JPH1123653A - Method and apparatus for testing reliability at joint of electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reproduce a dynamic state being produced through thermal expansion at the time of actual use of an electronic device mechanically in order to perform a reliability test of an area bonding system electronic device. SOLUTION: A board 2 mounting an electronic device 1 is chucked at a catching part 20 fixed to a tension test machine or a fatigue test machine and deformed in the direction of plane by applying a mechanical load. A reliability test can be performed at a mounting part under conditions agreeing with actual use of the electronic device 1 by deforming the board 2 in the plane direction thereby reproducing a dynamic state due to the difference of thermal expansion between an area bonding electronic device 1 and the board 2 being produced at the time of actual use of the electronic device 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component joint reliability test apparatus and an electronic component joint reliability test method for evaluating the joint reliability of an electronic component mounting portion.

[0002]

2. Description of the Related Art After an electronic component is mounted on a board, a reliability test is performed to determine whether the electronic component has been correctly mounted on the board. Hereinafter, a conventional reliability test will be described.

FIG. 8 is an overall perspective view of a conventional electronic component joint reliability test apparatus. In FIG. 8, reference numeral 1 denotes an electronic component to be subjected to a reliability test of a joint, and includes a bare chip and a CS.
This is an area-joining type electronic component having a large number of joining terminals on the lower surface such as P (Chip Scale Package). Reference numeral 2 denotes a substrate on which the electronic component 1 is mounted, which is made of a glass fiber-containing epoxy resin laminate or the like. Reference numeral 3 denotes a joining portion that electrically and mechanically joins the electronic component 1 and the substrate 2. Reference numeral 4 denotes a displacement acting member located on a side surface of the electronic component 1 for forcibly displacing the electronic component 1, and is made of a material having high rigidity such as steel. Reference numeral 5 denotes a fixing member provided around the substrate 2 for fixing the substrate 2, and is made of a highly rigid material such as steel. Reference numeral 6 denotes a connector provided on the substrate 2 for electrically connecting the substrate 2 to an external device. Reference numeral 7 denotes a wiring pattern formed on the substrate 2 for electrically connecting the joint 3 and the connector 6, and is made of copper or the like. Reference numeral 8 denotes an electrical performance measuring device for measuring the electrical performance of the electronic component 1 and the joint 3.

FIG. 9 is a side sectional view of a conventional electronic component joint reliability test apparatus during a forced displacement action. In FIG.
Reference numeral 9 denotes a solder provided inside the joint portion 3 for electrically and mechanically joining the electronic component 1 and the substrate 2. Reference numeral 10 denotes a resin for sealing a gap between the electronic component 1, the substrate 2, and the solder 9, and is made of epoxy or the like. However, the bonding portion 3 may not be sealed with the resin 10 only by bonding with the solder 9, or may be a resin mixed with a conductive material such as nickel instead of the resin 10, and may not use the solder 9.

[0005] The operation of the electronic component joint reliability test apparatus configured as described above will be described below. 8 and 9, the substrate 2 is fixed by a fixing member 5. When electronic components are actually used, heat generated by the electronic components,
Alternatively, a mechanical load such as a thermal stress is generated in the joint 3 due to a difference in a linear expansion coefficient between the electronic component 1 and the substrate 2 due to an increase in a use atmosphere temperature, and the thermal fatigue damage occurs. For the purpose of mechanically reproducing the mechanical load, the displacement action member 4 applies a forced displacement to the electronic component 1 in the horizontal direction.

FIG. 10 is a side cross-sectional view of a conventional electronic component joint reliability test apparatus during a forced displacement action. In FIG. 10, when a forced displacement in the horizontal direction is given to the electronic component 1, the solder 9 and the resin 10 forming the joint 3 are uniformly sheared by the horizontal displacement of the electronic component 1, resulting in a stress. And other mechanical loads. When the electronic component 1 is actually used, the temperature of the electronic component 1 changes due to power ON / OFF and changes in the ambient temperature, so that the horizontal forced displacement applied to the electronic component 1 is repeatedly applied. With the increase in the number of repetitions of the forced displacement, the solder 9 forming the joint 3,
Resin 10 causes fatigue failure. The fatigue damage during the reliability test is evaluated by measuring an increase in the electric resistance value of the joint 3 and the like by the electric performance measuring device 8 via the wiring pattern 7 and the connector 6.

[0007]

However, in the above-described conventional structure, the electronic parts are subjected to a forced displacement in the horizontal direction, so that the entire joint is uniformly sheared and deformed, and the heat generated between the parts and the substrate during actual use is reduced. There was a problem that the mechanical state of the joint due to the difference in expansion could not be reproduced.

SUMMARY OF THE INVENTION In view of the above-described problems, the present invention provides an electronic component joint reliability test apparatus and an electronic component joint reliability which can reproduce a mechanical state caused by a difference in thermal expansion at a joint between an electronic component and a substrate. The purpose is to provide a sex test method.

[0009]

According to the present invention, there is provided a reliability test apparatus for a joint of an electronic component, which grips opposing edges of a substrate on which the electronic component is mounted and applies a mechanical load in a plane direction to the substrate. And a connector for electrically connecting the wiring pattern of the substrate and the measuring device. With this configuration,
The mechanical state caused by the difference in thermal expansion at the joint between the electronic component and the substrate can be reproduced, and a measurement test of the reliability of the joint can be performed.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a substrate on which an electronic component is mounted, according to a first embodiment of the present invention; It has a connector for electrically connecting the pattern and the measuring device. With this configuration, a mechanical load caused by a difference in thermal expansion can be reproduced at a joint between the electronic component and the substrate.

According to a second aspect of the present invention, in a state where opposing edges of a substrate on which electronic components are mounted are chucked with a grip portion, and a mechanical load is applied to deform the substrate in a plane direction,
Measure the resistance of the joint between the electronic component and the board. With this configuration, it is possible to reproduce a dynamic state caused by a difference in thermal expansion at a joint between the electronic component and the substrate, and to perform a measurement test of the reliability of the joint.

According to a third aspect of the present invention, the wiring direction of the wiring pattern of the substrate is a direction that forms a predetermined angle with respect to the direction in which the mechanical load is applied when the substrate is deformed. This configuration has an effect of preventing a change in electric resistance value in the wiring pattern due to the expansion of the wiring pattern.

According to a fourth aspect of the present invention, the substrate is a substrate having a plurality of patterning layers, and a plurality of strain gauges formed on one of the layers by patterning in different directions. The strain in different directions was measured. This configuration has an effect of simultaneously measuring strains at arbitrary points on the substrate in a plurality of directions.

(Embodiment 1) FIG. 1 is an overall perspective view of an electronic component joint reliability test apparatus according to Embodiment 1 of the present invention. In FIG. 1, an electronic component 1, a board 2, a joint 3, a connector 6, a wiring pattern 7, and an electrical performance measuring device 8
These are the same as the conventional example. Reference numeral 20 denotes a gripper for chucking two opposing edges of the substrate 2 and applying a deformation in the surface direction of the substrate 2 by a mechanical load.
The grip 20 is made of a highly rigid material such as steel, and is attached to an existing fatigue tester, tensile tester, or the like.

FIG. 2 is a side cross-sectional view of the electronic component joint reliability test apparatus according to the first embodiment of the present invention before the substrate is deformed, FIG. 3A is a side cross-sectional view after the substrate is deformed, and FIG. () Is a partially enlarged side sectional view after the substrate deformation. 2 and 3, the solder 9 and the resin 10 are the same as in the conventional example. Also, as in the conventional example, the joint 3 is not sealed with the resin 10 only by the solder 9, or instead of the resin 10,
In some cases, a resin mixed with a conductive material such as nickel is used, and the solder 9 is not used.

The operation of the thus constructed electronic part joint reliability test apparatus will be described below. The substrate 2 is gripped by the grip portion 20. When a fatigue tester or a tensile tester to which the grip 20 is attached is operated, the grip 20 applies a mechanical load such as elongation or compression in the surface direction of the substrate.

FIG. 3A is a side sectional view when the substrate is deformed.
(B) is a side sectional view of the same part enlarged. In FIG.
Due to the applied mechanical load, the substrate 2 is deformed in the plane direction, and the substrate 2 generates a uniform vertical strain in the load direction. As the substrate 2 deforms, the solder 9 and the resin 10 forming the joint 3 undergo shear deformation. At this time, the magnitude of the shear strain γ differs depending on the distance x along the load direction from the center of the electronic component 1. That is, when x1 <x2, γ1 <γ2, and a dynamic state due to thermal expansion can be reproduced.

When the electronic component 1 is actually used, the power is turned on,
Since the temperature of the electronic component changes due to the change of the FF or the atmosphere, the substrate 2 is repeatedly deformed. As the number of repetitions of the deformation of the substrate 2 increases, the solder 9 and the resin 10 forming the mounting portion 3 cause fatigue damage. The fatigue failure during the reliability test is evaluated by measuring an increase in the electric resistance value of the joint 3 and the like with the electric performance measuring device 8 via the wiring pattern 7 and the connector 6 as in the conventional example.

In the above description, the case where the joint 3 is made of the solder 9 and the resin 10 has been described.
When the resin 10 is not sealed only by bonding with
The present invention can be similarly applied to a case where a resin 10 mixed with a conductive material such as nickel is used instead of 0 and the solder 9 is not used.

(Embodiment 2) Further, as another embodiment of the present invention, a case where the wiring pattern 7 is wired in a direction in which no vertical distortion occurs when the substrate 2 is deformed will be described.

FIG. 4 is a top view of an electronic component joint reliability test apparatus according to Embodiment 2 of the present invention. In FIG. 4, reference numeral 21 denotes a wiring pattern wired in a direction forming an angle θ with the x-axis when the load direction is the x-axis and the load and the vertical direction are the y-axis on the substrate 2, and is made of copper or the like. ing.

The angle θ is an angle in a direction in which no vertical strain is generated. Assuming that the substrate 2 is an isotropic homogeneous elastic body, when a uniform vertical stress acts only in the x direction, the Poisson When the ratio is v, it is given by θ that satisfies cos2θ = (v−1) / (v + 1). In the case of a glass fiber-containing epoxy resin substrate, the angle is preferably within ± 2 ° around θ = 61 °.

The operation of the electronic component joint reliability test apparatus configured as described above will be described below. The fatigue failure during the reliability test is evaluated by measuring an increase in the electric resistance value of the joint 3 by the electric performance measuring device 8 via the wiring pattern 21 and the connector 6. When a load is applied to the substrate 2 only in the x direction during the application of a load during the reliability test, the substrate 2 undergoes strain in the elongation direction in the x direction and strain in the compression direction in the y direction. At this time, since vertical distortion does not occur in the angle θ direction, the wiring pattern 21 wired in the θ direction does not cause a dimensional change in the wiring direction. Therefore, when the substrate 2 is deformed, a change in the electric resistance value in the wiring pattern 21 due to the extension of the wiring pattern 21 is prevented.

(Embodiment 3) FIG. 5 is a rear view of an electronic component joint reliability test apparatus according to Embodiment 3 of the present invention. In FIG. 5, reference numeral 22 denotes a strain gage provided on the back side of the electronic component 1 on the substrate 2 for detecting a strain in the load direction of the substrate 2 and is directly patterned on the substrate 2 by copper or the like. 23 is a strain gauge 22
Is a strain measuring device for measuring the value of the detected strain.

The operation of the electronic component joint reliability test apparatus configured as described above will be described below. When a load is applied to the board 2 during the reliability test and a strain is generated in the board 2, the strain gauge 22 detects the strain in the load direction, and the value of the strain is determined by the wiring pattern 21 and the connector 6.
Is measured by the strain measuring device 23 via Therefore, the strain gauge 22 for measuring the strain generated in the substrate 2 becomes unnecessary. Further, the substrate 2 is a multilayer substrate,
The case where the strain gauge 22 is provided also on the inner layer of the multilayer substrate will be described.

FIG. 6 is a perspective view of an inner layer of a multilayer substrate of an electronic component joint reliability test apparatus according to Embodiment 3 of the present invention. FIG. 6 (a) is an inner layer of the multilayer substrate, and FIG. It is. Reference numeral 24 denotes a multi-layer substrate used for enabling patterning of the inner layer, and is made of a glass fiber-containing epoxy resin laminate or the like. Reference numeral 25 denotes a strain gauge provided on a straight line passing through the electronic component 1 and the strain gauge 22 in the thickness direction of the multilayer board 24 in the inner layer of the multilayer board 24 to detect a load and a strain in a vertical direction. Like the gauge 22, the inner layer of the multilayer substrate 24 is directly patterned by copper or the like. The strain gauge 22 and the strain gauge 25 are patterned on a straight line in the thickness direction, and measure strains in directions different from each other.

The operation of the thus configured electronic component joint reliability test apparatus will be described below. During the reliability test, a load is applied to the multilayer substrate 24 to
When the strain occurs, the strain gauge 22 detects the strain in the load direction, and the strain gauge 25 detects the strain in the direction perpendicular to the load.

The strain detected from the strain gauges 22 and 25 is simultaneously measured by the strain measuring device 23 via the wiring pattern 21 and the connector 6. Since the strain gauges 22 and 25 are located on a straight line in the thickness direction with respect to the measurement direction of the multilayer substrate 24, strains in a plurality of directions at the measurement location can be measured simultaneously. When calculating the strain or the stress acting on the joint 3 from the value of the strain acting on the substrate 2 and the multilayer substrate 24, the strain generated in the substrate 2 and the multilayer substrate 24 is used as a boundary condition, and the finite element Use a numerical analysis method. Although the above description is about the case where the strain gauge 22 is provided on the back surface of the multilayer substrate, the same can be applied to the case where both the strain gauges 22 and 25 are provided on the inner layer of the multilayer substrate.

(Embodiment 4) FIG. 7 is a perspective view of an electronic component joint reliability test apparatus according to Embodiment 4 of the present invention. In FIG. 7, reference numeral 26 denotes a substrate on which the electronic component 1 is mounted, which is made of a glass fiber-containing epoxy resin laminate or the like, like the substrate 2. In the substrate 26, the substrate width A is sufficiently larger than the width of the grip portion 20, and the distance B between the grip portion 20 and the strain gauge 22 and the substrate width A
Are formed so as to satisfy the relationship A <B. Reference numeral 27 denotes a low strain region located on both sides of the grip portion 20. Both sides of the grip portion 20 have small stress and strain acting according to the Saint-Venant's theorem. Connector 6 is in low strain area 2
7. The wiring patterns 21 are all wired at the angle θ described in the second embodiment. Since A <B, if a pattern cannot be wired with a single straight line from the strain gauge 22 to the connector 6, the wiring pattern 21 is formed by combining the patterns wired at the angle θ. In the case of a glass fiber-containing epoxy resin substrate, the angle is preferably within ± 2 ° around θ = 61 °.

The operation of the electronic component joint reliability test apparatus configured as described above will be described below. The fatigue failure during the reliability test is evaluated by measuring an increase in the electric resistance value of the joint 3 by the electric performance measuring device 8 via the wiring pattern 21 and the connector 6. at the same time,
The strain gauge 22 detects the strain in the load direction of the substrate 26, and the value of the strain is represented by the wiring pattern 21, the connector 6
Is measured by the strain measuring device 23 via Since A <B when a load is applied to both ends of the substrate 26,
According to Saint-Venant's theorem, a uniform vertical stress is generated in a portion where the strain gauge 22 is provided in the load direction. Therefore, the strain gauge 22 has an effect that the strain becomes uniform in a region where the strain is detected. In addition, connector 6
Is provided in the low strain region 27,
Has the effect of reducing the mechanical load generated at the joint between the substrate and the substrate 26. Note that, as described in the third embodiment, a case where the substrate 26 is a multilayer substrate and a strain gauge is also provided in the inner layer of the multilayer substrate can be similarly implemented.

[0031]

As described above, according to the present invention, the substrate on which the area bonding component is mounted is deformed in the plane direction of the substrate by a mechanical load, so that the thermal expansion difference is generated at the bonding portion between the area bonding component and the substrate. The mechanical loads caused by the phenomena can be reproduced. Therefore, it is possible to perform a mounting part reliability test under conditions suitable for the actual use of the electronic component, and it is possible to increase the mounting part reliability. Further, by setting the wiring direction of the wiring pattern of the substrate to a direction in which vertical distortion does not occur when the substrate is deformed, it is possible to prevent a change in the electric resistance value in the wiring pattern due to the expansion of the wiring pattern. is there.
Therefore, it is possible to purely measure the decrease in the electrical performance of the electronic component and the junction, and to improve the measurement accuracy.

Further, a multilayer substrate is used as the substrate,
There are strain gauges formed by patterning of at least two or more on the straight line in the thickness direction of the front, back and inner layers of the multilayer substrate, and these strain gauges are arranged to measure strains in different directions. As a result, it is possible to simultaneously measure strains in a plurality of directions at an arbitrary point on the substrate. Therefore, it is possible to accurately obtain the boundary conditions and the like required when numerically analyzing the stress, strain, and the like acting on the joint, and to accurately evaluate the stress or strain of the joint.

Still further, a connector for electrically connecting the wiring pattern and an external measuring device is arranged in a low strain area near both sides of a grip on the board, so that a joint between the connector and the board is provided. It is possible to prevent fatigue damage. Therefore, disconnection of the connector joint portion does not occur during the reliability test, and a highly reliable mounting reliability test can be performed.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of an electronic component joint reliability test apparatus according to a first embodiment of the present invention.

FIG. 2 is a side cross-sectional view of an electronic component joint reliability test apparatus according to Embodiment 1 of the present invention before substrate deformation.

FIG. 3A is a side cross-sectional view of the electronic component joint reliability test apparatus according to the first embodiment of the present invention after the substrate is deformed. FIG. 3B is an electronic component joint reliability test apparatus according to the first embodiment of the present invention. Partially enlarged side sectional view after deformation of the substrate

FIG. 4 is a top view of an electronic component joint reliability test apparatus according to Embodiment 2 of the present invention.

FIG. 5 is a back view of an electronic component joint reliability test apparatus according to Embodiment 3 of the present invention.

FIG. 6A is a perspective view of an inner layer of a multilayer substrate of an electronic component joint reliability test apparatus according to a third embodiment of the present invention. FIG. 6B is a perspective view of the electronic component joint reliability test apparatus according to the third embodiment of the present invention. Substrate inner layer perspective view

FIG. 7 is a perspective view of an electronic component joint reliability test apparatus according to a fourth embodiment of the present invention.

FIG. 8 is an overall perspective view of a conventional electronic component joint reliability test apparatus.

FIG. 9 is a side cross-sectional view of a conventional electronic component joint reliability test apparatus during a forced displacement action.

FIG. 10 is a side cross-sectional view of a conventional electronic component joint reliability test apparatus during a forced displacement action.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electronic component 2 board 3 joint 4 displacement action member 5 fixing member 6 connector 7 wiring pattern 8 electrical performance measuring device 9 solder 10 resin 20 gripping portion 21 wiring pattern 22 strain gauge 23 strain measuring device 24 multilayer substrate 25 strain gauge 26 substrate 27 Low strain region

Claims (4)

[Claims] An electrical connection is made between a grip portion for chucking opposing edges of a substrate on which electronic components are mounted and applying a mechanical load in a plane direction to the substrate, a wiring pattern of the substrate, and a measuring device. An electronic component joint reliability test apparatus having a connector. 2. An electronic device according to claim 1, further comprising: gripping an opposing edge of the substrate on which the electronic component is mounted with a grip portion; applying a mechanical load to the substrate to deform the substrate in a plane direction; A method for testing the reliability of a joint of an electronic component, comprising measuring a resistance value. 3. A wiring pattern according to claim 2, wherein the wiring direction of the wiring pattern of the substrate is a direction forming a predetermined angle with respect to the direction of applying the mechanical load when the substrate is deformed. Test method for reliability of joints of electronic components. 4. A substrate having a plurality of patterning layers, wherein strains in different directions are measured by a plurality of strain gauges formed on one of the layers by patterning in different directions. 3. The method for testing the reliability of a joint of an electronic component according to claim 2, wherein