JPS5831540A - Manufacture of hybrid integrated circuit - Google Patents

Abstract

PURPOSE:To prevent a resin from oozing out through the boundaries between circuit surface end parts and external leads in the process for coating an element circuit surface with a resin, by dropping a synthetic resin while properly heating external lead terminal parts of the circuit. CONSTITUTION:External lead terminals 2 of a hybrid integrated circuit 1 are horizontally placed on bot plates 3 heated up to 100 deg.C, for example. After the element 1 is left as it is so that the lead-side end surfaces will be heated to 50-60 deg.C, a proper amount of a flowable low-viscosity synthetic resin 4, e.g., silicone resin KE1212ABC is dropped onto the central part of the circuit surface and left as it is for about 2-3 minutes until spreading all over the circuit surface. Since the temperature distribution is such that the ends of the circuit including the external leads are high in temperature, the flowage of the resin stops at the substrate end surfaces of the circuit element, and also there is no possibility of oozing out of the resin through the external leads and the bonding parts between the same and the element. Any flowable low-viscosity LTV type synthetic resin can be employed as the resin. Moreover, the required heating temperature is only 40-150 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a hybrid integrated circuit sealed with resin by IjII Co., Ltd., and particularly relates to a method for coating the surface of a hybrid integrated circuit with a fluid, low-viscosity synthetic resin with good reproducibility.

Hybrid integrated circuits are represented by thin-film integrated circuits and thick-film integrated circuits, in which circuits such as conductor layers, resistor layers, capacitors, etc. are printed on an insulating substrate such as glass or alumina ceramic by sputtering or screen printing. A pattern consisting of elements is formed, and then semiconductor elements are bonded to the required positions of the pattern to form an electrical circuit, and finally the circuit is sealed with resin etc. to give it sufficient weather resistance and mechanical strength. It is customary to do so.

In general, surface coating methods, botting methods, casting methods, transformer molding methods, etc. are used as sealing methods for hybrid integrated circuits.Recently, surface coating methods are often used due to the ease of work and economic efficiency. It has become so. In this surface coating method, only the circuit surface of a hybrid integrated circuit is coated with a flowable silicone- or epoxy-based synthetic resin to improve mechanical or chemical protection on the circuit area. Generally, this method is performed as follows. That is, an appropriate amount of synthetic resin with good fluidity is dripped onto the circuit surface of a hybrid integrated circuit placed horizontally using a dispenser or syringe, and the fluidity of the resin is used to cover the joints of external leads. In this method, the resin is poured onto every corner of the circuit surface to coat the circuit surface with a predetermined thickness. Jin's method uses a surface tension tube, and the resin stops with an appropriate contact angle between the ends of the circuit, but this effect is small at the end of the external lead from which it is taken out, and often the surface of the external lead and the circuit surface are small. It always oozes out through the boundary with Rand, and it is a six-friend. As a result, the resin creeps into the back side of the circuit or flows out along the external leads, causing problems not only in appearance but also in electrical performance, necessitating various modifications.

Conventionally, the solutions to this problem were to (1) reduce the amount of resin applied to the circuit surface as much as possible to reduce the flow of resin to the external lead or lead side end face, and (2) add a large amount of thixotropic material to the resin to reduce the flow. However, if there was too little resin, the weather resistance would deteriorate, and although the flow of resin to the leads or the end face of the leads could be stopped, the entire surface of the circuit would be exposed to JJ.
It is necessary to artificially stretch the resin forming the ig, which is disadvantageous in terms of reliability and workability.

The present invention aims to provide a method for manufacturing a hybrid integrated circuit that can solve the above problems.

That is, the present invention is characterized in that in the step of coating the element circuit surface of a hybrid integrated circuit with resin, the external lead terminal portion of the mosquito circuit is heated and the synthetic resin is dripped in a good condition. Preferably, it is heated to 40°C to 150°C.

The manufacturing method of the present invention will be described below by way of example with reference to FIG. Ilf! A. An active element of a semiconductor element and a passive element formed with a thick or thin layer are formed on an insulating substrate such as a ceramic substrate, and are further attached to the ceramic substrate as external leads only in two directions by thermocompression bonding or soldering. ing. After forming the hybrid integrated circuit element l by the above method, first, the external lead terminals 2 of the scissor element are heated to a temperature of, for example, 100°C.
The element is set so as to be placed on a hot plate 3 heated to . Next, when the resin is dropped onto the element surface, the resin is adjusted so that the element surface remains parallel so that it flows evenly in all directions. After placing the external lead terminal on the hot plate, heat it so that the lead side end surface of the scissor element reaches 50 to 60°C, that is, about 3°C.
After standing for 9 minutes, use a fluid low viscosity synthetic resin 4, such as silicone resin KE1212M Be (Shin-Etsu Cricone).
(manufactured by Co., Ltd.) was dropped onto the center of the circuit surface of the element using a dispenser/server 5. After the armpit 411WfI is left for about 2 to 3 minutes after being dropped until the illuminance reaches every corner of the cross-element circuit surface, it is dried in a constant temperature bath at 150° C. for 30 minutes for main drying.

As described above, according to the manufacturing method according to the present invention, when resin is dropped onto the circuit surface of an element, the resin flows out in all directions, and the temperature distribution is such that the edges of the element circuit including the external lead terminals are higher. The resin completely stopped flowing in the direction of the board, and on the other hand, the resin no longer leaked out through the external leads or the joints between the external leads and the mosquito circuit element. This is due to the surface tension of the resin and 1. It is a round product that takes advantage of the local decrease in fluidity due to the increase in viscosity due to Tv Josou 0 heat.

According to the above method, the resin flowing out along the external leads and the resin seeping out from the joint between the external leads and the element circuit surface are eliminated, and the conventional method of removing resin due to resin flowing out is eliminated. have all disappeared. Furthermore, in the conventional method, it was necessary to strictly control the amount of resin applied and the viscosity value in order to control the flow condition of the resin, but the method of the present invention eliminates this), making unattended operation possible. Workability has also been greatly improved. Furthermore, since the coating thickness can be made thicker than in the past, the weather resistance has also been improved.Also, the resin described in the method of the present invention is not limited to KE1212ABC, but can be used as a fluid, low viscosity LTV type resin. The same can be achieved using synthetic resin. Further, the heating temperature of the element described in the method of the present invention is not limited to 100°C, but can be similarly achieved at 40 to 150L.

[Brief explanation of drawings]

FIG. 1 shows a longitudinal sectional view for explaining an embodiment of the method for manufacturing a hybrid integrated circuit according to the present invention. In the figure, 1 is a hybrid integrated circuit element, 2 is an external lead terminal, 3 is a hot plate, 4 is a resin, and 5 is a dispenser syringe. Polish 1 figure

Claims (2)

[Claims] (1) A method for manufacturing a hybrid integrated circuit in which the surface of an element circuit is coated with a synthetic resin, characterized in that the synthetic resin is dropped while the external lead terminal portion of the circuit is heated. Method. (2) The method for manufacturing a hybrid integrated circuit according to claim (1), characterized in that the heating temperature of the circuit element is set at 40°C to 150°C.