JPS6175595A - Thick film 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] [Field of application of the invention] 1 (1) The present invention relates to a thick film multilayer board, and is particularly free from defects.

Regarding thick film multilayer boards.

[Background of the invention]

Used in communication devices, computers, home appliances, etc.

Circuit boards are becoming increasingly smaller and more densely packed.

For this reason, the creation of multilayer circuits is progressing by using glass-ceramic green sheets, which are capable of high-density, fine multilayer wiring, as printing substrates.

It is being Conductors, resistors and wires, on this board.

Figure 1 shows the structure of a thick film multilayer board with insulation layers.゛This consists of a first layer wiring conductor 2, a first layer resistor 3 which is stiffly connected on a green sheet 1 made of glass ceramics, an insulating layer 4 which covers these, a second layer wiring conductor 5, A second layer □ resistor 6 connected thereto was laminated by printing, and the printed laminate was sintered at, for example, 850° C. in a conventional thick film firing belt furnace.

However, with this wiring board, the board warped significantly during sintering, so the wiring conductors on the board broke, making it impossible to connect various parts 1.

This is because there is a difference between the amount of shrinkage of the green sheet that occurs during the sintering process and the amount of shrinkage of the printed laminate of this sheet.

Although the glass-ceramics of the green sheet and the glass-ceramics of the line layer are exactly the same, the reason why the warpage occurs as described above is due to the degree of filling of the glass powder in the green sheet and the printed insulating layer. This is thought to be due to the difference. At this time, there is a large difference t3r in the presence or absence of wiring formation depending on the month.
Not found [Ceramics Association, 1981 Annual Meeting Lecture Proceedings, Low Temperature Sintered Multilayer Ceramic Wiring Board (58, 5, 16)
].

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art described above and provide a warp-free multilayer circuit board.

[Summary of the invention]

The present invention is produced in a sintering process by forming the same number of insulating layers using the same glass ceramic paste on the front and back surfaces of a multilayer wiring board.

It is characterized by preventing substrate warpage.

That is, by sandwiching the green sheet between insulating layers on both sides, it is attempted to suppress the occurrence of warpage in one direction of the green sheet serving as a substrate.

It is.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in detail using FIG. 2.

A glass ceramic green sheet 1 was obtained by mixing and kneading a glass powder, a filler, a solvent, and a sintering agent, and molding the mixture by a conventional doctor blade casting method. On this green sheet 1-1, print and dry Af-pd-based conductor beanute to form an unfired first layer wiring conductor 2, and print and dry Rtb-Ot-based resistor beanute to connect to this. Then, an unfired first layer resistor 3 was obtained.

The insulating paste that covers these is a glass and filler compounded material with the same composition as Green Sheet 1.

This was made into a paste, which was printed and dried to form the insulating layer 4. Similar to the first layer on top of it.

The materials were printed and dried in the same manner as the first layer to form a second layer wiring conductor 5 and a second layer resistor 6.

Next, on the opposite side of this green sheet 1, the same insulating paste as the insulating layer 4 was printed and dried for 1° to form an insulating layer 7, and this was sintered at 850°C for 10 minutes to form a multilayer wiring board. Created.

The wiring board made in this way does not have cracks due to sintering shrinkage that occurs during the sintering process, and the IC on the board surface is
Chip, RAMIC chip controller (1 capacitor, and input/output leads are fully connected.

It was done.

This example shows a two-layer circuit with one insulating layer.

However, when the insulating layer is multilayered, the same six effects can be obtained by forming the insulating layer as thick as the number of layers and on the back surface thereof. At this time, the present effect can naturally be obtained even if a circuit is similarly formed on the back side.

〔Effect of the invention〕

As detailed above, according to the multilayer wiring board of the present invention,
A multilayer wiring board free of bulges can be obtained. 1゜As a result, there is no disconnection of the wiring conductor, making it reliable.

Highly accurate component mounting is possible.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional thick film multilayer wiring board. FIG. 2 is a sectional view 15 showing an example of the wiring board of the present invention. 1... Green sheet 2... First layer wiring conductor 3...
...First layer resistor. 4...Insulating layer 5...
...Second layer wiring conductor. hair? figure

Claims (1)

[Claims] A thick film multilayer board comprising a glass ceramic green sheet and a circuit provided on the surface of the green sheet, characterized in that insulating layers of the same quality are provided on both sides of the green sheet. .