyimide film and dried in a dryer at 100 ° C / 10 minutes and 200 ° C / 10.
Minutes to remove the solvent, peel off the polyimide film,
An adhesive film having a thickness of 30 μm was obtained.

Using this film, the same evaluations as in Example 2 were carried out. As a result, no pellet cracks were found, and the adhesive strength was 50 kgf / cm ² or more, which was a good result.

(Example 7) After the fine particles surface-treated with stearic acid as shown in (Table 1) were mixed with the varnish prepared in Example 1 and the suspension was prepared by the method shown in Example 4. , An adhesion test was conducted.

[0023]

[Table 1]

In all cases, no pellet crack was generated, and the adhesive strength was 50 kgf / cm ² or more, which was a good result. In addition, the calorific value of the pellets is that without Al powder (11-12 ° C /
Improved compared to W).

Similar results were obtained with fine particles surface-treated with zinc stearate or aluminum stearate instead of fine particles surface-treated with stearic acid.

(Comparative Example 1) An adhesion test was conducted in the same manner as in Example 1 using a usual condensation type polyimide precursor.
As a result, almost no adhesion was obtained even if thermocompression bonding was performed, and the adhesion strength was 100 kgf / cm ² or less.

(Comparative Example 2) As described in Example 1, the 12 mm square Au foil was placed on the ceramic substrate 1 having the external input / output terminal 2 and the Al wiring 3 and having the thickness of 2 mm and the length and width of 45 mm. Then, the semiconductor pellets 5 were bonded to each other by heating at 450 ° C. for 1 minute while pressing the semiconductor pellets 5 under a load of 500 g. As a result, the adhesive strength was 50 kgf / cm ² or more, which was a sufficient strength, and the heat value of the pellet was 8 ° C./W or less, which was a good value. However,
Since a rigid adhesive layer was formed by Au-Si eutectic, 2 out of 10 pellet cracks occurred.

As described above, according to the present invention, the heat-resistant adhesive containing the bismaleimide compound and the polyquinoline compound is suitable for die bonding with high adhesive strength at a low pressure during adhesion. The agent can be obtained. In addition, the heat-resistant adhesive of the present invention is a metal, a metal oxide, a metal carbide, in order to increase the conductivity of the adhesive layer formed by curing the adhesive, improve the thermal conductivity, and increase the strength of the adhesive layer, And, at least one kind of fine particles selected from metal nitrides can be mixed.

Examples of the bismaleimide compound in the present invention, including those mentioned above, include, for example, N, N'-ethylenedimaleimide, N, N'-hexamethylenebismaleimide, N, N'-dodecamethylenebis. Maleimide, N, N'-m-
Xylylene bismaleimide, N, N'-p-xylylene bismaleimide, N'-1,3-bismethylenecyclohexane bismaleimide, N, N'-1,4-bismethylenecyclohexane bismaleimide, N, N'- 2,4-tolylene bismaleimide, N, N'-2,6-tolylene bismaleimide, N, N'-3,3-
Diphenylmethane bismaleimide, N, N'-4,4-diphenylmethane bismaleimide, 3,3-diphenylsulfone bismaleimide, 4,4-diphenylsulfone bismaleimide, N, N'-4,4-diphenylsulfide bismaleimide, N , N'-p-benzophenone bismaleimide, N, N'-
Diphenylethane bismaleimide, N, N'-diphenyl ether bismaleimide, N, N '-(methylene-ditetrahydrophenyl) bismaleimide, N, N'-(8-ethyl)-
4,4-diphenylmethane bismaleimide, N, N`- (3,3-
Dimethyl) -4,4-diphenylmethane bismaleimide, N,
N '-(3,3-diethyl-4,4-diphenylmethane bismaleimide, N, N'-(3,3-dichloro> -4,4-diphenylmethane bismaleimide, N.N'-tolidine bismaleimide,
N, N'-isophorone bismaleimide, N, N'-p, p 'diphenyldimethylsilyl bismaleimide, N, N'-benzophenone bismaleimide, N, N'-diphenylpropane bismaleimide, N, N' -Naphthalene bismaleimide, N, N'-m-phenylene bismaleimide, N, N'-4,4- (1,1-diphenyl-silokuhexane) -bismaleimide, N, N'-3,5-
(1,2,4-Triazol) -bismaleimide, N, N'-pyridine-2,6-diyl bismaleimide, N, N'-5-methoxy-1,3-phenylene bismaleimide, 1,2 -Bis (2-maleimidoethoxy) ethane, 1,3-bis (3-maleimidopropoxy) propane, N, N'-4,4-diphenylmethane-bis-dimethylmaleimide, N, N'-hexamethylene-bis-
Dimethylmaleimide, N, N'-4,4 '-(diphenylether) -bis-dimethylmaleimide, N, N'-4,4'-(diphenylsulfone> -bis-dimethylmaleimide N, N'-4 ,Four'
-(Diamino) -triphenyl phosphate N, N'-difunctional maleimide compounds represented by bismaleimide, reaction products of aniline and formalin (polyamine compounds), 3,4,4'-tri Tris- (41-aminophenyl), a polyfunctional maleimide compound obtained by the reaction of aminodiphenylmethane, triaminophenol, etc. with maleic anhydride
-Phosphate, tris (d-aminophenyl) -phosphate, tos (4-aminophenyl-maleimide compound obtained by reaction of 4-aminophenyl-thiophosphate with maleic anhydride, 2,
2-bis [4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-chloro-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-promo-4
-(4-maleimidophenoxy) phenyl] propane, 2,
2-bis [3-ethyl-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-propyl-4- (4-maleimidophenoxy) phenyl) propane, 2,2-bis [3
-Isoprovir-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-putyl-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-sec
-Putyl-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-methoxy-4- (4-maleimidophenoxy) phenyl] propane, 1,1-bis [4- (4-maleimidophenoxy) propane ) Phenyl] ethane, 1,1-bis [3-methyl-4- (4-maleimidophenoxy) phenyl) ethane, 1,1-bis [3-chloro-4- (4-maleimidophenoxy) phenyl) ethane, 1 , 1-bis [3-promo-4- (4-
Maleimidophenoxy) phenyl] ethane, 1,1-bis [4
-(4-maleimidophenoxy) phenyl] methane, 1,1-bis [3-methyl-4- (4-maleimidophenoxy) phenyl] methane, 1,1-bis [3-chloro-4- (4-maleimidophenoxy) ) Phenyl] methane, 1,1-bis [3-promo-4
-(4-maleimidophenoxy) phenyl] methane, 3,3-bis [4- (4-maleimidophenoxy) phenyl] bentane,
1,1-bis [4- (4-maleimidophenoxy) phenyl] propane, 1,1,1,3,3,3-hexafluoro-2,2-bis [4-
(4-maleimidophenoxy) phenyl] propane, 1,1,1,
3,3,3-hexafluoro-1,2,2-bis [3-5-dimethyl-
(4-maleimidophenoxy) phenyl] propane, 1,1,1,
3,3,3-hexafluoro-2,2-bis [3-5-dipromo-
(4-maleimidophenoxy) phenyl] propane and 1,1,
1,3,3.3-Hexafluoro-2,2-bis (3-5-methyl-
An aromatic bismaleimide compound such as (4-maleimidophenoxy) phenyl] propane can be used, and is not particularly limited to the above. Also, alone or
It is possible to use two or more components in combination.

Examples of the polyquinoline compound, including those mentioned above, include 2- (2-fluorophenyl)-
A polymer consisting of 5-fluoro-4-phenylquinoline, 2
-(4-fluorophenyl) -5-fluoro-4-phenylquinoline polymer, 4- (2-fluorophenyl)-
A polymer consisting of 5-fluoro-4-phenylquinoline, 2
-(4-fluorophenyl) -7-fluoro-4-phenylquinoline polymer, 2,4-difluoroquinoline polymer, 2,5-difluoroquinoline polymer, 2,7-difluoroquinoline A polymer consisting of 2,7-difluoro-6-phenylquinoline, a polymer consisting of 4- (4
-Fluorophenyl) -7-fluoroquinoline polymer, 6,6'-bis [2- (2-fluorophenyl) -4-
Phenylquinoline] polymer, 6.6'-bis [2
-(4-fluorophenyl) -4-phenylquinoline] polymer, 6,6-bis [2- (4-fluorophenyl) -4
-Tert-Putylquinoline] polymer, 6,6'-bis [4- (4-fluorophenyl) -2-phenylquinoline] polymer, 6,6'-bis-2-fluoroquinoline polymer A polymer comprising 6,6′-bis-4-fluoroquinoline, a polymer comprising 6,6′-bis [4- (4-fluorophenyl) -2- (2-viridyl) quinoline], 6,
Polymer composed of 6'-bis [4- (4-fluorophenyl) -2- (methyl) quinoline], 6,6'-bis [2-fluoro-4
-Phenylquinoline] polymerization rest, oxy-6,6'-
A polymer composed of bis [2- (4-fluorophenyl) -4-phenylquinoline], 1,4-benzene-bis-2,2- [2
A polymer composed of-(4-fluorophenylquinoline), 1,
Polymer composed of 4-benzene-bis-2,2- [4-fluoroquinoline], 1,4-benzene-bis-2,2- [4- (4-
Fluorophenyl) quinoline], 1,1,1,
3,3,3-Hexafluoroisopropylidene-bis-[(4
A polymer consisting of -phenoxy-4-phenyl) -2- (4-fluoroquinoline)] is applied. These polymers can be used alone or in combination of two or more kinds.

That is, as the bismaleimide compound in the present invention, those represented by the following general formula (I) can be used.

[0032]

[Chemical 5]

(However, in the formula, R1 to R6 are H, CH2, C
Any of H3, C2H5, C3H7, F, CF3, and C2F5 is shown, and they may be different from each other. n is 0 or 1 to 4
May be different from each other by integers of. )

Further, as the polyquinoline compound in the present invention, those represented by the following general formula (II) or (III) can be used.

[0035]

[Chemical 6]

[0036]

[Chemical 7]

(In the formula, R1 and R2 are each independently an alkyl group, an aryl group, an alkoxy group, an allyloxy group, a formyl group (-COR), an ester group (-COR or -OCOR), an amide group (-NRCOR). Or -CONRR) represents a heteroaryl group, a cyano group or a divalent hydrocarbon group which may be formed by connecting two and may contain an unsaturated bond (wherein R represents a hydrogen atom, an alkyl group,
Alternatively, it represents a heteroaryl group. ), M and n are each independently an integer of 0 to 5, and X is a chemical bond —O—, —S.
-, -CO-, -SO-, -SO2-, -A-, (O-
A) q-O- or -O- (however, q is an integer of 1 to 3 and A is -Ar- (arylene group), -Hr- (heteroarylene group), -Ar-O-Ar-,- CO-Ar-,
Ar-S-Ar-, -Ar-SO-Ar-, -Ar- or -Ar-Q-Ar- is shown, and Q is the following general formula (IV),

[0038]

[Chemical 8]

L1 and L2 each represent a methyl group, a trifluoromethyl group or a divalent hydrocarbon which may contain an unsaturated bond formed by connecting two, Z1 and Z2 each independently represent a chemical bond or an arylene group. (Y represents —O— or —O—A—O—) As the form of the adhesive, a varnish-like adhesive or a film-like adhesive is preferable.

When the varnish-like adhesive is not mixed with at least one kind of fine particles selected from the group consisting of metal, metal oxide, metal carbide and metal nitride, the solid content weight ratio is from 1 to 1.
It is 50 wt% and the residual component is preferably a solvent. When the solid content weight ratio is less than this range, it is difficult to obtain a sufficient thickness of the adhesive, resulting in unevenness, and as a result, the adhesive strength is likely to be lowered. Further, if it is more than this, the varnish gels, and it becomes difficult to handle it as an adhesive.

Furthermore, when at least one kind of fine particles selected from the group consisting of metal, metal oxide, metal carbide and metal nitride is mixed in the varnish adhesive, the solid content weight ratio is 10 to 95 wt. %, And the residual component is preferably a solvent. When the solid content weight ratio is less than this range, it is difficult to obtain a sufficient thickness of the adhesive layer, which causes unevenness, and as a result, the adhesive strength is likely to be lowered. Moreover, if it is more than this, the viscosity of the varnish becomes high, and it becomes difficult to handle it as an adhesive.

At this time, the mixing ratio of (containing fine particles) / (bismaleimide compound and polyquinoline compound) is preferably 0.05 to 5 (weight ratio). If the mixing ratio is less than this, it is difficult to obtain the effect of mixing the fine particles. If it is more than this, the amount of the bismaleimide compound and the polyquinoline compound having an adhesive effect is too small, the effect as an adhesive is difficult to be obtained, and the adhesive strength is likely to be lowered.

Particularly preferably, the film-like adhesive used preferably contains at least one kind of fine particles selected from metals, metal oxides, metal carbides and metal nitrides, regardless of the solid content weight ratio. Is 60 to 100 wt%,
The residual component is preferably a solvent. Below this,
The adhesive strength is likely to decrease due to the occurrence of swelling of the adhesive layer due to the volatilization of the solvent when the adhesive is cured, and the adherend is likely to be contaminated. In addition, it may cause stickiness of the film before curing, which tends to reduce workability.

An organic solvent is suitable as the above solvent,
In particular, the solvent preferably used for the synthesis of the bismaleimide compound and the polyquinoline compound is good in terms of solubility. Specifically, at least one selected from methylcellosolve, methylethylketone, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, quinoline, cyclopentanone, m-cresol and chloroform. It is preferably of the type.

The fine particles selected from metals, metal oxides, metal carbides and metal nitrides will be described.

The fine particles are not particularly limited as long as they can increase the electrical conductivity and thermal conductivity, but preferably the metal is selected from Al, Ag, Au, Cu and Ni. At least one selected, the metal oxide is Al ₂ O ₃ , S
At least one selected from iO ₂ , In ₂ O ₃ , SnO ₂ , and Sb ₂ O ₅ , the metal carbide is SiC, and the metal nitride is AlN.

The above metal or metal oxide, metal carbide,
At least one particle size selected from the metal nitrides preferably has an average particle size of 10 μm or less from the viewpoint of maintaining the uniformity of the adhesive layer thickness.

Further, the particle shape is preferably scale-like, particularly in the case of a film adhesive, from the viewpoint of maintaining the uniformity of the thickness of the adhesive layer as described above. When a highly conductive metal component such as Al, Ag, Au, Cu, and Ni is scaled, the contact area increases, and the conductivity of the adhesive layer can be improved.

Further, these fine particles are preferably subjected to a surface treatment in order to prevent aggregation and improve the uniformity of the adhesive layer. The activator used for this surface treatment is not limited, but it is preferably treated with at least one of stearic acid, zinc stearate, and aluminum stearate.

The adhesive of the present invention is characterized by containing a bismaleimide compound and a polyquinoline compound as main components.

In the present invention, the blending ratio of the quinoline ring-containing polymer and the bismaleimide compound is 70 to 3 of the quinoline ring-containing polymer based on the total solid content of both.
It is preferably 0% by weight. If the amount of the quinoline ring-containing polymer is 70% by weight or more, the fluidity becomes poor and the adhesive strength is lowered. On the other hand, when it is 30% by weight or less, the fluidity is excellent, but the mechanical properties are poor and the flexibility is poor. By optimizing the blending amount, it is possible to adjust the physical properties such as melting, viscosity, and softening point and the adhesive ability, which are particularly suitable for the adhesion between the package base and the pellets.

By doing so, large pellet cracks, which were difficult when a rigid adhesive layer such as Au-Si eutectic is used, can be prevented and the yield is improved.

Further, the bismaleimide compound and the polyquinoline compound have high heat resistance, and since they undergo addition reaction type thermal polymerization, there is no degassing component, so that it is difficult to use an epoxy type or polyamic acid type adhesive. Gas generation in the high temperature process (400 ° C) during sealing can be prevented and blowholes are eliminated.

Furthermore, the adhesive of the present invention can be mixed with at least one kind of fine particles selected from metals, metal oxides, metal carbides, and metal nitrides.

By mixing the fine particles, the electrical conductivity and thermal conductivity of the adhesive layer can be increased, and the effect of escaping the heat generated when driving the element formed in the pellet to the substrate can be increased. Therefore, it is possible to prevent deterioration of the element characteristics due to heat generation.

As described above, according to this embodiment, an adhesive suitable for die bonding, which has high heat resistance, high adhesive strength, high stress relaxation property, and which does not cause pellet crack, can be obtained. Furthermore, as in the past, expensive Au-Si
Since it is not necessary to use crystals for die bonding,
Significant cost reduction is possible.

[0057]

EFFECTS OF THE INVENTION According to the present invention, with low pressure at the time of adhesion,
It is suitable for die bonding, which provides high adhesive strength.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a configuration for evaluating an adhesive according to one embodiment of the invention.

[Explanation of symbols]

1 ... Substrate 2 ... External input / output terminal 3 ... Wiring 4 ... Adhesive layer 5 ... Semiconductor pellet

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Haruo Akahoshi             7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture             Inside the Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Masahiro Suzuki             7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture             Inside the Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Akira Kageyama             2-1, 1-1 Nishishinjuku, Shinjuku-ku, Tokyo             Mitsui Building) Hitachi Chemical Co., Ltd. F term (reference) 4J040 EH021 EH031 GA03 HA066                       HB05 HB15 HB19 HB38 HC11                       HC22 JA01 JA05 JA09 KA23                       KA42 LA08 NA20

Claims (7)

[Claims] 1. A surface of a bismaleimide compound represented by the following general formula (I) and a polyquinoline compound represented by the general formula (II) or (III) and stearic acid, zinc stearate or aluminum stearate. A heat-resistant adhesive containing treated metal fine particles of any one of Al, Ag, Au, Cu and Ni. [Chemical 1] (However, in the formula, R1 to R6 are H, CH2, CH3, C2H5,
One of C3H7, F, CF3, and C2F5 is shown, and they may be different from each other. n is 0 or an integer of 1 to 4 and may be different from each other. ) [Chemical 2] [Chemical 3] (In the formula, R1 and R2 are each independently an alkyl group, an aryl group, an alkoxy group, an allyloxy group, a formyl group (-COR), an ester group (-COR or -OCO).
R), amide group (-NRCOR or -CONRR)
A heteroaryl group, a cyano group or a divalent hydrocarbon group which may be formed by connecting two to form an unsaturated bond (provided that R represents a hydrogen atom, an alkyl group or a heteroaryl group), m. And n are each independently an integer of 0 to 5, and X is a chemical bond —O—, —S—, —CO—, —.
SO-, -SO2-, -A-, (OA) q-O- or -O- (however, q is an integer of 1 to 3 and A is -Ar.
-(Arylene group), -Hr- (heteroarylene group),-
Ar-O-Ar-, -CO-Ar-, Ar-S-Ar
-, -Ar-SO-Ar-, -Ar- or -Ar-Q-
Represents Ar-, Q is the following general formula (IV), and L1 and L2 each represent a methyl group, a trifluoromethyl group or a divalent hydrocarbon which may contain an unsaturated bond formed by linking two, Z1 and Z2 each independently represent a chemical bond or an arylene group, and Y Is -O- or -OA-
Indicates O-) 2. The heat resistant adhesive according to claim 1, wherein the solid content weight ratio of the bismaleimide compound and the polyquinoline compound is 1 to 50 wt%, and the residual component is a solvent. Adhesive. 3. The heat-resistant adhesive according to claim 1, wherein the adhesive has a varnish form. 4. The heat-resistant adhesive according to claim 3, wherein the bismaleimide compound and the polyquinoline compound have a solid content weight ratio of 10 to 95 wt%, and the residual component is a solvent. Adhesive. 5. The heat-resistant adhesive according to claim 1, wherein the adhesive is in the form of a film. 6. The heat-resistant adhesive according to claim 5, wherein the bismaleimide compound and the polyquinoline compound have a solid content weight ratio of 60 to 100 wt%, and the residual component is a solvent. Adhesive. 7. The heat-resistant adhesive according to claim 4, wherein the solvent is methyl cellosolve, methyl ethyl ketone,
A heat-resistant adhesive characterized by being at least one of N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, quinoline, cyclopentanone, m-cresol, and chloroform.