JPS62145798A - Multilayer substrate - 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] [Industrial application field] The present invention relates to a multilayer board for electric circuits.

[Summary of the invention]

In a multilayer board, the present invention prints on both sides of a dielectric sheet, forms each wiring pattern including through holes equally on opposite sides of the dielectric sheet except for the through holes, and forms an insulating layer between the wiring patterns. After that, the wiring patterns and the insulating layers are integrated by pressure bonding, thereby making it possible to provide a multilayer board with increased connection reliability and adhesive strength between each layer.

[Conventional technology]

Conventionally, when manufacturing a multilayer board from an organic resin board, an electrical circuit is printed on the surface of the board, an adhesive for an electrical circuit insulating sheet is printed, and then multiple boards are bonded together under heat. A method of forming a multilayer substrate by directly bonding an adhesive and a conductor has been used.

However, multilayer boards produced using this method have the disadvantage that the adhesive strength or peel strength between the substrates is somewhat weak, and that the adhesive may wrap around the through holes during printing, resulting in poor conductivity. Ta.

[Problem that the invention seeks to solve]

The present invention provides a multilayer board that increases the reliability of the connections between the boards constituting the multilayer board and increases the adhesive strength between the boards, in order to solve the problem described in item 1. .

[Means for solving problems]

In the present invention, printing is performed on both sides of a dielectric sheet, and each wiring pattern including through holes is formed equally on the opposite side of the dielectric sheet except for the through hole, and the thickness of the wiring pattern is equal to the thickness of the wiring pattern between the wiring patterns. The present invention relates to a multilayer substrate in which glass insulating layers of the same thickness are formed and then the wiring patterns and the glass insulating layers are integrated by heat fusion.

〔Example〕

Next, one embodiment of the present invention will be described with reference to the drawings.

In this embodiment, silver paste is screen printed on both sides of a substrate 2 made of a dielectric sheet, for example, mica, to form wiring patterns 3 including through holes 1 that are approximately equal to each other except for through balls 1, and then the wiring patterns 3 In between, glass paste was printed as an insulating agent and an adhesive to the same thickness as the wiring pattern. Next, 1 at 400-700°C
The wiring pattern 3 and the glass insulating layer 4 were thermally fused and integrated by pressure bonding at a pressure of ~6 kg/cJ to obtain a multilayer board.

This multilayer board was printed from both sides A, B and C, D, so that the inner surface of the through hole 1 was printed twice, and the reliability of the connection was improved. Since the same materials were crimped together, uniform crimping became possible. Furthermore, since the thickness of the wiring pattern was doubled, the conductor resistance value was halved, resulting in improved high-speed response and high-frequency characteristics. The adhesive strength between the substrates is improved, and the bonding strength between the substrates is increased by 9
A value of 2 to 3 kg/ctA was obtained as the peel strength in the 0° direction, and therefore, this multilayer substrate was a sufficiently strong multilayer substrate.

〔Effect of the invention〕

In the present invention, printing is performed on both sides of a dielectric sheet, and each wiring pattern including through holes is formed equally on the opposite side of the dielectric sheet except for the through hole, and the thickness of the wiring pattern is equal to the thickness of the wiring pattern between the wiring patterns. After forming glass insulating layer patterns of the same thickness, the wiring patterns are connected to each other,
The glass insulating layers are then integrated by heat fusion to obtain a multi-layer substrate.

Therefore, the through-hole connection part is printed from both sides, and as a result, the inner surface of the through-hole is printed twice, and the through-hole is reliably connected between the front and back of the substrate and between the substrates, so that the through-hole connection is perfect. Therefore, the reliability of the connection is improved. Furthermore, the adhesive strength or peel strength is increased, and the possibility of peeling due to external force is reduced. Furthermore, the thickness of the wiring pattern is doubled, the resistance is halved, and the high frequency characteristics are improved. Furthermore, the insulation between the electrodes is improved, short circuits between the electrodes are eliminated, and insulation defects due to expansion of deformation of the electrodes during thermocompression bonding, that is, migration, are prevented, and the voltage resistance is highly stable, allowing high-density mounting. It is possible.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a multilayer substrate of the present invention, and FIG.
The figure is a sectional view showing an example of a conventional multilayer board. In addition, in the symbols used in the drawings: 1--
−−−−1−−−−−−−・1 board 3−−1−−−
----------- Wiring pattern 4 ---------- Glass insulating layer.

Claims (1)

[Claims] Printing is performed on both sides of the dielectric sheet, and each wiring pattern including through holes is formed equally on the opposite side of the dielectric sheet except for the through hole, and a layer of the same thickness as the wiring pattern is formed between the wiring patterns. A multilayer board in which a glass insulating layer is formed and then the wiring patterns and the glass insulating layers are integrated by heat fusion.