JPH04171794A - Manufacture of metal-clad laminate board - Google Patents

Abstract

PURPOSE:To ensure a reliability test even with a very thin base material layer by superimposing on one surface of a prepreg a metal foil with four sides each side being longer by a predetermined length than the prepreg and an upper mirror plate of the same size as the former, and further superimposing on the opposite surface a metal foil with four sides each side being shorter by a predetermined length than the prepreg and a lower mirror plate of the same size as the upper mirror plate. CONSTITUTION:A prepreg 2 is held between a metal foil 1 with its four sides, each side being longer about 5-150mm than the prepreg and a metal foil 8 with four sides, each side being shorter by about 5-100mm than the prepreg, and further an upper mirror plate 3 of the same size as the metal foil 1 is superimposed on the prepreg and a lower mirror plate 3 of the same size as the lower mirror plate superimposed. Further, a mold-release sheet 4 is bonded to the inner surface of the lower mirror plate 3 so as to overlap the end of the metal foil 8. The constituent material described above is heated and pressurized and molded to yield a metal-clad laminate board Hereby, there can securely be performed an electrical raliability test of the metal-clad laminate board comprising an about 50-100mum thick insulating base material before processing a circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a metal-clad laminate that does not stain the end plate and can pass electrical reliability tests.

[Conventional technology]

Recently, with the increase in density and miniaturization of printed wiring boards, it has become necessary to have even higher electrical reliability in the insulation properties of the Kanasu board. Therefore, it is necessary to conduct electrical reliability tests during the manufacturing process of metal-clad laminates.

As shown in Figure 3, the electrical reliability test was carried out by applying 5 t-poles of an earthwork metal foil IVc tester to a metal-clad laminate that had been manufactured and cut into a predetermined size as a ``C product. Perform the test by applying a voltage r.This test is important because it can be performed non-destructively before processing the metal foil into a circuit.
Ru.

[Problem to be solved by the invention]

There are the following issues in conducting electrical reliability tests without any problems.

In the manufacturing process of metal-clad laminates, as shown in FIG.
Heat and pressure molding is performed using a press to form a sandwiched structure. Is the prepreg resin leaking out from the peripheral equipment during this molding? To avoid contamination, place the four sides of the four sides of the pudding leg 2 in the metal recess.
Shorten by ~150mm. Is this size relationship in Figure 4? show.

However, this method does not damage the equipment due to the resin spilled, but the ends of the upper and lower foils partially touch each other, resulting in the state shown in Figure 5, which may cause electrical reliability testing. I can't do it. Therefore, after hot-pressing molding, the edges were cut to obtain a metal-clad laminate of a predetermined size, and then all tests were conducted as shown in FIG. This method has been commonly used in the past, but it does not cause any problems when the prepreg layer is thick.

However, if the prepreg layer is 100 μm or less, the sixth
As shown in the figure, the metal foil chips 7 generated during cutting are electrically 4il! ! It is not possible to conduct all electrical reliability tests due to the high power source.

The insulating base material layer (prepreg layer) of metal-clad laminates tends to become thinner and thinner as the density of printed IL boards increases, and in recent years metal-clad laminates with extremely thin base layers of 50 to 100 μm have become thinner and thinner. IJS8i layer machines have appeared.

Under these circumstances, it is necessary to conduct a complete electrical reliability test and screen out defects in advance before circuit processing of the metal foil, but the current situation is such that it is impossible to do so.

The present invention provides a method for manufacturing metal-clad laminates that allows electrical reliability testing to be performed before circuit installation even for extremely thin base material layers, and that does not require mirror sheet metal cutting. 7 purposes.

〔assignment? Means to solve]

In order to achieve the above object, the present invention provides a method for manufacturing metal clad laminates in which metal foil is layered on both sides of a prepreg, and furthermore, mirror layers are placed on both sides to form metal clad laminates under heat and pressure. The four sides on one side of the prepreg are 5~
150 square length metal foil and the same size overlapping sheet board, metal foil with four sides 5 to 100 mm shorter than the prepreg on the opposite side, and a lower iron plate of the same size as the mirror plate, and the inner surface of the lower mirror plate. A structure in which the part that does not overlap with the adjacent short metal foil and the part that is continuous with the VC releasable sheet are completely adhered? A plurality of sets are stacked and molded under heat and pressure, and the obtained metal-clad laminate is subjected to all electrical reliability tests after removing the plate r, and then the entire peripheral portion is removed to obtain a metal-clad laminate of a predetermined size.

In FIG. 1, which shows the g'' laminated structure 2, which explains the present invention through drawings, the prepreg 2' has four sides of t''L,
5~150ff1m long metal foil 1 and 5~100 (11+
Sandwich it between 1 short piece of metal foil 8 and 4, then layer 3 pieces of metal foil 1 and 3 pieces of the same size on top of that, and below that layer 6 pieces of lower mirror plate of 1 town size. On the inner surface of the lower whip 3, a releasable sheet 4 is formed in a portion that does not correspond to the metal foil 8 and in some continuous portions. This distance 8! The adhesive sheet must be overlapped with the end of the metal foil 8 because it prevents the resin flowing out from the prepreg 2 from forming a circle with the mirror plate when molding with the above configuration. Furthermore, although there are no conditions for IvI regarding the thickness of the releasable sheet, it is better to use it than prepreg.

Is the structure of the number set sandwiched between the laminated dog meeting mirror plates obtained by the method of the present invention? It is removed, subjected to electric FIFJ reliable testing in the manner shown in FIG. 2, and then cut to the periphery to obtain a metal-clad laminate of predetermined dimensions.

[Effect]

According to the method of the present invention, when an electrical reliability test sound is generated, the distance σ) fl! Although the surface distance of the edge layer 20 is long, there is no electrical short circuit.

Therefore, according to the method of the present invention, the test strip q-VtJ- and the insulating layer between the metal foils with the insulating layer 2 interposed therebetween can be accurately measured.

〔Example〕

Epoxy resin on glass cloth as prepreg 2 in Figure 1? Impregnated and dried to a thickness of 7 D am and a size of 1 oao++
71 pieces of no-square pieces were used. On top of that, the thickness is 35 l1
m size 1060111111 square copper i 1 km,
Below that, 8 liters of copper foil with a thickness of 65 μm and a size of 950 mm square.
I fell asleep. The size of the cast plate was 1060 mm square, and a releasable sheet of Nidofloor adhesive tape (Nitto Denko Co., Ltd.) of width (30+ am) was used in contact with the periphery of the inner surface of the mirror root.

200 sheets of copper-clad laminates were prepared by stacking 5 ICs of the above constituent materials as shown in FIG. 1 and hot-pressing them at ℃. All withstanding voltage tests at 500 volts of direct current were carried out under the conditions shown in FIG. 2.

(Comparative Example) The same prepreg and all the same @ foils used in Example Kf were used, the same 41iI composition as in the conventional method shown in FIG. 4 was used, and heat and pressure molding was carried out under the same conditions as in the Example. After removing 9Qmm from the periphery of the 200 mesh-covered laminates obtained, they were directly placed in the state shown in Figure 3.
Seven 5 nov withstand voltage tests were carried out. (Test) In the withstand voltage test of the @Zhanghuo laminates obtained by the method of the present invention in the examples, 199 out of 200 sheets took root.

One rejected sheet was found to be due to metal pieces being mixed into the prepreg layer as a result of cooking, and the effect of the present invention was 100%.

According to the conventional method in the comparative example, all 200 sheets were rejected. As a result of observing the exposed parts of the insulating base material of the copper-clad laminates, it was found that all of them were in a conductive state between the soil and the depressions, as shown in FIG.

〔Effect of the invention〕

From the results of Examples and Comparative Examples, the effect of non-invention is clear.

The present invention has made it possible to conduct electrical reliability tests on metal-clad laminates fabricated on thin insulating substrates of 50 to 100 .mu.m.

[Brief explanation of drawings]

Figure 1 is the laminated material structure of the present invention, Figure 2 is a diagram of the electrical reliability test of the present invention, Figure 6 is a diagram of the conventional electrical reliability test, and Figure 4 is the conventional laminate material configuration. , FIG. 5 is a molding state with a conventional structure, and FIG. 6 is an explanatory diagram of conventional metal foil chips. 1... Metal foil, 2... Prepreg, 3... End plate, 4...
...Release sheet, 5...Testing machine both poles, 6
......Testing machine, 7...Metal foil chips,
8...Metal foil. -7 chips

Claims (1)

[Claims] 1. On one side of the prepreg, the four sides are 5 to 15 times smaller than the prepreg.
Layer a 0 mm long metal foil and an upper mirror plate, and on the opposite side, overlap a metal foil whose four sides are 5 to 100 mm shorter than the prepreg and a lower mirror plate of the same size as the aforementioned mirror plate, and overlap the adjacent short metal foil on the inner surface of the lower mirror plate. After stacking and molding under heat and pressure a plurality of sets in which releasable sheets are adhered to the non-contact parts and some continuous parts, an electrical reliability test is conducted on the metal-clad laminate obtained by removing the end plate. 1. A method for manufacturing a metal-clad laminate, which comprises cutting a peripheral portion to a predetermined size.