JP2507238B2 - Method for manufacturing multilayer printed circuit board - Google Patents

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 printed circuit board used in electronic circuit equipment.

[0002]

2. Description of the Related Art A multilayer printed circuit board having five or more layers generally includes two or more inner layer printed circuit boards.
A copper foil or a copper foil-clad laminate is placed on at least one surface through a prepreg and laminated, and the whole is laminated under heat and pressure to form a multilayer printed circuit board, and then through for connecting circuits between layers. A multi-layer printed circuit board is obtained through various processes such as forming a hole hole, plating by connecting to a wall surface of the through hole hole by through hole, and forming a circuit pattern on an outer layer. In this way, through-holes are processed from the outside after heat-press lamination, and the walls of the through-holes are plated with through-holes to electrically connect the inner-layer interlayer and the outer-layer copper foil. It is necessary to align the interlayer positions of the circuit board accurately, and at least 50 to 1
It should be kept below 00 microns. Therefore, the conventional manufacturing method uses a method called pin lami. Taking a six-layer printed circuit board as an example, as shown in FIG. 7, the upper and lower alignment molds 10, 10 'with the guide bins 14, ... Double-sided printed circuit boards 18, 19, two single-sided copper clad laminates 16a, 16b for outer layers, and a prepreg 1 interposed therebetween
Guide holes 14 for positioning are formed in 7, 17 and 17, respectively, and guide pins 14, ...
4. One side copper clad laminate 16a for lower outer layer, prepreg 1
7, double-sided printed circuit board for inner layer 18, prepreg 17,
The inner-side double-sided printed circuit board 19, the prepreg 17, and the upper-side outer-layer single-sided copper clad laminate 16b are inserted into the guide holes in this order and aligned to stack one multilayer printed circuit board, and if necessary, stack multiple boards. In this case, stacking is performed in the same manner through a mirror surface plate 15 in which a hole into which a guide pin is loosely inserted is previously formed, and finally, the upper mold 10 'is combined and pressure-heated to be laminated and integrated. Position accuracy between two inner-sided double-sided printed circuit boards is about 10
It is said to be 0 micron or less. However, in this conventional method for manufacturing a multilayer printed circuit board, the resin of the prepregs 17, 17, 17 flows out during pressurization and heating, and the guide pin 1
There is a problem that the contraction due to the curing of the prepreg resin is applied to the guide pins as a large stress to reach around 4, ... Also,
Once the prepreg resin has adhered to the guide pins, the guide pins 14, ... Are to be removed. However, when the guide pins are removed, the weight of the molds 10 and 10 'is added to the laminated integrated product, making it very heavy. There is a problem in that it is often necessary to move it, and the moving work is dangerous, and there is also a problem that it takes time to remove the guide pin and other work to remove the plate. In addition, since the weight is heavy, it is difficult to mold with a large-sized press, and there is a problem that mass productivity is poor.

[0003]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides two or more printed wiring boards for inner layers with a conductive foil or a conductive foil-clad laminate on at least one surface via a prepreg. In a method for manufacturing a multilayer printed circuit board that is placed and overlapped, and is sandwiched between mirror plates to heat and pressure laminate them between hot plates, in the four sides or the opposite two sides around the mirror plate, perpendicular to the hot plate. A positioning jig having standing guide pins is arranged to form the inner layer printed wiring board in an enlarged width with respect to the mirror surface plate, and a guide for alignment between the inner layer printed wiring boards in the enlarged width portion. A multi-layer print characterized in that a hole is formed, and the guide pin of the positioning jig is inserted into the guide hole to maintain the alignment of the inner layer printed wiring boards with each other while heating and pressurizing and laminating the whole. Circuit board Than it was constructed in the manufacturing process. The positioning jig is formed into a rod shape or an annular shape as shown in FIG. As shown in FIG. 4, the rod-shaped members may be combined and fixed in an annular shape, or may be arranged in two opposite rows. Incidentally, in the case of arranging in opposite two rows, FIG.
As shown in (3), the vertical stability is improved by forming the protrusion 3a on the edge of the rod-shaped body. As shown in FIG. 5, the rod-shaped or ring-shaped positioning jig has a generally rectangular cross section, but if ribs 3b are formed in the longitudinal direction, it can be reinforced by reducing the increase in weight, so that it is a long object. However, the deformation is reduced. The positioning jig is preferably excellent in dimensional stability against heating temperature, to request of high accuracy, as shown in FIG. 6, the thermal expansion of the core on both sides of the core 3 ₁ When the positioning jig is formed by using the laminated structure sandwiched by the separate materials 3 ₂ and 3 ₂ having the coefficient of thermal expansion that compensates for the coefficient, the temperature change can be extremely reduced.

[0003]

According to the present invention, since the guide hole for alignment is formed in the enlarged width portion of only the inner layer printed circuit board having the enlarged width of the laminated material, the flow of the prepreg resin does not reach the guide pin. Therefore, the guide pin is less likely to be fixed by adhesion. Even if the flow of the prepreg resin reaches the guide pins, the overall weight is reduced by the weight of the positioning jig, and the risk of moving work to remove and remove the adhered guide pins is reduced. Reduce.

[0004]

As described above, according to the method for manufacturing a multilayer printed circuit board of the present invention, the position of the interlayer can be maintained with high accuracy by using a lightweight positioning jig, and at the same time, the guide pin is moved to the guide pin by the flow of the prepreg resin. Even if it is adhered to the guide pin, the total weight will be lightened by the weight of the positioning jig, which reduces the risk of moving work to remove the adhered guide pin and dismantle it. Then there is the effect. Also, since the conventional mirror surface plate is used as it is, except for using the positioning jig,
Molding is possible even with a large press, and it has the effect of being excellent in mass productivity.

[Brief description of drawings]

FIG. 1 is an explanatory cross-sectional view of a method for manufacturing a six-layer printed wiring board according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II ′ of FIG.

FIG. 3 is a layout view of a positioning jig.

FIG. 4 is a layout view of a positioning jig.

FIG. 5 is a three-dimensional cross-sectional view of a placement jig.

FIG. 6 is a three-dimensional cross-sectional view of a positioning jig.

FIG. 7 is an explanatory view of a method for manufacturing a six-layer printed wiring board for explaining a conventional example.

FIG. 8 is an explanatory view of a state in which a laminated integrated product and a lower mold are bonded and integrated in a conventional example.

[Explanation of symbols]

1, 1 ', 11, 11' ... Hot plates respectively. 2, 2 ', 12, 12' ... Cushion materials, respectively. 3 ... Positioning jig. 3a ... Projection. 3b ... rib. 4, 14 ... Guide pins respectively. 5, 15 ... Each is a mirror plate. 6a, 16a ... Single-sided copper clad laminates for outer layers on the lower side respectively. 6b, 16b ... Single-sided copper clad laminates for outer layers on the upper side. 7, 17 ... Each is a prepreg. 8a, 18a, 9a, 19a ... Double-sided printed circuit boards for inner layers, respectively. 10 ... Lower mold. 10 '... Upper mold.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B29L 31:34 B29L 31:34

Claims (1)

(57) [Claims] 1. Two or more inner layer printed wiring boards are placed on at least one surface of a conductive foil or a conductive foil-clad laminate through a prepreg, and they are superposed, sandwiched between mirror surface plates, and heated and pressed between hot plates. in the production process of the substrate for a multilayer printed circuit integrally laminated, the positioning jig having a guide pin provided upright perpendicularly to the heating plate around four sides or opposite two sides <br/> near specular plate The inner layer printed wiring board is formed in an enlarged width with respect to the mirror surface plate, and a guide hole for aligning the inner layer printed wiring boards with each other is formed in the enlarged width portion.
A method for manufacturing a multilayer printed circuit board, characterized in that a guide pin of the positioning jig is inserted into the guide hole, and the entire printed wiring boards for inner layers are kept in alignment with each other and integrated by heating and pressing. .