JPH0793502B2 - Method for manufacturing multilayer laminate - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a method for manufacturing a multi-layer laminate using a metal plate as a substrate.

[Prior art]

In supercomputers and the like, which are required to process large amounts of information at higher speeds, the amount of heat generated on a printed wiring board is greatly increasing with the mounting of electronic components and the densification of wiring. Therefore, in order to improve the reliability of the device, a printed wiring board with excellent heat dissipation is required. For this reason, the multilayer laminated board used as a printed wiring board uses a metal plate as a substrate. −37
It is provided in Japanese Patent Publication No. 720 and Japanese Patent Publication No. 1-29078. In these multi-layer laminated plates, excellent heat dissipation can be obtained due to the high heat conductivity of the metal plate. The multi-layer laminated plate using this metal plate as a substrate is manufactured using a metal plate provided with through holes. That is, as shown in FIG. 4A, a through hole 3 having a diameter larger than the diameter of the through hole 5 is provided in the metal plate 4 at a position where the through hole 5 is to be formed. By laminating through 1 and heating and pressurizing to perform laminating molding, the resin impregnated in the prepreg 1 is cured as shown in FIG.
And the resin impregnated in the prepreg 1 is made to flow into and fill each through hole 3 of the metal plate 4 and hardened. At this time, the inner layer circuit board is laminated between the metal plates 4 and a metal foil such as a copper foil is laminated on the outermost layer, if necessary. Next, the through hole 5 is perforated in the portion of the resin 21 filled in the through hole 3 as shown in FIG. 4 (c), and the inner periphery of the through hole 5 is plated with the through hole to form a fourth hole. As shown in FIG. 3D, the resin 21 may be used to form the through-hole plating layer 6 that ensures insulation with the metal plate 4.

[Problems to be Solved by the Invention]

However, in this structure, the prepreg 1 is not formed in the inner peripheral surface of the through hole 5 where the portion of the prepreg 1 is perforated.
Although the base material is exposed and has an uneven surface, the resin 21 is filled in the through hole 3 of the metal plate 4 from the prepreg 1 only at the portion where the through hole 3 is punched. 21 is an exposed smooth surface, and the through-hole plating layer 6
4 is inferior, the through hole plating layer 6 is peeled from the inner periphery of the through hole 5 at the position of the through hole 3 as shown in FIG. There was a problem of fear. In addition, the resin that flows into and fills the through hole 3 from the prepreg 1.
Since the coefficient of thermal expansion of 21 and the metal plate 4 are greatly different,
At the time of cooling after molding, the resin 21 shrinks more than the metal plate 4 and internal stress is generated in the resin 21, and cracks 23 occur in the resin 21 in the through holes 3 as shown in FIG. 4 (d). However, there is a problem in that the plating solution may enter from the crack 23, resulting in poor insulation. In particular, when processing information at high speed, a large amount of electric power is required, and when the amount of electric power is increased, heat generation increases, so that high heat dissipation characteristics are required, and power is supplied using the metal plate 4 as a conductor. In this regard, when such a large capacity power is supplied, the thicker the metal plate 4 is, the smaller the power loss is. Therefore, it is necessary to use a metal plate 4 having a thickness of 0.15 mm or more, and a metal plate having a thickness of about 0.2 to 3 mm is preferable for practical use. However, at this time, the metal plate 4
Since the thickness of the resin 21 filled in the through hole 3 also becomes large, the above-mentioned peeling of the through hole plating layer 6 from the inner periphery of the through hole 5 at the through hole 3 and the through hole There was a possibility that the above-mentioned cracks would be significantly generated in the resin 21 filled in the No. 3 resin. The present invention has been made in view of the above points, it is possible to reduce the peeling of the through-hole plating provided on the inner periphery of the through-hole, and reduce the occurrence of cracks in the resin filled in the through-hole. It is an object of the present invention to provide a method for producing a multi-layer laminated plate, which is capable of reducing the thickness of the metal plate even when the metal plate is thick.

[Means for Solving the Problems]

The method for producing a multilayer laminate according to the present invention is
A needle-shaped needle that does not melt by heat and pressure and has electrical insulation.
Rui or non-woven fabric made of thermosetting resin mixed with almost spherical filler
Prepreg 1 prepared by impregnating the
A needle-shaped needle that does not melt by heat and pressure and has electrical insulation.
A resin filled with resin 2 containing a spherical filler
Alternately stack multiple metal plates 4 with holes 3
Well, after this is laminated and integrated, the required through hole 3
A through hole 5 is punched in the resin 2 portion inside.
When manufacturing a multilayer laminate by
A copper plate having a roughened surface is used as the plate 4, and
At least one of the plurality of metal plates 4 is for power supply
Thickness of 0.5 to 3 mm to form the conductor
The present invention will be described in detail below.
It As the metal plate 4, a copper plate having excellent thermal conductivity and electrical insulation
Can be used, but the metal plate 4 is shown in FIG.
As shown in Fig.
The hole 3 is formed by drilling or punching.
This through hole 3 has a diameter larger than that of the through hole 5.
It is what is formed. Generally, the surface of a copper plate is in a state of a smooth mirror surface.
If the surface is smooth, the adhesion of the prepreg 1 to the resin
Becomes insufficient, and when drilling through holes and soldering
Between the copper plate and the resin of prepreg 1 when heating with
Interfacial peeling is likely to occur. Because of this, the surface of the copper plate
It is preferable to form a surface to increase the adhesion with the resin.
It is better to oxidize or electrolytically plate the surface of the copper plate
The surface can be roughened by applying. Oxidation treatment of copper plate is performed with an alkaline aqueous solution containing an oxidizing agent.
It is done by treating the plate,
Examples of the agent include sodium chlorite (NaClO ₂ )Such
Chlorates and potassium persulfate (K ₂ S ₂ O ₈ ) Is mainly
Used. Then, with an alkaline aqueous solution containing an oxidizing agent
When a copper plate is treated, first of all, by the action of alkali, Cu → Cu (OH) _Two Reaction of (I) occurs, and Cu (OH) _Two → CuO + H ₂ O (II) reaction occurs and a copper oxide film is formed on the surface of the copper plate.
It Specifically, it is thought that the following reactions are occurring.
It 2Cu + NaClO ₂ 2H ₂ O → 2Cu (OH) _Two ＋ NaCl Cu （OH） _Two → CuO + H ₂ O (III) In this way, a copper oxide film is formed on the surface of the copper plate.
By which the surface of the copper plate can be roughened
However, oxidation produces only cupric oxide (CuO).
The coating appears black when being treated, and the treatment at this time
Is called blackening treatment (or black oxide treatment)
In addition to cupric oxide (CuO), cuprous oxide (C
u ₂ O) is also included, the film turns brown and
Brown processing (or brown oxide processing)
It is called. Observed by 20,000 times electron micrograph
Then, the surface of the blackened copper plate is a long needle-shaped oxide.
It has a crystal structure, and is made of brown-treated copper plate.
The surface has a fine-grained crystal structure. Where blackened
This is because the needle-shaped crystals produced by the treatment are likely to collapse due to the high temperature.
There is no particular problem with epoxy multilayer boards, but polyimide multilayer boards
It is necessary to apply high temperature in the laminating process like
In some cases, the surface of the copper plate will be treated with brown.
Preferably. Blackening treatment and Browning treatment are used as oxidizing agents in alkaline solutions.
Therefore, it is essential to oxidize the surface of the copper plate.
Are the same, processing concentration, processing temperature, processing time
The only difference is the processing conditions. Generally processing conditions
If the (especially temperature) is gentle, the brown processing is performed. acid
As an alkaline aqueous solution for chlorination treatment, sodium chlorite is used.
Umm (NaClO ₂ ) And sodium hydroxide (NaOH), sodium phosphate
Thorium (Na ₃ PO _Four ) Is most commonly used
However, when blackening, the density is within the following range.
Is preferable, the liquid temperature is set to 60 to 95 ° C, and the treatment time is
It is preferable to set it for about 2 to 5 minutes. Sodium chlorite 30-90g / Sodium hydroxide 10-20g / Sodium phosphate 5-15g / In the case of browning, the concentration should be within the following range.
The liquid temperature is preferably set to 40 to 80 ° C and the treatment time is 2
It is preferable to set it for about 10 minutes. Sodium chlorite 30-150g / Sodium hydroxide 5-20g / Sodium phosphate 2-10g / As an alkaline aqueous solution for brown treatment, this chlorite
Of sodium phosphate, sodium hydroxide and sodium phosphate
In addition to the three-component system, for example, the following composition
It can also be used. Sodium chlorite 175 g / Sodium hydroxide 20 g / Sodium carbonate 16.5 g / Sodium phosphate 4.7 g / (Liquid temperature 65 ° C, processing time 4 minutes) Sodium chlorite 135 g / Sodium hydroxide 15.6 g / Sodium nitrate 11.8g / (liquid temperature 75 ℃, treatment time 5 minutes) Generally, blackened oxide film is not halo resistant.
Inferior in properties, but the brown oxide film is halo resistant
It has excellent longevity. Here, metallic copper has a chemical affinity of hydrogen.
Lower, do not make hydroxides or metal salts directly
However, in the state of cupric oxide, it reacts with hydrochloric acid and sulfuric acid to form metal.
Make salt and dissolve. So for example through-hole plating
Through holes for hydrochloric acid and sulfuric acid in the plating solution during processing
Cupric oxide in the oxide film exposed on the inner surface of
Acid penetrates from the inner circumference of the through hole at this melting point.
Dissolution erosion occurs. This dissolved and eroded part is halo
This phenomenon is called haloing because it looks white like
U When such haloing occurs, the through hole
The electrical insulation between the inner circumference and the copper plate cannot be ensured, and the through hole
Le reliability will be reduced. And such a halo
In order to prevent
Oxidation treatment, and then reduction treatment to dissolve in acid
Cuprous oxide that is difficult to dissolve and is difficult to dissolve in cupric oxide
Further, it may be reduced to metallic copper. As a reducing agent
Formalin, hypophosphite compounds, hydrazine compounds
Substance, sodium borohydride, borazane compound, boraze
Compounds, amine borane compounds, and metallic zinc
It is possible to use nascent hydrogen such as
It Further, the electrolytic plating treatment of the copper plate is performed, for example, in Japanese Patent Publication No.
Can be carried out according to the method disclosed in the publication.
The copper plate is used as a cathode by using an acidic copper electrolytic bath.
By energizing, powdery copper is deposited on the surface of the copper plate.
A rough surface can be formed on the surface of the copper plate. The electrolytic bath
Formed with a composition consisting mainly of copper sulfate and sulfuric acid, but in powder form
To deposit copper on the surface of a copper plate, the limiting current of the electrolytic bath
It is necessary to energize at a current density higher than the density, and
Powdered copper does not adhere to the copper plate because hydrogen is precipitated, and it is powdered
The surface of the copper plate cannot be roughened with copper. For this reason
In addition, the electrolytic bath should contain sodium nitrate, potassium nitrate, and
Add water-soluble nitrates such as ammonium acidate, copper nitrate, and nitric acid.
Add and use. When nitrate is added, nitrate ion
The hydrogen that is deposited on the cathode due to the reduction to the nitrogen ion
It was taken away and hydrogen bubbles were formed on the copper plate of the cathode.
And has strong adhesion to the surface of the copper plate.
The powdery copper can be deposited. like this
When roughening by bumping with electrolytic plating on the
The surface condition may be affected by high temperature.
Since it does not exist, the rough surface due to the above-mentioned oxidation treatment will collapse.
It is effective when it is necessary to apply high temperature.
The plating metal deposited on the surface of the copper plate is not particularly limited.
Although not specified, copper is the most practical. Further, the thickness of the metal plate 4 is set to 0.5 to 3 mm. Metal plate
When supplying a large amount of power with 4 as a conductor,
In order to obtain a good thickness, the thickness of the metal plate 4 should be 0.5 mm or less.
It is necessary to use the above. On the other hand, the metal plates 4 formed as described above are laminated in multiple layers.
The prepreg 1 used for the purpose is made of a thermosetting resin as a base material.
Also prepared by impregnating varnish and drying
However, a nonwoven fabric is used as the substrate in the present invention. Basis
It is common to use woven cloth such as glass woven cloth as the material.
However, woven fabric is a bundle of fibers woven as warp and weft.
Since the structure is dense, the resin to be impregnated is sufficient.
It is difficult to have a large amount. Here, as described below
Thermosetting resin with which the prepreg 1 was impregnated during lamination molding
Part of the resin flows into the through hole 3 of the metal plate 4, and the resin flows
Although the base material of the prepreg 1 is pulled toward the through hole 3 side,
If a glass woven fabric is used for the
To the side of the through hole 3 because it cannot be held in a sufficient amount
The pulled base material is attached to the metal plate 4 at the peripheral corner of the through hole 3.
The metal plate 4 between the base material and the metal plate 4 at this contact point.
Almost no fat is present, and heating or mechanical force acts
With this part, whitening called measling occurs.
It has For this reason, in the present invention, a nonwoven fabric is used as the substrate.
Prepreg 1 is prepared by using
Even if the electrical characteristics and heat resistance characteristics are taken into consideration,
It is preferable to use a non-woven fabric. Non-woven fabric is made from fibers, etc.
The tissue is sparse because it is formed by
The resin to be soaked can be retained in sufficient quantity. Gala
Compared with non-woven fabric and glass woven fabric,
Preg 1 can be impregnated with woven glass base material
Small amount of resin, resin content is about 50-60% by weight
However, the amount of resin that can be impregnated for glass based non-woven fabrics
Can be increased, and the resin content is 90% by weight or more
Is something that can be done. Use non-woven fabric as the base material
Increase the amount of resin impregnated in the prepreg 1 like
And a through hole from the prepreg 1 to the metal plate 4 when laminating
Even if the resin flows to 3 and the base material is pulled, it is sufficient for the base material.
Since a large amount of resin is stored, the base material and the metal plate 4
This resin is interposed between the base material and the through hole 3 of the metal plate 4.
To reduce the possibility of direct contact with the peripheral corners of the
As a result, the occurrence of measling is suppressed.
It was possible to get it. Also, since the woven cloth is a woven bundle of fibers, the resin is
It does not easily penetrate into the bundle of fibers, and the resin and fibers in this part
In many cases, the adhesiveness with
If a woven fabric is used as the base material, the
The interface between the fiber and the resin due to external stress during hole drilling
When peeling and applying through-hole plating, the plating solution
It may penetrate from the interface and cause plating penetration.
It On the other hand, in non-woven fabric, fibers are not bundled
Therefore, the penetration of resin is good and the adhesion between fiber and resin is sufficient.
Yes, it is strong against external stress and the interface peeling between fiber and resin does not occur.
Since it does not easily occur, the occurrence of such plating penetration is reduced.
Can be reduced. However, there are other
There is a possibility that plating penetration may be invented due to reasons
Has been pointed out. That is, the manufacture of nonwoven fabrics, especially glass nonwoven fabrics, has been
It is carried out as follows. First, the glass fiber
Mix with a coupling agent, surfactant, etc.
From the wire mesh belt to dehydrate the water
Glass fibers are accumulated to form a mat, and then this glass is
Prepared by mixing the binder with the solvent on the mat of fiber
Sprayed the binder solution, and then heat dry it.
Glass fibers were assembled with a binder by
It is possible to obtain a glass nonwoven fabric. Glass nonwoven
The cloth is made by gathering glass fibers with a binder in this way.
The surface of the glass fiber is
Is attached, and this glass non-woven fabric is used as the base material.
When prepreg 1 is prepared by impregnating it with resin,
A binder is interposed between the fiber and the resin to be impregnated
Therefore, the resin should not be directly adhered to the surface of the glass fiber.
Part of the glass fiber due to the coupling agent.
There is a portion where the resin cannot be chemically bonded to the surface.
There is a risk of twisting. Especially as described above
In the method of spraying the binder on the
Is attached to the surface of the glass non-woven fabric and forms a film.
It becomes a state, and such a problem at the surface layer part of the glass nonwoven fabric
It tends to occur. And like this with a binder
If the adhesion between the glass fiber surface and the resin deteriorates,
Interfacial peeling occurs in the part and plating penetration occurs
It will be. In order to prevent such problems, in the present invention, glass is used.
As the non-woven fabric 10, glass fibers 7 are accumulated as shown in FIG.
The mat 8 thus prepared is immersed in the binder solution 9 to form the mat 8
After impregnating the binder solution 9 therein, it is dried
It is preferable to use the one produced by You
That is, the glass fiber 7 is a short fiber obtained by cutting roving.
A fibrous material is used, for example, a diameter of 10 to 13
μ, length of several mm to tens of mm (10 to 20 mm is particularly preferable)
I) can be used. This glass fiber 7
After mixing with water, coupling agent, surfactant, etc.,
Of glass fiber 7 from tank 14 onto wire mesh belt 15
The wire mesh glass 15 to reduce the thickness from the inside.
Dehydration by removing water 16 by pressure etc.
A mat 8 in which the fibers 7 are accumulated is created. And this
The mat 8 is introduced into the dipping tank 18 together with the wire mesh belt 15 and
And soak it in a solder solution 9. Binder solution 9 is
Necessary with binders such as ril resin and epoxy resin
Solvent with silane coupling agent etc.
It is prepared by dissolving in. Methyl as a solvent
Ruethyl ketone, methyl cellosolve, toluene, alco
Although a binder or the like can be used,
Concentration is the amount of binder to be included in the glass non-woven fabric 10, etc.
It is arbitrarily set according to. Glass fiber as above
The mat 8 of the fiber 7 is dipped in the binder solution 9 to
After permeating the binder solution 9 into the
Drive the mat 15 to move the mat 8 between the upper and lower heaters 17,
And heat dry to evaporate the solvent of binder solution 9.
As a result, the glass fibers 7 are aggregated and bound by the binder.
Combined glass nonwoven fabric (also called glass paper)
You can get 10. This glass nonwoven 10
Is 40-100g / m ² It is preferable to make it to a moderate weight. In this way, the binder solution 9 is added to the mat 8 of the glass fibers 7.
By immersing the
The binder evenly over the entire glass non-woven fabric 10.
It can be made, but it is further created in this way
Of the glass non-woven fabric 10 contained in the glass non-woven fabric 10.
The solid content of the inder is glass fiber and binder
And the binder content of 15% by weight or less of the total amount of
It is preferable to adjust the impregnation amount of the liquid 9. Glass nonwoven fabric 10
When making prepreg 1 using
The normal state is through the coupling agent on the surface of the glass fiber 7.
The resin impregnated with the
Woven fabric 10 necessarily contains a binder, which
The inder is interposed between the glass fiber 7 and the impregnated resin.
Adhesion of the glass non-woven fabric 10 and the impregnated resin
As described above, the property is deteriorated.
As a result of tests conducted by the workers, the content of the binder is 15% by weight (
And preferably 12% by weight or less)
The adhesion between the cloth 10 and the impregnated resin is not soaked by plating.
It turned out that it wasn't bad until it happened. And
In this way, keep the binder content below 15% by weight.
Also, the binder solution 9 is spread on the mat 8 as in the conventional method.
When playing, binder on the surface of the glass nonwoven fabric 10
This binder adheres a lot because of the large amount of
Adhesion to the resin deteriorates at the part and plating penetration occurs
It may occur. For this purpose, as shown in FIG.
The mat 8 of the glass fiber 7 is dipped in the solution 9
Binder impregnation method (Vine
By the Dardip method), the entire glass non-woven fabric 10
The binder should be applied evenly
Yes. The upper limit of the binder content of the glass nonwoven fabric 10 is
It is preferable to set it to 15% by weight as described above.
The lower the content, the denser the glass nonwoven fabric 10 and the impregnated resin.
It can improve the adhesion, but the binder content is
When it becomes lower, the aggregate strength of the glass fiber 7 is lowered and the glass
Woven cloth 10 is more likely to be cut, so
The lower limit of the ratio is preferably set to about 5% by weight. The non-woven fabric prepared as above is used as the base material and heat is applied to this.
Prepare prepreg 1 by impregnating it with curable resin.
Can be manufactured, but as a thermosetting resin to be impregnated
Is an epoxy resin or polyimide resin, unsaturated polyester
The resin is not particularly limited, but in terms of electrical characteristics,
Poxy resin, polyimide resin, or modified resin of these
It is preferable to use fat. In addition, the multilayer laminated board is
Because high temperature processing is done during soldering and soldering, prepreg
This thermosetting resin for preparing 1 has a glass transition temperature
Excellent heat resistance of 170 ℃ (more preferably 180 ℃) or higher
It is preferable to use the one. For preparing prepreg 1
The glass transition temperature of the thermosetting resin used is 150 ° C.
The following is common, but in this case 260
When soldering is performed for 30 seconds in a solder bath at ℃, the thermal shock
Such as peeling off the plating tank applied to the through hole
In the present invention, the glass transition
It is preferable to use a material with a temperature of 170 ° C or higher and excellent heat resistance.
It's better. Also, when preparing prepreg 1,
The prepreg 1 resin has a semi-cured state with a melt viscosity at 130 ° C of 7
0 to 200 poise (more preferably 100 to 1000 poise)
It is preferable to adjust so that. Melt viscosity is not 70 poise
If it is full, resin will flow too much during lamination molding
It is preferable that the variation of the plate thickness becomes large within the plate
No, and if it exceeds 2000 poise, the resin flow is poor.
And voids tend to remain in the laminated plate after molding.
Not preferable. The semi-cured state is the so-called B
It means a state called tage
When pressure is applied, the resin melts and cures further,
Moreover, it means something that is not sticky to the touch. Then, the metal plate provided with the through holes 3 as shown in FIG.
When manufacturing a multilayer laminated board using 4 as a substrate
First, the resin 2 is filled in each through hole 3 of the metal plate 4. This
Although the resin 2 is not particularly limited,
Epoxy resin of the same type as the resin used to prepare prepreg 1
, Polyimide resin, and these modified resins in a semi-cured state
It is preferably used. This resin 2 filling the through holes 3 is filled with
It is used by blending a filler. With this filler
For Al ₂ O ₃ , Al ₂ O ₃ ・ H ₂ O, Al ₂ O ₃ ・ 3H ₂ O, silica, tar
C, MgO, CaCO ₃ , Sb ₂ O ₃ , Sb ₂ O _Five , E glass and D glass,
Spherical powders such as T glass, R glass, and Q glass, and E gas
Lath, D glass, T glass, R glass, Q glass, etc.
Glass fiber, Kevlar (made by DuPont), Technora
Finely cut aramid fiber (made by Teijin) etc.
It is possible to exemplify crushed acicular powder.
As described above, melting by the action of heat and pressure during lamination molding
Do not use a material that does not come off and has electrical insulation.
It is what is done. These are used alone or in combination of two or more.
It can also be used in combination. If spherical powder is used as the filler,
It is preferably 15 μm or more. With a center diameter of less than 15 μm
Is an effect of preventing the occurrence of cracks in the resin 2 in the through holes 3 described later.
The result is small, and the through-hole plating layer 6 described later adheres well.
The effect is not sufficient. On the other hand, using needle-shaped powder as a filler
When used with a center diameter of 10 μm or more and a straight length
The diameter is preferably twice the diameter or more. Central diameter less than 10 μm
If the length is less than twice the diameter, it is effective in preventing cracks.
The result is small and the adhesion effect of through-hole plating layer 6 is sufficient.
Can't get to. The central diameter is the diameter of the filler particles.
Means the peak value of the distribution of, that is, the diameter with the largest number of particles
To do. Filler is added to resin 2 in a compounding amount in the range of 10 to 1000 PHR.
To prevent cracks and through hole
It is possible to obtain the effect of improving the adhesion of the layer 6, but the filler
Coefficient of thermal expansion of resin 2 (coefficient of thermal expansion after resin is cured)
However, the difference from the coefficient of thermal expansion of the metal plate 4 is less than 20ppm / ℃
Sea urchin, that is, the coefficient of thermal expansion of the resin 2 with filler is α _R ,Money
The coefficient of thermal expansion of the metal plate 4 is α _M Then α _M −20ppm / ℃ ≦ α _R ≤ α _M Of the filler mixed in the resin 2 with filler so that it becomes +20 ppm / ° C.
It is preferable to set and set the type and amount of the compound. The filling of the resin 2 containing the filler into the through holes 3 of the metal plate 4
Prepare resin 2 with agent in liquid form such as varnish and pour it
Or prepare it in powder form and pour it in.
However, in terms of workability, it should be prepared in powder form and then flowed.
It is preferable that it is soaked. Prepare in powder form and sink
In case of filling, resin 2 into powder with central particle size of 100-350μm
It is preferable to use it. Resin 2 was crushed to this particle size
It may be mixed with the filler afterwards, but
2 and the filler are mixed in a varnish state and heated.
After removing the solvent and making it semi-cured,
Powder of resin 2 containing filler by crushing
It is preferably used as a powder. Center of resin 2
If the particle size is less than 100 μm, the re-aggregation property increases and the particles become lumpy.
And the filling property into the through hole 3 may decrease, and
On the contrary, when the center particle size of the resin 2 is 350 μm, the particles are too large to pass through.
It becomes impossible to densely fill the holes 3 and the filling property deteriorates.
There is a risk. In the present invention, the central particle size means the resin
The peak value of the particle size distribution of 2 particles, that is, the number of particles is the most
Means more particle size. Resin 2 with filler in powder form
When filling the through holes 3 of the metal plate 4, as shown in FIG.
Place the metal plate 4 on the prepreg 1 as shown in (b).
The lower opening of the through hole 3 is blocked, and the through hole 3 is often
Pour resin 2 with filler and squeegee 19 into metal plate
By rubbing the top of 4 to remove the excess
The resin 2 containing the filler is evenly filled in each through hole 3.
You can Next, the metal plate 4 having the through holes 3 filled with the resin 2 as described above
And prepreg 1 are laminated alternately to form a multi-layer laminate A
In doing so, the metal plate 4 and the metal plate 4 having the layer structure shown in FIG.
Put several pieces of prepreg 1 on top of each other and, if necessary,
On the outer surface of the outer layer prepreg 1, overlay a metal foil 12 such as copper foil.
Prepreg 1 between each metal plate 4 if necessary.
Single-sided printed wiring board or double-sided printed wiring board, through
Inner layer circuit formed with inner layer circuit such as layer printed wiring board
Stack the boards 11. Then, heat and pressure are applied to perform laminated molding.
To cure the resin impregnated in the prepreg 1.
2 and each metal plate 4 and the inner circuit board 11 are laminated and adhered, and FIG.
Alternating metal plate 4 and inner layer circuit board 11 in the layer structure shown in (b)
Is a multi-layer in which metal foil 12 is laminated and adhered to the outermost layer
The laminated board A can be obtained. Laminated in this way
At this time, the resin 2 filled in the through holes 3 of the metal plate 4 is also cured.
In addition, the metal plate 4 is made of resin in advance in this way.
When the resin 2 melts and hardens because it is filled with 2
The voids between the resin 2 powders are filled and the volume in the through holes 3 is
Some amount of resin is pre-prepared to replenish the depletion.
It is about to flow into the through hole 3 from the group 1
As in the example, all of the holes 3 are contained in the prepreg 1.
There is no need to fill with thermosetting resin. Conventional in Figure 4
In the example, all of the inside of the through hole 3 is contained in the prepreg 1 in this way.
The resin corresponding to the through hole 3
The outermost prepreg 1 is shown by a chain line in FIG. 4 (b).
There is a possibility that the hollow 20 may occur, but in the present invention,
As a result, a large amount of resin flows from the prepreg 1 into the through hole 3.
There is no danger of such a depression due to
Yes. Moreover, as described above, the coefficient of thermal expansion of the metal plate 4 and the through hole 3
The difference in the coefficient of thermal expansion of the resin 2 with filler filled in
If it is set to be smaller than ppm / ℃
The difference in the degree of shrinkage between the metal plate 4 and the resin 2
It can be made small, and due to the difference in the coefficient of thermal expansion, the through holes 3
Minimize the occurrence of dents in the resin 2 part of
be able to. Coefficient of thermal expansion of metal plate 4 and resin 2 with filler
If the difference in coefficient of thermal expansion between the
This is not preferable in practice because the depression becomes large. like this
In addition, in the present invention, the surface depression is small and
Multilayer product because it can be formed on a relatively flat surface
The metal foil 12 on the surface of the layer A is etched to form a circuit.
In doing so, there is a problem in applying the etching resist.
It is something that can be prevented. In addition, filling by adding a filler as described above
Since it is possible to suppress the shrinkage of the agent-containing resin 2 during cooling
The resin 2 containing the filler filled in the through holes 3 of the metal plate 4
The difference between the shrinkage during cooling after shaping and the shrinkage of the metal plate 4 is reduced.
Therefore, the conventional example of FIG.
As a result, the internal stress of the resin 2 based on this difference in contraction causes the through hole 3
That cracks occur in the filled resin 2 inside
It can be reduced. The occurrence of this crack
As described above, the coefficient of thermal expansion of the metal plate 4 can be reduced.
And the coefficient of thermal expansion of the filled resin 2 filled in the through holes 3
It is preferable to set a small difference of 20 ppm / ° C. or less.
Further, the filler compounded in the resin 2 acts as a reinforcing material.
This also prevents the occurrence of this crack. this
As described above, when acting as a reinforcing material,
When using spherical powder as a filler, the center diameter is 15
It is preferable that the particle size is at least μm, and needle-like powder is used as the filler.
When used as a center, the center diameter is 10 μm or more and the length is the diameter.
2 times or more is preferable. Here, the filling that is filled in the through holes 3 of the metal plate 4 as described above.
The prepreg 1 is the amount that resin 2 containing material loses its appearance during molding.
It will be replenished with resin flowing from the inside to the through hole 3,
As a result of the resin being replenished from the prepreg 1 as described above,
When the ratio of the filler in the holes 3 becomes small, the filling as described above is performed.
The effect of preventing the crack of the resin 2 in the through hole 3 by the filler
There is a possibility that you can not expect it, and from prepreg 1
Filler content is low in the area where the resin is replenished
In the through hole 3, there can be a portion with a large amount of filler and a portion with a small amount of filler
Then, a difference in the coefficient of thermal expansion locally occurs, causing a crack at this point.
A rack may occur. For this reason in the present invention
Is also a filler in the thermosetting resin for preparing the prepreg 1.
I try to mix them. As the filler, a filler to be mixed with the resin 2 is used.
It is possible to use the spherical powders and needle powders listed above.
Wear. Of course, the filler may be used alone or in combination with multiple types.
It is also possible to use a combination of items. As a filler
When using spherical powders, those with a center diameter of 20 μm or less
Is preferred. When using acicular powder as a filler
Has a center diameter of 15 μm or less and a length of less than twice the diameter.
Those are preferable. A sphere with a central diameter exceeding 20 μm
-Shaped fillers, with a central diameter of over 15 μm and a length of diameter
Needle-shaped fillers that are more than double the size can
When the molten resin of leg 1 flows, it flows along with the flow.
It becomes difficult to insert resin from the prepreg 1 into the through hole 3.
Filler into the through hole 3 when flowing in and replenishing
Movement is insufficient and the filler cannot be replenished sufficiently.
It has To prepare thermosetting resin to prepare prepreg 1
It is preferable to set the compounding amount of the filler in the range of 30 to 150 PHR.
Good If the compounding amount of the filler is less than 30 PHR,
Insufficient amount to obtain sufficient effect of filler composition
I can't. Also, if the compounding amount of the filler exceeds 150 PHR,
As the viscosity of the thermosetting resin varnish increases,
Difficult to impregnate non-woven fabric with thermosetting resin varnish
It may be difficult to make the prepreg 1.
It In addition, a thermosetting resin crocodile containing such a filler is also used.
For preparing prepreg 1 by impregnating the base material with
The woven cloth has a dense structure, so that the filler is introduced inside.
It is difficult to apply, and when woven fabric is used as the substrate, heat
Even if the curable resin varnish is mixed with a specified amount of filler
The prepreg cannot contain the specified filler.
There is a possibility that On the other hand, as a base material like the present invention,
If a non-woven fabric is used as the
For this reason, a large amount of filler can be introduced inside.
It is possible to prepare prepreg 1 containing the filler of
It will be. Then, prepare with a thermosetting resin that contains a filler in this way.
By using the prepreg 1 made,
Replenish the through hole 3 of the metal plate 4 with the thermosetting resin of the prepreg 1.
The filler can be replenished at the same time
To prevent the ratio of the filler in the through hole 3 from decreasing.
In addition to being able to
It is possible to prevent the formation of the
It is possible to prevent a difference in the coefficient of thermal expansion from occurring locally and
The occurrence can be suppressed. In addition,
For the thermosetting resin in the ring 1 and the resin 2 filled in the through holes 3,
Since both are filled with filler, the coefficient of thermal expansion of both
Can be close to the prepreg
Between the thermosetting resin No. 1 and the resin 2 in the through hole 3, an interlayer clath
Can be prevented from occurring. As described above, the multilayer laminated plate A as shown in FIG.
After creating, perform drilling etc.
The through hole 5 is drilled. Through hole 5 is shown in Fig. 2.
As shown in (c), the resin 2 filled in the through hole 3
Formed with a diameter smaller than the diameter of the through hole 3
Between the inner periphery of the through hole 5 and the metal plate 4.
The resin 2 layer is interposed between the
Will be secured by 2. In addition, in FIG. 2 (c)
In the example, let's make a through hole 5 through some metal plate 4.
The power supply from this metal plate 4
It is designed so that you can take a break. And
After processing the through hole 5 in this way,
Through hole plating such as copper plating is applied to the inner circumference of the base 5.
To form the through-hole plating layer 6 and the metal foil 12
By forming a circuit by etching, etc.
Of the inner layer circuit board 11 using the metal plate 4 as a substrate.
The outer layer circuit formed by processing the layer circuit and the metal foil 12 respectively.
It can also be finished on a printed wiring board provided
Of. In this thing, filling the through hole 3 of the metal plate 4
Since the resin 2 used contains a filler,
When the through hole 5 is drilled in the oil 2 part,
The filler is exposed on the inner periphery of the through hole 5 and the through hole 5
The inner peripheral surface of this is formed as an uneven surface by this filler
It will be. Therefore, the inner peripheral surface of the through hole 5 is a resin surface.
However, due to the uneven anchor effect of the filler,
The adhesion of the through-hole plating layer 6 can be improved.
The through hole plating layer 6 is a through hole.
It is possible to reduce the peeling from the inner circumference of the rule 5.
It can be done. Through holes due to unevenness of the filler
Filling to be mixed with the resin 2 in order to improve the adhesion of the kick layer 6
In the case of spherical fillers, the central straight line is 15 μm or less.
In the case of needle-shaped fillers, the center diameter is 10 μm or more and the length is
It is preferable that the diameter is at least twice the diameter.

【Example】

The present invention will be specifically described below with reference to examples. [1] Metal plate <Surface treatment No. 1 of metal plate-Oxidation treatment (blackening treatment)-> Using a copper plate of 500 mm × 400 mm × 0.5 mm, through holes with a diameter of 1.5 mm are arranged at a pitch of 1.8 mm, length 100 × width 60 The number of Then, this copper plate was first pretreated. The pretreatment is cupric chloride (CuCl ₂
・ 2H ₂ O) (2.4 kg) and industrial hydrochloric acid (35%) 18 were mixed in 42 water, soaked in a copper chloride solution at 25 ° C for 25 seconds and then washed with water, and then industrial hydrochloric acid 70 was added to 155 It was performed by immersing in a hydrochloric acid solution prepared by mixing it with water for 60 seconds and then washing with water. Next, sodium chlorite 31
g /, sodium hydroxide 15g /, sodium phosphate 12g /
The copper plate was blackened by immersing the copper plate in the blackening treatment liquid of 95 ° C. prepared with the above composition for 2 minutes. Thereafter, the copper plate was further washed with water and dried at 120 ° C. for 60 minutes. The surface of the copper plate after this blackening treatment was black. This copper plate is referred to as the level No. 1 of the "metal plate" item in Table 1. <Metal plate surface treatment No. 2-Oxidation treatment (Brown treatment)-
> A copper plate formed in the same manner as that used in No. 1 above was pretreated. The pretreatment is to first electroclean the copper plate with an electro bright # 402-L alkaline cleaner (Ebara Densan Co., Ltd.) for 4 minutes at a liquid temperature of 70 ° C, then wash it with water, and then electro bright. 2.5 minutes using Asido Cleaner # 4A (manufactured by Ebara Densan Co., Ltd.), liquid temperature 6
After acid cleaning under conditions of 7 ° C, washing with water, further using Electro Bright Cobra Etch (manufactured by Ebara Densan Co., Ltd.) for 1.5 minutes, soft etching of copper plate under conditions of liquid temperature 51 ° C, then washing with water, and Electro Bright # 49
9-B (manufactured by Ebara Densan Co., Ltd.) was performed for 1 minute at a liquid temperature of room temperature. Next, sodium chlorite 95g /, sodium hydroxide 6.5g
The copper plate was brown-treated by immersing the copper plate in a brown treatment liquid of 80 ° C. prepared with a composition of /, sodium phosphate 2.0 / for 2 minutes. After this, the copper plate was further washed with water and hot water and dried. The surface of the copper plate after the brown treatment was brown.
This copper plate is the No. 2 level of the item "metal plate" in Table 1.
And <Surface treatment No3 of metal plate-oxidation / reduction treatment-> As in No. 1 above, the copper plate is blackened to be oxidized, and the blackened copper plate is immersed in an aqueous solution of hypophosphorous acid adjusted to pH 5 for 20 minutes. Reduction process by
It was washed with water and dried. The copper plate thus oxidized / reduced is designated as No. 3 in the "Metal plate" item in Table 1. <Metal plate surface treatment No. _4- electrolytic plating treatment> CuSO ₄ 50g /, H ₂ SO ₄ 100g /, HNO ₃ 15g / bath temperature 2
An acidic copper electrolytic bath at 5 ° C. was prepared, a copper plate formed in the same manner as that used in No. 1 above was immersed in the electrolytic bath as a cathode, and electrolytic plating treatment was performed at a current density of 7 A / dm ² for 5 minutes. This copper plate is designated as level 4 in the "metal plate" item in Table 1. [2] Base Material <Glass Nonwoven Fabric Preparation No. 1> A novolak type epoxy resin used as a binder and an aminosilane coupling agent were dissolved in a mixed solvent of methyl ethyl ketone and toluene to prepare a binder solution. Then, using the apparatus for binder immersion method shown in FIG. 3, a mat having glass fibers having a center diameter of 13 μ and a center length (peak value of length distribution) of 15 mm was accumulated, and after the mat was immersed in the binder solution, By drying this, a glass nonwoven fabric having a binder (solid content) content of 12% by weight was obtained. The weight of this glass nonwoven fabric was 60 g / m ² . The glass nonwoven fabric obtained by this binder dip method,
It shall be the No. 1 level in the item "Substrate" in Table 1. <Glass Nonwoven Fabric Preparation No. 2> A binder dip method was used in the same manner as above except that the binder content was adjusted to 15% by weight. This glass non-woven fabric is designated as Level 2 in the item "Substrate" in Table 1. <Glass Nonwoven Fabric Preparation No. 3> A binder dip method was used in the same manner as above except that the binder content was adjusted to 18% by weight. This glass non-woven fabric is designated as No. 3 in the item "Substrate" in Table 1. <Creation of glass non-woven fabric No4> A mat of glass fibers is prepared in the same manner as No. 1 above, and the binder solution prepared in the same manner as No. 1 above is applied evenly on this mat with a spray device and then dried. Thus, a glass nonwoven fabric having a binder (solid content) content of 12% by weight was obtained. The weight of this glass nonwoven is
It was 60 g / m ² . The glass non-woven fabric obtained by this binder spray method is designated as No. 4 in the item "Substrate" in Table 1. [3] Resin <Resin Preparation No. 1> Polyfunctional epoxy resin (Quatrex 501 manufactured by Dow Chemical Co .; resin content 75% by weight, MEK 25% by weight) is added to 2-ethyl-4-methylimidazole per 100 parts by weight of the resin content. 0.2 parts by weight was blended to prepare a polyfunctional epoxy resin composition. The glass transition temperature of this resin in a cured state was 170 ° C. when measured by TMM. This resin is designated as Level 1 in the "Resin" section of Table 1. <Resin Preparation No. 2> An epoxy resin composition was prepared by blending 85 parts by weight of a bisphenol A type epoxy resin, 15 parts by weight of a phenol novolac type epoxy resin, 1 part by weight of dicyandiamide and 1 equivalent of benzyldimethyldiamine. The glass transition temperature of this resin in the cured state was 140 ° C. This resin is first
It shall be the No. 2 level of the "resin" item in the table. [4] Prepreg <Preparation of prepreg No1> In the combination shown in Table 2, No. 1 or No. 2 epoxy resin varnish was added to the “prepreg filler (spherical)” and “prepreg filler (needle-shaped) shown in Table 1. ) ”, The fillers of the levels No1 to No5 in each item were mixed and mixed uniformly. As the filler, spherical powder of E glass and acicular powder were used. Then, No. 1 to No. 5 base materials were dipped in this resin varnish to impregnate the resin varnish, and then heated at 150 ° C. for 5 minutes and dried to prepare a prepreg having a resin content of 91 wt%. Of the resin contained in this prepreg
When the melt viscosity at 130 ° C. was measured, it was 600 poise. This melt viscosity of 600 poise is designated as the level No. 1 in the "prepreg melt viscosity" item in Table 1. <Preparation No. 2 of prepreg> A prepreg was prepared in the same manner as No. 1 above, except that the drying condition was set to 150 ° C for 2 minutes. When the melt viscosity of the resin contained in this prepreg at 130 ° C. was measured, it was 4
It was 0 poise. This melt viscosity of 40 poise is designated as Level 2 in the "Prepreg melt viscosity" item in Table 1. <Preparation No. 3 of prepreg> A prepreg was prepared in the same manner as No. 1 above except that the drying condition was set to 150 ° C for 3 minutes. When the melt viscosity at 130 ° C. of the resin contained in this prepreg was measured, it was 7
It was 0 poise. This melt viscosity of 70 poise is designated as No. 3 in the "Prepreg melt viscosity" item in Table 1. <Preparation No. 4 of prepreg> A prepreg was prepared in the same manner as No. 1 above except that the drying conditions were set to 150 ° C for 7 minutes. When the melt viscosity of the resin contained in this prepreg at 130 ° C. was measured, it was 2
It was 000 poise. This melt viscosity of 2000 poise is the standard No. 4 in the "Prepreg melt viscosity" item in Table 1.
And <Preparation No. 5 of prepreg> A prepreg was prepared in the same manner as No. 1 above, except that the drying condition was set to 150 ° C for 8 minutes. When the melt viscosity at 130 ° C. of the resin contained in this prepreg was measured, it was 3
It was 000 poise. This melt viscosity of 3000 poise is the level 5 of the "prepreg melt viscosity" item in Table 1.
And [5] Filling resin <Preparation No. 1 of filling resin> With the combination shown in Table 2, the same resin varnish as used in the preparation of the above prepreg was added to No. 1 of the item "Filler for filling resin" in Table 1. The No. 4 fillers were compounded in a compounding amount of 400 PHR and mixed uniformly. As the filler, spherical powder of E glass and acicular powder were used. And this is 150 ℃
The mixture was heated for 5 minutes to remove the solvent and solidify, and this was further pulverized to prepare a powdery filling resin containing a filler. The coefficient of thermal expansion of this filled resin when cured was 24 ppm / ° C. Since the thermal expansion coefficient of the copper plate is 17 ppm / ° C, the difference from the thermal expansion coefficient of the copper plate is 7 ppm / ° C. The difference from the coefficient of thermal expansion of this copper plate is 7
Those with ppm / ° C shall be the level No1 of the item of “Difference in coefficient of thermal expansion between metal plate and filling resin” in Table 1. In addition, by adjusting the particle size of the pulverization, the resin for filling has a central particle diameter of 300 μm, 60 μm, and 1
One of 00 μm and one of 500 μm were prepared. Those with a median particle diameter of 300 μm are designated as level No. 1 in the “Fill particle size for filled trees” in Table 1, those with a central particle size of 60 μm are designated as level No 2, and those with a central particle size of 100 μm are designated as level No 3. The level No. 4 is the one with a central particle size of 500 μm. <Preparation No. 2 of Filling Resin> A powdery filling resin containing a filler was prepared in the same manner as in No. 1 above, except that the amount of the filler to be added to the resin varnish was set to 180 PHR. The coefficient of thermal expansion of the filling resin when cured was 37 ppm / ° C. Therefore, the difference from the coefficient of thermal expansion of the copper plate is 20 ppm / ° C. The difference between the coefficient of thermal expansion of this copper plate and the coefficient of thermal expansion of 20 ppm / ° C is set as the level No. 2 in the item "Difference in coefficient of thermal expansion between metal plate and filling resin" in Table 1. Further, by adjusting the particle size of the pulverization, resin having a central particle size of 300 μm, 60 μm, 100 μm, 500 μm was prepared as a filling resin. These are designated as Level No. 1, Level No. 2, Level No. 3 and Level No. 4 in the “Filling Resin Particle Size” item in Table 1. <Preparation of Filling Resin No3> A powdery filling resin containing a filler was prepared in the same manner as in No. 1 except that the compounding amount of the filler in the resin varnish was set to 120 PHR. The coefficient of thermal expansion of the filling resin when cured was 42 ppm / ° C. Therefore, the difference from the coefficient of thermal expansion of the copper plate is 25 ppm / ° C. The difference between the coefficient of thermal expansion of this copper plate and the coefficient of thermal expansion of 25 ppm / ° C shall be the level No2 of the item “Difference in coefficient of thermal expansion of metal plate and filling resin” in Table 1. Further, by adjusting the particle size of the pulverization, resin having a central particle size of 300 μm, 60 μm, 100 μm, 500 μm was prepared as a filling resin. These are designated as Level No. 1, Level No. 2, Level No. 3 and Level No. 4 in the “Filling Resin Particle Size” item in Table 1. Example 1 As the metal plate, the one having the level No. 1 of the item "metal plate" in Table 1 was used, and as the prepreg, the level No. of the item "base material" was used.
Using No. 1 of the "resin" item and No. 1 of the "filler for prepreg (spherical)" level No. 1 of the "prepreg melt viscosity" item Using the prepared one and using the level 1 of the "filler for the filling resin" item as the filled resin, the level No. of the item "Difference in thermal expansion coefficient between the metal plate and the filling resin"
The thermal expansion coefficient is adjusted as shown in 1 and the particle size is adjusted as shown in Level No. 1 of the "filling resin particle size" item. First, as shown in Fig. 1 (b), a metal plate is placed on the prepreg 1. 4 and stack each through hole 3 of the metal plate 4 with a squeegee 19.
Was filled with Resin 2 containing a filler. Then, three metal plates 4 and two double-sided printed wiring boards formed by etching a copper foil of a double-sided copper-clad epoxy resin laminated plate to form a circuit are used as the inner layer circuit board 11, and these are used as the second layer.
As shown in FIG. 1A, the prepregs 1 are alternately stacked and the uppermost layer and the lowermost layer are stacked with the prepreg 1 on the metal foil.
As the layer 12, copper foil having a thickness of 35 μm was used. Next, 20kg / c
20 minutes at 140 ℃, then 170 ℃ while maintaining the pressurization condition of m ²
By laminating and forming by heating for 90 minutes and cooling for 20 minutes, the metal plates 4 and the inner layer circuit board 11 were alternately laminated and the metal foil 12 was put on the surface of FIG. 2 (b). A multi-layer laminate as described above was obtained. FIG. 2 (c) of the multilayer laminated plate molded in this way.
As shown in FIG. 2 (d), a through hole having a diameter of 0.9 mm is drilled in the through hole 3 of the metal plate 4 in the multilayer laminated plate, and then copper plating is performed to form the through hole 5 as shown in FIG.
A through-hole plating layer 6 was applied to the inner circumference of the. Examples 2 to 31 The metal plates 4, the prepreg 1, and the filled resin 2 prepared in the combinations shown in Table 2 were used, and thereafter, a multilayer laminate was prepared in the same manner as in Example 1 above. Through holes 5 were processed and a through hole plating layer 6 was applied to this multilayer laminated plate. Comparative Example As the metal plate 4, a copper plate provided with the same through holes as above was used without surface roughening treatment. Also prepreg 1
Is a glass woven fabric of 210 g / m ² with a resin varnish (without a filler) of the multifunctional epoxy resin composition of the level No 1 of the “resin” item in Table 1 prepared in <Resin No. 1> above. It was prepared by impregnating the same with the above, heating at 150 ° C. for 5 minutes and drying. This prepreg 1 had a resin content of 55% by weight. Then, three metal plates 4, two double-sided printed wiring boards formed by etching the copper foil of the double-sided copper-clad epoxy resin laminated plate to form a circuit as the inner layer circuit board 11, and alternately through the prepreg 1 The uppermost layer and the lowermost layer are overlaid with each other by using a 35 μm-thick copper foil as the metal foil 12 through the prepreg, and then a multilayer laminated board is prepared in the same manner as in Example 1 above. The hole 5 is processed and the through hole plating layer 6 is formed.
Was applied. Regarding the multilayer laminates prepared in the above Examples 1 to 31 and Comparative Example, the adhesion of the through-hole plating layer, the presence or absence of cracks in the through-holes, the presence or absence of measling, surface irregularities Condition, presence or absence of soaking of plating solution in through holes, adhesion between metal plate and resin of prepreg, variation in thickness of multilayer laminated plate, formability, The offset of the filler and the filling property of the filling resin into the through hole were measured. For the adhesion test of the through-hole plating layer, use the multilayer laminate.
A sample cut into a size of 50 mm × 50 mm was used as a sample, and this sample was floated in a solder bath at 260 ° C for 60 seconds. Of the 50 through holes in the sample, peeling (blurring) occurred in the through hole plating layer. This was done by counting the number. The results are shown in the column of "Through hole plating adhesion" in Table 2. The presence or absence of cracks in the through-holes was measured by measuring the cracks in the through-holes of the metal plate among the 50 selected through-holes in the laminated plate before through-hole plating. This was done by counting the number. The results are shown in the column of "crack" in Table 2. The presence / absence of measling was measured by counting the number of measling. The results are shown in the column "Meads ring" in Table 2. The surface roughness is measured by measuring the depth of the recess on the surface of the copper foil of the multilayer laminate before processing the through holes by using a needle contact surface roughness meter (Surfcom 550 manufactured by Tokyo Seimitsu Co., Ltd.).
It was measured in A) and the maximum value is shown in the column of "surface irregularities" in Table 2. For the test for the presence of plating soak, the number of the 50 selected through holes where the through hole plating liquid soaked in the prepreg part
The measurement was performed by cutting the through hole, observing with a microscope, and measuring. The results are shown in the column of "Soak in plating solution" in Table 2. For the adhesion test between the metal plate and the prepreg resin, a sample obtained by cutting the multilayer laminated plate into 50 mm x 50 mm was used as a sample, and the sample was immersed in a solder bath at 260 ° C for 1 minute, and between the metal plate and the prepreg resin. It was carried out by inspecting whether blistering due to peeling occurred. The test was carried out on 10 samples, and the number of those in which blisters were generated is shown in the column of "Adhesion between metal plate and resin" in Table 2. The variation of the plate thickness of the multilayer laminated plate is measured by measuring the plate thickness at each point of a _{1 to} a ₄ and b shown in Fig. 5 of the multilayer laminated plate molded to a size of 500 mm × 300 mm. The value calculated by the formula of b plate thickness- (a ₁ plate thickness + a ₂ plate thickness + a ₃ plate thickness + a ₄ plate thickness) / 4 is shown in Table 2 It is shown in the column of "Thickness variation". The moldability was measured by etching and removing the copper foil on the surface of the multilayer laminate, and visually observing whether or not a void was generated on the exposed surface of the multilayer laminate. In the column of "formability" in Table 2, those in which voids are generated are indicated by "x", and those in which voids are not occurred are indicated by "○". The offset of the filler in the through hole is measured by
This was done by observing the cross section of 10 through holes and visually observing whether the filler was offset or evenly dispersed in the through holes. In the column of “Filler offset” in Table 2, “Fixed” indicates that the filler is offset, and “O” indicates that the filler is uniformly dispersed. The filling property of the filling resin into the through hole is measured by filling the through hole of the metal plate with a powdery filler-containing resin using a squeegee as shown in FIG. 1 (b). It was carried out by visually observing the surface of the through hole whether or not the resin containing the filler of (1) re-aggregated to generate a lump and whether or not there was a void in the through hole. In the column of “resin filling property” in Table 2, those having lumps and voids are indicated by “X”, and those without lumps and no voids are indicated by “◯”. As can be seen from the results in Table 2, each of the examples has a higher through-hole adhesion than the comparative example and can suppress the occurrence of cracks, and also causes measling. It is confirmed that it can be suppressed.

【The invention's effect】

As described above, the present invention is prepared by impregnating a non-woven fabric with a thermosetting resin containing a needle-shaped or substantially spherical filler that does not melt by heat and pressure during lamination molding and has electrical insulation. Alternately superimpose a plurality of prepregs and metal plates with through holes filled with a resin that contains a needle-shaped or substantially spherical filler that does not melt due to heat and pressure during lamination molding and that has electrical insulation properties. When a multilayer laminated plate is manufactured by laminating and integrating these to form a through hole in a resin portion in a required through hole, a copper plate whose surface is roughened as the metal plate is used. In addition to being used, at least one of the plurality of metal plates having a thickness of 0.5 to 3 mm for forming a conductor for power supply is used, so that the following effects can be obtained. Since the resin containing the filler is filled in the through holes of the metal plate, the filler is exposed at the inner peripheral surface of the through hole drilled at the through holes to form an uneven surface. The adhesion of the through-hole plating layer to the through-hole is improved by the anchor effect, etc., and even when using a thick metal plate of 0.5 to 3 mm to form a conductor for power supply, peeling of the through-hole plating layer is possible. Can be prevented. Since the shrinkage of the resin filled in the through holes of the metal plate after molding can be suppressed by the filler, it is possible to reduce the difference between the shrinkage of the resin after molding and the shrinkage of the metal plate. 0.5-3mm to form a conductor for power supply
Even when a thick resin is used, it is possible to reduce the occurrence of cracks in the resin filled in the through holes due to internal stress. Since the prepreg prepared by impregnating the thermosetting resin into the non-woven fabric is used, the non-woven fabric can be impregnated with a large amount of the thermosetting resin, and the prepreg can be impregnated during lamination molding. Even if the resin flows through the through hole of the metal plate, the non-woven fabric which is the base material of the prepreg does not directly contact the metal plate due to the interposition of a large amount of impregnated resin, and the occurrence of measling can be suppressed. As a prepreg to be used in combination with a metal plate having a through hole filled with a resin containing a filler, in order to use a prepreg prepared by impregnating a nonwoven fabric with a thermosetting resin containing a filler, a thickness of 0.5 Even if the resin containing the filler in the through holes of a metal plate with a thickness of ~ 3 mm is lost during molding, it can be replenished with the resin containing the filler in the prepreg, and the ratio of the filler in the through holes can be increased. Can be prevented from becoming small, and it is possible to prevent the generation of cracks due to the difference in the coefficient of thermal expansion by preventing the portions having a large amount of filler and the portions having a small amount of filler in the through holes. It is possible to add a large amount of a resin that is sparse and contains a filler, and it is possible to satisfactorily replenish the resin containing the filler in the through holes from the prepreg. Further, in the present invention, since the copper plate whose surface is roughened by oxidation treatment, oxidation / reduction treatment, or electrolytic plating treatment is used as the metal plate, the metal plate and the resin of the prepreg are roughened by the rough surface. The adhesion of can be improved. In addition, since the metal plate having a thickness of 0.5 to 3 mm is used, it is possible to obtain high heat dissipation performance by the metal plate and to allow a large amount of electric power to flow as the conductor. Further, a glass non-woven fabric is used as a non-woven fabric as a base material of the prepreg, and the glass non-woven fabric is dipped in a binder solution to impregnate the mat with the glass fiber, so that the mat solution is impregnated with the binder solution, and then dried. If it is made by (as defined in claims 5 and 6), the binder can be uniformly attached to the entire glass non-woven fabric and the binder does not deviate to a part. It is possible to prevent the adhesiveness between the resin and the thermosetting resin from being lowered, and it is possible to reduce the occurrence of interfacial peeling between the fiber and the resin and the penetration of the plating solution. If the thermosetting resin of the prepreg has a glass transition temperature of 170 ° C. or higher (claim 7)
It is possible to withstand high temperature processing such as circuit formation and soldering. Further, when the thermosetting resin of the prepreg has a melt viscosity at 130 ° C. of 70 to 2000 poises (claim 9), the thickness of the varieties of the prepreg does not vary and the variation of the thickness of the prepreg does not occur. It is possible to carry out lamination molding while suppressing the above. Further, if the resin containing a filler to be filled in the through holes of the metal plate is formed so that the difference in the coefficient of thermal expansion from the metal plate is 20 ppm / ° C. or less (claim 12), the resin after molding is formed. It is possible to reliably suppress the occurrence of the above-mentioned cracks caused by the difference between the shrinkage of the metal plate and the shrinkage of the metal plate, and also it is possible to form a dent on the surface of the multi-layer laminated plate caused by the resin shrinking more than the metal plate after molding. Can be reduced. As the filler to be mixed with the thermosetting resin of the prepreg, a spherical filler having a central diameter of 20 μm or less, or a needle-shaped filler having a central diameter of 15 μm or less and a length of 2 times or less of the diameter is used. When the compounding amount is set to 30 to 150 PHR (claims 10 and 11), when the resin is replenished from the prepreg into the through hole of the metal plate during molding, the filler is satisfactorily passed through the prepreg at the same time. It can be made to flow into the holes, and it is possible to prevent formation of a portion having a large amount of filler and a portion having a small amount of filler in the through hole, and to make a difference in the coefficient of thermal expansion locally in the through hole. It is possible to prevent the occurrence of cracks. Further, as the filler of the resin containing the filler to be filled in the through holes of the metal plate, a spherical filler having a diameter of 15 μm or more, or a needle-shaped filler having a diameter of 10 μm or more and a length of twice the diameter or more. If used (claims 13 and 14), it is possible to reliably obtain the effect of preventing cracks due to the filler due to the reinforcing effect. Further, if the resin of the resin containing the filler to be filled in the through holes of the metal plate is used in the form of powder having a particle size of 100 to 350 μm (claim 15), the workability in the through holes of the metal plate is improved. Moreover, the resin can be densely filled.

[Brief description of drawings]

FIGS. 1 (a) and (b) are partial cross-sectional views in respective steps of manufacturing a laminated plate according to the present invention, and FIGS. 2 (a), (b) and (c).
(D) is a partial cross-sectional view in each step of manufacturing the laminated plate in the present invention, FIG. 3 is a schematic view of an apparatus used for manufacturing the glass nonwoven fabric used in the present invention, and FIGS. 4 (a) and (b). (C)
(D) is a partial cross-sectional view in each step of manufacturing a conventional laminated plate, and FIG. 5 is a schematic view showing a method for measuring variations in plate thickness of a multilayer laminated plate. 1 is a prepreg, 2 is a resin, 3 is a through hole, 4 is a metal plate, 5
Is a through hole, and 6 is a through hole plating layer.

Front Page Continuation (72) Inventor Yoshihide Sawa 1048 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works, Ltd. (56) References JP 63-311795 (JP, A) JP 63-192297 (JP, A) ) JP-A-60-127782 (JP, A) JP-B-60-236294 (JP, B2)

Claims (15)

[Claims] 1. A prepreg prepared by impregnating a non-woven fabric with a thermosetting resin containing a needle-shaped or substantially spherical filler which does not melt by heat and pressure during lamination molding and has an electrically insulating property, and a lamination. Multiple sheets of metal plates with through holes that are not melted by heat and pressure during molding and that are electrically insulative and that are filled with a resin that is mixed with a needle-shaped or substantially spherical filler that has electrical insulation are stacked alternately. After molding and integration, when manufacturing a multilayer laminate by punching through holes in the resin portion in the required through holes, while using a copper plate having a roughened surface as the metal plate,
A method for producing a multilayer laminate, wherein at least one of the plurality of metal plates has a thickness of 0.5 to 3 mm for forming a conductor for power supply. 2. The method for producing a multi-layer laminate according to claim 1, wherein the roughening is performed by oxidizing the surface of a copper plate. 3. The method for producing a multi-layer laminate according to claim 1, wherein the roughening is performed by subjecting the surface of the copper plate to an oxidation treatment and then a reduction treatment. 4. The method for producing a multi-layer laminate according to claim 1, wherein the roughening is performed by electroplating the surface of a copper plate. 5. The method for producing a multilayer laminate according to claim 1, wherein the non-woven fabric is a glass non-woven fabric. 6. The glass non-woven fabric is obtained by immersing a mat in which glass fibers are accumulated in a binder solution to impregnate the mat solution with the binder solution and then drying the mat so that the content of the binder becomes glass fiber. The method for producing a multi-layer laminate according to claim 5, wherein the multi-layer laminate is formed as 15% by weight or less of the total amount of the binder. 7. The method for producing a multilayer laminate according to claim 1, wherein the thermosetting resin of the prepreg has a glass transition temperature of 170 ° C. or higher. 8. The multi-layer laminate according to claim 1, wherein the thermosetting resin of the prepreg is an epoxy resin, a polyimide resin, or a modified resin thereof. Manufacturing method. 9. The thermosetting resin of the prepreg is 130 ° C.
The method for producing a multilayer laminate according to any one of claims 1 to 8, characterized in that the melt viscosity thereof is 70 to 2000 poise. 10. The filler to be blended with the thermosetting resin of the prepreg is a spherical filler having a center diameter of 20 μm or less, and the blending amount is 30 to 150 PHR. A method for producing a multilayer laminate according to any one of 1. 11. The filler to be blended with the thermosetting resin of the prepreg is a needle-shaped filler having a central diameter of 15 μm or less and a length of 2 times or less, and the blending amount is 30 to 150 PHR. The method for manufacturing a multilayer laminate according to any one of claims 1 to 9, wherein: 12. The method for producing a multilayer laminate according to claim 1, wherein the filler-containing resin has a difference in coefficient of thermal expansion from a metal plate of 20 ppm / ° C. or less. . 13. The method for producing a multilayer laminate according to claim 1, wherein the filler of the resin containing a filler is a spherical filler having a center diameter of 15 μm or less. 14. The filler of a resin containing a filler is a needle-shaped filler having a central diameter of 10 μm or more and a length of twice the diameter or more. A method for producing the multilayer laminate described. 15. The resin of the resin containing a filler has a median particle size.
The method for producing a multilayer laminate according to any one of claims 1 to 14, which is a powder having a particle size of 100 to 350 µm.