JPS59106192A - 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 j The present invention provides a method in which a resistor is internally layered in an insulating layer on an insulating substrate,
The present invention relates to a thick film multilayer substrate in which mounted components are arranged on an upper layer pattern on the insulating layer.

[Prior art]

Conventionally, a circuit pattern is formed on an insulating substrate such as a ceramic board, and parts such as transistors and ICs are mounted on the exposed insulating layer (hereinafter, such parts are referred to as mounted parts). A thick film hybrid integrated circuit that electrically connects with circuit patterns to form the entire desired electronic circuit? Thick-film multilayer substrates that can be obtained are now available. Such a thick film multilayer board has the advantage that it is possible to form a circuit pattern as desired, and also to be able to attach a large number of mounted components, making it possible to form complex electronic circuits in a compact manner. are doing.

However, in recent years, as electronic devices have become smaller and more multifunctional, it has become necessary to increase the scale of electronic circuits formed on thick film multilayer substrates, and for this reason, thick film multilayer substrates have also become larger. At the same time, the number of circuit elements that can be incorporated has also increased significantly.

Therefore, the resistors that could not be mounted on the insulating layer of the thick film multilayer board as mounted components will be incorporated into the circuit pattern formed on the insulated board, increasing the number of mounted components accordingly. 3. Figure 1 is a cross-sectional view showing an example of such a conventional thick film multilayer board, in which 1.1 is a ceramic substrate, 2 is a lower conductor, 3 is a resistor, and 4 is an insulating layer. , 5 is an upper layer conductor, and 6 is a via hole.

Such a thick film multilayer substrate is formed as follows.

First, a circuit pattern consisting of a lower conductor 2 and a resistor 3 is printed and fired on a ceramic substrate 1, and an insulating layer 4 made of glass or the like is printed and fired thereon to cover the circuit pattern. At this time, a pie hole 6 is also formed in the insulating layer 4 at the same time. Next, the upper layer conductor 5 is printed and fired in a predetermined pattern on the insulating layer 4, and the conductor is filled and fired into the pie holes 6. Therefore, the upper layer conductor 5 is
It is electrically connected to the lower layer conductor 2 at a predetermined position of the circuit pattern through the wire hole 6. In this way, a thick film multilayer board is completed.

The upper layer conductor 5 serves as a mounting land or a wiring land for tower-mounted components, and terminals of tower-mounted components are attached to the lands by solder to form a thick film hybrid integrated circuit.

By the way, the resistance value of the resistor 3 formed on the ceramic substrate 1 depends on the width, thickness ζ, etc. of the resistor 3 when printed and fired.
It is possible that the resistance value differs greatly from the resistance value that should be set, so it is necessary to check each resistor 3.

However, as mentioned above, in the conventional thick-film multilayer substrate, each of the resistors 3 is layered inside the insulating layer 4, so it is not possible to directly check each resistor 3. . Therefore, after assembling all the necessary components on the thick film multilayer board by attaching and soldering them, there is a method of checking the performance of the formed electronic circuit to confirm the quality of the thick film multilayer board. It is being However, since the defective thick film multilayer board is discovered in the final process, the defective thick film multilayer board and all the mounted parts attached to it have to be discarded, resulting in all the mounted parts being wasted. Not only is it a waste of effort, but a lot of wasted work time is wasted attaching components to a defective thick film multilayer board that should be discarded, and in the end, the thick film hybrid integrated circuit formed on the thick film multilayer board is damaged. This will lead to an increase in costs.

[Object of the Invention] An object of the present invention is to provide a thick film multilayer substrate which eliminates the drawbacks of the above-mentioned prior art and allows direct checking of the resistance body sound built into the insulating layer.

[Summary of the Invention J To achieve this object, the present invention provides that for every resistor layered in an insulating layer, an upper layer conductor is provided on the insulating layer electrically connected to a terminal of the resistor. It is characterized by the provision of r.

[Embodiments of the invention j Embodiment 7 Drawings of the present invention will be described below.

FIG. 2 is a sectional view showing an embodiment of the thick film multilayer board according to the present invention, in which 5' is an upper layer conductor for checking, 6' is a via hole, and the parts corresponding to those in FIG. All the symbols are attached and some explanations are omitted. In Figure 42, the lower conductor formed between the two resistors 3 and 3 (this is denoted by the symbol 2') is the contact between the two resistors 3 and 3. The area near the surface is also the terminal of each resistor 3. An upper layer conductor 5' for checking is electrically connected to the lower layer conductor 2' through the conductor metal filled in the ear hole 6'. It is provided for each inner layered resistor 3, but it is necessary to newly connect the upper layer conductor 5' for chain hanging to the terminal of the resistor 3 to which the upper layer conductor 5, which serves as a mounting land or wiring land, is connected. There isn't.

Therefore, the terminals at both ends of all the resistors 3 are electrically connected to either the upper layer conductor 5 or the check upper layer conductor 5', and the resistors 3 are connected to the insulating layer 4. Even if it is an inner layer, the upper layer conductor 5, the upper layer check conductor 5', the resistance clear sound 1 negative connection of each resistor 3, and,
Can be easily measured. However, before mounting the mounted parts, it is not possible to thoroughly check the thickness of the thick film multilayer board. The yield of thick film hybrid integrated circuits based on multilayer substrates is improved.

It is possible to avoid wasteful work such as attaching mounting components to a defective thick film multilayer board.

Note that this embodiment can be manufactured by the same method as the conventional thick film multilayer substrate shown in FIG. 1, and the number of manufacturing steps is not increased. Also, in this example,
Although the upper layer conductor 5' (Fig. 2)' is specially used for checking, it can also be used as a mounting land for tower-mounted parts if necessary, and in this case, it can also function as a chip. Of course.

[Effect of the Invention J As explained above, according to the present invention, each resistor layered inside the insulating layer can be connected and easily checked, and the installation of tower-mounted parts can be easily performed. This method can be used to completely differentiate between good and defective products, improves the yield of thick film hybrid integrated circuits, and reduces costs. A thick film multilayer substrate with improved functions can be provided.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view showing an example of a conventional thick-film multilayer board;
The figure is a sectional view showing an embodiment of the thick film multilayer substrate according to the present invention. 1... Ceramic board, 2.2'... Lower layer conductor, 3
...Resistor, 4...Insulating layer, 5...Upper layer conductor, 5
'... Upper layer conductor for checking, 6.6'... Bias hole.

Claims (1)

[Claims] A circuit pattern consisting of a resistor and a lower conductor formed on an insulating substrate is covered by an insulating layer, and an upper layer is electrically connected to the lower conductor of the circuit pattern through the entire via hole on the insulating layer. In the thick film multilayer substrate on which a conductor is formed, the via hole and the upper layer conductor are provided for each terminal of the front resistor, and all the terminals of the resistor can be led out to the outside of the insulating layer. Thick film multilayer substrate with all the features.