JPH0530381B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a highly reliable heat-resistant laminate in which metals and/or ceramics are laminated to be used as materials for electronic parts and the like. [Prior art] Metals and ceramics are materials with excellent thermal conductivity, and their laminates are used for a variety of purposes, including materials for electronic components such as alumina substrates, and further development is expected in the future. ing. Conventionally, epoxy adhesives have been mainly used for the adhesive layer of this laminate (see, for example, Japanese Patent Laid-Open No. 18290/1983). However, epoxy adhesives have a problem in that they do not have sufficient heat resistance. Therefore, a method has been proposed that uses an adhesive layer made of aromatic polyamideimide, which has better heat resistance than epoxy adhesives, and an adhesive agent (see Japanese Patent Application Laid-Open No. 15826/1983). Unfortunately, however, none of these methods has been able to satisfy the recent demands for high heat resistance. [Problems to be Solved by the Invention] In other words, epoxy adhesives currently in practical use only have a heat resistance of about 200° C. and lack reliability at high temperatures. On the other hand, adhesives made of aromatic polyamide-imide and adhesion promoters do show significantly higher heat resistance than epoxy adhesives, but they do not work well in hot and humid conditions, that is, when subjected to both heat and humidity loads. The problem remained that adhesion was insufficient in such cases, and reliability was lacking in harsh environments. [Means for Solving the Problems] As a result of extensive studies in order to solve the above problems, the inventors of the present invention have found that heat-resistant The present invention has been achieved based on the discovery that an excellent laminate can be obtained that has excellent adhesion reliability under hot and humid conditions and takes advantage of the high heat resistance of metals or ceramics. That is, the present invention provides a laminate in which at least one layer is made of metal and the other layers are made of metal or ceramics, in which the adhesive layer has the general formula:

[Formula] or (However, X represents an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, or a methylene group, and n represents an integer of 2 or more) and a polar organic solvent-soluble aromatic polyamideimide resin with a thermal conductivity of 0.05 cal. The composition is characterized by having 1 to 35% by volume of a high thermal conductivity filler selected from beryllia, magnesia, boron nitride, alumina, silicon carbide, silicon nitride, carbon, and mixtures thereof with a temperature of /cm・sec・℃ or more. The present invention provides a heat-resistant laminate having the following properties. The present invention will be explained in detail below. At least one layer of the laminate of the present invention is a metal layer, and other layers can be selected from metal or ceramic depending on the purpose. Electronic component materials, especially heat-dissipating substrates, are often metals. As the metal layer, all metals that can be formed into a layer, such as copper and aluminum, can be used. Further, the ceramic layer may be any ceramic, and various types can be used. For example, alumina, zirconia, silicon nitride, boron nitride, silicon carbide, etc. can be used. Next, the aromatic polyamide-imide resin used in the adhesive layer, which is the main part of the present invention, is an aromatic polyamide-imide resin soluble in a polar organic solvent, and has the general formula:

[Formula] Or, (However, X represents an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, or a methylene group, and n represents an integer of 2 or more) or a mixture thereof is used. The reduced viscosity of the aromatic polyamideimide resin used in the present invention is not particularly limited as long as it is 0.5 or more, but
A solution viscosity of around 3.5 during use is practical.
If the reduced viscosity is too low, the mechanical strength and flexibility will decrease, and if the reduced viscosity is too high, the solubility in polar organic solvents will decrease, making it impractical. These aromatic polyamide-imide resins can be produced by a known method, for example, by reacting an aromatic diamine with trimellitic anhydride chloride or reacting an aromatic diisocyanate with bisimidodicarboxylic acid. One of these reactions will be described below as a representative example. (A)

【formula】 (X in the formula has the same meaning as above) or (B)

〔Example〕

Next, the present invention will be specifically explained using Examples and Comparative Examples, but the present invention is not limited thereto. The evaluation methods and conditions for the laminates in Examples and Comparative Examples are as follows. Solder heat resistance: test piece in a 300℃ solder bath
The presence or absence of blistering and peeling was observed when immersed for 30 seconds. Adhesion: Measured by cross-cut tape method.
After cross-cutting the metal foil surface of the test piece according to the cross-cut test method of JIS K 5400, PET tape was attached, and then it was peeled off to measure the number of squares remaining among the 100 squares. In the adhesion test, the laminate was heat-treated at 350°C for 3 hours and
The product was evaluated after being left in a pressurizer at 121°C and 2 atm for 1 hour, and its reliability under high temperature and heat and humidity was confirmed. Adhesion: Measured according to JIS C 6481 peel strength test method. Example 4 Organic polar solvent soluble aromatic polyamideimide resin (hereinafter abbreviated as PAI; reduced viscosity 1.6: specific gravity 1.5) synthesized from 4,4'-diaminodiphenyl ether (DADPE) and anhydrous trimellitic acid chloride (TMAC) 100 450 parts by weight of N-methylpyrrolidone was added to the parts by weight to dissolve the PAI. Next, fine boron nitride powder (BN) with an average particle size of 1.5 μm (Showa Denko BN: specific gravity 2.25)
A solution in which 20 parts by weight of NMP is dispersed in 50 parts by weight of NMP is mixed with the above PAI resin solution, and BN is mixed with a ball mill.
was uniformly dispersed to obtain a paste composition. Next, a copper plate (thickness 1 mm) was coated with the composition in a paste form with a thickness of 100 μm, and after preliminary drying at 90°C for 10 minutes, this composition was coated with a rolled copper foil (thickness 35 μm).
were stacked on top of each other, cushion materials made of Teflon and silicone rubber sheets were sandwiched between the top and bottom, and heat and pressure bonded at 10 kg/cm ² at 180°C for 30 minutes using a press. This laminate was evaluated using the method described above, and as a result, no blistering or peeling was observed in terms of solder heat resistance. Also, in the adhesion test, blank
1.61Kg/cm, 1.40 after high temperature treatment at 350℃ for 3 hours
Kg/cm, after pressurization (121℃2
Atmospheric pressure for 1 hour), the adhesion was 1.55 kg/cm, which was good in all cases. Example 2 A thin film with a thickness of about 10 μm was made using an applicator from the composition used in Example 1, and then heated at 130°C and 190°C.
Each sample was heat-treated at ℃ for 30 minutes. Next, a thin layer of N-methylpyrrolidone was sprayed onto the surface of this film, and the film was placed between an aluminum foil (thickness 15 μm) and an alumina thin plate (manufactured by Noritake, thickness 635 μm) and pressed from above and below with cushioning materials made of Teflon and silicone rubber sheets. A laminate of aluminum foil and alumina was obtained by heat-pressing at 5 kg/cm ² at 180° C. for 30 minutes using a press. This laminate was evaluated using the same method and conditions as in Example 1. As a result, blistering was observed in terms of solder heat resistance.
Even in the adhesion test, the blank was 100/100,
It was found that the laminate was 100/100 after high-temperature treatment at 350°C, and 100/100 after pressure vacuum treatment, making it an extremely reliable laminate. Examples 3 and 4 Metal laminates as shown in Table 1 were produced by the same method as in Example 1, and each laminate was evaluated. The results are shown in Table 1. Both laminates showed excellent effects.

[Table] Comparative example 1 Polyimide varnish (Toray Co., Ltd. Torenice 20%)
Solution) 500 parts by weight and BN (Showa Denko Shoby)
N) A solution in which 20 parts by weight of NMP was dispersed in 50 parts by weight of NMP was mixed, and BN was uniformly dispersed using a ball mill. Next, a copper plate and an aluminum foil were bonded under heat and pressure in the same manner and under the same conditions as in Example 1 to produce a laminate, and evaluated in the same manner. The results are shown in Table 2. Comparative example 2 Bisphenol type epoxy AER 331 manufactured by Asahi Kasei Corporation Epoxy equivalent 180-200) 100 parts by weight and BN20
A solution in which part by weight was dispersed in 50 parts by weight of NMP was mixed, and BN was uniformly dispersed using a ball mill. Next, add 25 parts by weight of 4,4'diaminodiphenylmethane.
A solution dissolved in 75 parts by weight of NMP was added to the above BN mixed epoxy and stirred. Next, a copper plate and an aluminum foil were bonded under heat and pressure in the same manner and under the same conditions as in Example 1 to produce a laminate, and evaluated in the same manner. The results are shown in Table 2. Comparative Example 3 400 parts by weight of NMP was added to 100 parts by weight of PAI used in Example 1 and dissolved. Next, add BN150 parts by weight.
A solution containing 200 parts by weight of NMP was mixed, and BN was uniformly dispersed using a ball mill. Next, a laminate was produced by heat-pressing a copper plate and an aluminum foil using the same method and conditions as in Example 1.
Evaluation was conducted in the same way. The results are shown in Table 2.

〔Effect of the invention〕

As described above, the present invention provides a laminate that has excellent solder heat resistance and exhibits the excellent effect of greatly improving adhesion reliability under hot and humid conditions. Therefore, by using the heat-resistant laminate of the present invention, it is expected that the reliability of electronic components against heat will be further improved. Furthermore, the heat-resistant laminate of the present invention has the advantage that its manufacturing process is simple and economical.

Claims (1)

[Claims] 1. In a laminate in which at least one layer is made of metal and the other layers are made of metal or ceramics, the adhesive layer has the general formula [formula] or, (However, X represents an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, or a methylene group, and n represents an integer of 2 or more) and a polar organic solvent-soluble aromatic polyamideimide resin with a thermal conductivity of 0.05 cal. The composition is characterized by having 1 to 35% by volume of a high thermal conductivity filler selected from beryllia, magnesia, boron nitride, alumina, silicon carbide, silicon nitride, carbon, and mixtures thereof with a temperature of /cm・sec・℃ or more. Heat-resistant laminate.