JPS62156900A - Manufacture of thick film circuit 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 [Technical Field of the Invention] The present invention relates to a method for manufacturing a thick film circuit board using a screen printing method.

[Technical background of the invention and its problems] Thick film circuits are generally manufactured by the following method. First, in order to obtain a predetermined circuit size on an insulating substrate 1 made of alumina or the like, as shown in FIG. The conductive paste contained therein is screen printed as shown in FIG. 4(b) and fired to form the first conductive layer 3. During this printing, a plurality of alignment marks 4 are printed at the same time to serve as a reference for alignment of the wiring layer to be printed in the next step.

Then, in order to align the center of the circle with the alignment mark 4, for example, as shown in FIG. 4(C), an alignment mark 6 is printed together with the resistor layer 5 using ruthenium oxide resistor paste by screen printing or the like. , formed by firing. In this way, a thick film circuit is formed by sequentially printing an arbitrary number of layers. In this method, if the first wiring layer is the first conductor layer, the actual I was able to print the circuit accordingly.

However, as shown in FIG. 5(b), when the first wiring layer is, for example, a resistor layer 5, it is very difficult to manage the alignment.

In other words, as shown in Fig. 5(b), alignment can be performed by controlling the distance (b') from the outside of the board to the alignment mark 6; however, unlike an alumina board, there may be variations in the board outline. Since the difference is as much as ±1%, if alignment is performed by trusting the alignment marks already formed in the first wiring layer, the first wiring layer in the second wiring layer will be aligned from the substrate outer groove 2 as shown in FIG. 5(C). The conductor layer 3 sometimes protruded.

This is also due to the fact that when machining grooves on the substrate outer shape using a laser beam, the outer shape of the substrate is brought into contact with a jig. As described above, there has been a problem in that alignment is difficult, resulting in deterioration in quality and yield.

[Object of the Invention] The present invention was made to solve such problems, and an object of the present invention is to provide a method for simply manufacturing a highly reliable thick film circuit.

[Summary of the Invention] That is, in the present invention, when a thick film circuit is formed on an insulating substrate in which a substrate outer groove is formed using a laser beam, an alignment mark is placed in a portion of the insulating substrate where circuit formation is not necessary, in the same manner as in the substrate outer groove. It is characterized in that it is formed using a laser beam when forming the alignment mark, and each layer is formed using this alignment mark as a reference.

[Embodiments of the invention] Next, one embodiment of the present invention will be described using the drawings.

Note that parts common to FIGS. 4 and 5 are indicated by the same reference numerals.

First, as shown in FIG. 1(a), using a YAG laser beam with a power output of 5W and a mode system of 7 φ, the substrate outer groove 2 and the alignment mark 7 are formed on the insulating substrate 1 in a pulse mode several times at predetermined locations. It was shaped by irradiation. The alignment mark 7 formed a land of approximately 0.2+nmφ.

Next, a resistor printing alignment mark 6 is printed and corrected together with the resistor layer 5, which is the first wiring layer, using a resistor paste containing ruthenium oxide powder so that the center of the circle matches this alignment mark 7. , dried at 150°C for 10 minutes, and fired at 850°C for 110 minutes.

As shown in FIG. 1(C), the first conductor layer 3, which is the second wiring layer, is printed. At this time, the formed alignment mark 7 and the conductor printing alignment mark laser beam are aligned in a circle. The silver-palladium-based conductor paste was printed with high accuracy while making corrections so that the centers coincided, and the first conductor layer 3 was formed within the predetermined substrate outer groove 2 with high precision by drying and baking. In addition to the above-mentioned embodiments, the alignment mark using the laser beam may be used, for example, as shown in FIG. For example, a round hole 7a with a diameter of 0.5 dragon φ may be used, or a straight line of X and Y, or a cross shape 7b, as shown in FIG. It is also possible to make alignment mark 4 appear. In addition, various shapes such as square, triangular, hook-shaped, etc. can be used.

[Effects of the Invention] As explained above, according to the method of the present invention, alignment marks are formed when forming the substrate outer groove, so alignment between the insulating substrate and the thick film circuit becomes easy, and the yield is improved. Productivity can be improved.

[Brief explanation of drawings]

FIG. 1 is a plan view of a substrate for explaining the method of the present invention, FIGS. 2 and 3 are plan views showing other shapes of alignment marks in the present invention, and FIGS. 4 and 5 are plan views of a conventional method. FIG. 2 is a plan view of a substrate for explaining. 1... Insulating substrate 2... Board outer groove 3... Conductor layer 4... Alignment mark for conductor printing 5...
...Resistor layer 6...Positioning mark 7.7a for resistor printing
, 7b ・・・・・・Positioning mark by laser beam

Claims (1)

[Claims] (1) When forming a thick film circuit on an insulating substrate on which a substrate outer groove has been formed using a laser beam, an alignment mark is formed using a laser beam at a portion of the insulating substrate where circuit formation is not required when forming the substrate outer groove; A method for manufacturing a thick film circuit board, characterized in that each layer is formed based on alignment marks.