JPS63260411A - Manufacture of multi-layer printed wiring board - Google Patents

Abstract

PURPOSE:To completely eliminator laminated void by preventing a vacuum leak of a carrier plate due to a warp and to contrive improvement in molding properties, by a method wherein registration is performed according to size of a laminated body by making use of an auxiliary frame on the inside of a frame made of a metal surrounding the outside of the laminated body. CONSTITUTION:Lower cushion paper 2a and a bottom force 3a are mounted on a carrier plate 1. Then a laminated body 4 of multi-layer plates composed of a plurality of sheets of inner layer base materials, outer layer base materials and prepregs is mounted, on which a top force 3b is put. Upper cushion paper 2b and a press plate 9 are put on the top force 3b further. Then a square vacuum frame 5 surrounding the outside of the laminated body 4 is mounted. The vacuum frame 5 is obtained by sticking heat-resistant rubber to the top and bottom of an aluminium frame. An auxiliary frame 8 is provided on the inside of the vacuum frame 5, the laminated body 4 is inserted into a hot platen press along with the carrier plate 1 after the laminated body 4 has been registered to a position of the auxiliary frame 8 and the laminated body 4 is laminated and unified through hot pressing by the hot platen press while making the inside of the vacuum frame 5 vacuous by evacuating the inside of the vacuum frame 5 through a drawing port 6a of a vacuum provided on a hot platen 6.

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 with excellent formability.

[Conventional technology]

A typical conventional manufacturing method for a multilayer printed wiring board involves inserting a plurality of inner layer substrates, outer layer substrates, and prepregs constituting a multilayer printed wiring board (hereinafter referred to as multilayer board) into a lamination mold. They are laminated and integrated by heating and pressing from the top and bottom using a hot platen press. However, with the recent diversification of inner layer pattern shapes (clearance patterns, signal patterns, and mixed patterns of both), increased multilayering, and thinning of the thickness between each layer, molding reliability (residual air bubbles: Problems have arisen with regard to voids) and plate thickness accuracy.

Therefore, in recent years, a method of manufacturing a multilayer board by vacuum forming has been proposed.

In this manufacturing method, as shown in FIG. 4, a lower cushion paper 2a and a lower mold 3a are placed on a flat carrier plate 1, and a laminate 4, an upper mold 3b and a lower mold 3a are placed on top of the carrier plate 1. After placing the upper cushion paper 2b in sequence, a rectangular vacuum frame 5 is placed on the carrier play 1. Next, this carrier plate 1.1 is inserted into a hot spring press (not shown), and the inside of the vacuum frame 4 is suctioned from the vacuum opening 6a provided in the heating plate 6 using a vacuum pump (not shown) to create a vacuum. The laminate 2 is laminated into a single layer by heating and pressurizing it from above and below while keeping the laminate 2 in this state.

As shown in Fig. 4, this fM manufacturing method using vacuum forming can eliminate residual air bubbles in the laminate by vacuuming, and has a low pressure of 10 to 20 kg/c.
rtr 2 (conventional pressure is 30-50 kg/cm
), it has the advantage of improving molding reliability, plate thickness accuracy, and dimensional accuracy of each layer.

[Problem that the invention seeks to solve]

However, in the conventional manufacturing method using the vacuum frame described above, when laminating small-sized laminates, the carrier plates 1 and 1 warp as shown by the arrows in Figure 4 due to suction inside the vacuum frame. As a result, vacuum leakage occurs and lamination voids tend to occur, making it difficult to produce a multilayer board with improved formability.

The purpose of the present invention is to: In the laminating process of a multilayer printed wiring board,
A multi-layer plate that can prevent vacuum cracking due to warping of the carrier plate, completely eliminate lamination voids (residual air bubbles), and can obtain a multi-layer board with improved moldability and dimensional accuracy by applying vacuum and low pressure. An object of the present invention is to provide a method for manufacturing a printed wiring board.

[Means for solving problems]

The method for manufacturing a multilayer printed wiring board of the present invention includes a plurality of sheets of inner layer base material, outer layer base material and A step of constructing a laminate by inserting prepreg,
A step of attaching a vacuum frame having a horizontally movable auxiliary frame inside the rectangular frame body to the f & layer body, and moving the auxiliary frame of the vacuum frame body to the left or right according to the size of the laminated body. and a step of inserting the laminate together with a carrier plate into a heat plate press, and heating and pressurizing it from above and below while evacuating the inside of the vacuum frame from the exhaust port of the heat plate press. be done.

〔Example〕

Next, the present invention will be explained with reference to the drawings. FIG. 1 is a sectional view for explaining one embodiment of the present invention, and FIG. 2 is a top view of FIG. 1.

First, as shown in FIGS. 1 and 2, the upper cushion paper 2a and the lower mold 3a are placed on the carrier plate 1. Next, a multilayer board laminate 4 consisting of a plurality of inner layer base materials, outer layer base materials, and prepreg is placed, and the upper mold 3b is placed thereon. Further, the upper cushion paper 2b and the presser plate 1-9 are placed on the upper mold 3b. The size of the laminate 4 is a hot platen press (870am x 770ml
>, the size is 330+sm x 600mm. Next, a rectangular vacuum frame 5 surrounding the laminate 4 is placed.

This vacuum frame is a 20 to 30 mm aluminum frame with heat-resistant rubber 7 bonded to the top and bottom, and as shown in FIG. 2, an auxiliary frame 8 is provided inside, and as shown in FIG. 3(a).

The attachment shown in (b) has the function of being able to move in the direction of the arrow in FIG. 2 depending on the direction.

After aligning the position of the auxiliary frame 8, the laminate 4 is inserted into a thermoelectric press (not shown) together with the carrier plate 1, and the inside of the vacuum frame 5 is evacuated from the vacuum opening 6a provided in the thermoelectric press 6 to create a vacuum. While maintaining the WJ condition (20 Torr or less), the temperature is 140 to 170℃ and the pressure is 10 to 20℃ using a hot platen press.
Laminated and integrated for 2 to 3 hours under the condition of /'C112,
A multilayer board according to this example was obtained.

〔Effect of the invention〕

As explained above, the present invention provides (i) warpage of the carrier plate by placing an auxiliary frame inside the metal frame surrounding the laminate and adjusting the position according to the size of the laminate. It is possible to prevent vacuum leaks caused by the process and completely eliminate stacking voids (residual air bubbles).

(ii) By applying vacuum and low pressure, a multilayer board with improved moldability and dimensional accuracy can be obtained.

There is an effect.

[Brief explanation of drawings]

FIG. 1 is a sectional view for explaining the present invention in detail, and FIG.
The figure is a top view of FIG. 1 and FIG. 3(a). (b) is a perspective view showing a method for attaching an auxiliary frame inside a vacuum frame used in the manufacturing method of the present invention, and FIG. 4 is a sectional view for explaining a manufacturing method using a conventional vacuum frame. 1...Carrier plate, 2a...Lower cushion paper, 2b...Upper cushion paper, 3a...Lower mold,
3b... Upper mold, 4... Laminated body, 5... Vacuum frame,
6... Heat plate, 6a... Vacuum opening, 7... Heat resistant rubber, 8... Auxiliary frame, 9... Presser plate. Semi-Z Ward

Claims (1)

[Claims] A step of constructing a laminate by inserting a plurality of inner layer base materials, outer layer base materials, and prepregs into opposing upper and lower molds disposed inside opposing upper and lower cushion papers on the upper surface of the carrier plate; , attaching a vacuum frame body having an auxiliary frame that can freely move left and right inside the rectangular frame body to the laminate;
A step of moving the auxiliary frame of the vacuum frame to the left or right according to the size of the laminate, inserting the laminate together with a carrier plate into a hot platen press, and evacuating the inside of the vacuum frame from the exhaust port of the hot platen press. 1. A method for manufacturing a multilayer printed wiring board, comprising the step of applying heat and pressure from above and below.