JPH0546996B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for manufacturing a multilayer printed wiring board, and particularly to a lamination method that improves the interlayer positional accuracy of inner layer substrates of a multilayer printed wiring board. [Prior Art] In recent years, there has been an increasing demand for higher density and higher multilayer multilayer printed wiring boards. For this reason, the positional accuracy between the layers of the inner layer substrate after lamination, that is, after the formation of the through hole, short circuit failures and insulation failures due to misalignment between the through hole and the inner layer pattern have become serious problems. The conventional method for laminating multilayer printed wiring boards is to install metal guide pins around the periphery of the lower lamination mold, and to drill guide holes with the same diameter as the guide pins in advance at the same positions as the guide pins in the lamination mold. After assembling the formed outer peripheral substrate, inner layer substrate, and prepreg into a desired configuration and placing a mold on top of the lamination, the layers were laminated under constant heating and pressurizing conditions. [Problems to be Solved by the Invention] However, in the conventional lamination method described above, (a) dimensional variation of the inner layer substrate (for example, glass cloth base material - epoxy resin laminate) during heating and pressurization; (b) Inner layer position accuracy after lamination may be affected due to deflection during lamination assembly due to variations in the pin position accuracy of the lamination mold, variations in the position accuracy of guide holes corresponding to the guide pin positions of the inner layer substrate, deformation of the inner layer substrate due to strain, etc. The drawback was that it was impossible to control with high precision. For this reason, for example, in Japanese Patent Application No. 55-117981, the pitch dimension between the guide holes of the inner layer substrate is reduced at a constant rate with respect to the pitch dimension between the guide pins of the lamination mold. Attempts have been made to control dimensional changes, but with the recent demand for even higher multilayers, it is necessary to make the inner layer substrate thinner. For example, for an inner layer substrate with a plate thickness of 0.1 to 0.2 mm, it is difficult to assemble it into a laminated mold. Sometimes, the guide hole of the inner layer substrate is easily deformed by the guide pin, and it is difficult to improve the positional accuracy of the inner layer substrate after lamination. [Differences between the invention and the prior art] In contrast to the conventional lamination method described above, the present invention (a) aligns the centers of a plurality of inner layer substrates with a guide hole formed at the center of the inner layer substrates, and (b) aligns the centers of a plurality of inner layer substrates with a guide hole formed at the center of the inner layer substrates, and (b) It has the original content of aligning the axes with the elongated guide hole and releasing strain in the direction of the elongated hole. [Means for Solving the Problems] In order to achieve the above object, the method for manufacturing a multilayer printed wiring board according to the present invention includes guiding a laminated base material consisting of an outer layer substrate, an inner layer substrate, and a prepreg onto a laminated mold. A method for manufacturing a multilayer printed wiring board in which the laminated wiring board is assembled and laminated based on pins, wherein the laminated base material has a circular guide hole and an elongated guide hole, and the circular guide hole is formed in the laminated base material. The elongated guide hole is provided at the center of the laminated base material where two axes connecting the midpoints of opposite sides of the laminated base material intersect. The laminated mold includes a first guide pin inscribed in the inner peripheral surface of the circular guide hole of the laminated base material, and a first guide pin inscribed in the inner peripheral surface of the circular guide hole of the laminated base material; A second guide pin is inscribed in the short diameter direction of the guide hole and has a clearance in the long diameter direction, and the laminated base material has a circular guide hole in which the first guide pin of the laminated mold is fitted. At the same time, the second guide pin of the laminated mold is inscribed in the short diameter direction of the elongated guide hole, and a clearance is provided in the long diameter direction to position the peripheral part of the base material. Accordingly, a plurality of laminated base materials are laminated one on top of the other on a laminated mold. [Examples] Examples of the present invention will be described below with reference to the drawings. (Example 1) FIGS. 1 to 3 are diagrams illustrating a first example of the present invention. As shown in FIG. 1, a guide hole 2 with a diameter of 4 to 6 mm is formed at the center of the inner substrate 1a, that is, at the intersection of the X and Y axes connecting the midpoints of opposite sides, and at both ends of the X and Y axes. , an elongated guide hole 3 having a length of 4 to 6 mm in the minor axis direction and 6 to 8 mm in the major axis direction is formed in the Y-axis direction by punching or router machining, respectively. Guide holes 2 and 3 are also formed in the outer layer board 1b and the prepreg 1c in the same way as in the inner layer board 1a. On the other hand, as shown in FIG. 2, on the laminated lower mold 4,
A guide pin 12a having an outer diameter inscribed in the guide hole 2 and a guide pin 13a having a diameter inscribed in the short diameter direction of the guide hole 3 are planted at the same position as the guide holes 2 and 3 of the inner layer substrate 1a. It has been done. In the first embodiment, on a laminated lower mold 4 having a thickness of 5 to 10 mm, an outer layer substrate 1b in which guide holes 2 and 3 are formed in the same way as the inner layer substrate 1a, a plurality of prepregs 1c, and a plurality of inner layer substrates 1a are placed. , the laminated structure substrate 1
They are assembled and stacked on the basis of circular guide pins 12a and 13a having outer dimensions inscribed in the short diameter direction of the circular guide holes 2 and elongated guide holes 3 of a, 1b and 1c, respectively. FIG. 3 is a plan view showing how the guide pins 12a, 13a and the guide holes 2, 3 of the inner layer substrate 1a are fitted when the inner layer substrate 1a is assembled on the laminated lower mold 4. After that, the laminated lower mold 4 shown in FIG.
A mold 5 with a thickness of 5 to 10 mm formed with pin fitting holes 12 and 13 into which the guide pins 12a and 13a fit is placed on top of the laminate, and is heated and pressurized under certain conditions using a laminate press to form a laminate. to complete the multilayer printed wiring board of the present invention. (Example 2) FIG. 4 is a diagram illustrating a second example of the present invention, and is a plan view of the inner layer substrate 1a assembled on the laminated lower mold 4. As shown in FIG. This embodiment is assembled in the same manner as in the first embodiment using an elongated guide pin 13b with a clearance of 0.2 to 0.5 mm on one side in the major diameter direction with respect to the elongated guide hole 3 of the inner layer substrate 1a. The multilayer printed wiring board of the present invention is completed by laminating and integrating the layers. The pin fitting holes of the upper and lower laminated molds 4 and 5 that fit into the elongated guide pin 13b are of course formed to have the same dimensions as the elongated guide pin 13b. The results of the inner layer position accuracy after lamination in Example 1 and Example 2 of a multilayer printed wiring board with a 10-layer configuration using a glass cloth base material-epoxy resin laminate with a thickness of 0.1 mm as the inner layer substrate are as follows. Table 1 also shows a comparative example in which the inner layer substrate 11 having guide holes 14 only at the four corners shown in FIG. 5 was laminated by the conventional method.

[Table] As shown in Table 1, the present invention makes it possible to suppress the inner layer position accuracy after lamination to approximately 1/2 of that of the conventional method.
Highly accurate and reliable multilayer printed wiring boards can be manufactured. [Effects of the Invention] As explained above, in the present invention, the center position of each inner layer substrate is fixed by the guide hole formed at the center of the inner layer substrate, and the elongated guide hole at the midpoint of each side allows By aligning the Y axis and providing clearance in the X and Y axis directions between the elongated guide hole and the guide pin, it is possible to absorb dimensional fluctuations during stacking of the inner layer substrates and distortion during assembly. This has the effect of improving the inner layer position accuracy.

[Brief explanation of the drawing]

Figure 1 is a plan view showing the inner layer substrate of the present invention, Figure 2 is a plan view showing the inner layer substrate of the present invention;
The figure is a perspective view showing the laminated upper and lower molds, FIG. 3 is a plan view showing Embodiment 1 of the present invention, showing a state in which the inner layer substrate of FIG. 1 is assembled to the laminated lower mold, and FIG. 4 is the laminated lower mold. FIG. 5 is a plan view showing a second embodiment of the present invention, showing a state in which the inner layer substrate of FIG. 1 is assembled into a mold, and FIG. 5 is a plan view showing a conventional inner layer substrate. 1, 11... Inner layer substrate, 2, 14... Circular guide hole, 3... Elongated guide hole, 4... Lamination lower mold, 5... Lamination upper mold, 12, 13... Circular Pin fitting holes, 12a, 13a...Guide pin, 1
3b...Elongated hole-shaped guide pin.

Claims (1)

[Claims] 1. A method for manufacturing a multilayer printed wiring board, in which a laminated base material consisting of an outer layer substrate, an inner layer substrate, and a prepreg is assembled and laminated on a lamination mold with guide pins as a reference, the laminated base material comprising: , has a circular guide hole and an elongated guide hole, and the circular guide hole is located at the center of the laminated base material where two axes connecting the midpoints of opposing sides of the laminated base material intersect. The elongated guide hole is formed in the shape of an elongated hole along the biaxial direction connecting the midpoints of opposing sides of the laminated base material, and is provided in the periphery of the laminated base material. The mold includes a first guide pin inscribed in the inner peripheral surface of the circular guide hole of the laminated base material, and a second guide pin inscribed in the short diameter direction of the elongated guide hole and having a clearance in the long diameter direction. The laminated base material has a first guide pin of the laminated mold fitted into the circular guide hole to fix the center position of the base material, and at the same time, the laminated metal mold is inserted in the short axis direction of the elongated guide hole. By inscribing the second guide pin of the mold and positioning the peripheral part of the base material with a clearance in the long diameter direction, it is possible to stack a plurality of laminated base materials vertically on a laminated mold. A method for manufacturing a multilayer printed wiring board.