JPH03239390A - Metal cored board and manufacture thereof - Google Patents

Abstract

PURPOSE:To improve the reliability of filling insulation of a through hole in a through hole section, the bonding property between a metal core and an insulation layer and the connection reliability of the through hole by installing a substrate which fills and bonds a specific compound with an aluminum sheet and the through hole where an outer layer copper foil or an outer layer one sided copper foiled substrate is laminated and formed with a bonded and insulated prepreg. CONSTITUTION:A substrate where a resin compound cured body 2b is filled and bonded with an aluminum sheet 1 and a through hole 5 are installed where an outer layer copper foil or an outer layer one sided copper foiled substrate 4 are laminated and formed with a bonding insulated pre-preg 3. The aluminum substrate is an aluminum sheet 1 with the through hole subjected to chromium sulfate acid treatment or phosphoric acid anodized aluminum processing, which is embedded in a resin compound where the percentage of silica particles with an average grain size of 4 to 20mum ranges from 50-180 pts. against the total amount of 100 pts. of epoxy resin and phenol resin after chemical etching. This construction makes it possible to improve the adhesion properties between a metal core and an insulation layer, the reliability of filling insulation of the through hole in the through hole section, and hence enhance through hole connection reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a metal core substrate for high-density packaging with excellent heat dissipation properties and a method for manufacturing the same.

[Prior art] A metal core double-sided board uses a metal plate with through holes as a core material,
It has an insulating layer on both sides and a conductive layer on the outside thereof, and has excellent heat dissipation. Conventionally, such metal-core double-sided boards have a metal plate with through holes as the core material, prepreg made of glass woven fabric impregnated with resin as an insulating layer on both sides of the metal plate, and a copper foil etc. It is manufactured by stacking the conductor layers and molding them under heat and pressure, filling the holes in the metal plate with the resin in the prepreg, and hardening the resin.

However, this manufacturing method has a drawback in that the thicker the metal plate becomes, the more difficult it becomes to fill the holes with resin.

Therefore, as an improvement on this manufacturing method, a method has been proposed in which metal foil is laminated and cured on both sides of a metal plate having through-holes for forming through-holes, with an insulating layer of glass nonwoven fabric impregnated with resin interposed therebetween. There is (JP-A-Sho Eil-4809
(See Publication No. 2).

However, in these methods, the resin filled into the through-hole has a large thermal expansion, and due to mismatch in thermal expansion with the metal core or the conductor layer in the through-hole part, the resin may peel off from the metal core or the conductor layer in the through-hole part may Cracks may occur. Furthermore, due to the shrinkage of the resin during curing and the difference in thermal expansion coefficient, the dents (rimples) in the through-hole area become large, resulting in decreased adhesion with the photosensitive dry film during wiring pattern formation, and the formation of fine patterns. Problems may occur.

Aluminum (M) is also used as the metal core due to its high rigidity and light weight, but in order to give the aluminum plate adhesive strength with the resin,
The surface is roughened by physical methods such as polishing or treated with sulfuric acid alumite.

Conventional metal-core substrates with aluminum plates as the core material cannot be said to fully satisfy various required characteristics such as reliability during thermal cycling under the harsh usage conditions of recent years. Further improvements are desired.

[Problems to be Solved by the Invention] As described above, conventional metal core substrates have problems such as reliability of filling insulation in the through hole portion, adhesion between the metal core and the insulating layer, and connection reliability of the through hole. There are problems such as low performance.

The present invention has been made in view of the above-mentioned circumstances, and provides a through-hole structure in which the metal core and the insulating layer have good adhesion, and the through-hole portion is filled and insulated with a resin composition having a small coefficient of thermal expansion. The purpose of the present invention is to provide a metal core substrate with high hole connection reliability and a method for manufacturing the same.

[Means for Solving the Problems] The present invention provides that the proportion of silica particles with an average particle size of 4 to 20 um is 50 to 180 parts to the total ffl<100 parts (parts by weight, the same shall apply hereinafter) of the epoxy resin and the phenol resin. A substrate manufactured from an aluminum plate with through holes embedded in a resin composition that has been chemically etched and then treated with sulfuric acid chromic acid or phosphoric acid alumite, and an outer layer copper foil or one-sided copper clad for the outer layer. The substrate is laminated with adhesive insulating prepreg, a metal core substrate provided with through holes, and (a) a resin composition in which an epoxy resin, a phenol resin, and silica particles are mixed are applied to a release film using an applicator. Step of applying (()〉Resin composition applied to the release film) Second,
A step of placing an aluminum plate having through holes, further covering it with a release film, and embedding the aluminum plate in the resin composition using a heating roller, (c) aluminum plate embedded in the resin composition. (d) removing the mold release film, and the resulting substrate and an outer layer copper foil or a single-sided copper-clad substrate for the outer layer, which will become part of the conductor layer on the front and back of the substrate. and (e) forming a through hole with a smaller diameter than the through hole in the center of the through hole, and forming a through hole with a smaller diameter than the through hole, and aligning the through hole with the inner surface of the through hole and the outer layer with copper foil or the outer layer. The present invention relates to a method for producing a metal core board, which comprises the steps of plating the surface of a single-sided steel-clad board to form a conductor layer, connecting the front and back conductors, and then etching the conductor layer to form a conductor circuit.

[Example] The metal core substrate of the present invention includes, for example, a substrate in which a cured resin composition (2b) is filled and adhered to an aluminum plate (1) as shown in FIG. The single-sided copper-clad board (hereinafter also referred to as outer layer copper foil) (4) is
It is formed by laminating layers of adhesive insulating prepreg (3) and is provided with through holes (5).

The aluminum substrate includes a resin composition in which the ratio of silica particles with an average particle size of 4 to 20 cavities is 50 to 180 parts to 100 parts of the total amount of epoxy resin and phenol resin.
It is manufactured from an embedded aluminum plate having through-holes that has been chemically etched and then treated with sulfuric acid chromic acid or phosphoric acid alumite.

The aluminum plate preferably has a thickness of 0.3 to 1.5 cm from the viewpoint of dimensional stability, heat dissipation, mechanical strength, etc. There is no particular limitation on the diameter of the through hole, and it may be the same as that in a normal metal core substrate.

The chemical etching is a process performed to chemically roughen the surface of an aluminum plate, and includes, for example, a process using a ferric chloride/hydrochloric acid solution.

The sulfuric acid chromic acid treatment or phosphoric acid alumite treatment is
This treatment is performed to form a thin alumite film on the surface of the aluminum plate, which has been roughened by the chemical etching, to improve adhesion to the cured product of the resin composition.

The sulfuric acid chromic acid treatment is usually carried out using a treatment solution of sodium dichromate/sulfuric acid at 60 to 65° C. for 4 to 10 minutes.

The phosphoric acid alumite treatment is usually carried out by immersing the aluminum plate in an aqueous solution of phosphoric acid for a treatment time of 15 to 20 V Sto to 3 degrees.

The thickness of the alumite layer formed by this process is 0.05 to 1 square because the surface of the aluminum plate has already been sufficiently chemically roughened by chemical etching. sex is improved. When the thickness of the alumite layer becomes thicker than 1 am, cracks tend to occur in the alumite layer and adhesiveness tends to decrease.

The resin composition has adhesive properties with an aluminum plate,
A solvent-free system of epoxy resin and phenolic resin is used from the viewpoint of heat resistance and water absorption, and this composition has a softening temperature of 20 to 40°C, has low stickiness at room temperature, and the cured product is not brittle. It is also preferable from this point of view. This resin composition further contains silica particles, but usually also contains an epoxy resin curing catalyst, a silane coupling agent, and the like.

The epoxy resin is preferably a bisphenol A type low viscosity epoxy resin having a viscosity of about 1000 poise or less from the viewpoint of fluidity when applied to a release film.

Specific examples of such epoxy resins include Epicoat #828 and Epicoat 11834 manufactured by Yuka Shell Epoxy ■.

Furthermore, as an epoxy resin component, in order to improve flexibility, epoxy resins such as Epicor HI100I and Epicor $ 1.004 manufactured by Yuka Shell Epoxy ■ are added at 20% (wt%) of the total resin content. Similarly, a cresol novolac epoxy resin such as EOCH manufactured by Nippon Kayaku ■ may be mixed with a bisphenol A type epoxy resin at 20% or less in order to improve heat resistance and adjust the softening temperature. % or less, and in order to impart flame retardancy, the brominated epoxy resin may be blended in an amount of about 50% or less of the total epoxy resin.

The phenol resin used as the curing agent is preferably a polyfunctional phenol novolac resin derived from phenol, cresol, alkylphenol, etc. and having a softening temperature of 80° C. or higher. For those with a softening temperature of less than 80℃,
Cured resin tends to become brittle.

0 The blending ratio of the epoxy resin component and phenol resin is
Epoxy group/phenolic hydroxyl group is 1.0/1,2~1
．． A ratio of 010.8 is preferable.

As the curing catalyst, common amines, phosphorus compounds such as triphenyl phosphate, imidazole compounds, etc. are used. Among these are potlife,
Imidazole compounds are preferred from the viewpoint of reactivity.

The blending ratio of the curing catalyst is preferably 0.01 to 0.5 parts based on 100 parts of the total amount of the epoxy resin component and phenol resin.

The silica particles are a component for adjusting the coefficient of thermal expansion of the cured resin to be close to that of aluminum, and have an average particle size of 4 to 20 mm, preferably 10 to 20 mm. If the average particle size of silica is less than 4, the viscosity -L of the resin composition after adding silica particles increases significantly, and the filling rate does not increase.
If the number of holes exceeds 20, the silica particles will settle after filling, making it difficult to uniformly fill the through holes of the aluminum plate.

The blending ratio of the silica particles is 50 to 1.80 parts, preferably 80 to 120 parts, based on 100 parts of the total amount of epoxy resin and phenol resin. If the proportion is less than 50 parts, the contribution to the coefficient of thermal expansion will be small, and if it exceeds 180 parts, the viscosity of the resin composition will become too high to be used as a solvent-free system.

A specific example of the silane coupling agent is KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd., and its blending ratio is equal to the total f of epoxy resin and phenol resin.
It is preferably 0.1 to 3 parts based on part f1loO.

Further, antimony oxide or the like may be added to impart flame retardancy.

The resin composition used in the present invention is usually prepared by first heating and melting an epoxy resin and a phenol resin at 90 to 100°C using a vacuum heating mixer or the like, and then adding silica particles and a silane coupling agent to make the resin composition uniform. It can be prepared by a method such as mixing with a curing catalyst, adding a curing catalyst, and degassing and mixing in a vacuum.

A substrate manufactured by embedding an aluminum plate in such a resin composition is one in which the through holes of the aluminum plate (1) are filled with the cured resin composition (2b) as shown in Figure 1. , thickness 20~30 on the front and back sides
0J+, more preferably about 20 to 100 parts of the cured resin composition (2b) is attached to the substrate.

It is difficult in manufacturing to make the thickness of the cured resin composition on the front or back surface less than 20 mm, and if it exceeds 300 mm, the resin layer tends to be prone to cracking.

As the outer layer copper foil, a copper foil having a thickness of about 15 to 100 inches is used, which is similar to that conventionally used for metal core substrates.

The single-sided copper-clad substrate for the outer layer has a thickness of 0.1 to 0.211111.
The glass epoxy laminate of No. 11 is laminated with copper foil on only one side.

There are no particular limitations on the adhesive insulating prepreg used to bond the substrate and the outer layer copper foil, etc., and glass cloth epoxy prepregs, glass cloth polyimide prepregs, etc. that have been conventionally used in the production of normal multilayer boards can be used. .

The adhesive insulating prepreg is preferably thin from the viewpoint of heat dissipation, with a thickness of 0.05 to 0.2! Preferably, it is o+v.

In addition to the above-mentioned layers, the metal core substrate of the present invention includes an adhesive insulating prepreg (3 layers) between the substrates as shown in FIG.
) can also sandwich the inner layer substrate (6).

As the inner layer board, an ordinary interior board for manufacturing multilayer boards is used.

The through hole is provided at the center of the through hole filled with resin and has a hole diameter smaller than the through hole in order to connect the conductor layer on the front surface and the back surface of the metal core substrate.

Such a metal core board of the present invention has a plated layer (a sword is formed) by plating the inner surfaces of the outer layer copper foil (4) and the through holes (5), as shown in FIGS. 3 and 4, for example. Afterwards, the outer copper foil layer (4) and the plating layer (7) are etched to form a conductive circuit for use.

Next, regarding the manufacturing method of the metal core substrate of the present invention, Sections 5a to 50 will be explained.
This will be explained using figures.

The method for manufacturing a metal core substrate of the present invention consists of the following steps.

3 4 That is, first, the resin composition (2a) is applied onto the release film (8) using an applicator (step (
a)) (see Figure 5a).

As the release film, for example, Tetra (polyvinylidene fluoride manufactured by DuPont), polypropylene, etc. are preferable from the viewpoint of heat resistance.

As a coating method, for example, the resin composition is heated to 80 to 90°C.
The release film L is coated using a Dokner knife heated to 90 to 100°C or a nozzle with a controlled gap.

The thickness of the applied resin composition is preferably 0.5 to 1.51.

This step (after the completion of the step, the next step begins) may be carried out continuously, or it may be carried out in batches.

Next, as shown in FIG. 5b, an aluminum plate (1) is placed on the resin composition (2a) applied to the release film (8).
, and then cover it with a release film (8).
Using a heating roller (9), the resin composition (2a) is sandwiched between mold release films (8) and embedded in the resin composition (2a), and the resin composition is applied to the front and back surfaces and through holes of the aluminum plate. Adhere and fill (step (b)).

Preferably, the temperature of the heating roller is 100 to 120'C.

Since the resin composition (2a) has a softening temperature of 20 to 40°C and is solid at room temperature, the presence or absence of voids in the through holes can be checked in an uncured state, and if voids are detected, By repeating step +b>, a void-free state can be achieved.

Next, the resin composition in which the aluminum plate (1) is embedded is heated to harden the resin composition to form a substrate as shown in FIG. 5c (step (c)).

There is no particular limitation on the heating method, and a release film (8
) The resin composition is filled in the through-holes in the form of sandwiched parts, and since it does not contain voids, it may be heated and cured in an oven as it is, or it may be heated and cured while being pressurized.

The heating conditions are as follows: 2 to 2 degrees Celsius at a low temperature of 70 to 110 degrees Celsius, from the viewpoints of preventing sedimentation of silica particles and reducing rimple (dent) of through holes due to contraction of resin after curing.
Preferably, the resin is held for 4 hours to gel, and then heated at 150 to 170°C for 1 to 2 hours to cure. Further, in the case of curing under pressure, sedimentation of the silica particles can be prevented by aging the aluminum plate embedded in the resin composition at 40 to 50° C. to an extent that does not result in gelation.

Next, the release film is removed, and the substrate and the outer layer copper foil (4) are aligned using reference holes (not shown),
Laminate molding is performed using adhesive insulating prepreg (3) (step (d)) (see Figure 5d).

The lamination molding method is not particularly limited, and for example, in the case of manufacturing a double-sided board, outer layer copper foil, prepreg, prepreg, etc.
When manufacturing a multilayer board by laminating the board, prepreg, outer layer copper foil, etc. in this order, the outer layer copper foil, prepreg, board, prepreg, inner layer board, prepreg, inner layer board, prepreg, board, prepreg, outer layer copper foil, etc. They can be formed by laminating them in this order.

Next, a through hole (5) having a smaller diameter than the through hole is formed in the center of the through hole, and the inner surface of the through hole (51) is subjected to plasma etching treatment if necessary.
5) After forming a conductor layer by plating on the inner surface and the surface of the outer layer copper foil (4) and connecting the front and back conductors (
FIG. 5e), the conductor layer is etched to form a conductor circuit (step (e)).

There is no particular limitation on the method of forming the through-hole (5), and a method similar to that used in manufacturing a normal metal core substrate, such as using a drill, can be used.

There are no particular limitations on the method and conditions for plating, and for example, plating made of copper or the like with a thickness of 10 to 50 mm may be plated using normal methods and conditions.
A plating layer of - degree is formed.

There are no particular limitations on the method of etching the conductor layer, and the etching can be carried out using conventional methods and conditions.

As explained above, in the metal core substrate of the present invention, the surface of the aluminum plate is subjected to chemical etching and then sulfuric acid chromic acid treatment or phosphoric acid alumite treatment, so that the aluminum plate and the cured resin composition are bonded together. It has excellent adhesion and the through-holes of the aluminum plate are filled with phenol-cured epoxy resin mixed with silica particles with a low coefficient of thermal expansion, making it easy to match thermal expansion with the aluminum plate and through-holes. It is in good condition with small rippling at the through hole.

In addition, in the manufacturing method of the metal core substrate of the present invention, the step of filling the through holes of the aluminum plate with the resin composition is performed independently, so it is possible to create a state without voids, and the reliability against heating and cooling cycles is improved. A metal core substrate with high heat dissipation properties can be obtained.

EXAMPLES Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.

Example 1 Two aluminum plates with thickness l, Dim and 0.8 mm (L80 mm x
After degreasing the surface (230 mm), it was chemically etched by immersing it in a 5:2:1 ferric chloride aqueous solution at room temperature for 5 minutes. Then, after removing smut with a dilute nitric acid aqueous solution and a dilute thorium hydroxide aqueous solution, it was immersed in a sulfuric acid chromic acid solution containing 300 g of sulfuric acid and 30 g of sodium dichromate at 60°C for 5 minutes, washed with water, and then heated at 50 to 60°C. The aluminum plate was dried for 15 minutes in a dryer to obtain a surface-treated aluminum plate.

Next, Epicoat 8828 (Uraka Shell Epoxy ■
epoxy resin) 84.85 parts and PS14-4
327 (phenol resin manufactured by Gunei Chemical Industry ■) 35.
Put 15 parts into a glass speaker and heat up to 10 parts using a mantle heater.
Heat to 0°C and dissolve, M-2150 (spherical silica particles manufactured by Nippon Steel Chemical Co., Ltd., average particle size 15 coral) 1.5
After adding 0 part and 0.45 part of KBM-403 (silane coupling agent manufactured by Shin-Etsu Chemical Co., Ltd.) and uniformly dispersing it, 0.15 part of 2-ethyl-4-methylimidazole was added.
A resin composition was prepared by adding 50% of the mixture and defoaming under vacuum.

Then, a 25-thick tetra film (polyvinylidene fluoride manufactured by DuPont) was placed on a hot plate at 100°C.
was spread, and the resin composition was injected into an applicator to form a resin composition sheet with a thickness L of 0 m111.

Next, the aluminum plate and Tetra film were layered on top of the aluminum plate in this order, and the aluminum plate was embedded in the resin composition by passing it between rolls heated to 110°C. Next, this was placed in a mold, a 5 kg weight was placed on it, and the mixture was heated in an oven at 70° C. for 15 hours, and then at 150° C. for 2 hours to harden it. After curing,
When examining whether there were any voids in the resin, no voids were found in the resin at the through-holes.

Next, copper foil with a thickness of 18AII11, prepreg with a thickness of 0.1 mm (manufactured by Sangawa Kagaku ■, GEPL-17 (1, the same applies hereinafter), 2 sheets, thickness 1, On + O + surface treated aluminum plate, thickness 0 .2 sheets of 1H prepreg, thickness 0.2
mmt inner layer board (copper thickness 35 cape, same below), 2 prepregs 0.1mmt thick, inner layer board 0.2mmt thick, 2 prepregs thickness O, in+nt, thickness 0
46mm surface treated aluminum substrate, thickness 0. io+
Two sheets of prepreg with a thickness of 1.5 m and a copper foil with a thickness of 18 mm were positioned in this order using the reference holes and laminated, and then heated at 180°C for 1 hour for 40 min.
A laminate was obtained by heating and pressing under the conditions of kg/cI#.

Next, a through hole was drilled in the center of the through hole of this laminate using a drill of 0.92 mm in diameter, and a copper coating layer with a thickness of 40 mm was formed on the inner surface of the through hole and the surface of the copper foil, and then the surface of the board was coated. A metal core substrate having a desired conductive circuit was obtained by patterning using a conventional method.

The characteristics of the obtained metal core substrate were evaluated by the method shown below. The results are shown in Table 1.

(Through hole void) If no void is observed, mark it as ○, and if it is found, mark as X.

(Through hole rimple) Measure the depth of the dent before drilling the through hole.

(Heat cycle resistance) 15 minutes at a high temperature of 125°C, 2 minutes at room temperature, -65
After repeating 300 cycles, each cycle consisting of 15 minutes at a low temperature of .degree. C. and 2 minutes at room temperature, the aluminum plate was examined for peeling of the resin and for cracks in the conductor layer of the through holes. Those with no peeling or cracks are marked as ○, and those with any peeling or cracks are marked as ×.

1 2 (Hot oil impact resistance) One cycle consists of immersion in hot oil at 260°C for 3 to 5 seconds, followed by immersion in room temperature trichlorene for 20 seconds, and after repeating 10 cycles, the resin from the aluminum plate was removed. Check for peeling and cracks in the through-hole conductor layer.

(Solder thermal shock resistance) After repeating 5 cycles, one cycle is immersion in solder at 260°C for 10 seconds and leaving it at room temperature for 5 minutes. Check for cracks.

Example 2 The same procedure as in Example 1 was used except that 110 parts of M-2120 (spherical silica manufactured by Nippon Steel Chemical Co., Ltd., average particle size 121 Im) was used as the silica particles, and 8 parts of KBM-4030 was used as the silane coupling agent. A metal core substrate was manufactured using the same method, and its characteristics were evaluated. The results are shown in Table 1.

Example 3 Instead of the sulfuric acid chromic acid treatment in Example 1, a phosphoric acid alumite treatment was performed by immersing it in an aqueous solution of 120 g/ρ of phosphoric acid at a voltage of 15 V for 10 minutes, washing with water, and drying to obtain a surface-treated aluminum plate. .

Next, Example 1 was used except that 80 parts of Fuzurex E-2 (average particle size 7.5 rhinoceros crushed silica particles manufactured by Morisha Co., Ltd.) was used as the silica particles, and 24 parts of K13M-4030 was used as the silane coupling agent. A resin composition was prepared in the same manner.

After embedding the aluminum plate in the resin composition in the same manner as in Example 1, the pressure was 20 kg/cJ and the temperature was 110 mm.
C. for 1 hour and 170.degree. C. for 1 hour for curing, then a metal core substrate was produced in the same manner as in Example 1, and its properties were evaluated. The results are shown in Table 1.

Comparative Example 1 Epicoat #828 40 parts, Epicoat #l-00
4 (epoxy resin manufactured by Yuka Shell Epoxy ■) and 30 parts of DEN481 (epoxy resin manufactured by Dow Chemical Company) were placed in a glass speaker and heated and melted at 90°C. degeneration D of
5 parts of ICY) and 0.2 parts of 34 benzyldimethylamine were added and uniformly dissolved, mixed and defoamed to prepare a resin composition.

Next, the same aluminum plate used in Example 1 was
The resulting resin composition was embedded in the same manner as in Example 1, and then heated for 1 hour at a pressure of 20 kg/cJ and a temperature of 110°C.
It was heated at 70° C. for 1 hour to cure it, and then a metal core substrate was manufactured in the same manner as in Example 1. Table 1 shows the results of evaluating the characteristics.

Comparative Example 2 Sulfuric acid 15 was used instead of the sulfuric acid chromic acid treatment in Example 1.
Immersed in a solution of 0g/β and 2A/dI112.
The aluminum plate was subjected to sulfuric acid alumite treatment for 0 minutes, washed with water, and dried to obtain a surface-treated aluminum plate.

Then, using the obtained aluminum plate, a metal core substrate was manufactured in the same manner as in Example 1 except that the resin composition prepared in Comparative Example 1 was used, and its characteristics were evaluated. The results are shown in Table 1.

Comparative Example 3 The surface of the same aluminum plate used in Example 1 was mechanically roughened by liquid honing to obtain a surface-treated aluminum plate.

Next, 125 parts of Epicoat 5048880 (an epoxy resin manufactured by Yuka Shell Epoxy ■), 4 parts of dicyandiamide, and 0.2 parts of dimethylbenzylamine were dissolved in 40 parts of methyl cellosolve, and a thickness of 0, io+m was added to this solution.
After soaking the glass cloth of No. t, it was dried at 130° C. for 15 minutes to obtain a hole-filling prepreg with a resin weight of 65%.

Next, three sheets of prepreg were laminated on each of the front and back surfaces of the surface-treated aluminum plate and cured at a pressure of 40 kg/c and a temperature of 170° C. to obtain a substrate. However, voids were observed in the through holes of this substrate.

A metal core substrate was manufactured in the same manner as in Example 1 except that the obtained substrate was used, and its characteristics were evaluated. The results are shown in Table 1.

[Margins below] 5 6 7 (Main symbols in the drawing) (1) Nialuminum plate (2a): Resin composition (2b): Cured resin introduction product (3): Adhesive insulation prepreg (4): Outer layer copper foil etc. (5) Varnish through hole (6): Inner layer substrate (7), Plating layer (8): Release film (9): Heating roller agent large i Masuo [Effects of the invention] The metal core substrate of the present invention is Since we use an aluminum plate treated with chromic acid or phosphoric acid alumite, the adhesion between the resin and the aluminum plate is excellent, and the aluminum plate is made of phenol-cured epoxy resin mixed with silica particles that have a small coefficient of thermal expansion. Since it is embedded in the aluminum plate, thermal expansion matching with the aluminum plate and the plating layer provided on the inner surface of the through hole is good, the connection reliability of the through hole is high, and rippling at the through hole portion is small.

Furthermore, in the method for manufacturing a metal core substrate of the present invention, the step of embedding the aluminum plate in the resin composition is independent, so a metal core substrate with high insulation reliability and no voids can be manufactured.

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional view of a double-sided board, Figure 2 is a vertical cross-sectional view of a multilayer board, Figure 3 is a vertical cross-sectional view of a double-sided board, Figure 4 is a vertical cross-sectional view of a multilayer board, and Figures 5a to 50 are FIG. 2 is an explanatory diagram of each step of the method for manufacturing a metal core substrate of the present invention. 8 4: Outer layer copper foil 5; Through hole Fig. 5a Fig. 5b Heating roller paper C spontaneous 1. Case Indication Requested Question No. 2-36657 No. 2, Name of the invention Metal core substrate and its manufacturing method 3, Person making the amendment (601) Mitsubishi Electric Corporation Representative Mamoru Shiki 4, Generation 25e Figure: Release film 5, Target of amendment (1) "Detailed Description of the Invention" column of the specification (2) Drawing 6, contents of amendment <1) Amend "1-" in line 6 on page 9 of the specification to "5 soku" . (2) "10-201jIn" on page 11, lines 14-15
is corrected to r6-15+mJ. (3) In the second line of page 18, "Outer layer copper foil (4), etc." is corrected to "Outer layer copper foil (4)." (4) "Adjustment" in lines 7-8 on page 24 is corrected to "preparation." (5) Figures 5C, 5d, and 5e of the drawings are corrected as shown in the attached sheet (no changes are made to the drawings except for Figure 5c). 7. List of attached documents (1) Amended drawings (Figures 5C, 5d, and 5e)
Figure 8: Release film

Claims (2)

[Claims] (1) After chemical etching, sulfuric acid chromic acid treatment or A board manufactured from an embedded aluminum plate with through-holes treated with phosphate alumite and a copper foil outer layer or a single-sided copper-clad board for the outer layer are laminated and molded using adhesive insulating prepreg, and through-holes are formed. metal core board. (2) (a) A step of applying a resin composition prepared by mixing an epoxy resin, a phenol resin, and silica particles to a release film using an applicator; , a step of placing an aluminum plate having through holes, further covering it with a release film, and embedding the aluminum plate in the resin composition using a heating roller; (c) an aluminum plate embedded in the resin composition; (d) removing the mold release film, and forming the obtained substrate and an outer layer copper foil or a single-sided copper clad substrate for the outer layer, which will become part of the conductor layer on the front and back sides of the substrate; and (e) forming a through hole with a smaller diameter than the through hole in the center of the through hole, and aligning the through hole with the inner surface of the through hole and the outer layer of copper foil or the outer layer. A method for manufacturing a metal core board, which consists of the steps of plating the surface of a single-sided copper-clad board to form a conductor layer, connecting the front and back conductors, and then etching the conductor layer to form a conductor circuit.