JPH06194235A - Electronics parts - Google Patents

Abstract

PURPOSE:To decide whether an electronic parts meets a guaranteed temperature at a glance and to identify thermally destructed parts by providing the surface of an electronic parts with a stuck part of heat reversible discoloration resin and heat irreversible discoloration resin. CONSTITUTION:On the upper side of an electronic parts main body 1, a stuck part of a heat-reversible discoloration resin 3 and a heat-irreversible discoloration resin 4 is provided. For the resin 3, the one that changes color reversibly at least one time within the range about 20-200 deg.C is used. By this, by just observing the color of the resin 3, operation temperature of the electronic parts is monitored, so that application sutability of the electronic parts can be decided basing on its guaranteed temperature. Further, for the heat irreversible discoloration resin 4, the one that has discoloration temperature of about 20-200 deg.C and, when the discoloration temperature is exceeded, changes color irreversibly, and further its discoloration temperature is equal or slightly higher than parts' guaranteed temperature, is used. By this, a thermally destructed part is identified without desassembling electronic parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, a transistor,
The present invention relates to various electronic components such as diodes, ICs, capacitors, resistors, etc., and more particularly, to an electronic component capable of visually recognizing a surface temperature during operation of the electronic component and a history of the surface temperature.

[0002]

2. Description of the Related Art Heat (temperature) is one of the typical ones that cause changes in the characteristics of electronic parts. For example, the IV characteristic of a diode or the like shifts as the temperature changes. In general, an electronic component has a specified operating temperature range (hereinafter referred to as a guaranteed temperature) that guarantees the above characteristics and the like according to the application. In a usage environment in which the above-mentioned guaranteed temperature is exceeded, the specified characteristics of the electronic component may not be obtained, or even destruction may occur. This guaranteed temperature, for example, the guaranteed temperature based on the heat generated when an electronic component operates against a load current, is generally obtained by using an infrared thermometer or by directly contacting the surface of the electronic component with a contact thermometer, thermocouple, or the like. The temperature of is measured and set. Moreover, the guaranteed temperature is obtained by measuring the amount of heat generated when a load is applied to the electronic component in a single state.

However, when actually using the electronic component, the component is rarely used alone and is generally mounted on a mounting board together with many other electronic components. The operating temperature of an electronic component when it is mounted on a mounting board together with a large number of other electronic components is higher than when it is used alone, because the heat generated by the component itself due to the load and the heat transmitted from the peripheral components are combined. It gets quite hot.
As a result, there are cases in which the device cannot be used even when used with a load amount that would keep the guaranteed temperature range. Therefore, standard components that can be applied to the mounting density are often specified, but when electronic components are actually mounted on the mounting board and used, the types of peripheral components and the distance between adjacent components are difficult. However, there are various cases depending on the application, and there may be defects even though they are used in the applicable range according to the standard. Therefore, the standard based on the stipulated guaranteed temperature is only a guide and is not necessarily practical. After all, it is impossible to know whether the electronic component can be applied to the intended use without examining the operating temperature after actually using the electronic component.

Further, when an electronic device or the like fails during use, it is investigated which part in the mounting board, on which a large number of electronic parts mounted on the electronic device are mounted, that is, which part is defective. You may want to. Conventionally, this investigation has been performed by individually measuring the electrical characteristics of the components in the mounting board or by disassembling and analyzing the individual electronic components.

However, most of the causes of failures during the operation of electronic parts are thermal breakdowns that occur when an overcurrent is applied or the operating environment exceeds the guaranteed temperature. In such cases, the investigation of defective parts is done by the heat (temperature) applied to the parts.
The most rational means is to know the history of
There is no corroborative method of measuring the above history.

[0006]

The surface temperature is measured by an infrared thermometer as in the prior art to check the operating temperature when the electronic component is actually in use, and a contact thermometer for each component is used. If the surface temperature is measured by using, a separate measuring device and technique are required, which is very inefficient in terms of time and cost.

When an electronic device or the like breaks down during use, it is very inefficient to measure the electrical characteristics of each of a large number of electronic parts used and disassemble and assemble it. . Moreover, even if a defective part is detected by these methods, the thermal history can be obtained only by an estimated value and confirmation cannot be confirmed. Therefore, there remains a question to know an appropriate part from this estimated value.

It is an object of the present invention to provide an electronic component which allows the surface temperature of the electronic component to be known at a glance and to judge whether or not the application condition based on the guaranteed temperature of the electronic component is met.

Further, according to the present invention, even if a large number of electronic components are scattered on the mounting board, the electronic components are thermally destroyed or heat exceeds the guaranteed temperature at a glance. It is also an object of the present invention to provide an electronic component capable of identifying whether or not it has been used.

[0010]

As a result of earnest studies to achieve the above object, the present inventor used a thermoreversible color-changing resin to monitor the surface temperature of an electronic component during operation, and We have found that what can be achieved by using a resin to know the history of heat applied to an electronic component during operation.

That is, the present invention relates to an electronic component characterized in that an adhered portion of a thermoreversible color-changing resin and a thermo-irreversible color-changing resin is provided on the surface of the body of the electronic component.

In the present specification, the term "thermoreversible color-changing resin" refers to a phenomenon in which a color change occurs at a predetermined color change temperature as a boundary due to a temperature rise, and the color returns to the original color when the temperature falls below the color change temperature. Is a resin that has the characteristic of being repeatedly repeated. Further, the "thermoirreversible discolorable resin" refers to a resin having a characteristic that once the discoloration temperature exceeds the discoloration temperature, the original color is not restored even if the temperature drops thereafter.

[0013]

The thermoreversible color-changing resin applied to the surface of the electronic component of the present invention changes color due to the transition of the temperature on the surface of the component during operation, and the thermo-irreversible color-changing resin has a surface temperature which changes the color change temperature of the resin. Discolors when exceeded. Therefore, by visually observing the color of the resin, it is possible to know the surface temperature of the component during operation and to know the thermal history of whether the component had a temperature higher than the guaranteed temperature in the past.

[0014]

Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to these embodiments and can be widely applied to various electronic parts.

FIGS. 1 and 2 show an embodiment in which the electronic component is a surface mount type diode. In these figures, reference numeral 1 indicates an electronic component main body, and reference numeral 2 indicates an external terminal.

In FIG. 1, a thermoreversible color-changing resin 3 and a thermo-irreversible color-changing resin 4 are coated on the upper surface of the electronic component body 1.

In the present invention, it is preferable to use, as the thermoreversible color-changing resin 3, a resin whose color reversibly changes at least once within the range of about 20 to 200 ° C.

In the present invention, the thermo-irreversible discoloration resin 4 has a discoloration temperature within the range of about 20 to 200 ° C.
A resin that irreversibly changes its color when it exceeds the color change temperature can be used. In the present invention, the thermo-irreversible discolorable resin 4 preferably has a discoloration temperature which is substantially the same as or slightly higher than the guaranteed temperature of the electronic component.

The deposition of these resins can be carried out, for example, by a known printing method.

In FIG. 1, the adhered portions of the thermoreversible color-changing resin 3 and the thermo-irreversible color-changing resin 4 are provided separately from the mark (not shown) and the like, but as shown in FIG. If resin is used, it is not necessary to separately provide the adhered portion.

In these embodiments, the adhered portion of the color-changing resin is provided on the upper surface of the electronic component body 1, but the invention is not limited to this, and it may be a visible portion in the mounted state.

Further, in the present invention, if a plurality of thermoreversible color changing resins 3 having different color changing temperatures are used in combination, the change in the surface temperature can be monitored more finely.

In addition, in the case of electronic components having polarities such as diodes, transistors, capacitors, etc., reverse mounting can be prevented by using the resin adhered portion as a polarity discrimination mark.

[0024]

According to the electronic component of the present invention, the electronic component can be simply viewed by visually observing the color of the thermoreversible color-changing resin-adhered portion provided on the electronic component without requiring any special device or technique. The operating temperature of the electronic component can be known, and true applicability based on the guaranteed temperature of the electronic component can be determined.

Further, according to the electronic component of the present invention, even if a thermal defect or breakage occurs in the electronic component, the thermo-irreversible discoloration resin adhered portion provided on the electronic component is not separately disassembled and folded. It can be confirmed simply by visually observing the color.
Therefore, even if some of the components in the mounting board on which a plurality of electronic components are mounted are thermally defective or destroyed, the target component can be easily identified.

The electronic component of the present invention has the above-mentioned characteristics and is extremely highly practical.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing an embodiment of the present invention.

[Explanation of symbols]

 1 Electronic component body 2 External terminal 3 Thermo-reversible discoloration resin 4 Thermo-irreversible discoloration resin

Claims (1)

[Claims] 1. An electronic component, wherein an adhered portion of a thermoreversible color-changing resin and a thermo-irreversible color-changing resin is provided on the surface of the electronic component body.