JP2001203453A - Manufacturing method for multilayer laminated board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a multilayer laminated board, capable of obtaining the multilayer laminated board in which irregularities or wrinkles are not generated on the surface of a metal foil, in which a slight touching part is not generated in the circumference of a resin lump, and whose outward appearance is satisfactory. SOLUTION: A prepreg 2 for an inner layer is partially welded. An inner- layer material 3, in which circuit boards 1a, 1b for inner layers are fixed temporarily, is formed. Metal foils 8 are piled up via sheets for bonding on both outer sides of the inner-layer material 3, so as to form a laminated object 10. The laminated object 10 is then heated and pressurized. In a first step, a molding pressure is set at 2 kg/cm2 or lower, until the resin lump in a state whose resin generated in the inner-layer material 3 becomes a gel after the start of a heating operation reaches a temperature at which it is softened. In a second step, the molding pressure is set in a range of 4 to 10 kg/cm2, until the resin of the preperg 2 for the inner layer becomes 120 deg.C, after it is resoftened. In a third step, the laminated object is pressurizes under a prescribed pressure, until it reaches a minimum melting viscosity which the resin of the prepreg 2 possesses for the inner layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer laminate used for a multilayer printed wiring board.

[0002]

2. Description of the Related Art When manufacturing a multilayer printed wiring board used for electric and electronic equipment, a multilayer laminate containing an internal circuit board is used. This multilayer laminate, for example,
After the prepreg is laminated as an adhesive sheet on both outer sides of one or more inner layer circuit boards on which a conductor circuit is formed,
A laminate is formed by further laminating a metal foil on the outside, and then the laminate is manufactured by a method of manufacturing by heating and pressurizing, or an adhesive resin layer is applied on both outer sides of the inner layer circuit board. To form a laminate by stacking semi-cured metal foils,
Then, the laminate is manufactured by heating and pressing.

In the case where two or more internal circuit boards are manufactured as the above-mentioned multilayer laminate, the conductor circuits formed on the respective internal circuit boards are aligned before forming the multilayer laminate. Then, a temporarily fixed inner layer material is manufactured. As a method for producing the inner layer material, a resin fusion fixing method is known. One example will be described with reference to FIG. The above-mentioned resin fusion method uses two inner-layer circuit boards 21 on which a conductor circuit is formed with an inner-layer prepreg 22 interposed therebetween.
a, 21b are superimposed while being aligned, and then an outer peripheral portion 24 outside the circuit surface 23 on which the conductor circuit is formed in plan view.
Are heated and pressurized, and the resin of the molten inner layer prepreg 22 is welded to the upper and lower inner circuit boards 21a and 21b to form the inner layer material 26. Reference numeral 25 in the drawing indicates a welded portion where the inner layer prepreg is partially welded.

[0004] Thereafter, in the multilayer laminate, an outer layer prepreg 27 is laminated on both outer sides of the inner layer material 26, and a metal foil 28 is further laminated on the outer side thereof to form a laminate. It is manufactured. When molding this laminate, the molding pressure is 10 kg / cm ^{2 to} 30 kg / c.
It is carried out in m ^2.

[0005]

However, the inner layer material 26 temporarily fixed by the above-mentioned resin fusion fixing method,
The resin is a resin mass in a gelled state. Multilayer laminates often have irregularities and wrinkles on the surface of the metal foil where the resin mass is located, and also often have blurring around the resin mass, and these irregularities, wrinkles, and fading The defect may hinder the performance of the printed wiring board.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an external appearance which does not cause unevenness or wrinkles on the surface of a metal foil and does not cause blurring around a resin block. It is an object of the present invention to provide a method for producing a multilayer laminate in which a good multilayer laminate can be obtained.

[0007]

According to a first aspect of the present invention, there is provided a method for manufacturing a multilayer laminate, comprising: stacking a plurality of inner layer circuit boards via an inner layer prepreg; partially welding the inner layer prepreg; After forming the inner layer material which temporarily fixed the inner layer circuit boards facing each other via the inner layer prepreg, on both outer sides of the inner layer material, a metal foil is laminated via an adhesive sheet to form a laminate, and then In the method for producing a multilayer laminate in which the laminate is formed by heating and pressing, the molding pressure of the laminate is increased in the following steps.
During the first step, from the start of heating, to the temperature at which the resin mass in the gelled state of the resin, which is generated by partial welding of the inner layer prepreg, re-softens, the molding pressure is 0.1 to 2 mm.
and kg / cm ^2, which is the second step, while the resin inner layer prepreg for later re-softening is 120 ° C., a molding pressure 4 kg / cm ² or more, and 10 kg / cm ² less than the range, the third In this step, the pressure is increased to a predetermined pressure until the minimum melt viscosity of the resin of the prepreg for the inner layer is reached.

The present inventor has conducted intensive studies to achieve the above object, and as a result, during molding, the molding pressure was maintained at ² kg / cm ² or less until the resin mass again became softened, After that, the molding pressure should be 4 kg / cm ² or more,
By keeping the resin mass in a smooth state with the melted resin of the inner layer prepreg or the resin of the adhesive sheet while maintaining the resin mass in the range of less than kg / cm ² , the surface of the metal foil of the multilayer laminate may have unevenness. It has been found that no wrinkles are formed and no blurring occurs around the resin mass, and the present invention has been completed.

As described above, by setting the molding pressure in the first step to 0.1 to ² kg / cm ² , irregularities and wrinkles are generated on the surface of the metal foil, and blurring is generated around the resin block. Can be prevented, and the second step (S
The molding pressure of 2) is 4 kg / cm ² or more and 10 kg / cm
By making the range of less than ² , the periphery of the resin mass is smoothed with the resin of the molten inner layer prepreg or the resin of the bonding sheet, so that it is possible to prevent the occurrence of blurring around the resin mass. It is possible to reach a predetermined molding pressure during the third step (S3).

[0010] According to a second aspect of the present invention, there is provided a method for manufacturing a multilayer laminate.
2. The method for manufacturing a multilayer laminate according to claim 1, wherein the distance from the first step to the third step is 50 mm.
It is characterized by pressurizing under a reduced pressure of not more than Hg.

[0011] The method for producing a multilayer laminate according to claim 3 is characterized in that:
The method for manufacturing a multilayer laminate according to claim 1 or 2, wherein power is supplied to the metal foil, and the laminate is heated by resistance heating.

[0012] The method for producing a multilayer laminate according to claim 4 is characterized in that:
The method for producing a multilayer laminate according to any one of claims 1 to 3, wherein the metal foil via the bonding sheet is obtained by applying a bonding resin to an inner layer material side of the metal foil and semi-curing the metal foil. It is characterized by being.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a multilayer laminate according to the present invention will be described with reference to the drawings.

1 and 2 show an embodiment of a method according to the first aspect of the present invention. FIG. 1 is an explanatory view for explaining a method for manufacturing a multilayer laminate, and FIG. It is explanatory drawing which shows each step and molding pressure and molding temperature typically.

As shown in FIG. 1, the multilayer laminated board to which the present invention is applied uses an inner layer material 3 in which two or more inner layer circuit boards 1a and 1b are temporarily fixed by a resin fusion bonding method.
The inner layer material 3 is overlapped with the inner layer prepreg 2 while aligning the inner layer circuit boards 1a and 1b, and then, as shown in the plan view of FIG. Are heated and pressurized to melt the resin of the inner layer prepreg 2 to temporarily fix the upper and lower inner layer circuit boards 1a and 1b to each other. Reference numeral 6 in the drawing indicates a welded portion of the portion where the inner layer prepreg 2 is welded. The welding portion 6 is a resin mass in which the resin is in a gelled state. Pre-preg for inner layer 2
The conditions for melting the resin (a) may vary depending on the resin of the inner layer prepreg 2 and the like.
About 60 seconds.

Next, as shown in FIG. 1A, in the multilayer laminate, an outer layer prepreg 7 is laminated as an adhesive sheet on both outer sides of the inner layer material 5, and a metal foil 8 is further laminated on the outer side. A laminate 10 is formed, and the laminate 10 is sandwiched between flat plates 9 made of stainless steel or the like, a cushion material (not shown) is stacked as necessary, and further sandwiched between a pressing plate 11 as a molding device, and heating and heating are performed. Pressed and molded. The heating medium circulates through the pressure plate 11, and the laminate 10 is heated via the pressure plate 11.

The inner layer circuit boards 1a and 1b include those in which a conductor circuit is formed on the surface of an insulating substrate or in a through hole. The insulating substrate is, for example, a resin obtained by impregnating a base material with a resin and curing the resin. Examples of the resin include epoxy resins, phenol resins, polyimide resins, and unsaturated polyester resins. And the mixture, and examples of the base material include inorganic materials such as glass fibers. The conductor circuit is formed by etching a metal foil disposed on a surface of an insulating substrate or by plating.

The prepreg 2 for the inner layer or the prepreg 7 for the outer layer is formed by coating a base material such as glass fiber with a thermosetting resin such as an epoxy resin, a phenol resin, a polyimide resin or an unsaturated polyester resin. It is impregnated to make the resin in a semi-cured state.

The metal foil is not limited as long as it is conductive, and examples thereof include copper, aluminum and nickel.

A method for manufacturing the above-mentioned multilayer laminate will be described with reference to FIG. In the method for manufacturing a multilayer laminate, the molding pressure of the laminate 10 is increased in the order of a first step (S1), a second step (S2), and a third step (S3) to reach a predetermined molding pressure. It is something to do.

The first step (S1) is a period from the start of heating to the temperature at which the resin mass of the welded portion 6 is re-softened (reference numeral a in the drawing).
Means that the molding pressure is 0.1 to ² kg / cm ² (the symbol P in the figure)
1). Since the resin mass is in a gelled state, the resin mass is again in a softened state when heated. This re-softened state is, for example, 10% when an epoxy resin or the like is used as a material.
The temperature is about 0 to 110 ° C. The first step (S
By setting the molding pressure of 1) to 2 kg / cm ² or less, it is possible to prevent unevenness and wrinkles from occurring on the surface of the metal foil and blurring around the resin block.

The second step (S2) is performed after re-softening.
The resin of the inner layer prepreg 2 is 120 ° C.
b), and this second step (S2) is performed
Form pressure 4kg / cm^Two More than 10kg / cm^Two Less than
It is assumed to be a range (reference numeral P2 in the figure). The second step (S
2) molding pressure of 4 kg / cm^Two More than 10kg / cm
^Two With the range of less than, the periphery of the resin
Of the inner layer prepreg 2 and the outer layer prepreg 7
Smoothing around resin mass due to smoothing with resin
Can be prevented.

The third step (S3) is a period from after the second step (S2) to a temperature at which the resin of the prepreg 2 for the inner layer reaches the minimum melt viscosity (reference numeral c in the figure). During step (S3), the pressure is increased to a predetermined pressure (P3 in the figure).

Further, during the period from the first step to the third step, pressurizing the laminate under a reduced pressure of 50 mmHg or less can suppress generation of molding voids in the laminate. Is preferred.

When a plurality of laminates are inserted between the pressurizing plates 11 and 11 for molding, the laminate 10 is apt to have irregularities and wrinkles on the surface of the metal foil and has a high molding temperature. It is preferable to combine the above steps.

In the method for manufacturing a multilayer laminate, the molding pressure of the laminate 10 is increased in the order of a first step (S1), a second step (S2), and a third step (S3), and a predetermined pressure is applied. By forming in the above, a multilayer laminate having a good appearance can be obtained without causing irregularities and wrinkles on the surface of the metal foil and without causing blurring around the resin mass.

The embodiment of the present invention is not limited to the above. FIG. 3 shows an example of an embodiment of a method according to the fourth aspect. Only different points from the above embodiment will be described. The multilayer laminate is provided on both outer sides of the inner layer material 5,
An adhesive resin is applied to the surface of the metal foil 8a on the inner layer material side, and a laminate having a semi-cured resin layer 12 is laminated to form a laminate 10. The semi-cured resin layer 12 forms an adhesive sheet. Examples of the adhesive resin include thermosetting resins such as epoxy resin, phenol resin, polyimide resin, and unsaturated polyester resin. These resin layers 12 are formed to a thickness of about 50 to 100 μm. When the metal foil 8a having the resin layer 12 is used, the outer layer prepreg may be omitted.

FIG. 4 shows an example of an embodiment of a method according to the third aspect of the present invention. Only different points from the above embodiment will be described. In the method for manufacturing the multilayer laminate, when sandwiching the laminate between the pressing plates 11, both ends of the metal foil 8b are electrically connected to one pressing plate 11a and the other pressing plate 11b. In a state where the pressure is applied between the pressure plates 11a and 11b, power is supplied through the pressure plates 11a and 11b.
In the method for manufacturing the multilayer laminate, the metal foil 8b is heated by resistance heating when power is supplied. The above-described method for manufacturing a multilayer laminate is preferable in that even if a large number of, for example, 10 to 20 sets of laminates are inserted between the pair of pressure plates 11a and 11b, heat dispersion hardly occurs.

[0029]

EXAMPLES In both Examples and Comparative Examples, the inner layer material used was prepared as follows. As an inner layer circuit board, an insulating board made of glass fiber / epoxy resin with a thickness of 0.1 mm, and a conductor circuit formed by etching a copper foil of 0.035 mm thickness provided on both sides of the insulating board Was used. As the prepreg for the inner layer, a glass fiber impregnated with an epoxy resin to reduce the resin amount to 52% by weight (trade name: R-1661, manufactured by Matsushita Electric Works, Ltd., thickness: 0.1 mm) was used. Next, the circuit board for the inner layer is sandwiched from above and below through one piece of the prepreg for the inner layer, and four portions of the outer peripheral portion of the circuit surface are heated under the condition of contact pressure at a temperature of 250 ° C. for 45 seconds,
An inner layer material temporarily fixed by the resin fusion method was obtained. The temperature at which the resin of the prepreg for the inner layer reached the minimum melt viscosity was 127.5 ° C.

(Example 1) As the prepreg for the outer layer, the same prepreg as the prepreg for the inner layer was used.
A 12 mm copper foil was used. One outer layer prepreg was laminated on both outer sides of the inner layer material, and a copper foil was further laminated on the outer side to form a laminate. The ten laminates were alternately sandwiched between flat plates made of stainless steel, and inserted between heat medium type press plates.

The molding pressure was applied so that the laminate near the pressure plate was as follows.

110 ° C. at which the resin mass re-softens from the start of molding
In the first step, the molding pressure was 2 kg / cm ² . Next, in the second step from 110 ° C. to 120 ° C., the temperature is heated at a rate of 1.5 ° C./min, and the molding pressure is set at 0.3 k / min.
Pressure was applied at a rate of g / cm ² / min. The molding pressure at 120 ° C. was 4 kg / cm ² . Then, the third step from 120 ° C. to 127.5 ° C. is to raise the temperature to 1.5 ° C.
/ Min at a rate of 5 kg / cm ² / min. When the temperature reaches 127.5 ° C,
The molding pressure was a predetermined pressure of 30 kg / cm ² .

Further, after raising the temperature and maintaining the temperature at 180 ° C. for 40 minutes, it was cooled to obtain a multilayer laminate. Until the temperature reached 150 ° C., the laminate was molded under a reduced pressure of 50 mmHg, and then released to atmospheric pressure for molding.

Example 2 Laminates were prepared in the same manner as in Example 1, and these ten laminates were alternately sandwiched between flat plates made of stainless steel and inserted between heat medium type pressurizing plates. The molding pressure was applied so that the laminate near the pressure plate was as follows.

110 ° C. at which the resin mass re-softens from the start of molding
In the first step, the molding pressure was 2 kg / cm ² . Next, in a second step from 110 ° C. to 120 ° C., the temperature is heated at a rate of 1.5 ° C./min, and the molding pressure is set at 1.1 k / min.
Pressure was applied at a rate of g / cm ² / min. The molding pressure at 120 ° C. was 9 kg / cm ² . Then, the third step from 120 ° C. to 127.5 ° C. is to raise the temperature to 1.5 ° C.
/ Min at a rate of 4 kg / cm ² / min. When the temperature reaches 127.5 ° C,
The molding pressure was a predetermined pressure of 30 kg / cm ² .

Further, after raising the temperature and maintaining the temperature at 180 ° C. for 40 minutes, it was cooled to obtain a multilayer laminate. Until the temperature reached 150 ° C., the laminate was molded under a reduced pressure of 50 mmHg, and then released to atmospheric pressure for molding.

Example 3 In Example 1, the temperature was 1
Example 1 except that molding was performed under a reduced pressure of 50 mmHg up to 30 ° C., and reduced under a reduced pressure of 80 mmHg until the temperature was 130 to 150 ° C., and then released to atmospheric pressure to perform molding. In the same manner as in the above, a multilayer laminate was obtained.

(Example 4) In the same manner as in Example 2, a laminate was prepared, and fifty of these laminates were alternately sandwiched between flat plates whose surfaces had been subjected to insulation treatment, and were inserted between pressure plates.
Power was supplied to both ends of all the copper foils and heating was performed by resistance heating. The temperature of the laminate was heated in much the same way.

110 ° C. at which the resin mass re-softens from the start of molding
In the first step, the molding pressure was 2 kg / cm ² . Next, in a second step from 110 ° C. to 120 ° C., the temperature is heated at a rate of 1.5 ° C./min, and the molding pressure is set at 1.1 k / min.
Pressure was applied at a rate of g / cm ² / min. The molding pressure at 120 ° C. was 9 kg / cm ² . Then, the third step from 120 ° C. to 127.5 ° C. is to raise the temperature to 1.5 ° C.
/ Min at a rate of 2.2 kg / cm ² /
Min. When the temperature reached 127.5 ° C., the molding pressure reached a predetermined pressure of 20 kg / cm ² .

Further, the temperature was raised and maintained at 180 ° C. for 40 minutes, followed by cooling to obtain a multilayer laminate. Until the temperature reached 150 ° C., the laminate was molded under a reduced pressure of 50 mmHg, and then released to atmospheric pressure for molding.

Example 5 A metal foil was coated with a thermosetting resin on the inner layer material side of a copper foil and semi-cured (trade name: R-0880, manufactured by Matsushita Electric Works, Ltd., thickness 0.08 mm) )
Was used. The copper foil with resin was laminated on both outer sides of the inner layer material to form a laminate. The ten laminates were alternately sandwiched between flat plates made of stainless steel, and inserted between heat medium type press plates.

A multilayer laminate was obtained in the same manner as in Example 1 except that the laminate was formed using the copper foil with resin.

Example 6 A multilayer laminated board was obtained in the same manner as in Example 4, except that the laminate was the same copper foil with resin as in Example 5. .

(Comparative Example 1) Laminates were prepared in the same manner as in Example 1, and ten of these laminations were alternately sandwiched between flat plates made of stainless steel and inserted between heat-medium type pressurizing plates. The molding pressure was applied so that the laminate near the pressure plate was as follows.

110 ° C. at which the resin mass re-softens from the start of molding
Until then, the molding pressure was 3 kg / cm ² . Next, 11
Between 0 ° C. and 120 ° C., the temperature was heated at a rate of 1.5 ° C./min, and the molding pressure was applied at a rate of 0.3 kg / cm ² / min. The molding pressure at 120 ° C. was 5 kg / cm ² . Next, from 120 ° C. to 127.5 ° C., the temperature was increased at a rate of 1.5 ° C./min, and the molding pressure was increased to 5 ° C.
Pressure was applied at a rate of kg / cm ² / min. Temperature is 127.5
℃, the molding pressure is the predetermined pressure of 30 kg
/ Cm ² .

Further, the temperature was raised and maintained at 180 ° C. for 40 minutes, and then cooled to obtain a multilayer laminate. In addition, until the temperature reaches 150 ° C., the laminate is 50 mmHg.
, And then released to atmospheric pressure to perform molding.

(Comparative Example 2) Laminates were produced in the same manner as in Example 1, and these ten laminates were alternately sandwiched between flat plates made of stainless steel and inserted between heat medium type press plates. The molding pressure was applied so that the laminate near the pressure plate was as follows.

110 ° C. at which the resin mass re-softens from the start of molding
Until the molding pressure is 10kg / cm ^Two And Then, 1
Between 10 ° C and 120 ° C, keep the temperature at 1.5 ° C / min
And press the molding pressure to 0.3kg / cm^Two Per minute
Pressurized. The molding pressure at 120 ° C. is 12 kg / cm
^Two Met. Then, from 120 ° C. to 127.5 ° C.
During this time, the temperature is heated at a rate of 1.5 ° C./min, and the molding pressure is increased.
3.6kg / cm^Two / Min. Temperature 12
When the temperature reaches 7.5 ° C., a predetermined pressure of 30 kg / cm^Two When
became.

Further, the temperature was raised and maintained at 180 ° C. for 40 minutes, and then cooled to obtain a multilayer laminate. Until the temperature reached 150 ° C., molding was performed under a reduced pressure of 50 mmHg, and thereafter, molding was performed by opening to atmospheric pressure.

(Comparative Example 3) Laminates were prepared in the same manner as in Example 1, and ten such laminations were alternately sandwiched between flat plates made of stainless steel and inserted between heat medium type press plates. The molding pressure was applied so that the laminate near the pressure plate was as follows.

From the start of molding, the resin mass is re-softened at 110 ° C
Until then, the molding pressure was 2 kg / cm ² . Next, 11
Between 0 ° C. and 120 ° C., the temperature was increased at a rate of 1.5 ° C./min, and the molding pressure was increased at a rate of 4.2 kg / cm ² / min. When the temperature reached 120 ° C., the molding pressure reached a predetermined pressure of 30 kg / cm ² .

Further, the temperature was raised and maintained at 180 ° C. for 40 minutes, and then cooled to obtain a multilayer laminate. Until the temperature reached 150 ° C., molding was performed under a reduced pressure of 50 mmHg, and thereafter, molding was performed by opening to atmospheric pressure.

(Comparative Example 4) Laminates were prepared in the same manner as in Example 1, and ten of these laminations were alternately sandwiched between flat plates made of stainless steel and inserted between heat medium type press plates. The molding pressure was applied so that the laminate near the pressure plate was as follows.

During the period from the start of molding to 120 ° C., the temperature was 3 ° C.
/ Min. The molding pressure at 120 ° C is 1
It was 0 kg / cm ² . Next, the temperature was heated at a rate of 1.5 ° C./min, and the molding pressure was applied at a rate of ² kg / cm ² / min. When the temperature reached 135 ° C., the pressure reached 30 kg / cm ² .

Further, the temperature was raised and maintained at 180 ° C. for 40 minutes, and then cooled to obtain a multilayer laminate. Until the temperature of the laminate reached 150 ° C., molding was carried out under a reduced pressure of 80 mmHg, and thereafter, molding was carried out by releasing to atmospheric pressure.

(Evaluation) The appearance of the multilayer laminates obtained in the examples and comparative examples was observed and evaluated. In Examples 1 to 3, 5 and Comparative Example, a multilayer laminate formed near the pressure plate was evaluated. The appearance of the metal foil of 100 multilayer laminates of each example and comparative example was visually observed, and the presence or absence of unevenness and the rate of occurrence of wrinkles were evaluated. Further, the metal foil was etched, and the presence or absence of blurring around the resin mass was visually observed.も の indicates no blurring, Δ indicates a blurring of less than 5 mm, and × indicates a blurring of 5 mm or more.

As shown in Table 2, it was confirmed that the multilayer laminates of Examples 1 to 6 had better appearance than the comparative examples.

[0058]

[Table 1]

[0059]

[Table 2]

[0060]

According to the method for manufacturing a multilayer laminate according to claims 1 to 4, since the molding pressure of the laminate is applied in the order of the first step, the second step, and the third step, the pressure on the surface of the metal foil is increased. A multilayer laminate having a good appearance can be obtained without unevenness or wrinkles or blurring around the resin mass.

[Brief description of the drawings]

FIG. 1 is an explanatory view illustrating an example of a method for manufacturing a multilayer laminate of the present invention.

FIG. 2 is an explanatory diagram schematically showing each step of the present invention and a molding pressure and a molding temperature.

FIG. 3 is an explanatory view illustrating an example of a method for manufacturing a multilayer laminate of the present invention.

FIG. 4 is an explanatory view illustrating an example of a method for manufacturing a multilayer laminate of the present invention.

FIG. 5 is an explanatory view illustrating a conventional method for manufacturing a multilayer laminate.

[Explanation of symbols]

 1a, 1b Inner layer circuit board 2 Inner layer prepreg 3 Inner layer material 6 Welded part 8 Metal foil 10 Laminate

Claims (4)

[Claims] A plurality of inner layers are provided via an inner layer prepreg.
Circuit boards are stacked and the inner layer prepreg is partially welded.
And a circuit board for the inner layer facing through the prepreg for the inner layer
After forming the inner layer material temporarily fixed to each other,
Laminate metal foil on both outsides via an adhesive sheet
The laminate is then heated and pressed to form
In the method for producing a multilayer laminate, the molding pressure of the laminate is
Multi-layer, characterized by applying a force in the following steps
A method for manufacturing a laminate. Is the first step, heating start?
The resin generated by partial welding of the prepreg for the inner layer
Until the gelled resin mass re-softens,
Forming pressure 0.1 ~ 2kg / cm^Two And the second step
After the re-softening, the resin of the prepreg for the inner layer is 120
℃, the molding pressure is 4kg / cm^Two More than 10k
g / cm ^Two And the third step is for the inner layer
Until the minimum melt viscosity of the prepreg resin is reached
Pressurize to a predetermined pressure. 2. The method for manufacturing a multilayer laminate according to claim 1, wherein the pressure is applied under a reduced pressure of 50 mmHg or less during the steps from the first step to the third step. 3. The method according to claim 1, wherein power is supplied to the metal foil to heat the laminate by resistance heating. 4. The metal foil via the bonding sheet is obtained by applying a bonding resin to a surface of the metal foil on the inner layer material side and semi-curing the metal foil. The method for producing a multilayer laminate according to any one of the above.