JPH04256209A - Forming method for electronic parts and armoring - Google Patents

Abstract

PURPOSE:To prevent a vibration electrode from touching armoring resin owing to the flow of wax for cavity formation on the surface of an electronic parts elements, to control the method of the adhesion of wax and to reduce the variance of an electric characteristic. CONSTITUTION:Releasing agent 7 such as fluorine is applied on the surface of an oscillator element 1 and wax 8 is supplied to the part of the vibration electrode 3. Wax 8 is prevented from flowing to a periphery and becoming wide by surface tension. Thus, necessary cavity thickness is obtained and the contact of armoring resin 9 and the vibration electrode 3 can be prevented. Since the spreading and the thickness of wax 8 can be controlled by the density of releasing agent 7, a uniform cavity 10 can be formed and the variance of the electric characteristics of the oscillator can be reduced.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component and a method for forming its exterior. Specifically, the present invention relates to an electronic component such as a piezoelectric oscillator or a piezoelectric filter in which a cavity is formed in an exterior resin using cavity-forming wax, and a method for forming the exterior.

0002

BACKGROUND ART In electronic components such as piezoelectric oscillators, for example, a vibration cavity is formed between the exterior resin and the vibrating electrode so that the vibration of the vibrating electrode is not hindered by the exterior resin.

FIGS. 3 to 5 show a method for forming a cavity using a thickness longitudinal vibration (TE) mode oscillator element as an example. After fixing the lead terminal 5 to the lead electrode 4 of the oscillator element 1, which has the vibrating electrode 3 and the lead electrode 4 formed on the surface of the piezoelectric substrate 2, with solder 6, first, as shown in FIG. Cavity forming wax 8 is attached to the tip of iron 11, and by bringing the tip of iron 11 into contact with vibrating electrode 3 of oscillator element 1, wax 8 is supplied to the surface of vibrating electrode 3 as shown in FIG. After this, the vibrating electrode 3 is moved to the wax 8
The oscillator element 1 covered with
is dip-molded to produce oscillator B covered with exterior resin. At this time, the wax 8 is melted by the heat of the exterior resin material and absorbed into the exterior resin 9, and as shown in FIG.
is formed.

0004

[Problems to be Solved by the Invention] However, when wax is applied using the conventional method, the fluidity of the wax changes due to variations in the temperature of the iron, and the elongation and thickness of the wax vary, making it difficult to form a stable cavity. It was difficult to form.

[0005] For example, as the temperature of the iron increases, the wax stretches better, so the wax spreads out thinner as shown in Figure 4, and there is a possibility that the thickness of the cavity will be insufficient and the exterior resin will come into contact with the vibrating electrode. . Furthermore, as the wax stretches to a large extent, the cavity becomes wide, and vibration damping at the outer circumferential portion of the vibrating electrode is insufficient, resulting in problems such as oscillation at the fundamental wave in oscillators that use triple harmonics. was.

[0006] Furthermore, the elongation of the wax cannot be sufficiently controlled and the cavity dimensions become non-uniform, resulting in large variations in electrical properties.

The present invention has been made in view of the drawbacks of the conventional examples described above, and its object is to reduce the variation in coating of cavity-forming wax.

[0008]

Means for Solving the Problems In the electronic component of the present invention, a cavity forming wax is applied to the surface of the electronic component element, and a mold release agent is applied to the surface of the electronic component element at least in an area including the edge of the applied wax. has been primed.

[0009] Furthermore, the present invention provides an electronic component exterior forming method for forming a cavity between the inner surface of an exterior resin enclosing an electronic component element and the electronic component element. After applying a mold release agent to the surface of the electronic component element, a cavity forming wax is applied to the cavity forming position of the electronic component element, and then an exterior resin is molded on the outer surface of the electronic component element, and the wax is applied to the exterior resin. The feature is that a cavity is formed between the exterior resin and the electronic component element by absorption.

0010

[Function] In the present invention, since the mold release agent is pre-coated on the electronic component element before applying the wax, the applied wax is repelled by the mold release agent, and the wax is removed from the electronic component due to the surface tension. It becomes difficult to spread on the element. As a result, when the electronic component is coated with the exterior resin, the cavity within the exterior resin spreads thinly, thereby preventing the exterior resin from coming into contact with the electronic component element. Furthermore, in the oscillator, it is possible to prevent fundamental wave oscillation in the oscillator using the third harmonic wave.

Furthermore, by changing the concentration and type of the mold release agent, the surface tension of the wax can be controlled, and the size and thickness of the cavity can be adjusted uniformly. As a result, variations in electrical characteristics of electronic components can be reduced.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will now be described in detail with reference to the accompanying drawings. After soldering the lead terminals 5 to the extraction electrodes 4 of the oscillator element 1 in which the vibrating electrode 3 and the extraction electrode 4 are formed on the surface of the piezoelectric substrate 2, a concentration of 2 is applied to the surface of the oscillator element 1 by a method such as dipping. % or less of a mold release agent 7 such as fluorine-based material is applied. Thereafter, a cavity-forming wax 8 is applied onto the vibrating electrode 3 of the oscillator element 1 using a soldering iron 11 (see FIG. 3). When the wax 8 is attached to the vibrating electrode 3 of the oscillator element 1 in this way, the surface tension of the wax 8 increases as shown in FIG. This prevents the particles from agglomerating and spreading thinly over the oscillator element 1. That is, the wax 8 gathers so as to surround the vibrating electrode 3, and the necessary thickness is obtained. Furthermore, the spread or thickness of the wax 8 can be controlled by adjusting the surface tension by adjusting the concentration of the release agent 7. Note that the mold release agent 7 may be applied to the entire surface of the oscillator element 1, but it may also be applied only to the surrounding area excluding the vibrating electrode 3, or the mold release agent 7 may be applied to the area including the vibrating electrode 3 and the wax 8 is applied. The coating may be applied to a wider area than the area to be coated. That is, it is necessary to apply the wax to an area including at least the edge of the applied wax 8.

After that, the oscillator element 1 with the vibrating electrode 3 covered with wax 8 is immersed in a molten exterior resin material such as epoxy resin, and the exterior resin 9 is dip-molded on the outer surface of the oscillator element 1. , an oscillator A covered with an exterior resin 9 is manufactured. At this time, the wax 8 melted by the heat of the exterior resin material is absorbed into the exterior resin 9, and as shown in FIG. 2, a cavity 10 is created in the area where the wax 8 was applied. Since this cavity 10 has a sufficient thickness, contact between the vibrating electrode 3 and the exterior resin 9 can be prevented. Further, since the spread of the wax 8 can be controlled by adjusting the concentration of the release agent, etc., the dimensions of the cavity 10 can be made uniform, and variations in the electrical properties of electronic components such as piezoelectric components can be reduced.

[0014]

According to the present invention, since the surface tension of the wax can be increased by the release agent, unnecessary spreading of the wax can be prevented. Therefore, when the electronic component is covered with the exterior resin, contact between the exterior resin and the electronic component element at the cavity position can be prevented. In particular, in the case of an oscillator, it is possible to prevent fundamental wave oscillation in an oscillator that uses triple waves.

Furthermore, by controlling the surface tension of the wax with a mold release agent, the spread and thickness of the wax can be adjusted, and variations in the electrical characteristics of electrical parts can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a state after wax is supplied to an oscillator element coated with a mold release agent in an embodiment of the present invention.

FIG. 2 is a partially cutaway side view showing an oscillator packaged with an exterior resin in the above embodiment.

FIG. 3 is a perspective view showing a method of supplying wax to a vibrating electrode portion.

FIG. 4 is a cross-sectional view showing a state after wax is supplied to the surface of an oscillator element in a conventional example.

FIG. 5 is a partially cutaway side view showing an oscillator covered with an outer resin in the conventional example described above.

[Explanation of symbols]

1 Oscillator element 7 Mold release agent 8 Wax 9 Exterior resin 10 Cavity

Claims (2)

[Claims] 1. An electronic component in which a cavity-forming wax is applied to the surface of the electronic component element, and a mold release agent is primed on the surface of the electronic component element in at least an area including the edge of the applied wax. [Claim 2] A method for forming an exterior of an electronic component for forming a cavity between the inner surface of an exterior resin surrounding the electronic component and the electronic component, the method comprising applying a mold release agent to the surface of the electronic component. After that, a cavity forming wax is attached to the cavity forming position of the electronic component element, and then an exterior resin is molded on the outer surface of the electronic component element, and the wax is absorbed into the exterior resin, so that the exterior resin and the electronic component element are bonded together. A method for forming an exterior of an electronic component, the method comprising forming a cavity between the parts.