JPH0241190B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a composite electronic component mounted with a component including a movable operating part such as a variable resistor, or a component sensitive to heat such as a light emitting diode.

<Prior art> In composite components such as hybrid integrated circuits, in addition to capacitor elements, resistance elements, and inductance elements, active elements such as transistors and IC elements are mounted on an insulating substrate, 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. For this reason, in the past there have been devices that have been covered with a sealing cover so that only the movable operation part is exposed, but this requires a large number of parts, and the assembly to seal it is troublesome and difficult to work with. It's bad and expensive.

In addition, although parts do not include movable operation parts, such as light-emitting elements, light-receiving elements, or heat-sensitive parts such as humidity sensors are mounted on an insulating substrate and configured as composite electronic parts. teeth,
There is a risk that these heat-sensitive parts may deteriorate or lose their functions due to the heat generated during molding, which covers the entire body with an insulating layer. It was not possible to form an insulating layer.

<Summary of the Invention> The purpose of the invention is to provide a component having a movable operation part,
It is an object of the present invention to provide a method for manufacturing a composite electronic component that makes it possible to form a protective insulating layer on the composite electronic component that includes heat-sensitive components and is mounted thereon.

According to this invention, an electronic component that does not include a movable operation part and is relatively resistant to heat is first mounted on a wiring board, and then is relatively easily peeled off on a predetermined portion of the wiring board that includes at least some electrodes. A protector made of silicone resin is formed, and then the entire wiring board and electronic components including the protector are molded to be covered with an insulating layer, and the protector is removed from the molded product. A predetermined portion is exposed, and a component including a movable operating portion or a component sensitive to heat is connected to the exposed electrode and mounted on the predetermined portion.

<Example> Next, a method for manufacturing a composite electronic component according to the present invention will be explained with reference to the drawings. In FIG. 1, necessary wiring 12 is provided on an insulating substrate 11 such as a ceramic substrate, and connected to the wiring 12, a transistor 13, an IC element 14, and a capacitor 1 are connected.
5. Mount the resistance element 16 and the like on the wiring board 11.

Next, as shown in FIG.
A protector 17 is formed on the substrate 11 and includes at least a portion of the electrode portion 12' of the second electrode. The protector 17 is made of a silicone resin that hardens at room temperature and has a viscosity of 1500 Poise, and is easily peeled off from the insulating substrate 1 and the wiring 12, that is, has weak adhesive strength.

After that, the insulating substrate 11 includes the components and the protector 17.
The entire area is covered with an insulating layer 18 by molding as shown in FIG. The insulating layer 18 is preferably molded using a resin powder mold. That is, the entire insulating substrate 11 is kept in a heated state, and then, for example, epoxy resin powder is sprinkled on it, and the resin powder is melted by the heat to form an insulating film, thereby preventing such problems. By repeating this process several times, an insulating layer 18 of a desired thickness is formed. Alternatively, instead of sprinkling resin powder, inserting a heated insulating substrate into a tank containing resin powder may be repeated. In addition to this type of mold, a so-called lip mold may be used, in which the entire body including the insulating substrate 11 is immersed in a molten resin material and pulled up, and the insulating layer 18 is formed by heating or naturally hardening.

Next, as shown in FIG. 4, the protector 17 covered with the insulating layer 18 is taken out from the insulating substrate 11 to expose the electrode 12', and the exposed electrode is covered with an electronic component as shown in FIG. For example, in this example, a variable resistor 19 is connected and mounted on the wiring board 11. The variable resistor 19 includes an adjustment shaft 21,
In other words, it is a component that includes a movable operating section.

Components including movable operation parts such as the variable resistor 19 include variable capacitors, variable inductance elements, and switches, etc.
It can be attached on top. In addition to components that include this movable operation part, for example, components that are sensitive to heat and whose functions deteriorate due to heat applied during molding of the insulating layer 18, such as light emitting elements such as light emitting diodes and phototransistors, etc. A light receiving element or a humidity sensor can also be mounted on the substrate 11 by being connected to the exposed electrode 12'.

<Effects> As described above, according to the method of manufacturing a composite electronic component according to the present invention, silicon is preliminarily formed on the substrate 11 including the electrode 12' portion to which a component including a movable operation part or a component sensitive to heat is to be attached. A protective body made of resin is formed, a protective insulating layer 18 is formed over the whole in that state, and then the protective body is removed and parts including movable operation parts and heat-sensitive parts are attached to the exposed electrodes. Therefore, the insulating layer 18 will not make the movable operation part inoperable, or there is no risk that the functions of heat-sensitive parts will deteriorate during the formation of the insulating layer 18, and other parts will not be affected. The protective insulating layer 18 not only provides humidity and mechanical protection, but also provides protection against other insulation deterioration such as adhesion of dust to the connection portions of the electrodes and contact with other objects. Note that the present invention can be applied to the case where components including such movable operation parts and components that are sensitive to heat are attached not only at one location on the board 11 but also at multiple locations.

[Brief explanation of the drawing]

1 to 5 are cross-sectional views showing an example of a method for manufacturing a composite electronic component according to the present invention. 11: Insulating substrate, 12: Wiring, 12': Electrode,
13: Transistor, 14: IC element, 15: Capacitor, 16: Resistance element, 17: Protector, 1
8: Insulating layer, 19: Variable resistor as a part including a movable operation section, 21: Adjustment shaft as a movable operation section.

Claims (1)

[Claims] 1. A step of mounting an electronic component on a wiring board, a step of forming a protective body made of silicone resin that is relatively easy to peel off on a predetermined portion of the wiring board, including some electrodes, and then the entire process. a molding step of covering the molded product with an insulating layer, a step of removing the protector from the molded product to expose a predetermined portion including the partial electrode, and connecting the electronic component to the exposed electrode. A method for manufacturing a composite electronic component, comprising the step of mounting it on a predetermined part.