JPH11274248A - Bonding strength testing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To test the strength of bonding for each bonding member such as a ball without heating. SOLUTION: A weight sensor 5 for pull test and a supporting part 6 are mounted on a vertical movable part 4 to be moved up and down in the Z-axis direction by a pulse motor 43 and further, a metal pipe 6a is freely attachably and detachably mounted on the supporting part 6. The metal pipe 6a is prepared by cutting the top end of an injection needle available on the market, for example, almost orthogonally with the direction of extension. The metal pipe 6a is filled with an adhesive agent to generate adhesive power at an ordinary temperature in a short time, and a ball 36 as the bonding member is fixed to the metal pipe 6a by this adhesive agent. After fixing, upward power is applied through the vertical movable part 4 and in that case, the test of strength can be performed for each ball 36 based on an electric signal detected by the weight sensor 5 for pull test. In place of the metal pipe 6a, a configuration for engaging the ball 36 or the like can be used as well.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for testing the bonding strength of wire-bonded semiconductor components.

[0002]

2. Description of the Related Art A bonding strength test is one of important inspection items in a wire bonding process performed through all LSIs including a monolithic and a multilithic chip. The bonding strength test includes, for example, a pull test for testing a tensile strength of a bonding member such as a ball and a shear test for testing a shear strength.

As a bonding strength tester, a device which uses a dial gauge type dynamometer, strain gauge probe or the like and which is pulled or pushed by a human hand has been used conventionally. Further, as an apparatus having higher accuracy, a semi-automatically operated bonding strength test apparatus is also used. Meanwhile, a conventionally used bonding strength test apparatus performs a bonding strength test on the entirety of the plurality of connection portions by pulling the entirety of the semiconductor chip joined to the substrate by the plurality of bonding members. Things.

[0004] With such an apparatus, there is a problem that a bonding strength test cannot be performed for each bonding member. Therefore, recently, an apparatus for performing a bonding strength test for each bonding member has been proposed (for example, Japanese Patent Application Laid-Open No. 8-1141).
No. 17). In this proposal, the probe is heated to a temperature at which the bonding member is melted, and the probe and one bonding member are brought into contact with each other and cooled and solidified, thereby joining the probe and one bonding member. I do. Then, the pulling force is measured by pulling the probe.

[0005]

In the above-mentioned proposal, the bonding between the probe and the bonding member having the strength required for conducting the strength test by fixing after melting by heating is performed. However, the state of the bonding surface between the bonding member and the semiconductor changes due to the heating, so that accurate test results may not be obtained. In addition, since a configuration for heating the probe and a configuration for controlling the probe are required, there is a problem that the entire apparatus is increased in size and the cost is increased.

Accordingly, an object of the present invention is to provide a small and low-cost bonding strength test apparatus capable of performing a bonding strength test for each bonding member such as a ball without including a process of heating the bonding member. Is to provide.

[0007]

According to the first aspect of the present invention, there is provided a sample stage on which a wire-bonded semiconductor component is mounted and displaceable in X and Y directions, and a Z-axis direction orthogonal to the sample stage. A possible support portion, a load sensor connected to the support portion and detecting a load applied in the Z-axis direction, and a predetermined portion of the sample which is detachably mounted on the support portion and which is subjected to the strength test within a short time at room temperature. A bonding strength test apparatus, comprising: a test portion fixing portion fixed or engaged with a test portion; and means for controlling a drive source for causing displacement of the sample stage and the support portion, respectively.

According to the invention described above, it is possible to eliminate the necessity of heating each bonding member such as a ball in order to fix the bonding member to the structure for performing the strength test.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an overall configuration of an embodiment of the present invention will be described with reference to FIG. In FIG. 1, reference numeral 1 denotes a sample stage on which a semiconductor component to be subjected to a strength test is mounted. The sample stage 1 is attached to a lower XY stage 3 via a connecting portion 2. The XY stage 3 can be moved in the horizontal direction by pulse motors 41 and 42 provided in the main body in the X and Y directions, respectively.

The vertical moving part 4 includes an arm for connecting to the vertical moving part on the main body side and an AC synchronous motor 44 for sensor rotation fixed to this arm in a case (not shown). It is housed and has a sensor mounting part (not shown) provided below. The vertical moving unit 4 is moved up and down in the Z-axis direction by a pulse motor 43. Further, a binocular stereo microscope 9 and an illumination lamp 10 are provided for observing the sample stage 1.

In FIG. 1, a load sensor 5 for pull test and a support section 6 are mounted on the sensor mounting section, and settings for performing a pull test are shown. Here, a metal pipe 6a, which will be described later, is detachably attached to the support portion 6. Weight sensor for pull test 5
As the device, a device having a function of converting a load change in the Z direction into an electric signal can be used. For example, a semiconductor load sensor having high sensitivity, high accuracy, and high response utilizing the piezoresistance effect can be used.

The ball mounted on the bonding pad 35 is moved in the horizontal direction by the XY stage 3 by mounting the shear test weight sensor and the shear test support on the sensor mounting section. It is also possible to set to perform the share test.
Further, a destructive test and a non-destructive test can be performed as required.

When a pull test is performed in one embodiment of the present invention, the metal pipe 6a is fixed to the ball 36 by a method to be described later, and then the vertical motor 4 is pulled upward by the pulse motor 43. The weight at this time is converted into an electric signal by the pull test weight sensor 5, and the electric signal is supplied to the control circuit 52 via the amplifier 51. A control microcomputer 45 is provided in the control circuit 52, and the control microcomputer 45 performs a predetermined control based on an electric signal generated by the pull test weight sensor 5.

That is, control of the microcomputer 54 for calculating the measurement result based on the electric signal generated by the weight sensor 5 for pull test, control of the motor drive circuits 48 and 49, and the like are performed. Here, the calculation microcomputer 54 calculates the maximum value, the minimum value, the average value, the standard deviation value, and the like of the measurement data. The calculation result may be printed out by, for example, the printer 55 or the control microcomputer 45.
To perform predetermined processing such as screen display and recording on an FD or the like.

Further, an operation panel 46, a display panel 47 and an interface 56, a display microcomputer 57, and a CRT 58 are provided in connection with the control microcomputer 45. The operation panel 46 includes a switch for switching between a pull test and a shear test, a joystick lever for moving the sample stage 1, and an AC synchronous motor 4.
Operation switches for controlling the rotation of the motor 4 are provided.
The display unit 47 displays, for example, the measured weight, the determination result regarding the quality of the test result, and the like. On the other hand, the control microcomputer 45 via the interface 56
The display microcomputer 57 that communicates with the CRT 58 controls the CRT 58 to display measurement results and the like.

The pulse motors 41 and 42 are driven by a motor drive circuit 48. The motor drive circuit 48 and the pulse motor 43 are controlled by a motor drive circuit 49. As mentioned above,
These motor drive circuits 48 and 49 are controlled by the control microcomputer 45. On the other hand, the AC synchronous motor 44 is controlled by a motor drive circuit 50 according to a command issued via an operation panel 46.

Although the above description is based on the setting for performing the pull test, the setting for performing the shear test is also based on the electric signal generated by the shear test weight sensor instead of the pull test weight sensor 5. A similar process is performed for operation control, calculation and display of measured values, and the like.

Next, the procedure for performing the pull test will be described in detail. As the metal pipe 6a, for example, as shown in FIG. 2A, a commercially available injection needle 100 obtained by cutting the tip of the injection needle 100 in a direction substantially perpendicular to the extension direction can be used. In this case, the injection needle 100 having a thickness suitable for the ball 36 is used.

A method for fixing the metal pipe 6a thus formed to the ball 36 will be described. In order to perform such fixation, an adhesive that generates an adhesive force within a short time at room temperature is used. As a commercially available adhesive having such properties, for example, Alon Alpha (trade name) manufactured by Toa Gosei Co., Ltd. can be used. In addition, the outer diameter surface of the metal pipe 6a is previously subjected to a spraying process using a commercially available Teflon-based spray or the like, so that the instant adhesive does not adhere to the outer diameter surface.

The metal pipe 6a thus treated is immersed in a reservoir containing the instant adhesive so that the instant adhesive penetrates into the inner diameter of the needle. Can be filled into pipes. In general, when applied to a thin film, the instant adhesive causes a curing reaction at the same time as the application, and cures in 10 to 20 seconds. However, if it is stored with a certain capacity, it does not cure for several days.

The metal pipe 6a in which the inner diameter of the needle is filled with the instantaneous adhesive as described above is mounted on the support 6 by the following operation. That is, as shown in FIGS. 3A and 3B, the support portion 6 has an operation portion 101 and a holding portion 102, and the holding portion 102 is closed by being tightened by a spring 103. I have. However, by applying a force to the operation unit 101 with a hand or a predetermined jig or the like, the fastening by the spring 103 can be temporarily released and the holding unit 102 can be opened. The force applied at this time and the movement of the holding unit 102 are shown in FIG.
A, indicated by an arrow in FIG. 3B.

When attaching the metal pipe 6a, the tightening by the spring 103 is temporarily released by applying a force to the operation unit 101 with a hand or a predetermined jig, and the holding unit 102 is opened. The metal pipe 6a is sandwiched. (See FIG. 3A). Thereafter, when the force applied to the operation unit 1 is removed, the holding unit 102 is closed, and the metal pipe 6a is fixed to the holding unit 102 (see FIG. 3B). In addition, after completion of the measurement or the like, the metal pipe 6a can be removed from the support section 6 by opening the holding section 102 by applying a similar force.

Prior to the start of the strength test, the XY stage 3 and the like are operated so that the metal pipe 6
The position in the X-Y direction and the height of the sample stage 1 are controlled so that a makes proper contact. Then, a start button of the strength test (for example, provided on the operation panel 46)
When is pressed, the vertically moving part 4 descends as shown in FIG. 4A, and the metal pipe 6a contacts the ball 36 as shown in FIG. 4B. In this state, the ball 36 is pressed down from above under a predetermined load, time, or the like condition, and the ball 36 is fixed to the metal pipe 6a by the action of the instant adhesive.

If the position of the ball 36, conditions for pressing the ball 36 from above, and the like are properly set, the strength of the fixing at this time will be sufficient for performing a pull test. After the fixation, a pulling force (indicated by a white arrow in FIG. 4C) is applied via the vertical moving portion 4. As a result, a break occurs as shown in FIG.
The output of the sensor 5 at the time of peeling off is used as a measured value of the pull test.

By the way, after the pull test is completed,
The ball 36 separated from the substrate is held in the metal pipe 6a. In this state, the tip of the metal pipe 6a is heated by, for example, a gas stove or the like, and the separated ball 36 is heated.
Can be melted and removed from inside the metal pipe 6a. By this heating, of course, the adhesive can be removed, so that the metal pipe 6a can be used repeatedly.

In place of the metal pipe 6a, FIG.
It is also possible to use a joint portion 200 having a joint surface 200a in contact with a larger area (for example, an upper hemispherical portion) of the surface of the ball 36 as shown in FIG. In this case, the joining surface 200a needs to be formed with sufficient precision so as to well conform to the shape of the ball 36. In this case, the adhesive may be applied directly to the joint surface 200a.

Next, another embodiment of the present invention will be described in which the ball 36 is mechanically engaged without using an adhesive when performing a pull test. In another embodiment of the present invention, for example, an engaging portion 300 as shown in FIG. 5 is used instead of the metal pipe 6a and the like in the above-described embodiment of the present invention. FIG.
A shows the non-use state of the engagement part 300.
FIG. 5B shows the state of use.

In use, for example, by applying a force indicated by an arrow W to the lever 300a with a hand or the like, for example, three hooks 300b are pushed out as indicated by an arrow V. The hook 300b has an appropriate elasticity, and the lever 300b is engaged with an object such as the ball 36.
Even when the application of the force to a is stopped, a force for engaging and pinching the object is applied. A pull test can be performed in such a state.

An engaging portion 300 is attached to the pull test weight sensor 5.
6A is illustrated in FIG. 6A. While pushing out the hook 300b by applying the force shown by the arrow W, the hook 300b is moved downward as shown by the arrow U to approach the ball 36. Then, when the hook 300b reaches an appropriate position with respect to the ball 36 and stops applying force to the lever 300a, the hook 300b and the ball 36 are engaged.

As the mechanism related to the operation of the hook 300b, a mechanism generally used in a machine tool or the like can be used. Therefore, a force required for the operation may be applied through a component having a shape different from that of the lever 300a. As the material of the hook 300b, a material having mechanical properties such as elasticity suitable for engagement in consideration of the shape of the ball 36 may be used. The material of the hook 300b may be any material other than metal, such as plastic, as long as it has suitable mechanical properties for engagement.

The shape of the hook 300b is the ball 3
The shape may be suitable for engagement in consideration of the shape and the like of FIG.
In this case, the shape of the hook 300b generally does not need to be as precise as the metal pipe 6a and the joint 200 in the above-described embodiment of the present invention.

The operation of the hook 300b is not limited to manual operation, but may be operated by a motor or the like. Furthermore, a configuration in which engagement, pull test, and the like are consistently and automatically controlled based on information from an optical sensor or the like that grasps the position of the ball 36 is also possible.

The present invention is not limited to the above-described embodiment, and various applications and modifications can be considered without departing from the gist of the present invention.

[0034]

As described above, according to the present invention, a ball or the like of a wire-bonded semiconductor component is formed into a metal pipe previously filled with an instant adhesive or a ball or the like coated with an instant adhesive. By fixing to a joint surface formed so as to be well fitted, sufficient fixing strength for performing a pull test is provided. Further, the present invention uses a configuration in which a ball or the like of a wire-bonded semiconductor component is engaged, and has an engagement strength sufficient for performing a pull test.

For this reason, it is possible to eliminate the need to heat the bonding member such as a ball to the structure for detecting the tensile force and the tensile force. Therefore, it is possible to eliminate the possibility that the state of the bonding surface between the bonding member and the semiconductor changes due to the heating and the correct test result cannot be obtained.

Further, since the configuration relating to the heating and the control thereof is not required, it is possible to reduce the size of the entire apparatus and the cost.

[Brief description of the drawings]

FIG. 1 is a block diagram for describing an overall configuration of an embodiment of the present invention.

FIG. 2 is a schematic diagram for explaining a method of producing a metal pipe by cutting a commercially available injection needle.

FIG. 3 is a schematic diagram for explaining a method of attaching a metal pipe to a support portion.

FIG. 4 is a schematic diagram for explaining an operation performed during a pull test.

FIG. 5 is a schematic diagram for explaining an engagement portion used in another embodiment of the present invention.

FIG. 6 is a schematic diagram for explaining an engagement operation in another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sample table, 5 ... Pull test weight sensor, 6 ... Support part, 6a ... Metal pipe, 35 ...
・ Bonding pad, 36 ... ball, 45 ...
Control microcomputer, 200: joining part, 300: engaging part, 300b: hook

Claims (5)

[Claims] 1. A sample stage on which a wire-bonded semiconductor component is mounted and displaceable in an X direction and a Y direction; a support portion displaceable in a Z axis direction orthogonal to the sample stage; A load sensor for detecting a load applied in the Z-axis direction, the load sensor being detachably mounted on the support portion, and being fixed or engaged with a predetermined portion of the sample related to the strength test within a short time at room temperature. And a means for controlling a drive source for causing displacement of the sample stage and the support, respectively. 2. The bonding strength test apparatus according to claim 1, wherein the test portion fixing portion is a metal pipe filled with an adhesive that generates an adhesive force within a short time at room temperature. 3. The bonding strength test apparatus according to claim 2, wherein the metal pipe is obtained by cutting a tip of an injection needle in a direction substantially orthogonal to an extension direction thereof. 4. The test portion fixing portion according to claim 1, wherein the test portion fixing portion has a joining surface formed so as to conform to a shape of a predetermined portion of the sample related to the strength test, and the joining portion is short at room temperature. A bonding strength test apparatus characterized in that an adhesive which generates an adhesive force is applied within a time. 5. The bonding strength test apparatus according to claim 1, wherein the test portion fixing portion has an engagement member formed to engage with a predetermined portion of the sample related to the strength test.