JP2005238867A - Fixing method for electric part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce stress concentration on a skin of a substrate due to thermal environment (temperature cycle) with securing sufficient spread of adhesive capable of enduring the mechanical environment such as vibration when fixing a wire to the substrate with the adhesive. <P>SOLUTION: The fillet having a gradual slant is constituted with the same adhesive on both ends of the adhesive for fixing a wire and a seat is constituted on the substrate contact surface of the fillet. It is realized by devising the shape of the same adhesive as the means reducing the stress concentration on the skin of the substrate while maintaining the adhesion strength of the wire. It is inexpensive and reliability can be improved due to the use of the same adhesive without using a separate member. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for fixing an electric component for fixing an electric component for use on a satellite to a main material using an adhesive.

  In the case where an electronic element placed on a ceramic substrate is resin-sealed with an epoxy resin, the resin has a linear expansion coefficient α of α ≦ in order to have durability of the epoxy resin and to prevent peeling of the epoxy resin. An epoxy resin having a resin property of 20 (ppm / ° C.) and satisfying Eα 1.7 ≦ 1000 {(ppm / ° C.) 1.7 GPa} in which the relationship between the elastic modulus E of the resin and the linear expansion coefficient α satisfies Eα 1.7 ≦ 1000 {(ppm / ° C.) 1.7 GPa} Resin sealing is performed so that the angle θ is θ ≦ 50 °. That is, it is disclosed that durability is ensured by selecting the linear expansion coefficient α and elastic modulus E of the resin, and that the epoxy resin is prevented from peeling from the ceramic substrate by setting the fillet angle θ (for example, patents). Reference 1).

Japanese Patent Laid-Open No. 11-16929 (FIG. 1)

  The prior art is to prevent the epoxy resin from peeling from the ceramic substrate, but the present invention has a problem that the surface material (CFRP) on the aluminum honeycomb is peeled off by the epoxy adhesive. When electrical components on a satellite-mounted flat plate are bonded and fixed to a substrate, vibration is ensured by securing a sufficient amount of adhesive. It is designed to withstand even when external force such as impact is applied, but it is vibration. When securing the amount of adhesive applied to fix electrical components on a flat plate that can withstand mechanical environments such as impact, the stress generated during thermal shrinkage of the adhesive when the temperature cycle is applied as the thermal environment is on the substrate side There is a problem that the substrate stress is concentrated and the surface of the main material is peeled off.

  In order to solve this problem, vibration is ensured by ensuring a sufficient amount of adhesive. It is designed to withstand even when external force such as impact is applied, but it is vibration. When the amount of wire fixing adhesive that can withstand the mechanical environment such as impact is secured The fixing method using an adhesive that does not reach the peeling limit when the thermal shrinkage of the adhesive is applied as a thermal environment The purpose is to obtain.

  According to a first aspect of the present invention, there is provided a method for fixing an electric component, the substrate comprising a substrate, an electric component for transmitting generated current, and an electric component fixing method for fixing the electric component to the substrate with an adhesive. And a fillet having an angle of 30 degrees or less by the same adhesion is formed on both ends of the contact portion between the substrate and the substrate.

  According to a second aspect of the present invention, there is provided a method for fixing an electric component, the substrate comprising a substrate, an electric component for transmitting a generated current, and an electric component fixing method for fixing the electric component to the substrate with an adhesive. A fillet having an angle of 30 degrees or less by the same adhesion is formed at both ends of the contact part between the fillet and the substrate, and a seat is formed on the contact surface between the fillet and the substrate for adhesion.

  It is possible to reduce the stress transmitted to the substrate caused by the thermal contraction of the adhesive and to reduce the stress on the substrate. Since it has high performance and a long service life, it is possible to realize a low cost.

Embodiment 1 FIG.
FIG. 3 is a view for explaining a conventional wire adhesive application shape, wherein 1 is an adhesive, 2 is a wire, 3 is a substrate, and 3a is a substrate stress concentration portion.

  vibration. When the application amount of the adhesive 1 for fixing the wire 2 that can withstand the mechanical environment such as impact is secured, the stress generated when the adhesive 1 is thermally contracted when the temperature cycle is applied as the thermal environment is transmitted to the substrate 3 side, There existed the subject of forming the substrate stress concentration part 3a.

  FIG. 4 is a drawing for explaining the adhesive application shape of the analysis model. 4 is an aluminum honeycomb, 5 is an adhesive, 6 is a substrate, 7 is an adhesive height, 8 is a substrate height, and 9 is a fillet tension. Height. Adhesive 5 is an epoxy adhesive and was analyzed using the characteristics of S691.

  The main material is aluminum honeycomb 4, the height is 12.5 mm, the length of the substrate 6 including the fillet overhanging portion is Lj, the substrate height 8 of the substrate 6 is 1.5 mm, the height of the adhesive 7 is hj, the fillet The overhang height 9 is fh, and the fillet angle θj is the analysis set value and parameter.

  As a thermal stress analysis condition, a thermal stress analysis was performed in order to obtain the generated stress of the surface material (CFRP) of the solar cell panel. In the case of wire potting analysis, the adhesive application shape of the analysis model in FIG. 4 is modeled.

  The analysis used general purpose FEM-S / W ANSYS, the element was a plane stress element of a two-dimensional solid, and the minimum mesh size was 0.1 mm. Above the glass transition temperature Tg, it was assumed that the creep deformation of the adhesive was dominant and the thermal stress generated in the surface material was negligible, and the temperature load was -180 ° C from Tg.

  Table 1 shows the results of wire potting analysis. Table 1a shows the case where the fiber direction is vertical, and Table 1b shows the case where the fiber direction is parallel.

From these experimental facts and analysis results, the stress peeling in the direction perpendicular to the fiber is about 5 kgf / mm ² , so the allowable stress was determined to be about 4 kgf / mm ² in anticipation of safety.
Similarly, the stress for peeling in fiber direction is about 25 kgf / mm ^2, the allowable stress was determined as about 20 kgf / mm ² in anticipation of safety.

The stress of the surface material was the maximum principal stress of the surface layer (first layer) and the maximum stress in the x direction, and the stress of the adhesive was the maximum principal stress.
From the result of the surface material stress of the analysis result of Table 1a being smaller than the allowable stress 4 kgf / mm for the stress peeling in the direction perpendicular to the fiber,
(1) When the fillet angle is about 30 degrees (from Table 1a NO3, 4)
(2) When the adhesive length Lj is 5 mm (from Table 1a NO9)
(3) When the adhesive height is 0.5 mm (from Table 1a NO5)
The result showed that CFRP peeling hardly occurred.

For the stress peeling in the direction parallel to the fiber, the surface material stress of the analysis result of Table 1b is smaller than the allowable stress 20 kgf / mm,
(4) When fillet angle is 30 degrees (from Table 1b NO3, 4)
(5) When the adhesive length Lj is 5 mm (from Table 1b NO9)
(6) When the adhesive height is 0.5 mm (from Table 1b NO5)
The result showed that CFRP peeling hardly occurred.

  The principal stress direction in the case of the fiber vertical direction is the direction in which the surface material is peeled and broken, and the principal stress direction in the case of the fiber parallel direction is the direction in which the surface material is broken. In each case, the fillet angle is about In the case of 30 °, when the adhesive length Lj is 5 mm, the result is that the adhesive height is 0.5 mm, and the difference between the main stress and the allowable stress is considered to have the greatest effect. It can be seen that the large fillet angle is 30 degrees. In addition, as the fillet angle is reduced to 90 degrees, 60 degrees, and 30 degrees according to NO1 to NO4 in Tables 1a and 1b, the surface material principal stress decreases, so the surface material at an angle of 30 degrees or less. It can be clearly estimated that the main stress is smaller than the surface material main stress of 30 degrees.

  Table 2 shows the results of wire potting analysis. Table 2a shows the case where the fiber direction is vertical and the fillet angle is 30 degrees. Table 2b shows the case where the fiber direction is parallel and the fillet angle is 30 degrees.

  The stress of the surface material was the maximum principal stress of the surface layer (first layer) and the maximum stress in the X direction, and the stress of the adhesive was the maximum principal stress.

The stress that peels in the direction perpendicular to the fiber is 4 kgf / mm ² in view of safety, and the stress that peels off in the fiber direction is about 20 kgf / mm ^{2 in view of} safety. .

From the results in Table 2, when the fillet angle is 30 degrees, the surface material principal stress in the direction perpendicular to the fiber is 2.59 kgf / mm ^{2 at the} maximum for NO5 in Table 2a regardless of the adhesive height hj and the adhesive length Lj. As can be seen from the graph, the surface material principal stress in the fiber direction is not more than the allowable stress as shown by the maximum NO5 in Table 2b of 10.13 kgf / mm ² , and the possibility of peeling of the surface material CFRP is low. As can be seen, the fillet angle of 30 degrees is the most important factor and is a necessary and sufficient condition.

  FIG. 1 is a view for explaining a wire adhesive application shape according to Embodiment 1, wherein 1a is an adhesive fillet, and 1-3 are the same as those in FIG.

  For example, the substrate 3 relates to a wire 2 for transmitting a generated current when it becomes a substrate of a solar cell panel for space and a method for fixing the wire 2 to the substrate 3 by an adhesive.

  By constructing the wire 2 on both ends of the fixing adhesive 1 and the adhesive fillet 1a with the same adhesive, the stress transmitted to the substrate 3 caused by the thermal contraction of the adhesive 1 can be reduced and the stress on the substrate can be reduced. Can be reduced.

  The wire 2 in the present invention is represented as the wire 2 as a representative of the electrical component, but this is merely an example, and the printed circuit board and the ultra-high frequency device include a diode, a transistor, an IC, an optical All of elements, surface acoustic wave elements, resonators and the like having a shape on a flat plate are shown. The same applies to the following embodiments.

  It is possible to reduce the stress transmitted to the substrate 3 caused by the thermal contraction of the adhesive 1 and to reduce the stress in the substrate, so that stress concentration at the substrate stress concentration portion 3a can be alleviated. effective.

Embodiment 2. FIG.
FIG. 2 is a diagram for explaining a wire adhesive application shape according to the second embodiment, wherein 1b is an adhesive seat, 1-3 are the same as the conventional description, and 1a is the same as the description of the first embodiment. is there.

  For example, the substrate 3 relates to a wire 2 for transmitting a generated current when it becomes a substrate of a solar cell panel for space and a method for fixing the wire 2 to the substrate 3 by an adhesive.

  An adhesive fillet 1a is composed of the same adhesive on both ends of the fixing adhesive 1, and an adhesive seat 1b is constructed on the contact surface of the adhesive fillet 1a with the substrate.

  By configuring the adhesive seat 1b, it is possible to further reduce the stress concentration on the substrate.

  Since the stress concentration on the substrate can be reduced, there is an effect that the stress concentration in the substrate stress concentration portion 3a can be relaxed and the reliability can be improved.

3 is a diagram for explaining a wire adhesive application shape according to the first embodiment. It is drawing for demonstrating the wire adhesive application shape by Embodiment 2. FIG. It is drawing for demonstrating the conventional wire adhesive application | coating shape. It is drawing for demonstrating the adhesive agent application shape of an analysis model.

Explanation of symbols

  1 Adhesive, 2 Wire, 3 Substrate, 4 Aluminum honeycomb, 5 Adhesive, 6 Substrate, 7 Adhesive height, 8 Substrate height, 9 Fillet overhang height.

Claims (6)

In the fixing method of the electric component for fixing the substrate and the electric component for transmitting the generated current and the electric component to the substrate with an adhesive,
An electrical component fixing method comprising: forming and bonding a fillet having an angle of 30 degrees or less with the same adhesive at both ends of a contact portion between the adhesive and the substrate. In the fixing method of the electric component for fixing the substrate and the electric component for transmitting the generated current and the electric component to the substrate with an adhesive,
Forming a fillet having an angle of 30 degrees or less by the same adhesion at both ends of the contact portion between the adhesive and the substrate,
Forming a seat on the contact surface of the fillet and the substrate;
An electrical component fixing method comprising bonding. 3. The electric component fixing method according to claim 1, wherein the electric component is a wire. 3. The electric component fixing method according to claim 1, wherein the electric component is a diode. 3. The electric component fixing method according to claim 1, wherein the electric component is a substrate. The method for fixing an electrical component according to any one of claims 1 to 5, wherein an epoxy-based adhesive is used as the adhesive.

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