JPS61224497A - Manufacture of multilayer board - 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 [Technical Field of the Invention] The present invention relates to an M selection method that can produce a high quality multilayer board without misalignment or warping.

[Technical background of the invention] In recent years, as various electronic devices become more complex, systems, and multifunctional, multilayer boards have become increasingly important as wiring boards that can be mounted in high density. Strong response to carbonization and price reduction (is being sought after).

This multilayer board is generally manufactured by the following method.

That is, as shown in FIG. 6, first, an outer layer printed board and a plurality of inner layer printed boards on which a circuit pattern has been formed in advance are laminated with prepreg interposed therebetween, and this laminate 7 is taken as one set, and multiple sets are assembled. are stacked with the intermediate plate 2 sandwiched between each laminate, and set in the mold 3. At that time, in order to align the printed boards with each other, reference bolts are inserted into several reference holes 4 that have been previously drilled at corresponding predetermined positions on the inner wall of the mold 3, the intermediate plate 2, and the laminate 1. Insert 5.

Thereafter, this is inserted between the hot plates 6 and 6 of a hot press, and is heated and press-formed under predetermined conditions to be integrated.

[Problems with the background technology] However, with such conventional methods, the molding size and number of molded products are limited by the mold, and it takes time to prepare the heated press, making it difficult to improve productivity. The problem was that it was blocked.

[Purpose of the Invention] The present invention has been made to solve the above-mentioned problems of the conventional technology, and it is possible to eliminate misalignment and warpage between inner printed boards without using a mold and a reference bolt that have the above-mentioned problems. The present invention aims to provide a method for manufacturing a multilayer board that can produce a high quality multilayer board and improve productivity.

[Summary of the Invention] That is, the method for manufacturing a multilayer board of the present invention includes a first step in which an outer printed board and a plurality of inner printed boards on which a circuit pattern has been formed in advance are laminated with a prepreg sandwiched between each printed board.
and a second step of integrally heating and press-molding these laminates.
The process is characterized in that the plurality of inner layer printed boards are bonded and fixed while aligning the circuit patterns with each other.

The method of the present invention will be explained below with reference to the drawings.

In the method of the present invention, as shown in FIG. 1, first, a predetermined inner layer circuit pattern is formed on the copper foil surface of a copper-clad laminate made of glass cloth-epoxy resin, glass cloth-polyimide resin, etc. A predetermined number of sheets 1a are laminated with a prepreg 1b made of the same material as the copper-clad laminate interposed therebetween, and at this time, an adhesive S is applied to both sides of the spacer P at the periphery of each inner layer printed board. Partially adhered via adhesive block 1C.

Note that as the spacer P used in the adhesive block 10, one that can be deformed by pressure during pressing is suitable.

Further, the mutual positioning of the inner layer printed boards is carried out using, for example, a positioning jig having positioning pins 8 protruding from a flat plate 7 at the positions of the reference holes of the inner layer printed boards, as shown in FIG. 9 indicates the bonding position.

Next, a copper-clad laminate made of the same material as the copper-clad laminate used for the body or the inner layer printed board is superimposed on the outside of the adhesively fixed inner layer printed board 1d via a similar prepreg 1b as an outer layer printed board 1d. Ru.

As shown in FIG. 3, a plurality of sets of the simulated laminate 1 were inserted between the hot plates 6 and 6 of a hot press via the intermediate plate 2, and then heated and pressure-molded under predetermined conditions. and integrate it.

Note that the adhesive S mentioned above includes epoxy, epoxyphenol, cyanoacrylic, polyimide amide,
Heat-resistant adhesives such as polyimide adhesives, Trenice (trade name) adhesives, and metalloxane adhesives can be used, and cyanoacrylic acid ester adhesives are particularly preferred in terms of workability and economy.

Commercially available acrylic ester adhesives include, for example, Aron Alpha #301 (manufactured by Toagosei Kagaku Co., Ltd.), Viscof 7M (manufactured by Matsumoto Kosho Co., Ltd.), Permabon-1-'922 (Kanebo Co., Ltd., NSC Co., Ltd.), There are products such as the Diabond SG series (Honeymoon adhesive).

Note that the method of the present invention can be similarly applied to the production of multilayer boards by a mass lamination method using a large multi-stage hot press.

[Example of selling out] Examples and comparative examples of the present invention will be described below.

Example 1 A glass cloth-epoxy resin prepreg was inserted between two inner-layer printed boards obtained by forming a predetermined inner-layer circuit pattern on the copper foil surface of a glass cloth-epoxy resin double-sided copper-clad laminate, and Using the positioning jig shown in FIG. 1, spacer pieces coated with adhesive on both sides were arranged at the four corners, and the inner layer printed boards were laminated and fixed.

Next, copper-clad laminates were stacked on both sides with glass cloth and epoxy resin prepreg interposed therebetween, with copper foil facing outward. They were stacked with plates inserted and inserted into a heated press.

Thereafter, the mixture was heated and pressed to produce a multilayer board. - Example 2 As shown in FIG. 4, the same inner layer circuit pattern 11 is formed on 12 partitioned copper foil surfaces of a glass cloth-epoxy resin double-sided copper-clad laminate 10 to create a multi-sided copper-clad laminate 10. An inner layer printed board was obtained.

Next, using this multi-sided inner layer printed board, Example 1
A multilayer board was manufactured using a mass lamination method using a large multistage heated press in the same manner as above.

Comparative Example The same inner layer printed board, outer layer printed board, and prepreg as in Example 1 were used, and they were laminated in the same manner as in Example 1 except that the inner layer printed boards were not bonded to each other. The mold and reference bolts were used to insert into a heated press according to the conventional method shown. After that, Example 1
Pressure and heat molding was performed under the same conditions as above to produce a multilayer board.

Regarding these Example 1, Example 2, and Comparative Example, the positional deviation between the inner layer printed boards, dimensional shrinkage change, and warpage were measured. The results are shown in the table below.

The number of sheets measured was 5 for each multilayer board, and the average value is shown.

Moreover, the approximate position of the origin aO and the measurement point al''a4 for measuring positional deviation and dimensional shrinkage change is shown in the m5 diagram.

(The following is a margin.) As is clear from the table, there was no difference in positional deviation and dimensional shrinkage change among the three, and good results were obtained. In addition, with regard to warpage of the multilayer board, better results were obtained in the example than in the comparative example, and this is because no standard bolts are used, so no excessive force is applied during forming, and internal stress is reduced. This is thought to be due to the smaller size.

[Effects of the Invention] As explained above, according to the present invention, since the inner layer printed boards are adhesively fixed to each other in advance at the stage of lamination, there is no need for a mold or reference bolt when loading into a hot press, which improves workability. In addition to improving productivity, it is possible to produce multilayer boards of high quality. Moreover, it is also applicable to a mass lamination method, which can further increase productivity.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view exemplary showing the laminated state of an outer printed board and an inner printed board in the present invention, FIG. 2 is a perspective view showing an example of a positioning jig used in the method of the present invention, and FIG.
The figure is a sectional view showing an example of the state of charging into a hot press in the method of the present invention, FIG. 4 is a top view showing a multi-sided circuit pattern of an inner layer printed board in another embodiment of the present invention, and FIG. FIG. 6 is a top view showing the positions of measurement points for examining the characteristics of the multilayer board INed by the invention method, and FIG. 6 is a sectional view showing an example of the state of charging into a hot press in the conventional method. 1...... Laminate 1a... Inner layer printed board 1b...
...Prepreg 1C...Adhesive block 1d...
・・・・・・Outer layer printed board 3・・・・・・・・・Mold 6・・・・・・・・・・・・Netsusaka Applicant Toshiba Chemical Co., Ltd. Representative Patent Attorney Sasa Suyama - Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 11

Claims (2)

[Claims] (1) The first step is to laminate an outer printed board and a plurality of inner printed boards on which a circuit pattern has been formed in advance with a prepreg sandwiched between each printed board, and to heat and pressure mold these laminates together. A multilayer board manufacturing method comprising a second step, wherein the first step comprises bonding and fixing the plurality of inner layer printed boards while aligning the circuit patterns with each other. Method of manufacturing the board. (2) The method for manufacturing a multilayer board according to claim 1, wherein the inner printed boards are bonded together using an adhesive.