JPS58142599A - 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 The present invention relates to a thick film multilayer substrate, and more particularly to a thick film multilayer substrate 1[4ζ] used in a hybrid integrated circuit suitable for manufacturing high precision thick film resistors.

Thick-film hybrid integrated circuits, which are currently widely used in electronic devices, are becoming more and more popular due to demands for smaller size and improved reliability of electronic devices. In order to achieve this high density actual value, a thick film multilayer board with two layers of thick film resistors is manufactured.

FIG. 1 shows a sectional view of this type of thick film multilayer substrate.

In the figure, 1 is a ceramic substrate, 2 is a lower conductor, and 3a
is the lower resistor, 3b is the lower resistor that requires high precision,
4 is an insulator layer, 5 is an upper conductor, and 6 is an upper resistor.

Figure 2 shows the construction of a thick film multilayer substrate having the above-mentioned structure. A conventional method for manufacturing a thick film multilayer substrate will be explained below.

First, the lower conductor 21 is stamped on the ceramic substrate 1, and s
Baking at sso℃ (first step ml) Second, print the lower resistor 3a * 3b and baking at sso℃ (first step 1)
2). In order to increase the accuracy of the resistance values of the lower resistors sa and sb, trimming is performed (3rd step @ 13) Next, 4 layers of insulator are printed after the lower conductor tank and the lower resistors 3a * 3b, and sso' C. (4th step 14). 1ζ The upper conductor 5 is stamped thereon and fired at 580°C (5th step 515). Subsequently, the upper resistor 6 is printed and sso'c
The upper resistor is formed by firing (6th d@18).

Finally, in order to improve the accuracy of the resistance value of the upper resistor 6, trimming is performed (7th step @17), and a thick film multilayer substrate is fabricated.

However, in the above-mentioned conventional thick-film multilayer substrate, the resistance values of the lower resistors 3m and 3b are trimmed to improve accuracy, but the trimming em of the lower resistor 3<the third
Engineering@13) Subsequent manufacturing operations 1114゜I Is, 16
jj oil! Since it is exposed to a high temperature of 80°C, the resistance value changes by 5ss degrees. Therefore, if a resistor that requires high precision is included in the lower resistor 3b, there is a drawback that the yield of thick film multilayer substrates will be deteriorated.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to provide a thick film multilayer substrate having high precision resistance with high yield.

A feature of the present invention is that in a thick film multilayer board in which thick film resistors are formed in two layers, a lower resistor and an upper resistor, with an insulating layer in between, the resistor that requires high precision is formed in the upper resistor. The point is that it was made to be done.

The present invention will be explained below by way of examples. FIG. 3 shows an embodiment of the invention. In the figure, 6' is a resistor that requires strict precision, and corresponds to the lower resistor 3b in FIG. Further, other symbols indicate the same or equivalent items as in FIG. 1.

This embodiment differs from the conventional example shown in FIG. 1 in that the resistor 3b, which requires strict precision, is moved from the lower position of the thick film multilayer substrate to the upper position.

That is, in FIG. 3, the lower conductors 2, 2 connected to both ends of the resistor, which require strict precision, and the upper conductors 5, 5 formed almost directly above the lower conductors 2, 2 connect the via holes of the insulator 4. electrically connected via. A resistor 6', which requires strict precision, is formed between the upper conductors 5, 5.

Of course, it is striking that the circuit connections in FIG. 1 and those in FIG. 3 are exactly the same.

Therefore, according to this embodiment, since the resistor that requires high precision is formed by the upper resistor, the plate resistor is not exposed to high and low temperatures after being formed. For this reason,
By trimming, a highly accurate state can be maintained, and a thick film multilayer substrate including high precision resistors can be obtained at a high yield.

Next, the manufacturing process 1 of this embodiment will be explained with reference to FIG. 2.

First, a lower conductor layer is printed on the ceramic substrate 1, and 85
Fire at 0°C (first step 1111). Next jK.

For example, the lower resistor 3a other than the resistor that requires accuracy within ±5- is printed and fired at 850°C (second step @1
2). Next, trim the lower resistor 3& (3rd
Engineering '1711B'). Next, lower conductor 2 and lower resistor 3a
is printed on the insulator 41 covering it and fired at 580°C (
4th Engineering@14). The upper conductor 5 is printed on the plated insulator 4 and fired at 580° C. (Step 5 @ 15). Furthermore, an upper resistor 6 and a resistor 6' which requires accuracy within ±Ss are printed and fired at 580° C. (6th step 516). Finally, a trimming session is performed to form a thick film multilayer substrate (7th step @
17).

In this way, the resistor 6', which requires high accuracy, is not fired at high temperatures after being trimmed, so that there is no change in resistance value.

As described above, according to the present invention, since the resistor that requires high precision is formed by the upper resistor, the resistance is not changed by the process 1 after forming the cough resistor, and the resistor is highly accurate. resistance can be obtained. Therefore, there is a significant effect that the yield is improved because the resistance value of the thick film multilayer substrate is not required.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a conventional thick film multilayer substrate, FIG. 2 is a manufacturing process diagram of the thick film multilayer substrate, and FIG. 3 is a longitudinal sectional view of a thick film multilayer substrate according to an embodiment of the present invention. 3... Resistor that does not require high precision, 3b... Resistor that requires high precision, 4... Insulator, G... Upper conductor, 6... Upper resistor, 6'...・・Michihito Hiraki, a patent agent for resistors that require high-precision construction

Claims (1)

[Claims] (1) Thick film multilayer formed on an insulating substrate, consisting of a lower conductor, an insulator layer, and an upper conductor, with a lower resistor or upper resistor formed as necessary between the armpit conductors or between the upper conductors. A thick film multilayer substrate characterized in that a resistor requiring high precision is formed in an upper resistor in the substrate.