JPS636891A - Composite metal core printed circuit substrate - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention 1 (Industrial Application Field) The present invention relates to a composite metal core printed circuit board that has excellent through-hole processability and heat dissipation properties, and facilitates high-density mounting.

(Prior art) Metal core printed circuit boards have a metal plate as a core with insulating layers on both sides, and a conductive layer on the outside, and have particularly excellent heat dissipation and mechanical properties. ,−
It is used for membrane circuits and hybrid integrated circuits. Initially, these metal core printed circuit boards were mainly those with copper foil on one side, and up until the recent high-density mounting stage, the circuits had been made into fine patterns and the circuit density was increased. There are limits to this. Therefore, there is a need for a type that can accommodate higher density while retaining the excellent characteristics of the prior art, and as a result, substrates capable of double-sided through holes have been developed. For example, the core is a metal plate with holes for forming through-holes, and metal foil is laminated on both sides of the core with an insulating layer of glass woven cloth impregnated with resin (Japanese Patent Laid-Open No. 61-46092). ,
Furthermore, it is possible to perform heating and pressure molding under reduced pressure conditions to fill the holes for through-hole molding with resin and remove air bubbles, etc.
I Kaisho e1-9284'ls) W X San T
Il.

However, even with the above-mentioned double-sided through-hole substrate, not only are the characteristics of the through-holes sufficiently satisfactory, but also considerable equipment is required to perform heating and pressure forming under reduced pressure conditions, which causes problems in the manufacturing process. This has the disadvantage that it becomes IN, further increasing the cost. In addition, in terms of heat dissipation,
Another drawback remains that it cannot adequately deal with localized heat generation caused by high-density packaging.

(Problems to be Solved by the Invention) The present invention has been made in view of the above circumstances. To provide a composite metal core printed circuit board that can be processed through holes to the same extent as an i-board, has excellent heat dissipation even when it comes to local heat generation, is lightweight and compact, and can be easily mounted at high density. It is something.

[Structure of the invention] (Means and effects for solving the problem) As a result of intensive research to achieve the above object, the inventor has discovered that a composite material having a metal layer only in necessary parts can be used. It was discovered that this method enables highly reliable through-hole processing, has excellent heat dissipation properties, and is compatible with high-density mounting, and that when used, the electronic separate device can be made smaller and lighter, and the present invention was completed. This is what I did.

That is, the present invention is characterized in that, in a metal core printed circuit board having a conductive layer on at least one side through insulating layers on both sides of the metal core, a composite material having a metal layer on a part is used as the joint core. This is a composite metal core printed circuit board. Hereinafter, the configuration of the present invention will be explained in detail.

The composite used as the metal core in the present invention is not particularly limited as long as it has a metal layer on the lower part thereof, and various materials may be used. For example, a laminate with a metal plate on the inside, a laminate with a circuit on the surface, a VA laminate with a metal plate on the inside and a circuit on the surface, a multilayer board, polyphenylene sulfide resin or polyether. Examples include a sheet-like product formed by wrapping a metal plate with imide resin or the like, a molded product with a circuit formed thereon, and the like. The metal layer may be metal foil, metal plate, metal mesh, metal plating, etc., but usually a metal plate is used, and metal plates include tAtfi, stainless steel plate, aluminum plate, brass plate, copper plate, nickel plate, and invar plate. etc.

Next, the substrate of the present invention will be explained with reference to the drawings. FIG. 1 is a sectional view of a substrate i in which a metal plate 2 is fitted into a portion of a laminate 1, that is, a composite β- having a metal layer is used as a metal core.

The composite 3 shown in FIG. 1 is produced, for example, by the following steps. First, a base material such as glass woven cloth or glass paper is impregnated with thermosetting resin such as epoxy resin or polyimide resin.
A laminate 1 obtained by stacking the required number of coated and dried prepregs and molding them under heat and pressure is prepared, and as shown in FIG.
As shown in a), when this laminated board 1 is used as a circuit board, the part that generates the most heat is punched out to an appropriate size, and the punched part 1a is
As shown in FIG. 2(b), a metal plate 2 having the same thickness as the laminate 1 and the same size as the punched portion 1a is inserted/
Let υ be compound 3.

The substrate 6 in FIG. 1 has the composite 3 as a metal core, an insulating layer 4 on both sides using the same prepreg as that used for the composite 3, and a conductive layer 5 on the surface of the substrate to form the composite metal core. This is a printed circuit board.

The metal layer 2 portion of the composite 3 may have any pattern;
O-type metal layer 32 in FIG. 3, P-type metal layer 42 in FIG.
Alternatively, a metal layer 52 having a plurality of holes 7 for through holes as shown in FIG. 5 may be used.

The metal layer 2, like the metal layer 62a in the composite 63 shown in FIG. 6, may be on the same plane as the laminate 1 (or it may be included inside the laminate 1 and not exposed on the surface).
In short, it is necessary to select the most suitable pattern for the heat generating portion.

Furthermore, like the composite 63 shown in FIG. 6, it may have a metal layer 62a in a necessary part of the interior and a metal layer 62b in a necessary part of the surface, or the composite 63 may have multiple layers instead of one layer. may be incorporated.

The insulating layer used in the present invention may be a prepreg prepared by coating a base material with a thermosetting resin in advance, impregnating it, and drying it to a semi-cured state;
A thermosetting resin powder in a semi-hardened state is used. Glass woven cloth, glass paper, etc. are used as the base material of the prepreg of the insulating layer, and phenol resin, epoxy resin, polyimide resin, etc. are used as the thermosetting resin.

The resin and base material used for this insulating layer are preferably the same as the resin and base material of the composite, but may be different.

The conductive layer used in the present invention may be any layer as long as it can form a circuit, such as a metal foil, a plating layer, or a conductive paste layer. When using metal foil such as copper foil,
When manufacturing the substrate of the present invention, it can be formed into a laminate as the outermost layer, and it is suitable for being made by humans, so it has great manufacturing advantages.

The conductive layer may be on one side, but if it is on both sides, copper foil-t
j4tFB, copper foil-plated layer (by additive method)
, plating layer-plating layer, etc. may be used.

The circuit board of the present invention may be one in which two or more sets of a conductive layer, an insulating layer, a metal fur insulating layer, and a conductive layer are laminated with another insulating layer interposed therebetween.

If a composite material having a metal layer in a portion is used as the metal core, heat can be easily dissipated from a portion that does not easily generate heat through the metal layer. To further increase heat dissipation efficiency, the insulating layer of the substrate can be shaved to expose a portion of the metal layer of the composite for contact with other cooling fins. Similarly, a part of the insulating layer of the board is scraped off and a chip is placed in the thinner part of the insulating layer to be used as a chip-on-board. In this case, heat can be dissipated from the metal layer under the chip. can. Since the parts other than the metal layer of composite materials are ordinary glass substrates or synthetic resins, the same method used for processing conventional glass substrate laminates can be applied to small diameter through-holes, which increases the reliability of through-holes. You can get something with high quality.

(Examples) Next, the present invention will be specifically explained by examples, but the present invention is not limited by these examples.

Example 1 520x 400x O, 5mm (7) jjU';1
．． 300x 150x 0.5 with a punching press as shown in part 1a of Figure 2 (a'') on the FAFIJ board (TLB-551 manufactured by Toshiba Chemical ■, product name).
Process the part with a size of mm by hammering method. Next, after chemically treating a copper plate of the same size and thickness as the punched part, it is attached to the punched part 1a of the glass epoxy laminate as shown in Fig. 2(b).
Insert it like this. As shown in Figure 1, a composite is made of a glass epoxy laminate in which a copper plate is fitted and integrated, epoxy prepreg is placed on both sides, and an electrolytic copper foil with a thickness of 18 μm is layered on the outside. Sandwiched between stainless steel plates and pressed at 175℃ and 40kmcan2.
After molding for 180 minutes, a composite metal core printed circuit board having a thickness of t and 6 mm was obtained. Although components that tend to generate heat are placed on this substrate, the heat dissipation is good, and the processing of component holes and conduction holes similar to glass substrate laminates is easy, and the reliability is high. Admitted.

Example 2 520X 400X O, 61111 glass polyimide 8! A portion measuring 250 x 400 x O, 6 am was router-processed on an i-layer board (TLB-583 manufactured by Toshiba Chemical ■, trade name). Next, a chemically treated copper plate of the same size was inserted into this hammered part to create a composite.

Polyimide prepreg (Toshiba Chemical I@
(manufactured by TLP-583), and then a layer with a thickness of 1 mm on both sides.
An 8 μm electrolytic copper foil was placed, and then this was sandwiched between stainless steel plates and molded for 230 minutes at a temperature of 195° C. and a pressure of 45 kg/cm 2 to obtain a composite metal core printed circuit board with a thickness of 1.6 mm. Highly integrated devices were placed on top of the copper plate of this board, and heat dissipation was good. In addition, component holes and conductive holes similar to glass substrate laminate 1 could be easily and reliably processed, and the effects of the present invention were confirmed.

Example 3 A composite metal core/printed circuit board was obtained in the same manner as in Example 2 except that an aluminum plate was used instead of the copper plate. The substrate had excellent heat dissipation properties, was easy to process through-holes, and was highly reliable, thus confirming the effects of the present invention.

Example 4 As shown in FIG. 6, a glass epoxy laminate having a copper plate 62a inside and 10 μm copper foil on both sides was used as a circuit 6.
After forming 2b, the circuit surface was chemically treated to obtain composite 63. Next, epoxy prepreg 4 is layered on both sides of this composite 63, and 18 μm electrolytic copper foil 5 is further placed on both sides, and sandwiched between stainless steel plates at a temperature of 175°C and a pressure of 40k.
The composite metal core printed circuit board was molded for 180 minutes under the conditions of g/cm2. This substrate has excellent heat dissipation properties, and like a glass substrate laminate, component holes and conductive holes can be easily processed and is highly reliable, and the effects of the present invention were recognized.

[Effects of the Invention] As explained above, the composite metal core printed circuit board of the present invention can process component holes and conductive holes with high reliability similar to that of general glass substrate laminates, and also has the following advantages: It has particularly excellent heat dissipation properties in response to localized heat generation due to the arrangement of heat-generating parts, and as a result, high-density mounting is possible.Furthermore, there is no need for complex manufacturing processes such as vacuum molding, and product cost increases can be suppressed. It is something that is higher up.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a composite metal core printed circuit board according to an embodiment of the present invention, and FIGS. IJ manufacturing process complete process diagram, Figure 3~
FIG. 5 is a perspective view showing another composite used in the substrate of the present invention, and FIG. 6 is a sectional view showing another embodiment of the substrate of the present invention. DESCRIPTION OF SYMBOLS 1... Laminate board, 2.62a, 62b... Metal scrap, 3.63... Composite, 4... Insulating layer, 5...
・Conductive layer. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. Composite metal core printing characterized in that a metal core printed circuit board having a conductive layer on at least one side through insulating layers on both sides of the metal core is characterized in that a composite material having a metal layer in part is used as the metal core. Circuit board.