JPH11129394A - Thermal barrier for laminate molding and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal barrier for laminate molding, which can mold lightweight laminates with simple structure. SOLUTION: A thermal barrier for laminate molding is formed by laminating two or more metallic sheets 1 with resin layers 3, composed of fused and hardened prepreg 2, therebetween, where each of one ends and each of the other ends of the adjacent metallic sheets 1 are alternately joined, and the adjacent metallic sheets 1 are bonded through the resin layers 3 excluding the joined ends. Thereby, two or more metallic sheets 1 are integrally laminated by bonding through the resin layers 3 composed of the prepreg 2 with the one ends and the other ends alternately joined.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method in which a metal foil is heated and pressurized by generating heat by energizing a metal foil.
The present invention relates to a thermal barrier used when forming a metal foil-clad laminate.

[0002]

2. Description of the Related Art A metal foil-clad laminate used for processing a printed wiring board or the like is formed by laminating a plurality of prepregs and laminating a metal foil such as a copper foil on one or both outer surfaces thereof.
It is manufactured by heating and pressurizing it to form a laminate. In the case of a multilayer printed wiring board, it is manufactured by laminating a prepreg on one or both sides of an inner circuit board, further laminating a metal foil on the outside of the prepreg, and heating and pressurizing the laminate to form a laminate. And when performing the lamination molding as described above, a combination of the above prepreg and metal foil or a combination of an inner layer circuit board, a prepreg and metal foil is stacked in multiple stages, and this is set between hot plates. The pressing is generally performed by a so-called multi-stage hot press.

However, in such a multi-stage hot press using a hot plate, the heating temperature is different between a combination near the hot plate and a combination far from the hot plate, and the heating temperature is not uniform due to the uneven heating temperature. The quality of the laminated metal foil-clad laminate may vary. Therefore, in a multi-stage hot press, the number of stacks that can be stacked is limited.

Therefore, a method of connecting a power supply to the metal foil and energizing the metal foil to generate heat in the metal foil to heat the metal foil is disclosed in JP-T-7-508940 and JP-T-8-506289. It is provided in gazettes and the like. FIG. 2 shows an example thereof. First, a long metal foil 10 is used, and a plurality of sets of a plurality of sets of metal foils 10 are folded and bent between the metal foils 10 facing each other. By alternately sandwiching the combination body 11 and the plurality of electrically insulating molding plates 12, the metal foil 10 bent in a meandering shape with a plurality of layers, a plurality of sets of the combination body 11 stacked in multiple stages, and a plurality of A stacked block 13 composed of the forming plate 12 is manufactured. Combination body 11
Are formed as a set of a plurality of prepregs 14 (or as a set of a prepreg and an inner circuit board). When the stacking block 13 is set between the pressure plates 15 and a power source is connected to the metal foil 10 and the metal foil 10 is energized while being pressed by the pressure plate 15, the metal foil 10 generates heat by Joule heat, With this heat generation, each combination 11
Can be formed by heating the prepreg 14.

[0005] According to this method, each combination 11
Can be directly heated using the metal foil 2 as a heat source, so that the prepregs 14 of each of the combined bodies 11 stacked in multiple stages can be uniformly heated, and the metal foil 2 Can be obtained by multi-stage molding without variation in quality.

However, when the metal foil 10 is energized to generate heat as described above, and the molding is performed by applying pressure by the pressing plate 15 while heating with the generated heat, the combined block of the stacked blocks 13 which is close to the pressing plate 15 is formed. In 11, the heat generated from the metal foil 10 is easily absorbed by the pressing plate 15 and escaped, and the heating temperature of the combination body 11 close to the pressing plate 15 may be low, resulting in insufficient curing. There is a problem.

For this purpose, a heating element called a thermal barrier A is provided between the pressure plate 15 and the stacking block 13 so as to prevent the heat generated by the metal foil 10 from being absorbed by the pressure plate 15 and escaped. I have to. FIG. 3 shows an example of a conventionally used thermal barrier A, in which a long metal sheet 16 formed of a copper foil or the like is folded and bent in a plurality of layers, and each of the folded and bent portions faces the facing metal. An electrically insulating intermediate plate 17 is sandwiched between the sheets 16, and the metal sheets 16 and the intermediate plates 17 are alternately overlapped. This is sandwiched between a pair of upper and lower metal outer plates 18, 18. One end of one exterior plate 1
8, the other end of the metal sheet 16 is electrically connected to the other exterior plate 18, and the upper and lower exterior plates 18, 18 are integrally joined by an electrically insulating joining plate 19, so that the whole It is formed in a shape.

The thermal barrier A thus formed is placed between the upper end of the stacking block 13 and the upper pressing plate 15 as shown in FIG. The outer plate 18 on the upper side of the upper thermal barrier A and the outer plate 18 on the lower side of the lower thermal barrier A are connected to a power source and energized while being pressed and pressed by the pressure plate 15. Thus, molding can be performed.

That is, in this case, the upper outer plate 18 of the upper thermal barrier A, the metal sheet 16 of the upper thermal barrier A, and the lower outer plate 1 of the upper thermal barrier A
8. Stacked block 1 in contact with this exterior plate 18
3 metal foil 10, the upper outer plate 18 of the lower thermal barrier A in contact with the metal foil 10, the lower thermal barrier A metal sheet 16, and the lower outer plate 18 of the lower thermal barrier A. Conduction is performed in this order. Therefore, when current is supplied, a current flows through the conduction path, and the metal foil 10 of the stacked block 13 can be heated by Joule heat to perform molding. Also in each of the thermal barriers A, the metal sheet 16 can be heated by Joule heat, and the heat generated by the thermal barrier A causes heat from the combined body 11 close to the pressure plate 15 of the stacking block 13 to the pressure plate 15. It can be prevented from being absorbed and escaped.

[0010]

However, in the thermal barrier A, the metal sheet 16 and the plurality of intermediate plates 17 are formed by folding and bending the long metal sheet 16 into a plurality of layers and sandwiching the intermediate plate 17 therebetween. The metal sheet 16 and the plurality of intermediate plates 17 are alternately formed.
The outer plate 18 and the joining plate 19 are arranged so that they do not fall apart.
It is necessary to use it by housing it in a casing formed of the outer plate 18 and the joining plate 19.
The weight is increased by the casing formed by the above, and there is a problem in handling.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a thermal barrier for forming a laminate which has a simple structure and can be formed in a light weight, and a method for producing the same. It is.

[0012]

The thermal barrier for forming a laminate according to the present invention is formed by laminating a plurality of metal sheets 1 via a resin layer 3 in which a prepreg 2 is melt-cured, and the adjacent metal sheets are formed. Sheets 1 are alternately joined at one end and the other end, and adjacent metal sheets 1 are bonded with a resin layer 3 except for the joined end. .

According to a second aspect of the present invention, a plurality of metal sheets 1 and a plurality of prepregs 2 are alternately stacked, and the prepreg is alternately provided between one end of the adjacent metal sheets 1 and the other end. The overlapping position of the metal sheet 1 and the prepreg 2 is adjusted so that the metal sheet 2 is not located, and the superposed product of the metal sheet 1 and the prepreg 2 is heated and pressed.

The invention according to claim 3 is characterized in that an auxiliary prepreg 4 is superimposed on the metal sheet 1 on the side opposite to the prepreg 2 at the end where the prepreg 2 is not located.

[0015]

Embodiments of the present invention will be described below. In the present invention, the metal sheet 1 is not particularly limited as long as it has conductivity, but may be a copper foil, an aluminum foil, a nickel foil, an alloy foil of these metals, or a composite foil of these foils. What was formed with foil can be used. The thickness of the metal sheet 1 is 0.03
A thickness of about 5 to 0.070 mm is preferable for generating resistance heat. As the metal sheet 1, a metal sheet 1a having a shorter width and a metal sheet 1b having a longer width are used, and a metal sheet 1c for an outer layer whose width is longer than the metal sheet 1b is used. It is.

In the present invention, the prepreg 2 may be made of a woven or non-woven fabric of glass fiber or organic fiber, or a base material such as paper, or a phenol resin, an epoxy resin, a polyimide resin, an unsaturated polyester resin, or a polyphenylene ether resin. A resin prepared by impregnating with a varnish of a curable resin and drying to prepare a B-stage state can be used. The prepreg 2 is formed to have a dimension substantially equal to the width dimension of the metal sheet 1a.
In addition, an auxiliary prepreg 4 having a small width is used.

In manufacturing the thermal barrier A, a plurality of metal sheets 1a and a plurality of prepregs 2 are alternately stacked, and the metal sheet 1b is placed outside the metal sheet 1a located at the outermost layer via the prepreg 2. Layer. At this time, as shown in FIG. 1A, the metal sheets 1a, 1a and 1a, 1a, 1b are arranged so that the prepregs 2 are not alternately positioned between one end and the other end. This is for adjusting the overlapping position of the prepreg 2 and the prepreg 2. Therefore, one end and the other end of the adjacent metal sheets 1a, 1a and 1a, 1b are alternately joined to the joint 2
0, the prepreg 2 is interposed between the adjacent metal sheets 1a, 1a and 1a, 1b at portions other than the ends, and the end of each prepreg 2 on the side opposite to the joining portion 20 is protruded. The joining portion 20 of the metal sheet 1a as the portion 21
Rather than projecting outward.

Also, the ends of the metal sheets 1a and 1b on the side where the prepreg 2 is not located, that is, the metal sheets 1a and 1b
The auxiliary prepreg 4 is overlapped on the opposite side of the prepreg 2 at the joint 20 of b. The width of the auxiliary prepreg 4 is substantially equal to the sum of the width of the protrusion 21 of the prepreg 2 and the width of the joint 20 of the metal sheet 1a. 20 from the prepreg 2 to the protrusion 21.

Further, an outer layer metal sheet 1c is superposed on the outside of the metal sheet 1b. The overlapping position of the outer metal sheet 1c is adjusted so that one end of the outer metal sheet 1c protrudes outward from the joint 20 of the metal sheet 1b.
The auxiliary prepreg 4 is sandwiched between the joint 20 of FIG. 2B and the end of the outer layer metal sheet 1c. After the metal sheets 1a, 1b, and 1c, the prepreg 2, and the auxiliary prepreg 4 are overlapped as described above, the prepreg 2 and the auxiliary prepreg 4 are melt-hardened by heating and pressing the laminated material to form a laminate. Each of the above-mentioned metal sheets 1a,
1b and 1c can be laminated and integrated to produce a thermal barrier A as shown in FIG. 1 (b).

Here, as described above, one end and the other end of the adjacent metal sheets 1a, 1a and 1a, 1b alternately face each other as the joining portion 20, so that they are laminated as described above. At the time of molding, the joining portions 20 facing each other are pressed and brought into close contact with each other. In particular, the auxiliary prepreg 4
Since the auxiliary prepregs 4 are overlapped with each other, a large pressing force acts on the joining portion 20 at the time of lamination molding with the thickness of the auxiliary prepreg 4, and the joining portion 20 can be strongly adhered and joined. The joint 20 is made of the adjacent metal sheet 1
1a and 1a and 1a and 1b are alternately provided at one end and the other end, so that a plurality of metal sheets 1a and 1b are connected in series while meandering as shown in FIG. 1B. Will be. Further, the joining portion 20 is embedded in the resin layer 3 formed by the projecting portion 21 of the prepreg 2 and the auxiliary prepreg 4, and is not exposed to the outside. Further, an outer layer metal sheet 1c is joined to the outside of the metal sheet 1b in a state of being electrically connected to the metal sheet 1b, and the outer layer metal sheet 1c forms the surface of the thermal barrier A.

Thermal barrier A produced as described above
, A metal-clad laminate can be formed as shown in FIG. That is, a long metal foil 10 is used, and a plurality of sets of the combination body 11 and a plurality of sheets of the electrically insulating material are folded between the metal foils 10 which are folded and bent a plurality of times and which are opposed to each other. Forming plate 12
Are alternately sandwiched to produce a stacked block 13 composed of a plurality of metal foils 10 bent in a meandering shape, a plurality of sets 11 combined in multiple stages, and a plurality of forming plates 12. The combination body 11 is formed by combining a plurality of prepregs 14 as a set (or as a set of a prepreg and an inner layer circuit board as a set). As the prepreg 14, a base material such as a woven or nonwoven fabric of glass fiber or organic fiber or paper is impregnated with a varnish of a thermosetting resin such as a phenol resin, an epoxy resin, a polyimide resin, an unsaturated polyester resin, or a polyphenylene ether resin. What was prepared by drying can be used. Further, as the metal foil 10, a copper foil, an aluminum foil, a nickel foil, an alloy foil of these metals, a composite foil of these foils, or the like can be used.

The upper and lower sides of the stacking block 13 are sandwiched between a pair of thermal barriers A, A, which are sandwiched and set between the upper and lower pressure plates 15, 15. The outer metal sheet 1c on the upper side of the thermal barrier A and the outer metal sheet 1c on the lower side of the lower thermal barrier A are connected to a power source and energized to perform molding. That is, when the electric current is supplied in this manner, the electric current is applied to the outer metal sheet 1 c and the metal sheet 1
a, the metal sheet 1b, flows through the outer layer metal sheet 1c, and further flows into the metal foil 10 in contact with the outer layer metal sheet 1c. Accordingly, the metal foil 10 generates heat by Joule heat due to the flow of the current, and the heat generated by the metal foil 10 heats the prepreg 14 of the combined body 11 of each set of the stacked blocks 13 to laminate the metal foil 10 and the prepreg 14. It can mold an integrated metal foil-clad laminate,
In addition, the metal sheet 1 of each thermal barrier A is generated by the current flow.
a, 1b, and 1c generate heat by Joule heat, so that heat can be prevented from being absorbed by the pressure plate 15 and escaping from the combined body 11 of the stacked block 13 near the pressure plate 15. Note that a cushion material such as cellulose paper or aramid fiber paper or a heat conduction adjusting material may be interposed between the thermal barrier A and the stacking block 13 or between the thermal barrier A and the pressure plate 15.

In the above-described embodiment, the thermal barrier A according to the present invention is used in a method of applying heat to a metal foil to generate heat to perform heat and pressure molding. It is not limited to use in such a construction method, but can also be used as a heat source at the time of heat and pressure molding, and by applying a current between the upper and lower outer metal sheets 1c, It can be used alone as a general heater.

[0024]

As described above, the thermal barrier for forming a laminate according to the present invention is formed by laminating a plurality of metal sheets via a resin layer in which a prepreg is melt-cured, and alternately arranges adjacent metal sheets. And the other end is joined together and the adjacent metal sheets are bonded with a resin layer except for the end to be joined, so that a plurality of metal sheets are alternately connected to one end. The part and the other end are bonded together with a prepreg resin layer in a state where they are joined, and they are laminated and integrated.Therefore, there is no need to put them in a casing, and the structure can be easily formed. It can be formed as well as lightweight.

Further, the method for manufacturing a thermal barrier for forming a laminate according to the present invention is characterized in that a plurality of metal sheets and a plurality of prepregs are alternately overlapped, and between one end of an adjacent metal sheet and the other end. Adjust the overlapping position of the metal sheet and prepreg so that the prepreg does not alternate between
Because the metal sheet and the prepreg were formed by heating and pressing, the metal sheets were alternately laminated with the resin layer of the prepreg with one end and the other end joined alternately. The thermal barrier for forming a laminate can be easily manufactured simply by heating and pressing.

In producing the thermal barrier for forming a laminate by heat-press molding as described above, an auxiliary prepreg is placed on the side of the metal sheet opposite to the prepreg at the end where the prepreg is not located. With the thickness of the auxiliary prepreg, the pressing force can be greatly applied to the end of the metal sheet on the side where the prepreg is not located at the time of the heat and pressure molding, and the end portions of the adjacent metal sheets are connected to each other. Can be strongly adhered and joined.

[Brief description of the drawings]

FIG. 1 shows an example of an embodiment of the present invention,
(A) is an exploded sectional view, (b) is a sectional view.

FIG. 2 is a front view showing the formation of a laminate.

FIG. 3 is a sectional view showing a conventional thermal barrier.

[Explanation of symbols]

 Reference Signs List 1 metal sheet 2 prepreg 3 resin layer 4 auxiliary prepreg

Continued on the front page (51) Int.Cl. ⁶ Identification code FI // B29K 105: 08 B29L 9:00 31:34

Claims (3)

[Claims] A metal sheet is formed by laminating a plurality of metal sheets via a resin layer in which a prepreg is melt-cured, and adjacent metal sheets are alternately joined at one end and the other end. A thermal barrier for forming a laminate, characterized in that adjacent metal sheets except for the end to be joined are bonded with a resin layer. 2. A metal sheet and a prepreg, wherein a plurality of metal sheets and a plurality of prepregs are alternately stacked, and the prepreg is not alternately positioned between one end and the other end of an adjacent metal sheet. A method for producing a thermal barrier for forming a laminate, comprising: adjusting the overlapping position of the metal sheet; and heating and press-molding the overlapped product of the metal sheet and the prepreg. 3. The method for manufacturing a thermal barrier for forming a laminate according to claim 2, wherein an auxiliary prepreg is overlapped on the side of the metal sheet opposite to the prepreg at the end where the prepreg is not located.