JP2000164608A - Resin-sealed semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To markedly lessen operation man-hours required for manufacturing a resin-sealed semiconductor device by a method wherein inner leads are bonded to a semiconductor chip through the intermediary of a specific coat layer, then the inner leads are connected to the semiconductor chip with bonding wires, and the chip and the bonding wires are sealed up with sealing resin. SOLUTION: A coat layer 1 of positive-type photosensitive resin composition composed of 100 pts.wt. polyamide represented by a formula and 1 to 100 pts.wt. photosensitive diazo quinone compound is provided on the circuit element forming surface of a semiconductor chip 2. The coat layer 1 is made to serve as an adhesive agent, the inner leads of a lead frame 3 are bonded to the semiconductor chip 2, the inner leads are connected to the semiconductor chip 2 with bonding wires 4, and the semiconductor chip 2 and the other components are sealed up with sealing resin 5. In a formula, X denotes a tetravalent cyclic compound group, Y denotes a bivalent cyclic compound group, E is an aliphatic or a cyclic compound group possessed of an alkenyl group, a and b denote a molar fraction, a + b = 100 mol%, R1 and R2 are each a bivalent organic group, and R3 and R4 are each a monovalent organic group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive photosensitive resin composition capable of obtaining a pattern with high sensitivity and a high residual film ratio, and a lead-on-chip (Lead On Ch) using the same.
The present invention relates to a semiconductor device having an ip) structure.

[0002]

2. Description of the Related Art With an increase in the size of a semiconductor element, a plurality of inner leads are adhered to the circuit element surface forming surface of the semiconductor element via an insulating film coated with an adhesive on both sides with the adhesive. The lead and the semiconductor element are connected by a bonding wire, and a lead-on-chip (Lead On Chip = hereinafter LO)
C) semiconductor device (Japanese Patent Publication No. 61-21813)
No. 9) has been proposed. However, in a resin-encapsulated semiconductor device, an insulating film is prepared in which an adhesive is applied to both surfaces in advance, and the insulating film is first adhered to a lead frame, and then the semiconductor element is adhered using the adhesive on one surface. There was a problem that workability was poor. Further, a polyimide film is usually used as the insulating film. However, the polyimide film has a high water absorption, and there is a problem in that the absorbed moisture vaporizes and expands in the package at the time of solder reflow, thereby causing cracks in the package.

[0003] Japanese Patent Application Laid-Open No. Hei 6-37243 proposes a method for solving the above problem. When this is used, a part of the semiconductor element manufacturing process can be simplified, and there is an effect of shortening the process and improving the yield. However, since a solvent such as N-methyl-2-pyrrolidone is required for development, safety, There is a problem in handling.

[0004]

SUMMARY OF THE INVENTION The present invention relates to the aforementioned L
An object of the present invention is to provide a semiconductor device having improved workability during production of a sealing resin semiconductor device having an OC structure and having various reliability.

[0005]

The present invention provides a compound represented by the general formula (I):
Having a coating layer of a positive photosensitive resin composition comprising 100 parts by weight of a polyamide and 1 to 100 parts by weight of a photosensitive diazoquinone compound on a circuit element forming surface of a semiconductor chip, and using the coating layer as an adhesive. A plurality of inner leads are adhered to the semiconductor chip, and the inner leads and the semiconductor chip are connected by bonding wires and sealed with a sealing resin (Lead On C).
(b) a resin-encapsulated semiconductor device characterized by having a structure comprising a bisphenol compound represented by the general formula (II) and a trisphenol represented by the general formula (III) in a positive photosensitive resin composition; The above-described semiconductor device using a positive photosensitive resin composition comprising a compound and a total of 1 to 30 parts by weight of both.

[0006]

Embedded image

[0007]

Embedded image

[0008]

Embedded image

The polyamide of the formula (I) comprises a bisaminophenol having the structure of X, a dicarboxylic acid having the structure of Y and an acid anhydride having the structure of E. When heated, the ring is dehydrated and closed, and changes to a heat-resistant resin called polybenzoxazole. X of the polyamide (I) of the present invention is, for example,

[0010]

Embedded image

However, the present invention is not limited to these. Among them, particularly preferred are:

[0012]

Embedded image

[0013] It is more selected. In the formula (I), Y
Is, for example,

[0014]

Embedded image

However, the present invention is not limited to these. Particularly preferred among these are:

[0016]

Embedded image

[0017] It is selected more. In addition, E of the formula (I)
Is, for example,

[0018]

Embedded image

However, the present invention is not limited to these. Among them, particularly preferred are:

[0020]

Embedded image

[0021] In the present invention, a polyamide is synthesized by reacting a dicarboxylic acid derivative having a structure of Y with a bisaminophenol having a structure of X, and then an acid anhydride having at least one alkenyl group or alkynyl group represented by E in the formula (I). The terminal amino group is capped with a substance. Further, Z in the formula (I) is
For example

[0022]

Embedded image

However, the present invention is not limited to these. Z in the formula (1) is used, for example, when particularly excellent adhesion is required to a substrate such as a silicon wafer, and the use ratio b is up to 40.0 mol%. If it exceeds 40.0 mol%, the solubility of the resin is extremely reduced, and undeveloped portions (scum) are generated, and pattern processing cannot be performed. In using these X, Y, E, and Z, one type or a mixture of two or more types may be used.

The photosensitive diazoquinone compound used in the present invention is a reaction product of a compound having a 1,2-benzoquinonediazide or 1,2-naphthoquinonediazide structure and a phenol compound as a support.

In the positive photosensitive resin composition of the present invention, a photosensitive resin having a structure represented by the general formula (II) or (III) for the purpose of obtaining particularly high sensitivity and a high residual film ratio during development. It is important to add a diazoquinone compound to the composition. The development mechanism of the positive photosensitive resin utilizes the difference in solubility between the exposed part and the unexposed part as described above.
In order to obtain a high sensitivity and a high residual film ratio, it is necessary to change the solubility so that the exposed portion becomes more soluble and the unexposed portion becomes less soluble in order to increase the difference. The change in the difference in solubility largely depends on the structure of the phenolic compound as the support. Therefore, at the time of development, a photosensitive diazoquinone compound having a support capable of promoting the solubility in the exposed portion and promoting the dissolution inhibiting effect in the unexposed portion and maintaining a sufficient remaining film ratio was searched for. Was found to exhibit a high residual film ratio while maintaining high sensitivity. Examples of the photosensitive diazoquinone compound include the following, but are not limited thereto.

[0026]

Embedded image

[0027]

Embedded image

The amount of the photosensitive diazoquinone compound in the polyamide is 1 to 100 parts by weight of the polyamide.
When the amount is less than 1 part by weight, the patterning property of the resin is poor. On the contrary, when the amount exceeds 100 parts by weight, not only the sensitivity is significantly reduced, but also the tensile elongation of the film is significantly reduced. I do.

A dihydropyridine derivative can be added to the positive photosensitive resin composition of the present invention, if necessary, to enhance the photosensitive characteristics. Examples of the dihydropyridine derivative include 2,6-dimethyl-3,5-diacetyl-
4- (2'-nitrophenyl) -1,4-dihydropyridine, 4- (2'-nitrophenyl) -2,6-dimethyl-3,5-dicarbethoxy-1,4-dihydropyridine, 4- (2 ', 4'-Dinitrophenyl) -2,6
-Dimethyl-3,5-dicarbomethoxy-1,4-dihydropyridine and the like.

In the positive photosensitive resin composition of the present invention, it is further important to use a bisphenol compound represented by the general formula (II) in combination with a trisphenol compound represented by the general formula (III). When these phenolic compounds represented by the general formulas (II) and (III) are added to a positive photosensitive resin composition composed of a polybenzoxazole precursor and a diazoquinone compound, the adhesion to a sealing resin is improved. Further, a positive photosensitive resin composition which has a high sensitivity and a high residual film ratio at the time of development, and has excellent preservability without phenol precipitation or the like even when stored at a low temperature of -60 to -50 ° C. Is obtained. The adhesion to the sealing resin is determined by the general formula (I
It is effective to some extent to add only the phenolic compounds represented by I) and general formula (III) to a certain extent. However, when the addition amount of each compound alone is increased, the bisphenol compound represented by general formula (II) becomes −60 When stored at a low temperature of -50C, precipitation tends to occur. Further, the trisphenol compound represented by the general formula (III) has a remarkable decrease in the residual film ratio. However, by using the bisphenol compound represented by the general formula (II) and the trisphenol compound represented by the general formula (III) in combination, the disadvantages of each compound can be improved, and the photosensitivity of high sensitivity and the sealing resin can be improved. Excellent adhesion was also exhibited.

The amount of the phenol compound added is such that the bisphenol compound represented by the general formula (II) and the trisphenol compound represented by the general formula (III) are added to 100 parts by weight of the polyamide represented by the general formula (I). The total amount is 1 to 30 parts by weight. When the addition amount of both phenol compounds is more than 30 parts by weight, -60 to -50 as described above.
Precipitation occurs during storage at a low temperature of ℃, and a significant decrease in the residual film ratio occurs during development. When the addition amount is less than 1 part by weight, not only the adhesion to the sealing resin is lowered but also the sensitivity at the time of development is lowered. Examples of the bisphenol compound represented by the general formula (II) include, but are not limited to, the following.

[0032]

Embedded image

[0033]

Embedded image

[0034]

Embedded image

[0035]

Embedded image

Of these, particularly preferred are:

[0037]

Embedded image

Is as follows. In addition, examples of the compound represented by the general formula (III) include the following, but are not limited thereto.

[0039]

Embedded image

[0040]

Embedded image

[0041]

Embedded image

Of these, particularly preferred are:

[0043]

Embedded image

Is as follows. If necessary, additives such as a leveling agent and a silane coupling agent can be added to the positive photosensitive resin composition of the present invention. In the present invention, these components are dissolved in a solvent and used in the form of a varnish. As the solvent, N-methyl-2-pyrrolidone,
γ-butyrolactone, N, N-dimethylacetamide,
Dimethyl sulfoxide, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl lactate, ethyl lactate, butyl lactate, methyl-1,3-butylene glycol acetate,
1,3-butylene glycol-3-monomethyl ether, methyl pyruvate, ethyl pyruvate, methyl-3
-Methoxypropionate, etc., which may be used alone or as a mixture.

In the method of using the positive photosensitive resin composition of the present invention, the composition is first applied to a suitable support, for example, a silicon wafer, a ceramic substrate, an aluminum substrate or the like.
In the case of a semiconductor device, the amount of coating is 0.1 μm for the final film thickness after curing.
It is applied so as to have a thickness of 1 to 20 μm. When the thickness is 0.1 μm or less, it is difficult to sufficiently exert the function as a protective surface film of the semiconductor element, and when it is 20 μm or more, it becomes difficult to obtain a fine processing pattern, In addition, processing takes time and the throughput is reduced.
Examples of the coating method include spin coating using a spinner, spray coating using a spray coater, dipping, printing, and roll coating. Next, after pre-baking at 60 to 130 ° C. to dry the coating film, a desired pattern shape is irradiated with actinic radiation. As the actinic radiation, X-rays, electron beams, ultraviolet rays, visible rays and the like can be used, but those having a wavelength of 200 to 500 nm are preferable. Next, a relief pattern is obtained by dissolving and removing the irradiated portion with a developer. Examples of the developer include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, primary amines such as ethylamine and n-propylamine, diethylamine, and di-n. Secondary amines such as propylamine, tertiary amines such as triethylamine and methyldiethylamine, alcoholamines such as dimethylethanolamine and triethanolamine,
An aqueous solution of an alkali such as a quaternary ammonium salt such as tetramethylammonium hydroxide or tetraethylammonium hydroxide, and an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as alcohol such as methanol or ethanol or a surfactant. Can be suitably used. As a developing method, a system such as spray, paddle, immersion, and ultrasonic wave can be used. Next, the relief pattern formed by development is rinsed. As the rinse liquid,
Use distilled water. Next, heat treatment is performed to form an oxazole ring, and a final pattern having high heat resistance is obtained.

Next, an example of application to a semiconductor device having a LOC structure using the photosensitive resin composition of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a resin-encapsulated semiconductor device having a LOC structure according to the present invention. A chip 2 has a coating layer of a photosensitive resin composition of the present invention. Chip 2 as adhesive 1
And the lead frame 3 are bonded and fixed, the chip 2 and the lead frame 3 are connected with the gold wire 4, and then sealed with the resin sealing 5. As the bonding method, the chip is 200
Heat to ４５０450 ° C. and crimp for several seconds at a pressure of 0.1 to 10 kg / cm ² . FIG. 2 is a cross-sectional view of a conventional resin-encapsulated semiconductor device having a LOC type structure. The chip 2 and the lead frame 3 are bonded and fixed via an insulating film 6 with an adhesive 1 ′, and then sealed with a sealing resin 5. It is stopped. Conventionally, since the chip 2 and the lead frame 3 are bonded after bonding the insulating film 6 with the adhesive 1 'to the lead frame 3, workability is not good. As the insulating film of the insulating film 6 with the adhesive 1 ', a water absorbing coefficient and a linear expansion coefficient of 20
Since a polyimide film of about μm was used, there was a problem that package cracks occurred during solder immersion, but the adhesive layer of the photosensitive resin of the present invention did not cause package cracks due to a thin film with a low water absorption, A resin-encapsulated semiconductor device having a highly reliable LOC structure can be obtained.

[0047]

The present invention will be described below in detail with reference to examples. << Example 1 >> * Synthesis of polyamide Dicarboxylic acid derivative 443. obtained by reacting 1 mol of diphenyl ether-4,4'-dicarboxylic acid with 2 mol of 1-hydroxy-1,2,3-benzotriazole.
2 g (0.9 mol) and hexafluoro-2,2-bis (3-amino-4-hydroxyphenyl) propane 36
6.3 g (1.0 mol) were put into a four-neck separable flask equipped with a thermometer, a stirrer, a raw material inlet, and a dry nitrogen gas inlet tube, and 3000 g of N-methyl-2-pyrrolidone was added.
And dissolved. Then use an oil bath at 75 ° C
For 12 hours. Next, 5-norbornene-2,3- dissolved in 500 g of N-methyl-2-pyrrolidone.
32.8 g (0.2 mol) of dicarboxylic anhydride were added,
The reaction was further stirred for 12 hours to complete the reaction. After filtering the reaction mixture, the reaction mixture was poured into a solution of water / methanol = 3/1, the precipitate was collected by filtration, washed sufficiently with water, and dried under vacuum to obtain the desired polyamide (A-1). Obtained.

* Preparation of Positive Photosensitive Resin Composition 100 g of the synthesized polyamide (A-1) and 25 g of diazoquinone (B-1) having a structure of the following formula were added to N-methyl-
After dissolving in 250 g of 2-pyrrolidone, the solution was filtered through a 0.2 μm Teflon filter to obtain a photosensitive resin composition.

* Characteristic evaluation After applying this positive photosensitive resin composition on a silicon wafer using a spin coater, it was dried on a hot plate at 120 ° C. for 4 minutes to obtain a coating film having a thickness of about 5 μm. . G-line stepper exposure machine NSR-1505G3A
50 mJ / c through a reticle by Nikon Corporation
Increase from m ² by 10mJ / cm ² 540mJ / cm
Exposure was performed up to ² . Next, the exposed portion was dissolved and removed by immersion in a 1.40% aqueous solution of tetramethylammonium hydroxide for 60 seconds, and then rinsed with pure water for 30 seconds. As a result, it was confirmed that a pattern was formed from a portion irradiated with an exposure amount of 230 mJ / cm ² .
(The sensitivity is 230 mJ / cm ² ). At this time, the residual film ratio (film thickness after development / film thickness before development × 100) showed a very high value of 93.1%. The water absorption was 0.3%.
Next, the silicon wafer was diced into 6 × 15 mm, and the obtained semiconductor chip was bonded to a 42 alloy lead frame at 400 ° C. for 1 second (1 kg / cm ² ). After that, 300mi of LOC structure with epoxy resin type sealing material
It was sealed in an SOJ having a width of l. 85 of this sealed product
After standing at 85% RH for 16 hours, the IR flow (24
(0 ° C. × 10 seconds), and the number of cracks generated in the package was examined. The number of cracks generated was 0/20.

Example 2 In the synthesis of the polyamide in Example 1, it was obtained by reacting 1 mol of diphenyl ether-4,4'-dicarboxylic acid with 2 mol of 1-hydroxy-1,2,3-benzotriazole. A polyamide (A-2) was synthesized using a dicarboxylic acid derivative obtained by reacting 1 mol of azine pinic acid with 2 mol of 1-hydroxy-1,2,3-benzotriazole instead of the dicarboxylic acid derivative obtained above. The other evaluations were the same as in Example 1.

Example 3 In the synthesis of the polyamide in Example 1, instead of hexafluoro-2,2-bis (3-amino-4-hydroxyphenyl) propane, 3,3'-diamino-4,4'- Polyamide (A-3) is synthesized using dihydroxydiphenyl sulfone,
Otherwise, the same evaluation as in Example 1 was performed.

Example 4 In the synthesis of a polyamide in Example 1, a polyamide (A-4) was synthesized using maleic anhydride instead of 5-norbornene-2,3-dicarboxylic anhydride, and the other steps were performed. The same evaluation as in Example 1 was performed.

Example 5 The procedure of Example 1 was repeated except that the photosensitive diazoquinone compound B-1 in the photosensitive resin composition was changed to B-2 and the amount of the component was changed as shown in Table 1. The same evaluation as in Example 1 was performed.

Example 6 The procedure of Example 1 was repeated except that the photosensitive diazoquinone compound B-1 in the photosensitive resin composition was changed to B-3 and the amount of the component was changed as shown in Table 1. The same evaluation as in Example 1 was performed.

Example 7 The same evaluation as in Example 1 was performed except that the amount of the photosensitive diazoquinone compound B-1 in the photosensitive resin composition in Example 1 was changed as shown in Table 1.

Example 8 The same evaluation as in Example 1 was performed except that 10 g of bisphenol compound C-1 was added to the photosensitive resin composition in Example 1.

Comparative Example 1 Kapton film (water absorption 2
%), The semiconductor chip and the 42 alloy lead frame were pressed at 400 ° C. for 1 second (1 kg / cm) using an insulating film having both surfaces coated with a polyetheramide-based adhesive in the same manner as in Example 1. ² ) Bonded and sealed with epoxy resin sealing material. When the package crack of this semiconductor device was examined, it was 15/20.

Comparative Example 2 An adhesive similar to that of Comparative Example 1 was applied to an Iupirex film (water absorption: 1%), and a semiconductor device was fabricated in the same manner as in Example 1. When the package crack of this semiconductor device was examined, it was 9/20.

[0059]

[Table 1]

[0060]

Embedded image

[0061]

Embedded image

[0062]

According to the present invention, the bonding between the chip and the lead frame can be greatly reduced as compared with the prior art. In addition, it is possible to prevent the moisture absorbed in the insulating film from evaporating and expanding in the package during the reflow, so that the occurrence of a package crack can be prevented. Therefore, an inexpensive and highly reliable resin-encapsulated semiconductor device having a LOC structure can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a resin-sealed semiconductor device having a LOC structure according to the present invention.

FIG. 2 is a cross-sectional view of a resin-sealed semiconductor device having a LOC structure according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Adhesive 1 'Adhesive 2 Chip 3 Lead frame 4 Gold wire 5 Sealing resin 6 Insulating film

Continued on the front page F-term (reference) 2H025 AA01 AA14 AB16 AB17 AC01 AD03 BE01 CB25 CB32 CB45 CC06 CC20 4J001 DA01 DB03 DC04 DC08 DC10 DC14 DD02 EB34 EB57 EB58 EB60 EC66 EC67 EC70 EC79 EE22C EE27C GE01 J07J18J18 J18 J18B18 J18 HC14 MA02 NA20 5F047 AA11 BA24 BA35 BA39 BB11 BB16 BB19

Claims (4)

[Claims] 1. Polyamide 10 represented by the general formula (I)
A coating layer of a positive photosensitive resin composition comprising 0 parts by weight and a photosensitive diazoquinone compound in an amount of from 1 to 100 parts by weight on a circuit element forming surface of a semiconductor chip; A resin seal having a lead-on-chip (Lead On Chip) structure in which a lead is bonded to the semiconductor chip, and the inner lead and the semiconductor chip are connected by a bonding wire and sealed with a sealing resin. Stop type semiconductor device. Embedded image 2. The positive photosensitive resin composition according to claim 1, further comprising a bisphenol compound represented by the general formula (II) and a trisphenol compound represented by the general formula (III) in a total of 1 to 30% by weight. The resin-encapsulated semiconductor device according to claim 1, wherein the resin-encapsulated semiconductor device is a positive photosensitive resin composition obtained by mixing parts. Embedded image Embedded image 3. The resin-encapsulated semiconductor device according to claim 1, wherein X in the polyamide of the general formula (I) of the positive photosensitive resin composition according to claim 1 is selected from the following. Embedded image 4. The resin-encapsulated semiconductor device according to claim 1, wherein Y in the polyamide of the general formula (I) of the positive photosensitive resin composition according to claim 1 is selected from the following. . Embedded image