JPS6110981Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to the improvement of a mold used when laminating laminated printed boards, and more specifically, to prevent deformation due to pressure and heating during lamination of laminated printed boards, and to produce high quality molds with good flatness. This invention relates to improvements in molds for producing laminated printed boards.

In recent years, with the miniaturization of transistors, ICs, and other electronic components, the wiring density of printed circuit boards has become higher, and the intervals between printed boards are placed very close together during mounting, resulting in slight tilting, tilting, or Warpage and the like also have a large effect on reliability.

Conventionally, molds for laminated printed boards of this type have usually had a shape as shown in FIG.

In the figure, 1 is a mold called an upper mold, and 2 is a mold called a lower mold, both of which have flat surfaces facing each other to at least hold the laminate, and are used as a pair.
Reference numeral 3 denotes a laminate consisting of a substrate and a prepreg, which is heated under pressure by molds 1 and 2 to melt the adhesive in the laminate and complete the bonded laminate printed board.

However, when the above mold for a laminated printed board is used, the adhesive melted by heating tends to flow out and become thinner at the peripheral edges of the printed board, as shown in FIG.

FIG. 3 is a diagram showing a cross section of the conventional laminated printed board after lamination. According to the double-sided flat mold, the edge portions become thinner for the reasons described above, and the difference from the center portion is usually small. There will be a variation of about ±0.3mm.

This has led to problems such as warping and twisting of the board, causing many problems in mounting components.

In view of the above-mentioned problems, the purpose of the present invention is to provide a mold for obtaining a highly reliable laminated printed board that has a uniform board thickness and is free from warping, twisting, etc. after lamination. There is a particular thing.

The feature of the present invention is that the shape of the mold used during laminated molding is such that the thickness of the mold at the center part that holds the laminate is thicker than that at the ends.

An embodiment of the present invention will be described below with reference to the drawings.

Fig. 4 shows an embodiment of the laminated printed board mold of the present invention, in which A is a top view, A ₁ and A ₂ are side sectional views, and B is a top view of another embodiment. Figures B ₁ and B ₂ are a side view and a cross-sectional view, respectively.

Figure A shows the upper and lower molds 1 and 2, with their peripheral parts 8 bordered and their central parts 7 thickened.
Place a flat plate on the back of the mold as shown in A ₁ to make the center part evenly thick.

In another embodiment, as shown in Figure _A2 , plates each having a spherical surface on one side are stacked to raise the back surface of the central portion.

Figure B ₁ is a model in which the wall thickness is increased at the back of the mold itself from the ends of the mold to the center.
shows a spherical surface, and _B2 in the same figure shows a shape in which the central part is flat and the ends are inclined and tapered.

The cross section of printed boards laminated using the molds shown in Figures A and B above is as shown in Figure 5, and the cross section of printed boards laminated using the molds shown in Figure 4A is as shown in Figure A, with a center portion 5 and an end portion 6. The thickness is approximately the same, and the seam is slightly thinner.

Furthermore, when using Fig. 4B, as shown in Fig. 4B, the center portion 5 and the end portions 6 are laminated with almost the same thickness compared to those in Fig. 3, although there are manufacturing variations of course. Can be done.

As a result of experiments, the inventor of each of the molds shown in FIG. 4 A and B based on the present invention found that the thickness can be reduced from the conventional ±0.3 mm to ±0.1 mm or less. Make sure you get the printed board.

As explained above, in the mold for laminated printed circuit boards according to the present invention, the center part of the mold is made thicker than the end parts, so that the pressing force during lamination is applied more to the center part, so the thickness after pressure heating is It is possible to obtain a highly reliable laminated printed board that is substantially uniform, flat, and has little variation, and its practical effects are extremely large.

[Brief explanation of the drawing]

FIGS. 1, 2, and 3 are cross-sectional views illustrating lamination using a conventional mold for laminated plates. FIG. 4 is a top and side sectional view of a mold for laminated printed boards according to the present invention. FIG. 5 is a sectional view of a printed board laminated by the mold of FIG. 4. 1, 2... Mold, 3... Laminate, 4... Adhesive (resin, etc.), 5... Central part of the laminate, 6... End of the laminate, 7... Center part of the mold, 8... ...Mold end.

Claims (1)

[Scope of utility model registration request] A mold comprising a pair of upper and lower molds having opposing surfaces for holding a laminate, the laminate being interposed between the opposing surfaces, and pressurized and heated to form a laminated printed board. A mold for a laminated printed board, characterized in that a portion of the mold that clamps the center of the laminate is thicker than a portion that clamps the end portions of the laminate.