JPS63164247A - Semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a semiconductor device characterized by excellent heat cycle resistance, thermal shock resistance, and moisture resistance and high reliability, by applying a specified heat resisting resin on the surface of a semiconductor element, heating and hardening the resin, and packaging the element with an epoxy resin material. CONSTITUTION:The essential components of a heat resisting resin are as follows: an organic tetracarboxylic acid dianhydride component; and a diamine component of silicon diamine shown by the general formula of the Formula I, wherein the component, whose number (m) of siloxane bonds is in the range of 1-10, is 0.05-30 mol % of the total diamine component, and the component, whose number is in the range of 11-500, is 0.05-30 mol %. Said resin is applied on the surface of the semiconductor element. The element is heated and hardened. The resin is deposited on the surface of the semiconductor to a thickness of 0.1-100 mum. Thereafter, the element is packaged with an epoxy resin. In the Formula I, R1 is a methylene group, a phenylene group or a substituted phenylene group; R2 is a methyl group, a phenyl group or a substituted phenyl group; and (n) is 1 when R1 is the phenylene group or the substituted phenylene group, and the integer of 3 or 4 when the R1 is the methyl group.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor device using a heat-resistant resin having a small elastic modulus, low water absorption, and good moisture resistance. The purpose of this is to apply a heat-resistant resin that has excellent heat resistance, electrical insulation, and film-forming properties as a polyimide resin, and has a small elastic modulus and low water absorption to the surface of a semiconductor element. , heat the element surface to high temperature, high temperature,
It is an object of the present invention to provide a highly reliable semiconductor device that is protected from high bias voltages, and furthermore protected from heat-resistant cycles and heat resistance.

[Prior art]

Conventionally, polyimide has been used for surface protection films, glabella insulating films, junction protection films, etc. of semiconductor devices because of its excellent heat resistance, as well as excellent electrical insulation and mechanical strength. Due to trends such as increasing the size of products and making sealing resin packages thinner and smaller, there is a demand for significant improvements in heat cycle resistance, shock resistance, heat resistance, etc., and conventional polyimide resins have not been able to meet these demands, and their protective effects have deteriorated. For example, conventional polyimide resins have poor adhesion to semiconductor elements and also have high water absorption, resulting in poor moisture resistance.

In addition, due to its high elastic modulus and thermal shock resistance, the reliability of semiconductor devices has become less than satisfactory due to displacement of aluminum wiring and cranking of the bancibasin film.

[Purpose of the invention]

As a result of studies aimed at overcoming such drawbacks, the present invention includes a relatively low molecular weight silicone diamine and a relatively high molecular weight silicone diamine as essential components in the diamine component.
By applying a heat-resistant resin reacted with an organic tetracarboxylic dianhydride component in an organic polar solvent to a semiconductor element, a semiconductor device with excellent heat cycle resistance, heat crank resistance, moisture resistance, etc. can be obtained. This discovery led to the completion of the present invention.

[Structure of the Invention] The present invention comprises a 111 organic tetracarboxylic dianhydride component and a compound having the following formula: n is an integer of 3 or 4 when R is a phenylene group or a substituted phenylene group, and is an integer of 3 or 4 when it is a methyl group. A diamine component containing 0.05 to 20 mol% of one diamine component and 0.05 to 30 mol% of one in the range of 11 to 500 is an essential component, and is reacted at a temperature of 0 to 200 ° C. This semiconductor device is characterized in that a heat-resistant resin is coated on the surface of a semiconductor element and then heated and cured to adhere to the surface of the semiconductor.

As the diamine component used in the present invention, in addition to the above-mentioned silicone diamine, the following aromatic diamines can also be used in combination to impart various properties.

Examples include m-phenylenediamine, p-phenylenediamine, and 4,4'-diaminodiphenylpropane.

Further, the organic tetracarboxylic dianhydride component used in the present invention may be one type or a mixture of two or more types, but examples of the tetracarboxylic dianhydride used include pyromellitic dianhydride, 3.3', These include 4°4'-benzophenonetetracarboxylic dianhydride, 2.3.6.7-naphthalenetetracarboxylic dianhydride, and the like.

The amount of silicone-based diamine, which is an essential component, is preferably 0.1 to 50 mol% based on the total diamine component.

Among these, the amount of relatively low molecular weight silicone diamine in which the number m of siloxane bonds (0-3i) is 10 or less is preferably 0.05 to 20 mol% based on the total diamine component. When using the resin of the present invention as a surface protective film for a semiconductor element, Si.

Although it is a necessary component to improve the adhesion to inorganic materials such as 5ift and plasma silicon nitride films and maintain the moisture resistance reliability of semiconductor devices, if it exceeds 20 mol% of the total diamine component, the cured film becomes brittle. It is not preferable because it tends to cause cranking, and it is not preferable if it is less than 0.05 mol % because the effect of improving adhesion cannot be obtained.

In addition, the amount of relatively high molecular weight silicone diamine with m of 11 to 500 is 0.05 to 3% of the total diamine component.
0 mol% is preferable. This requires a soft resin with a low elastic modulus in order to relieve the stress generated by thermal cycles, thermal shock, etc. on semiconductor elements, but if it is 0.05 mol% or less, the elastic modulus is low. On the other hand, if it exceeds 30 mol %, the heat resistance will drop significantly and the characteristics inherent to polyimide resins will no longer be obtained, which is undesirable. -5i-), m is preferably 1 to 500.

If a long-chain silicone diamine with a m number of more than 500 is used, the reaction with the tetracarboxylic dianhydride will be difficult to proceed quantitatively, and it will remain in the system as an unreacted product, resulting in a large molecular weight (or It does not have a pleasant aroma because it reduces flexibility and makes cracks more likely to occur.

The solvent of the reaction system in the present invention is an organic polar solvent whose functional group does not react with tetracarboxylic dianhydride or diamines. In addition to being inert to the system and being a solvent for the products, the organic polar solvent must be a good solvent for at least one, and preferably both, of the reaction components.

Typical solvents of this type are N,N-dimethylformamide, N,N-dimethylacetamide,
Examples include N-methyl-2-pyrrolidone, and these solvents may be used alone or in combination. The method for manufacturing a semiconductor device using this heat-resistant resin is to dissolve the resin composition in a solvent and mix it uniformly, and to
%, cast onto the surface of a wiring conductor layer on a semiconductor substrate or an insulator substrate, and apply it to a uniform thickness in the range of O,l - 100μ, and then heat it in a dryer at a temperature of 50 to 500℃. , 2 or more steps if necessary: 5
A resin film is formed by drying for 30 minutes to 30 hours. As a device for casting the resin, a dispenser, a roller wheeler, a spinner, a roll coater, a doctor blade, a gisa, a flow coater, etc. are used. For drying, electric heat, infrared rays, steam, high frequency, a combination thereof, etc. are used.

A polyimide resin film formed on a semiconductor element may be partially etched depending on the method of use.

The main reason is the opening of the bonding butt portion or the conduction between layers of multilayer wiring.

Typical etching methods include ashing with plasma in the case of a dry method, and use of a strong alkali such as hydrazine or tetramethylammonium hydroxide as an etching solution in the case of a wet method.

In the method of the present invention, in order to further improve the adhesion between the resin coating film and the substrate, it is more effective to undercoat the substrate with a surface treatment agent. This is particularly effective for circuit boards with silicone substrates or gold plating, which usually have poor adhesion.

It is effective to use ordinary silane cuffing agents and borane coupling agents as surface treatment agents, but silane coupling agents are particularly effective for coating films obtained from the resin used in the present invention. Examples of agents include vinylsilane, aminosilane, and epoxysilane, but when aminosilane is interposed between the coating film made of the resin used in the present invention and the silicone substrate, it produces a very synergistic effect and significantly improves adhesive properties. improves. As an aminosilane coupling agent, n-β-(aminoethyl)
T-aminopropylmethoxysilane, n-β(aminoethyl)T-aminopropylmethyldimethoxysilane, n
-Phenylγ-aminopropyltrimethoxysilane, T
-aminopropyltrimethoxysilane, etc.

The appropriate thickness of the film of the resin of the present invention is 0.1-100 .mu.-. A film thickness of 0.1 μm or less does not have much of a protective effect against thermal shock during thermal cycles, and reliability is reduced due to misalignment of the aluminum wiring and cranking of the pansivation film. On the other hand, if the film thickness is 100 μm, the film may peel off from the semiconductor element or may be cracked, reducing the protective effect.

Finally, a semiconductor device can be obtained by mold-sealing the semiconductor element whose surface is coated with a heat-resistant resin with an epoxy resin using a known transfer molding method.

〔Effect of the invention〕

The heat-resistant resin used in the present invention has a Si + 5
iOt* is a resin with a low elastic modulus that has excellent adhesion to inorganic materials such as plasma silicon nitride, and its water absorption is much lower than that of ordinary wholly aromatic polyimide resins, so it can be used as a protective film on the surface of semiconductor elements. When used, it has become possible to obtain semiconductor devices with high reliability and excellent heat cycle resistance, heat shock resistance, and moisture resistance because the stress of the epoxy resin encapsulant is alleviated.

〔Example〕

[Example 1] 19.02 g (95 mol%) of 4°4'-diaminodiphenyl ether and 1.24 g (95 mol%) of 4°4'-diaminodiphenyl ether were placed in a four-piece parallel flask equipped with a thermometer, a stirrer, a raw material inlet, and a dry nitrogen gas inlet. Take 17.46 g (4.5 mol%) of N-methyl-2-pyrrolidone (0.5 mol%) and add anhydrous N-methyl-2-pyrrolidone in an amount to make the solid content of the total raw materials 15% by weight. and dissolved. Next, the flask was immersed in a water bath at 0 to 50°C, and while suppressing heat generation, 21.81 g of purified pyromellitic dianhydride (0.1 mol, 100 mol%) was added.
) was added. After the tetracarboxylic dianhydride was dissolved, the temperature of the system was maintained at 20° C. and the reaction was continued for 10 hours. Dry nitrogen gas is part of the reaction! The reactor was allowed to flow throughout the entire process from the preparation stage to the removal of the product. The resulting product was a pale yellow viscous solution.

Further, the above varnish was diluted to a 12% by weight solution with an N,N-dimethylacetamide solution and applied using a spinner onto a Si wafer and a semiconductor element wafer having a passivation film of plasma silicon nitride at 150°C.
, heated at 250℃ and 350℃ for 30 minutes each.
A film of μ was formed. For those coated on Si wafers, a stripping test (J
15-D-0202) was carried out to evaluate the adhesion of the resin, and the results shown in the table were obtained.

For semiconductor elements coated with resin, open the bonding pad area with etching liquid, scribe the chip,
Furthermore, it is mounted on the lead frame and EMI! -5000(
The sample was molded into the shape of 16 DIP using Sumitomo Bakelite ■, and a heat resistance cycle test and a corrosion test were conducted on this sample, and the results shown in the table were obtained. Heat shock resistance test is 16p
The operation of inDIP treatment at -65'0.150° C. for 30 minutes each was defined as one cycle, and the mold 0 resin was opened every 100 cycles to check for occurrence of displacement of the bancivation crank and aluminum wiring. Corrosion test is P
CT (pressure, Kutzker test: 125℃, 23
A pressurization test in saturated steam under atmospheric pressure was conducted for 1000 hours, and open failures and leakage failures due to corrosion of the aluminum wiring were investigated using a tester.

The test was conducted using 20 sample patterns, and the oven failure and Lio failure patterns after 1000 hours The reaction composition of acid anhydride and diamine was set as shown in Table 1, and the reaction was carried out using the same equipment and operation as in Example 1. did.

Further, these varnishes were subjected to the same heat treatment as in Example 1 and then subjected to various characteristic tests, and the results obtained were as shown in the table.

As is clear from the results in Table 1, the heat-resistant resins of Examples 1 to 3 obtained by the present invention have a small elastic modulus, so when used as a surface protective film of a semiconductor element, stress caused by thermal stress It can be seen that it has a very large effect of alleviating the water absorption, and has a low water absorption (and has a large adhesion force), so it also has the effect of preventing corrosion of the M circuit of the element.

Furthermore, in Comparative Example 1, the film thickness was too thin, resulting in a decrease in heat shock resistance. On the other hand, in Comparative Example 2, the film was too thick and reflux occurred when the film peeled off from the semiconductor element, resulting in poor moisture resistance. Comparative Example 3 does not contain any silicon diamine, so the film strength is high, but the elastic modulus is also high, so the stress relaxation effect and adhesion are poor, and good results are not obtained in both heat shock resistance and moisture resistance. Comparative Example 4 does not contain high molecular weight silicone diamine, so it has a high elastic modulus and a high water absorption rate, so it has poor heat shock resistance and moisture resistance.

Margin below

Claims (1)

[Claims] Organic tetracarboxylic dianhydride component and general formula (1) ▲Mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R_1 is a methylene group, a phenylene group, or a substituted phenylene group, and R_1 is a methyl group, phenylene group or substituted phenylene group, n is an integer of 1 when R_1 is a phenylene group or substituted phenylene group, and 3 or 4 when R_1 is a methylene group). Those in which m is in the range of 1 to 10 account for 0.05 to 20 mol% of the total diamine component, and 11 to 5
A heat-resistant resin whose essential component is a diamine component containing 0.05 to 30 mol% of a diamine in the range of 0.00 is applied to the surface of the semiconductor element and cured by heating to form a film thickness of 0.00 on the semiconductor surface.
A semiconductor device characterized in that the semiconductor device is sealed with an epoxy resin material after being adhered to a thickness of 1 μ to 100 μ.