JPS5950238B2 - How to mount electronic components - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for mounting electronic components including semiconductor chips.

The present invention relates to a method for mounting electronic components that reduces manufacturing man-hours by placing electronic components into an injection mold, filling the mold with an insulating material such as plastic, and forming an electronic circuit using a screen printing method.

An object of the present invention is to reduce the mounting cost of electronic components. Another object of the present invention is to improve the reliability of electronic devices.

A conventional method of embedding electronic components in an insulating material and forming a wiring pattern had a structure as shown in FIG.

That is, a semiconductor chip 3 is embedded in a recess 2 for fitting provided in an insulating substrate 1 made of ceramic or the like, and a surface 5 of the semiconductor chip 3 and a surface 6 of the insulating substrate 1 are made on the same plane using a resin 4 such as Teflon. Moreover, the semiconductor chip 3 and the recess 2
After filling the resin 4 and fixing the semiconductor chip 3 so that no gap is left between them, the wiring pattern 7 is formed by a method such as vapor deposition. According to such a conventional method, there is a step of making the insulating substrate 1, a step of inserting the semiconductor chip 3, and a step of inserting the resin 4.
A process of filling and smoothing is required. Furthermore, when embedding a plurality of semiconductor chips, the resin 4 described above
The disadvantage is that the number of filling times increases in proportion to the number of semiconductor chips.

Furthermore, since the wiring pattern 7 is formed by vapor deposition or the like, the amount of processing per process is small, which increases the number of man-hours. When the wiring pattern 7 is formed, the wiring pattern is likely to be disconnected depending on the degree of filling and smoothness of the resin 4, which is one of the causes of lower reliability. However, the present invention aims to reduce the number of manufacturing steps and reduce manufacturing costs by simultaneously inserting a plurality of electronic components and forming a wiring pattern using a screen printing method when forming a board.

An embodiment in which the present invention is applied to an electronic circuit block of a portable electronic watch will be described with reference to FIGS. 2 and 3. Reference numeral 10 denotes an upper mold having an inlet 11 for resin.

12 is a lower mold having vacuum suction ports 13, 14, and 15.

A mold 1 for injection molding is formed by the above-mentioned upper mold 10 and lower mold 12.
6 is composed.

(FIG. 2a) With the mold 16 open, the semiconductor chip 2 is positioned at a predetermined position on the lower mold 12 by the chip conveying means 17 and fixed by the vacuum 18.
(Figure 2b) Other resistors 1 constituting the electronic circuit block
9. Set the capacitor 20, close the mold 16, and fill the resin 23 from the inlet 11. (FIG. 2c) Next, the mold 16 is opened, the product is taken out, and the conductive paste 1 is formed as a wiring pattern 7 by screen printing to complete the electronic circuit. (FIG. 3) As is clear from the above explanation, the conventional problem of requiring a lot of man-hours because electronic components are simultaneously assembled in the process of making a conventional insulating substrate is eliminated.

Further, since the wiring pattern is formed by a screen printing method or the like, the amount of processing is large and the number of man-hours can be reduced.

When the position of the semiconductor chip 2 moves due to reasons such as the selection of molding material or the inflow port not being in the optimal position. Alternatively, a convex portion 24 as shown in FIGS. 4 and 5 may be provided on the lower die 12 to position the semiconductor chip 2. In this case, the convex portion 24 is the wiring pattern 2
Of course, 2 must be formed in the escaped position. In the description of the present invention, the case where it is applied to the electronic circuit of a portable watch has been described, but it goes without saying that the present invention can be applied to other electronic devices that require the same technology, such as calculators, table clocks, electronic circuits of cameras, etc.

In the description of the present invention, the wiring pattern is formed by screen printing, but the present invention is not limited to this method, and methods of printing conductive paste by offset printing, letterpress printing, etc. are included in the present invention. Ru.

Further, in the description of the present invention, the electronic circuit block was formed by injection molding of plastic, but other methods such as potting may be used, or other materials such as ceramic may be used, and various combinations of these may be considered.

As described above, according to the present invention, after a plurality of electronic components are put into a mold, a molding material is filled and molded, and a wiring pattern is formed by screen printing, etc., the manufacturing process can be shortened, and an electronic circuit block can be manufactured. The manufacturing cost can be reduced.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a conventional mounting method. FIGS. 2a-2c are cross-sectional views showing an embodiment of the mounting method of the present invention. FIG. 3 is a sectional view showing one embodiment of an electronic circuit block according to the present invention. FIGS. 4 and 5 are a plan view and a sectional view, respectively, showing other embodiments. 2 is a semiconductor chip, 10 is an upper mold, 11 is an inlet, 12 is a lower mold, 13, 14, 15 are vacuum suction ports, 16 is an injection mold, 17 is a chip conveying means, 19 is a resistor, and 20 is a capacitor. , 22 is a wiring pattern, and 24 is a convex portion.

Claims (1)

[Claims] 1. In an electronic component mounting method in which an electric circuit resin board is formed by resin-sealing between a lower mold and an upper mold, and an electronic component is fixed to the resin substrate, the lower mold has an electronic component mounted thereon. It has a vacuum suction port opposite to the part to be exposed, and the connection surface of an electronic component such as a semiconductor chip or a resistor is placed so as to be in contact with the lower mold, and the vacuum suction port is used to apply suction from the vacuum suction port. Then, with the electronic component and the lower mold fixed, resin is flowed in from the inlet provided in the upper mold or the lower mold to form a resin substrate in which the periphery of the electrical component is filled with resin. . A method for mounting an electronic component, characterized in that the upper mold and the lower mold are removed and the connecting surface of the electronic component exposed on the same surface as the resin substrate surface is wired by a printing method.