JPH027197B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a composite electronic component such as a hybrid integrated circuit, particularly a composite electronic component mounted with a component including a movable operating part such as a variable resistor.

<Prior art> In composite components such as hybrid integrated circuits, active elements such as transistors and IC elements are mounted on an insulating substrate in addition to capacitor resistance elements and inductance elements, and electrical wiring connections are made between them. These devices, especially active devices, are sensitive to humidity. In addition, the parts that connect these parts and the wiring on the board, that is, the electrode parts, are exposed to the outside and there is a risk of dust adhering to them or coming into contact with other objects. It has been common practice to cover the entire composite electronic component with an insulating layer such as a resin material in order to increase the mechanical strength of the component.

However, when components having movable operation parts such as variable resistors, variable capacitors, variable inductance elements, and switches are mounted as one element in a composite electronic component, it is not possible to cover them all with an insulating layer. Therefore, in the past, there were devices that were covered with a sealing cover so that only the movable operation part was exposed, but this required a large number of parts and the assembly work to seal it was laborious and difficult to work with. It is bad and expensive.

<Summary of the Invention> An object of the present invention is to provide a method for manufacturing a composite electronic component that can easily and inexpensively apply insulation coating to a composite electronic component on which components including a movable operating section are mounted. .

According to this invention, a composite component including a movable part and other electronic components are mounted on a wiring board to form a composite component body, and then at least a movable operating part is covered with a relatively easy-to-peel protector. An insulating layer is applied to the entire body of the composite electronic component, including the parts, by molding. Thereafter, the protector is removed from the molded composite component body to expose the movable operating section. In this way, the exposed movable operation part can be operated from the outside, and the other parts are covered with an insulating layer to provide a protective effect.

<Example> Next, an example of the present invention will be described with reference to the drawings. As shown in FIG. 1, wiring 12 is formed on an insulating substrate 11 such as a ceramic substrate, and a resistor element 13, an IC element 14, a capacitor 15, a transistor 16, etc. are formed on the substrate 11. A composite component main body 18 is constructed by further mounting a component including a movable operating section, for example, a variable resistor 17. The variable resistor 17 includes an adjustment shaft 19, that is, a movable operating section, for adjusting its resistance value.

As shown in FIG. 2, a protector 21 that is relatively easy to peel off is attached to cover at least the movable operating portion 19. The protector 21 is easy to peel off from the electronic component 17, that is, has weak adhesive strength, and is also easy to peel off from the insulating layer covering the composite component body 18 later, for example. Room temperature curing silicone resin with a viscosity of about 1500 Poise can be used. In Figure 2, variable resistor 1
Protector 2 is applied by dropping silicone resin onto the entire surface from which adjustment shaft 19 of No. 7 protrudes.
This is the case when 1 is added. This protector 21 also fits into the driver groove formed on the end face of the adjustment shaft 19, and the protector 21 is attached to the component 17.

Next, as shown in FIG. 3, an insulating layer 22 covering the entire composite component body 18 including the protector 21 is coated by molding. This molding is preferably a so-called powder mold. That is, by sprinkling, for example, epoxy resin powder on the composite component body 18 in a heated state, or placing it in a resin powder tank containing resin powder, the adhering resin powder is melted by the heat of the composite component body 18. An insulating film is formed by repeating this process several times to form an insulating layer 22 of a predetermined thickness. Alternatively, the entire composite component main body 18 is placed in a molten resin bath and pulled up to form the insulating layer 22 by heating or natural curing. In short, it is preferable to form the insulating layer 22 by a molding method that does not use a metal mold. Alternatively, box-shaped molding may be performed. In the case of box-shaped molding, fluororesin is preferred.

After forming the insulating layer 22 in this way, for example, the insulating coating layer 22 on the protector 21 is cut out with a cutter as shown by the dotted line 23, the protector 21 is removed, and the adjustment shaft, that is, the movable operation part 19 is removed. 4.Exposed to the outside as shown in Figure 4.

In this example, since a sealed variable resistor 17 is used, there is no risk that the resin material will enter the variable resistor 17 when covering the insulating layer 22. 11, the entire variable resistor 17 is covered with the protector 21 as shown in FIG. There is no possibility that the resin layer 22 may enter through the gap with the substrate 11 and fix the movable part in the variable resistor 17. Thereafter, as shown in FIG. 6, the entire body is covered with an insulating layer 18 by molding, and as shown in FIG. 7, the protector 21 is removed to expose the operating portion 19 to the outside.

As components including a movable operating section, the present invention is applicable not only to the variable resistor as described above, but also to the case where a switch, a variable inductor element, a variable capacitor, etc. are mounted on the substrate 11.

<Effects> As described above, according to the present invention, an insulating layer that protects the parts other than the movable operation part from the outside can be formed by molding a composite electronic component equipped with parts including a movable operation part. In that case, the movable operation part is covered with a protective body before the step of forming the insulating layer 22, but the protective body may be simply covered with a material such as room-temperature curing silicone resin, as described above. The protective body can be easily attached, and the formation of the insulating layer and the removal of the protective body are also easy.Removal of the protective body exposes the movable operating part to the outside, thereby preventing the movable operating part from being exposed. Can be operated from outside. Therefore, a large number of parts are not required, and the manufacturing process is extremely simple and inexpensive.

[Brief explanation of drawings]

FIGS. 1 to 7 are cross-sectional views for explaining the steps of the method for manufacturing a composite part according to the present invention. 11: Insulating substrate, 13: Resistance element, 14: IC
Element, 15: Capacitor, 16: Transistor,
12: Wiring, 17: Variable resistor as a component having a movable operation section, 18: Composite component main body, 19: Adjustment shaft as a movable operation section, 21: Protector, 22:
Insulating layer.

Claims (1)

[Claims] 1. A process of making a composite part body in which a component having an electronic component and a movable operation part is mounted on a wiring board, and providing relatively easy-to-remove protection to at least the movable operation part of the parts including the movable operation part on the composite part body. a molding step of covering the entire composite component body including the protector with an insulating layer, and removing the protector from the molded composite component body to expose the movable operating section. A method for manufacturing a composite part comprising a process.