JPS63166533A - Manufacture of metallic core metal-clad laminated board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is a method for manufacturing a metal core metal laminated plate with high thermal conductivity, excellent heat dissipation properties, and a heat coefficient of heat j# for ceramic chips, silicon chips, etc. Regarding.

(Prior art) Conventionally, as a printing material 11je, a resin layer made of 2-enol resin, Epo-7 resin, etc. has often been used.However,
Recently, as electronic A devices have become more compact, more compact, and more dense, how can we reduce the high density of heat generated by -17 fL?
The challenge is to make the thermal expansion coefficient close to that of the ceramic chips, crimped chips, etc. that are buried or mounted, that is, to prevent the substrate from becoming more bulky and to make the connectors more similar to each other.

In contrast, conventional organic substrates have poor heat dissipation properties due to their low thermal conductivity, making it difficult to implement high-temperature mounting. For this reason, metal core substrates are attracting attention, which have a gold plate with excellent thermal conductivity as a core material and an insulating layer on the surface.

(Problems to be Solved by the Invention) This metal core substrate is made by providing a thin layer of an organic insulator such as epoxy resin on the surface of a metal plate with good thermal conductivity such as aluminum, and then adding a circuit to the J:. A structure in which a metal foil tube such as fII4 foil is pasted is a product.However, in such a structure, there is a resin layer with poor thermal conductivity between the circuit and the gold, so the metal The high thermal conductivity of the plate cannot be fully utilized.
Countermeasures have been considered, such as reducing the thickness of the insulating layer or incorporating a highly thermally conductive agent into the resin, but these measures are not sufficiently effective.

For this reason, a method of using ceramic such as alumina, which has good thermal conductivity, as an insulating layer has been considered. That is, this is a method in which a ceramic layer is provided on the surface of gold s41 serving as a core material by a method such as thermal spraying. However, this method has drawbacks such as insufficient adhesion between the metal plate and the ceramic layer, or poor voltage resistance and temperature resistance due to the presence of pores in the ceramic layer. In addition, in the case of such a structure, the formation of the circuit requires complicated labor such as conductor paste and metal paste, which increases the cost.

Also, regarding this 5-point meta: Considering the low heat resistance of metal-clad laminates, the gold plate is 421! Materials with low thermal expansion coefficients such as gold and Invar metal, which have thermal expansion coefficients close to those of silver and silicon, can be used. However, since the insulating layer is mainly made of resin, if a metal plate with a low coefficient of thermal expansion is used, there is a large difference in the coefficient of thermal expansion between the insulating layer made of gold and resin. #11 It is unreliable when peeled due to warping or heat damage.

The present invention improves these shortcomings and provides a metal core gold-plated lateral layer material that has excellent heat dissipation properties, low thermal expansion coefficient, and a thermal expansion coefficient close to that of ceramic chips, silicon chips, etc. .

(Problem t - Means for Solving) That is, the present invention sprays ceramic onto one side of a metal foil to form a ceramic sprayed layer, and impregnates the pores of the ceramic sprayed layer with an uncured thermosetting resin. The special mission was to overlay the gold pieces so that they were in contact with the ceramic sprayed layer side of the metal foil, and then crimped and integrated them all.

Copper foil, which is widely used for general printed wiring boards, is suitable as the metal foil, but aluminum foil, nickel foil, fI & foil, etc., or their swirled foils, and their spirals can also be used. nru.

Alumina, which has excellent electrical properties such as electrical insulation, is suitable as the hepteramic material, but other materials such as spinel, mullite, silicon carbide, and aluminum nitride can also be used. Further, for the ceramic spraying tk on the gold I/II4 groove, gas spraying, plasma spraying, water plasma spraying, reduced pressure plasma spraying, etc. can be used.

Gold J#! The ceramic sprayed layer formed on the foil is impregnated with the uncured thermosetting resin to seal the pores.The ceramic sprayed layer has electrical properties such as withstand voltage and insulation resistance, especially when moisture is absorbed. This is for the purpose of improvement. Ceramic spraying 1C
Compared to other ceramic coatings such as VD@, PVD method, and Sol-Guru method, it has advantages such as faster film formation speed, better stability, and ability to coat large areas. , the sprayed layer has a runner-up in which many pores occur. This porosity is generally about 5 to 15 vol%, and can be reduced by vacuum spraying, but it is still about 1% and cannot be reduced to zero. Therefore, if water is present, it will penetrate into the pores and cause a significant decrease in electrical properties such as insulation resistance and withstand voltage. Therefore, it is necessary to improve the water absorption properties by sealing these pores.

Since the resin used for pore sealing is required to have tm property to the pores,
It is desirable that the resin has a low viscosity, and a thermosetting resin that hardens after sealing and does not adversely affect electrical properties etc. is suitable. Epoxy resins, polyimide resins, phenol resins, vinyl ester resins, unsaturated polyester resins, etc. can be used as such 5-carbon resins. The impregnability of these resins can be achieved by spraying, brushing, hot cloth method using a roller, doctor blade method, etc. on the ceramic sprayed layer formed on Kanasu foil, and vacuum impregnation is more effective. Impregnating properties can be further improved. In addition, if the resin has both viscosity and insufficient impregnating properties, the resin may be diluted with a solvent. In that case, the bath agent is removed by heat treatment after impregnation, and then - Handling becomes easier if the product is made into a B stage to eliminate stickiness at room temperature.

The thus obtained ceramic thermal sprayed metal foil with pores sealed with T-resin has a sealed resin layer on the surface of the ceramic layer, and is smooth when completely cured, so the gold Jli plate used as the core material By applying pressure and heating at the same time, the resin acts as an adhesive and can be integrated. Depending on the application, if you want to ensure the thickness of the resin layer to a certain extent, it is best to place a pre-plate between the metal plate and the ceramic I-.

Legs can be interposed. 1 Repregs used include fiber base materials such as glass fiber, Kepler fiber, paper, and quartz fiber impregnated with evoki resin, polyimide resin, phenol resin, unsaturated polyester resin, vinyl ester resin, and the like. Note that it is desirable that the resin for the prepreg and the resin used for sealing the resin be of the same Pji type in consideration of the adhesion and compatibility between them, but they may be different as long as there is no adverse effect.

As the metal plate used as the core material, an aluminum plate, a steel plate, an iron plate, a stainless steel plate, a brass plate, a 42 sweet gold plate, an invar alloy metal, etc. are used. Among these gold S plates, 42 gold alloys and invar alloys have very low thermal expansion sa < (3
~4 X 10-'/”C), Ceramic (657X
10-6IC), silicon (3~4XIQ-6/”C)
Since it is close to , the thermal expansion vR coefficient of the metal core metal clad laminate can be visualized using these, which is very effective in improving the connection reliability during actual step operation. In addition, the 42-base gold invar material can be used in a state where it is clad with copper, aluminum, or other gold, if necessary.

In the present invention, the ceramic layer may be formed on only one side or both sides of the gold JI@ plate, if necessary.

(Function) The metal core gold-clad laminate obtained by the method of the present invention has a ceramic layer in close contact with the metal foil that forms the circuit, and also has a metal plate through seven thin adhesive layers, so it can be heated easily. The dissipation properties are very good. In the conventional method, a resin layer with low thermal conductivity is in contact with the circuit to ensure insulation, but in the method of the present invention, the metal core material is a ceramic layer with good thermal conductivity. The heat dissipation of the plate can be effectively used.

Furthermore, in the ceramic sprayed layer t-insulating layer, the pores present in the sprayed layer caused a significant deterioration in electrical properties when water was absorbed, but this can be improved by sealing the pores with a resin. 1k, conventional, ceramic t directly on metal 8i
- With the thermal spraying method, forming the circuit requires additional processes such as T-G spraying or conductive paste, but
Gold I! as in the method of the invention! By using the method of irradiating ceramics on I4 foil, circuits can be easily formed by etching on the laminated board fabrication wave.

Therefore, the process is also simplified and costs can be reduced.

In addition, if a metal plate with low heat resistance II #coefficient of coefficient 2 is used, an invar alloy, etc. is used, it is easy to reduce the thermal expansion of the entire base bottle, and the resulting warpage and decrease in the adhesion of the insulating layer can be avoided. It can be improved. .

The present invention will be described below with reference to Examples.

(11! Example) Fig. 1 is a laminated configuration diagram of a metal core metal clad laminate of the present invention, and Fig. 2 is a schematic cross-sectional view of the obtained metal core metal clad laminate.

Alumina was thermally sprayed to a thickness of about 100 μm on one side of a copper foil 1 having a thickness of 55 μm by plasma spraying to obtain a copper foil having an aluminum layer 2 on one side. Next, a solution of uncured epoxy medium resin diluted with a bath agent is applied to the alumina layer obtained in this way to impregnate it, and the alumina layer is heated in a heating furnace to remove the surfactant and at the same time, the resin is The mixture was made into a B stage, and the mixture was heated to a sticky state at room temperature. The alumina thermal sprayed 1ll11 foil sealed with this A fat and the core material of 1all thick 42@gold plate 4t - No. 1 - are stacked together as shown in Figure 2. A metal core steel clad laminate 1III'f having the configuration shown was obtained.

This metal core steel clad laminate had excellent heat dissipation properties, and no deterioration in electrical properties was observed when moisture was absorbed. Furthermore, the circuit could be formed in the same manner as for a general steel-clad metal core substrate.

Furthermore, warpage is more likely to occur on busy boards, and the coefficient of thermal expansion is 5.
The temperature was very low compared to the conventional metal core metal clad laminate which was 12 to 15 x 10''''/°C.

(Effects of the invention) By the method of the present invention, a substrate with excellent heat dissipation properties that could not be obtained with conventional metal core substrates, as well as excellent electrical properties when absorbing moisture, and mounting of silicon chips, ceramic chips, etc. A substrate having a low coefficient of thermal expansion and excellent connection reliability with these nuts can be easily obtained.

[Brief explanation of the drawing]

FIG. 1 is a laminated structure diagram of the metal core gold SR's layer structure of the present invention, and FIG. 2 is a schematic cross-sectional view of the obtained metal core metal clad laminate. Explanation of code: 1°C drop 2 Alumina layer 3 Epoxy resin layer 442 units Kinkyo Figure 1 Figure 2

Claims (1)

[Claims] 1. A ceramic sprayed layer is formed on one side of a metal foil, and the pores of the ceramic sprayed layer are impregnated with an uncured thermosetting resin, so that the ceramic sprayed layer is in contact with the ceramic sprayed layer side of the metal foil. A method for manufacturing a metal core metal clad laminate, which comprises stacking metal plates and pressing them together to integrate them. 2. The method for manufacturing a metal core metal clad laminate according to claim 1, wherein the ceramic sprayed layer and the metal plate are integrated by interposing a prepreg and press-bonding the ceramic spray layer and the metal plate. 3. The method for manufacturing a metal core metal clad laminate according to claim 1 or 2, wherein the ceramic is mainly composed of alumina. 4. The method for manufacturing a metal core metal clad laminate according to claim 1 or 2, wherein the resin impregnated into the pores of the ceramic is an epoxy resin. 5. The method for manufacturing a metal core metal clad laminate according to claim 1 or 2, wherein the resin impregnated into the pores of the ceramic is a polyimide resin. 6. The method for manufacturing a metal core metal clad laminate according to claim 1 or 2, wherein the metal foil is copper foil. 7. The method for producing a metal core metal clad laminate according to claim 1 or 2, wherein the metal plate is a 42 alloy or a clad plate mainly composed of a 42 alloy. 8. The method for manufacturing a metal core metal clad laminate according to claim 1 or 2, wherein the metal plate is an invar alloy or a clad plate mainly composed of an invar alloy.