CN113933180B

CN113933180B - Apparatus and method for testing interconnect bonding portions

Info

Publication number: CN113933180B
Application number: CN202010656412.6A
Authority: CN
Inventors: 宋景耀; 李锐丰; 陈建敏; 吴茂发; 陈健佳
Original assignee: ASM Technology Singapore Pte Ltd
Current assignee: ASMPT Singapore Pte Ltd
Priority date: 2020-07-09
Filing date: 2020-07-09
Publication date: 2025-06-20
Anticipated expiration: 2040-07-09
Also published as: CN113933180A; KR102603357B1; TWI783556B; TW202223357A; KR20220007015A

Abstract

An interconnect bonding part testing device for testing the bonding strength of an electronic device, the electronic device comprising at least one interconnect bonding part attached to the electronic device. The interconnect bonding part testing device has a positioning mechanism and a test tool assembly mounted on the positioning mechanism. The test tool assembly is configured to push a first portion of the interconnect bonding part and lift a second portion of the interconnect bonding part, the positioning mechanism operates to align the test tool assembly with the interconnect bonding part during the test, and applies a thrust to the first portion of the interconnect bonding part and a pull to the second portion of the interconnect bonding part. The interconnect bonding part testing device has a fixture comprising at least one force sensing element mounted thereon. The at least one force sensing element is configured to apply resistance to the test tool assembly when engaged with the test tool assembly.

Description

Apparatus and method for testing interconnect bonds

Technical Field

The present invention relates to an apparatus and method for testing the strength of an interconnect bond, such as a wire bond, on an electronic device, and more particularly to an apparatus that can perform both shear and tensile testing.

Background

Wire bonders are used to electrically interconnect semiconductor wafers with substrates during assembly and packaging of semiconductors. Wire is provided to the capillary from a coil containing bonding wire to perform wire bonding. Typically, each bond includes a length of gold or copper wire bonded to the surface of the substrate.

Testing the strength of the bond is important for a user to verify that a particular wire or interconnect bond formed is acceptable. The test tools used to test the bond strength of these bonds must be able to accurately measure very small forces and deflections, subject to the size of the bond.

There are a variety of known types of bonding tests, such as shear tests and pull tests. Shear test the shear strength of the bond was tested by applying a shear force to the sides of the bond to shear the bond away from the substrate. The pull test tests the pull strength of the wire bonding portion by pulling the wire away from the wire bonding portion.

Machines that perform these tests typically have a test tool that can be placed against the bond to perform the test. The test tool may then be moved to perform a test, which typically involves measuring the force required to break the bond. This is time consuming because the user must perform such tests manually and also use different machines to perform the different types of tests.

In addition, the machine performance may change over time, such that the force generated by the motor or the force detected by the sensor may drift over time. If this occurs in a pipeline, test accuracy can be compromised. Thus, in order to perform preventative maintenance on a tester, a user needs to manually perform force tests on a regular basis (sometimes weekly or even daily). This is cumbersome and time consuming, thereby reducing the overall equipment efficiency of the machine.

It would therefore be beneficial to design an interconnect bond test apparatus that avoids and overcomes these disadvantages.

Disclosure of Invention

It is therefore an object of the present invention to seek to provide an interconnect bond test apparatus adapted to perform shear and pull tests on interconnect bonds formed on electronic devices.

It is a further object of the present invention to seek to provide an interconnect bond test apparatus adapted to perform a self-monitoring machine force test.

Accordingly, a first aspect of the present invention provides an interconnect bond testing apparatus for testing bond strength of an electronic device, the electronic device comprising at least one interconnect bond attached to the electronic device, the interconnect bond testing apparatus comprising a positioning mechanism, a test tool assembly mounted on the positioning mechanism and configured to push a first portion of the interconnect bond and pull a second portion of the interconnect bond during testing, a clamp comprising at least one force sensing element mounted on the clamp and configured to apply a resistance to the test tool assembly when engaged with the test tool assembly, wherein the positioning mechanism is operative to align the test tool assembly with the interconnect bond and to apply a pushing force to the first portion of the interconnect bond and a pulling force to the second portion of the interconnect bond during testing.

In one embodiment, the test tool assembly includes a first test tool configured to apply a pushing force to push a first portion of the interconnect bond and a second test tool configured to apply a pulling force to pull a second portion of the interconnect bond.

In one embodiment, the direction of the pushing force is perpendicular to the direction of the pulling force.

In one embodiment, the interconnect bond test apparatus further includes at least one sensor connected to the first test tool and the second test tool, the at least one sensor operative to determine a reaction force applied to the first test tool and the second test tool when the pushing force and the pulling force are applied.

In one embodiment, the at least one sensor is a first force sensor.

In one embodiment, a bottom end of the first test tool remote from the positioning mechanism has a tip portion configured to engage a first portion of the interconnect bond upon application of a pushing force.

In one embodiment, the second test tool has a drag hook at its distal end remote from the positioning mechanism, the drag hook being configured to engage to the second portion of the interconnection bond upon application of a pulling force.

In one embodiment, the at least one force sensing element comprises at least one flexure.

In one embodiment, the clamp further comprises a constant weight mounted to the clamp, and the test tool assembly is configured to engage and lift the constant weight.

In one embodiment, the constant weight is a self-weight.

In one embodiment, the at least one force sensing element further comprises a second force sensor.

In one embodiment, the second force sensor is a strain gauge.

In one embodiment, the clamp further comprises a lever block mounted on the clamp, and the test tool assembly is configured to engage and lift the lever block.

In one embodiment, the second force sensor is a piezoelectric sensor.

In one embodiment, the second force sensor is a curved sensor.

According to a second aspect of the present invention there is provided a method of testing bond strength of an electronic device comprising at least one interconnection bond attached to the electronic device, the method comprising the steps of providing a test tool assembly mounted on a positioning mechanism, moving the test tool assembly with the positioning mechanism to align the test tool assembly with the interconnection bond, applying a pushing force with the test tool assembly to a first portion of the interconnection bond and a pulling force to a second portion of the interconnection bond, engaging the test tool assembly with a force sensing element mounted on the clamp, and determining a reaction force applied to the test tool assembly by the force sensing element.

In one embodiment, the test tool assembly includes a first test tool configured to apply a pushing force to a first portion of the interconnect bond and a second test tool configured to apply a pulling force to a second portion of the interconnect bond.

In one embodiment, the step of applying the pushing and pulling forces further comprises the step of determining the reaction forces applied to the first and second test tools with at least one sensor connected to the first and second test tools.

The above-mentioned and other features, aspects, and advantages are better understood by the following description, appended claims, and accompanying drawings.

Drawings

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which.

Fig. 1 is an isometric view of an interconnect bond testing apparatus in accordance with a first preferred embodiment of the present invention.

FIG. 2 is a front view of the positioning mechanism with the test tool assembly mounted thereon.

Fig. 3 is an isometric view of a clamp with a force sensing element and self-weight mounted thereon.

Fig. 4A is an elevation view of the positioning mechanism with the test tool engaged with the clamp during a self-monitoring machine shear test.

Fig. 4B is a close-up view of the force sensing element marked with a reference mark.

Fig. 5A is an isometric view of a clamp with a force sensing element engaged with a first test tool.

Fig. 5B is a graph of the reaction force of the machine's learned shear tool tip versus the distance the shear tool is moved.

Fig. 6A is an isometric view of a lifting tool engaged with and lifting a deadweight.

FIG. 6B is a side view of the pulling tool shown in FIG. 6A with a sensor attached thereto.

Fig. 6C is a graph of the force required by the pulling tool to lift the self-weight over a period of time.

Fig. 7A is an isometric view of an interconnect bond testing apparatus in accordance with a second preferred embodiment of the present invention.

Fig. 7B is a side view of the interconnect bond test apparatus shown in fig. 7A.

Fig. 8A is a cross-sectional side view of an interconnect bonding test apparatus according to a second preferred embodiment of the present invention.

Fig. 8B is a plan view of a wire bond test apparatus in accordance with a second preferred embodiment of the present invention.

Fig. 8C is a cross-sectional view taken along line A-A shown in fig. 8B.

Fig. 9A is a cross-sectional side view of a third preferred embodiment of the present invention with a flex-sheet mounted on the clamp.

Fig. 9B is a plan view of fig. 9A, with a plurality of flexure strips mounted on the clamp.

Fig. 10 is a side view of a shear tool pushing a pressure sensor.

Detailed Description

Fig. 1 is an isometric view of an interconnect bond testing apparatus 10 in accordance with a first preferred embodiment of the present invention. For example, a wire bonder may be utilized to create the interconnect bond under test. In general, the interconnect bond testing apparatus 10 includes a positioning mechanism 20 on which a test tool assembly 22 is mounted, a pair of front and rear rails 12, 14, and a clamp 30.

The clip 30 is mounted to the frame 18, and the frame 18 is in turn mounted to the front rail 12. The clip 30 may have a plurality of through holes 38. The clamp 30 may be mounted to the frame 18 by any suitable fastening means, such as screws or fasteners secured with through holes 38. Alternatively, the clip 30 may be mounted to the frame 18 by a suitable adhesive. The frame 18 may be mounted to the front rail 12 by any suitable fastening means, such as screws or fasteners. Alternatively, the frame 18 may be mounted to the front rail 12 by a suitable adhesive. Thus, the position of the clamp 30 relative to the front rail 12 is fixed.

The front rail 12 and the rear rail 14 are laterally spaced apart from each other such that the front rail 12 is located between the clip 30 and the rear rail 14. The front rail 12 is generally parallel to the rear rail 14. Between the front rail 12 and the rear rail 14 is provided a stage 16 adapted to receive electronic devices supported by a substrate, such as a lead frame 19, for testing. The present embodiment will be described with reference to a lead frame. However, those skilled in the art will appreciate that the bond strength test disclosed in the present invention is equally applicable to substrates other than lead frames.

The lead frame 19 may be held on the stage 16 by a clamping device. For example, the lead frame 19 may be mechanically clamped to the stage by a clamp (not shown) and then further held to the stage 16 by a vacuum suction device provided on the stage 16. The lead frame 19 is adapted to engage with the test tool assembly 22 during a shear test or a pull wire test.

The positioning mechanism 20 may be connected to an XY drive mechanism (not shown) that drives the positioning mechanism 20 through the XY axis in the horizontal plane. Alternatively, the XY drive mechanism may be connected to the stage 16 holding the lead frame 19, thereby driving the stage 16 through the XY axis in the horizontal plane. A separate Z-drive mechanism (not shown) may be coupled to the positioning mechanism 20 to drive the vertical movement of the positioning mechanism 20 in the Z-direction. X, Y and the Z-drive mechanism may be operated together or separately in accordance with programmed instructions from the processor to move positioning mechanism 20. For example, positioning mechanism 20 may be programmed to move such that test tool assembly 22 is over an interconnect bond and bonded to an interconnect bond on leadframe 19.

The interconnect bond test apparatus 10 may be configured to perform a shear push-ball test and a pull-wire test on interconnect bonds of an electronic device, for example. While this disclosure relates to interconnect bonding, it will be understood by those skilled in the art from this disclosure that the present invention is not so limited. For example, the interconnect bond may be, but is not limited to, a wire bond, a ball bump, a post-bond wire (BSOB), a post-Bond Ball (BBOS), a Ball Vertical Array (BVA), a stacked die wire bond, a die attach bond, and a wedge bond. How to perform the shear push ball test and the pull wire test according to the embodiment of the present invention will be described below.

Referring to fig. 1, the test tool assembly 22 is configured to perform a shear push-ball test and/or a pull-wire test on electronic devices supported on the lead frame 19. The stacked lead frames to be tested may be loaded onto a magazine (not shown) located spaced apart from the stage 16. The user determines the lead frame to be tested. During testing, a feeder (not shown) pushes the selected lead frame onto stage 16. The lead frame 19 may be mechanically clamped to the stage by a clamp (not shown) and then further held to the stage 16 by creating a vacuum suction on the stage 16.

During a shear ball push test, the XY drive mechanism drives the positioning mechanism 20 to move so that the shear tool of the test tool assembly 22 is above the interconnect bond to be tested. Next, the Z-drive mechanism drives the positioning mechanism 20 vertically downward toward the interconnect bond to be tested. Once the shear tool is in contact with the top surface of the electronic device or leadframe 19 adjacent to the interconnect bond to be tested, the positioning mechanism 20 is lifted vertically upward to a predetermined height to lift the shear tool 24 to the same height. The predetermined height may be determined by user programming and depends on the size of the interconnect bond to be tested. Thereafter, the XY drive mechanism drives the positioning mechanism 20 to move so that it pushes the interconnection bond until the interconnection bond is completely sheared off. When the shear tool pushes the interconnection bond, the interconnection bond applies a reaction force to the tip of the shear tool. The sensor connected to the shear tool may then measure the reaction force required to push the interconnect bond completely off the leadframe, thereby yielding the ball shear force.

In an alternative arrangement in which the XY drive mechanism is connected to the stage 16, the XY drive mechanism drives the stage 16 holding the lead frame 19 such that the shear tool of the test tool assembly 22 is above the interconnect bond to be tested. Next, the Z-drive mechanism is configured to drive the positioning mechanism 20 vertically downward toward the interconnect bond to be tested. Once the shear tool is in contact with the top surface of the electronic device or leadframe 19 adjacent to the interconnect bond to be tested, the positioning mechanism 20 is raised vertically upward to a predetermined height to raise the shear tool 24 to the same height. The predetermined height may be determined by user programming and depends on the size of the interconnect bond to be tested. Thereafter, the XY drive mechanism drives the stage to push the tip portion of the shear tool 24 until the interconnect bond is completely sheared off.

During pull-wire testing, the XY drive mechanism drives the positioning mechanism 20 to move so that the pull tool of the test tool assembly 22 is positioned over the interconnect bond to be tested. Next, the Z-drive mechanism drives the positioning mechanism 20 vertically downward toward the interconnect bond to be tested. The draw hook on the pulling tool engages the wire of the interconnect bond to be tested. Next, the Z-drive mechanism drives the pulling tool to pull the wire interconnecting the bonds upward toward the positioning mechanism until the wire breaks or the bonds break and are lifted off of the lead frame 19 (as would occur earlier). The sensor connected to the pulling tool measures the pulling force required to lift the wire until the wire breaks or the bond breaks, thereby deriving the wire pulling force.

In an alternative arrangement in which the XY drive mechanism is connected to the stage 16, the XY drive mechanism may drive the stage 16 holding the lead frame 19 such that the pull tool of the test tool assembly 22 is above the interconnect bond to be tested. Next, the Z-drive mechanism drives the positioning mechanism 20 vertically downward toward the interconnect bond to be tested. The draw hook on the pulling tool engages the wire of the interconnect bond to be tested. Next, the Z-drive mechanism drives the pulling tool to pull the wire interconnecting the bonds upward toward the positioning mechanism until the wire breaks or the bonds break and are lifted off of the lead frame 19 (as would occur earlier). Thus, the interconnect bond testing apparatus of the present invention allows for both shear testing and tensile testing to be performed on the same machine. So that different types of tests can be performed without using multiple machines or manually modifying the test tools of the machines. This has the advantage that little manual intervention is required, as the shear push test and pull test can be automated and the results sent to the processor.

And the user can select which test (shear push test or pull test) to perform by himself, and programming can be performed according to the user's requirements. For example, a user may prefer to perform a pull-wire test prior to performing a shear push-ball test for cost savings. In this example, the wire pulling test is performed until the wire breaks, and the remaining ball bonding portion is still available for performing the shear push ball test, so that the waste of resources can be minimized. But if the shear push-ball test is performed first, the pull wire test cannot be performed on the same ball bond because the ball bond has been sheared off by that time.

After the shear ball pushing test and the pull wire test are performed on the lead frame, a pushing device (not shown) pushes the lead frame to detach it from the stage 16. The stage 16 is then ready to receive the next leadframe for testing. This allows for a fully automated test of the entire interconnect bond without manual intervention.

In operating the interconnect bond test apparatus 10 described above, the performance of the drive mechanism and sensors may change over time, resulting in erratic driving force and sensed force over a period of time, such that the test results become increasingly inaccurate. It is therefore desirable to periodically check the interconnect bond test apparatus 10 to ensure that it continues to function as intended, particularly without human intervention.

Fig. 2 is a front view of positioning mechanism 20 with test tool assembly 22 mounted thereon. The test tool assembly 22 includes a shear tool 24 and a pull tool 26. The shearing tool 24 has a tip 25 at a bottom end remote from the positioning mechanism 20. Preferably, the tip portion 25 is tapered in shape (as more clearly shown in fig. 5A). The shear tool 24 is connected to a sensor (not shown). The pulling tool 26 has a pulling hook 27 at the bottom end remote from the positioning mechanism 20. The pull tool 26 is connected to a sensor 38 (shown in fig. 6B).

Also mounted on the positioning mechanism 20 is an image sensor 28 that is positioned spaced apart from the test tool assembly 22. Thus, the image sensor 28 may move with the positioning mechanism 20. The image sensor 28 may be in the form of a camera and positioned such that the clip 30 is viewable through the image sensor 28. The image sensor 28 is operable to align the test tool assembly 22 with the fixture 30 to perform a self-monitoring machine force test.

Fig. 3 is an isometric view of a clip 30 that may be used with a preferred embodiment of the present invention. The clamp 30 has mounted thereon a force sensing element 32 and a weight 34. Preferably, the force sensing element 32 is mounted to the top surface of the clamp 30 and is urged by the shear tool 24 during self-monitoring machine shear force testing. Preferably, the area around the force sensing element 32 should remain clear to avoid any interference during the self-monitoring machine shear force testing of the test tool assembly 22. The force sensing element 32 may be made of any flexible material or of a suitable material that will elastically deflect, deform or shear when a force is applied thereto. The force sensing element 32 may be, but is not limited to, a flexure, a sheet, machined metal, a spring-held component, a strain gauge, a piezoelectric sensor, a bending sensor, or a force sensor. Preferably, the shape of the force sensing element 32 is a regular shape with a plurality of side walls, e.g. may have four side walls. This is beneficial because it allows the force sensing element 32 to have multiple points of contact during self-monitoring machine shear force testing. The shear tool 24 may be configured to apply a force to any of the four sidewalls of the force sensing element 32 to urge the force sensing element 32.

The clip 30 may have a plurality of through holes 38 for mounting the clip 30 to the frame 18 by suitable fastening means such as screws and fasteners. The embodiment shown in fig. 3 shows two holes. Any number of holes may be used to operatively connect clip 30 to front rail 12.

The constant weight portion (e.g., self-weight 34) is located on a clamp support 35 mounted on the side wall of clamp 30. Alternatively, the jig support 35 may be integrally formed with the jig 30. Preferably, the clip support 35 extends from the clip 30 in a direction parallel to the front rail 12. Self-weight 34 is configured to rest on a top surface of clamp support 35. Self-weights 34 may be made of any material of known mass (e.g., free weight). Wire 36 is attached to the top surface of self-weight 34. The wire 36 is adapted to engage the pull tool 26 during a self-monitoring machine pull test. Wire 36 may be made of a metal that is at least malleable so that wire 36 does not break when lifting tool 26 lifts self-weight 34. Preferably, the wire 36 is made of a hard material such as metal.

Fig. 4A is a front view of positioning mechanism 20 with shear tool 24 engaged with force sensing element 32 during a self-monitoring machine shear force test. During self-monitoring machine shear testing, an XY drive mechanism coupled to positioning mechanism 20 drives positioning mechanism 20 to a position such that test tool assembly 22 is located vertically above clamp 30.

A reference mark 39 (see fig. 4B) may be marked on the jig 30 so as to be observable by the image sensor 28. Reference mark 39 may be marked on force sensing element 32 such that when image sensor 28 captures an image of reference mark 39, shear tool 24 aligns force sensing element 32 above to perform a self-monitoring machine shear force test. Reference marks 39 may also be marked on the deadweight 34 so that when the image sensor 28 captures an image of the reference marks 39, the pull tool 26 can align the deadweight 34 above to perform a self-monitoring machine pull test. Alternatively, the reference marks 39 may be marked on both the force sensing element 32 and the self-weight 34 at the same time, such that when the image sensor 28 captures an image of either of the two reference marks 39, the shear tool 24 and the pull tool 26 may be aligned over the force sensing element 32 or the self-weight 34, respectively, to perform a self-monitoring machine force test. The reference mark 39 may have any form or shape, or it may be located at any position along the jig, the force sensing element, or the weight, as long as it can be observed by the image sensor 28. Preferably, the reference mark 39 is located on the top surface of the clamp, force sensing element or self-weight, so that an unobstructed image of the reference mark 39 can be obtained by the image sensor 28.

When image sensor 28 captures an image of reference mark 39 marked on fixture 30, image sensor 28 may confirm that test tool assembly 22 is aligned with fixture 30. Any deviations and deviations from alignment captured by the image sensor 28 may be corrected by signals sent to the XY drive mechanism.

Upon confirming alignment of the test tool assembly 22 with the clamp 30, the Z-drive mechanism may drive the positioning mechanism 20 to move the shear tool 24 in a vertical direction toward the force sensing element 32. In the embodiment shown in fig. 4A, the shear tool 24 is in contact with the force sensing element 32. At this stage the pulling tool 26 is in the "rest" position during which the pulling tool 26 is not engaged with the wire 36 of the deadweight 34.

Fig. 5A is an isometric view of clamp 30 with force sensing element 32 engaged with shear tool 24. The tip 25 of the shear tool 24 is configured as a sidewall of the impulse force sensing element 32. The Z-drive mechanism drives the positioning mechanism 20 vertically downward until the tip portion 25 contacts the top plate 31 on the top surface of the jig 30. When contacting the top plate 31, the positioning mechanism 20 is lifted vertically upward to a predetermined height to lift the shear tool 24 to the same height as well. The predetermined height may be determined by user programming and depends on the characteristics of the force sensing element 32 used. The top plate 31 may be made of a hard material such as sapphire.

Thereafter, the positioning mechanism 20 may be driven by the XY driving mechanism to move in the S direction as shown in fig. 5A and push the side wall of the sensing element 32. The force sensing element 32 will elastically deform and generate a reaction force R on the tip portion 25. A sensor coupled to the shear tool 24 may measure the reaction force R acting on the tip 25 and send the data to the processor. The processor records the value of the reaction force R and the distance traveled by the shear tool 24.

The machine may learn the relationship between the reaction force R acting on the tip 25 and the distance traveled by the shear tool 24, the result of which is shown in fig. 5B. In the embodiment shown in fig. 5A, the shear tool 24 pushes the force sensing element 32 in the S direction. It should be noted that the shear tool 24 may also be configured to apply a force to any of the four sidewalls of the force sensing element 32 to urge the force sensing element 32 to derive the reaction force R on the tip portion 25 of the shear tool 24.

In fig. 5B, the relationship between the reaction force R generated at the tip portion 25 of the shear tool 24 and the distance the shear tool 24 moves is learned, thereby obtaining a learned slope. The self-monitoring machine shear force test may be programmed to be performed on a regular basis according to the user's preferences and needs. For example, the self-monitoring machine shear force test may be set to be performed weekly or monthly. The results obtained for each shear force test may be tabulated and the slope compared to the learned slope. Ideally, any differences and deviations from the learned slope should be minimal. The tolerance may be determined by the user. Preferably, the recommended tolerance is +/-0.5%. If the test results fall outside of the allowable tolerances, the processor may alert the user to perform the necessary compensation and/or corrective action on the shear tool 24 and/or the sensor.

Advantageously, the shearing tool 24 and the tip portion 25 are made of a hard material, such as metal. For example, the shearing tool may be made of titanium or an aluminum-lithium alloy, and the tip portion may be made of tungsten carbide. The tip portion 25 is typically sized or shaped according to the interconnect bond to be tested. Thus, the tip portion 25 is replaceable, and accordingly, a larger or smaller tip portion may be used for a larger or smaller bonding portion.

Fig. 6A is an isometric view of the lifting tool 26 engaged with and lifting the deadweight 34. Self-weight 34 is placed on clamp support 35. The pulling tool 26 has a pulling hook 27, which is located at the end of the pulling tool 26 remote from the positioning mechanism 20. The wire 36 attached to the top surface of the weight is adapted to engage the retractor 27 and be pulled upward in the direction of the positioning mechanism 20. During a self-monitoring machine pull test, when the pull tool 26 is aligned with the wire 36 of the deadweight 34, a Z-drive mechanism (not shown) drives the pull tool 26 vertically downward, thereby engaging the draw hook 27 with the wire 36. Next, the Z-direction drive mechanism drives the pull tool 26 upward toward the positioning mechanism 20. The lifting tool 26 lifts the self-weight 34 upward in a direction L away from the clamp support 35. As shown in fig. 6B, a sensor 38 is connected to the pulling tool 26. The sensor 38 may be a load cell. The sensor 38 may be used to measure the force required to lift the weight 34 off the clamp support 35. As shown by the curve in fig. 6C, the force required to lift the self-weight 34 off of the clamp support 35 is constant and does not change over time.

Alternatively, a self-monitoring machine pull test may be performed on the force sensing element 32. In this case, the force sensing element 32 may be mounted on the clamp 30 such that a portion of the force sensing element 32 extends from the clamp 30 (not shown). A notch (not shown) may be formed near the edge of the force sensing element 32 and adapted to engage the draw hook 27 of the pull tool 26. During a self-monitoring machine pull test, when the pull tool 26 is aligned with a notch on the force sensing element 32, the Z-drive mechanism drives the pull tool 26 vertically downward, thereby engaging the draw hook 27 with the notch on the force sensing element 32. The Z-drive mechanism then drives the pull tool 26 upward in the direction of the positioning mechanism 20. The force sensing element 32 will elastically deform and exert a reaction force on the retractor 27. The sensor connected to the pulling tool 26 can measure the reaction force acting on the pulling hook 27 and send the data to the processor. The processor records the value of the reaction force and the distance the pull tool 26 is moved. The machine may learn a relationship between the reaction force acting on the drag hook 27 and the distance traveled by the pulling tool 26, the result being similar to the learned slope shown in fig. 5B.

The self-monitoring machine pull test may be programmed to be performed on a regular basis according to the user's preferences and needs. For example, the self-monitoring machine pull test may be programmed to be performed weekly or monthly. The results obtained for each tensile test may be compared to a constant force curve or a learned slope. Ideally, any difference or deviation from the constant force curve or learned slope should be minimal. The tolerance may be determined by the user. Preferably, the recommended tolerance is +/-0.5%. If the test results fall outside of the allowable tolerances, the processor may alert the user to perform the necessary compensation and/or corrective action on the pull tool 26 and/or the sensor 38. Thus, the performance of the machine may be self-monitored over time.

Advantageously, the retractor 27 is made of a hard material, such as metal. The retractor 27 is typically sized according to the interconnect bond to be tested. The retractor 27 is therefore replaceable and larger or smaller retractors can be used accordingly. Thus, the performance of the machine can be self-monitored over time without human intervention to perform force tests using different test tools. This will reduce the possibility of equipment failure, lower maintenance costs, reduce downtime, and improve production quality.

Fig. 7A and 7B are isometric and side views of an interconnect bond testing apparatus in accordance with a second preferred embodiment of the present invention. The clip 30 has an interior cavity 47 and the clip 30 is mounted on the frame 18 such that the front rail 12 is received within the clip interior cavity 47 (as shown in fig. 7B). The jig is accommodated in the housing 40. The top surface of the housing 40 has a pair of grooves located at an end of the housing 40 adjacent the front rail 12. The recess is adapted to receive a shear tool 24 and a pull tool 26 during a self-monitoring machine force test. The force sensing element is mounted on the clamp such that the force sensing element is located above the front rail 12. As shown in fig. 7B, the tip 25 of the shear tool 24 and the pull tool 26 are located above the front rail 12. Thus, in this embodiment, the working area of the self-monitoring machine force test is above the front rail 12. This is particularly advantageous for machines where the force sensing element is not properly reached for self-monitoring machine force testing due to the short travel of the positioning mechanism and space constraints.

Fig. 8A is a cross-sectional side view of an interconnect bonding test apparatus according to a second preferred embodiment of the present invention. The force sensing element in this embodiment may be a lever block 42. The lever block 42 is mounted to the clamp 30 by a U-shaped bracket 51 and is secured by a suitable fastening means such as a fastener 44. When a pulling force is applied to the opposite end of the lever block 42, the lever block 42 rotates about the pivot 43. The opposite end of the lever block 42 is provided with a notch adapted to engage the retractor 27 and be lifted upwardly in the direction of the positioning mechanism.

During a self-monitoring machine pull test, when the pull tool 26 is aligned with a notch on the lever block 42, a Z-drive mechanism (not shown) drives the pull tool 26 vertically downward, thereby engaging the draw hook 27 with the notch on the lever block 42. The Z-drive mechanism then drives the pull tool 26 upward in the direction of the positioning mechanism 20. Accordingly, the pulling tool 26 lifts the opposite end of the lever block 42 in the direction L1, thereby rotating the lever block 42 about the pivot pin 43. As previously shown in fig. 6B, a sensor 38 is connected to the pulling tool 26. The sensor 38 may be a load cell. The sensor 38 can measure the reaction force acting on the retractor 27 and send information to the processor. The processor records the value of the reaction force and the distance the pull tool 26 is moved. The machine can learn the relationship between the reaction force R acting on the drag hook 27 and the distance traveled by the pulling tool 26, the result of which is shown in fig. 5B.

Fig. 8B is a plan view of an interconnection bond testing apparatus according to a second preferred embodiment of the present invention, and fig. 8C is a sectional view taken along the line A-A shown in fig. 8B. One end of the clamp 30 is mounted with a second force sensing element, which may be a strain gauge, for example, it may be a load cell type strain gauge 41 as shown in fig. 8B. The opposite end of the load cell strain gauge 41 from the clamp 30 is provided with a tab 45. The load cell strain gauge 41 is mounted to the clamp 30 by the projection 52 and secured by the C-clamp fastener 46. The C-clip-like fastener 46 securely retains the load cell strain gauge 41 to the clamp 30.

During self-monitoring machine shear testing, the tip 25 of the shear tool 24 is configured to push against the tab 45 of the load cell 41. The Z-drive mechanism drives the positioning mechanism vertically downward until the tip portion 25 is aligned with the boss 45 of the load cell 41. Thereafter, the positioning mechanism may be driven by the XY driving mechanism so as to move and push the bump 45 in the S1 direction as shown in fig. 8C. The load cell type strain gauge 41 will elastically deform and generate a reaction force on the tip portion 25. A sensor coupled to the shear tool 24 may measure the reaction force acting on the tip 25 and send information to the processor. The processor records the value of the reaction force and the distance traveled by the shear tool 24. The machine may learn the relationship between the reaction force acting on the tip 25 and the distance traveled by the shear tool 24, the result of which is shown in fig. 5B.

Fig. 9A is a cross-sectional side view of a clip according to a third preferred embodiment of the present invention, with a flex sheet mounted thereon. A force sensing element, such as flex sheet 48, is mounted to clamp 30 by fastener 44. The self-monitoring machine pull test may be performed in a similar manner as described in the embodiments above. During self-monitoring machine pull testing, the pull tool 26 may be configured to lift the free end of the flex sheet 48 proximate the front rail 12. The sensor connected to the pulling tool 26 can measure the reaction force acting on the pulling hook 27 and send information to the processor. The processor records the value of the reaction force and the distance the pull tool 26 is moved. The machine can learn the relationship between the reaction force acting on the drag hook 27 and the distance traveled by the pulling tool 26, the result of which is shown in fig. 5B.

Fig. 9B is a plan view of fig. 9A, wherein a plurality of flexure strips are mounted on the clamp 30. The clamp 30 has mounted thereon a force sensing element, such as a plurality of flex tabs 49. The plurality of flex tabs 49 are configured to engage the tip portion 25 of the shear tool 24 during a self-monitoring machine shear test. The shear tool 24 pushes the plurality of flex tabs 49 at the protrusion 53, which is located at the end of the plurality of flex tabs 49 that is remote from the clamp 30. A sensor coupled to the shear tool 24 may measure the reaction force acting on the tip 25 and send the information to the processor. The processor records the value of the reaction force and the distance traveled by the shear tool 24. The machine may learn the relationship between the reaction force acting on the tip 25 and the distance traveled by the shear tool 24, the result of which is shown in fig. 5B.

While various examples have been provided with respect to using a force sensing element to perform a self-monitoring machine force test, it will be appreciated by those skilled in the art in light of the present disclosure that the examples provided herein are not so limited. For example, force sensors, piezoelectric sensors, or other sensors suitable for measuring force directly or indirectly may be used in place of flexures and flexures mounted to the clamp 30, as schematically illustrated in FIG. 10.

Although the present invention has been described in considerable detail with reference to certain embodiments, other embodiments are possible.

Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.

Claims

1. An interconnect bonding portion testing device for testing the bonding strength of an electronic device, the electronic device comprising at least one interconnect bonding portion attached to the electronic device, the interconnect bonding portion testing device comprising:

Positioning mechanism;

a test tool assembly comprising a first test tool and a second test tool mounted on the positioning mechanism, the first test tool being configured to push a first portion of the interconnect bonding portion during testing and the second test tool being configured to lift a second portion of the interconnect bonding portion during testing; and

a fixture comprising at least one force sensing element mounted thereon for performing a self-monitoring machine force test, and wherein the at least one force sensing element is configured to apply a resistive force to the test tool assembly when engaged with the test tool assembly,

wherein the positioning mechanism is operated to move during testing so that the test tool assembly is positioned to align with the interconnect bonding portion, and a push force is applied to a first portion of the interconnect bonding portion with the first test tool and a pull force is applied to a second portion of the interconnect bonding portion with the second test tool,

Wherein, the positioning mechanism is further operable to move so that the test tool assembly is positioned to engage with any one of the at least one force sensing element to perform the self-monitoring machine force test.

2. The interconnect bonding part testing device according to claim 1, wherein the positioning mechanism can also be operated to move the testing tool assembly so that after the second testing tool applies a pulling force to lift the second part of the interconnect bonding part, the first testing tool can be operated to apply a pushing force to push the first part of the interconnect bonding part.

3 . The interconnection bonding portion testing apparatus according to claim 1 , wherein a direction of the pushing force is perpendicular to a direction of the pulling force.

4. The interconnect bonding portion testing device according to claim 2, further comprising at least one sensor connected to the first test tool and the second test tool, wherein the at least one sensor operates to determine the reaction force applied to the first test tool and the second test tool when the push force and the pull force are applied.

The interconnect bond testing apparatus according to claim 4 , wherein the at least one sensor is a first force sensor.

6 . The interconnect bond testing apparatus according to claim 2 , wherein a bottom end of the first testing tool remote from the positioning mechanism has a tip portion, the tip portion being configured to engage with the first portion of the interconnect bond when a pushing force is applied.

7 . The interconnect bond testing device according to claim 2 , wherein the second testing tool has a hook at a distal end thereof away from the positioning mechanism, the hook being configured to engage with the second portion of the interconnect bond when a pulling force is applied.

8 . The interconnect bond testing apparatus of claim 1 , wherein the at least one force sensing element comprises at least one flexure.

9 . The interconnect bond testing apparatus of claim 8 , wherein the fixture further comprises a constant weight mounted to the fixture, and the test tool assembly is configured to engage and lift the constant weight.

10 . The interconnect bonding portion testing apparatus according to claim 9 , wherein the constant weight portion is a deadweight block.

11 . The interconnect bond testing apparatus of claim 1 , wherein the at least one force sensing element comprises a second force sensor.

12 . The interconnect bond testing apparatus according to claim 11 , wherein the second force sensor is a strain gauge.

13 . The interconnect bond testing apparatus of claim 12 , wherein the fixture further comprises a lever block mounted to the fixture, and the test tool assembly is configured to engage and lift the lever block.

14. The interconnect bond testing apparatus according to claim 11, wherein the second force sensor is a piezoelectric sensor.

15 . The interconnect bond testing apparatus according to claim 11 , wherein the second force sensor is a bending type sensor.

16. A method for testing the bond strength of an electronic device, the electronic device comprising at least one interconnect bond attached to the electronic device, the method comprising the steps of:

providing a test tool assembly mounted on the positioning mechanism, wherein the test tool assembly includes a first test tool and a second test tool;

moving the test tool assembly with the positioning mechanism to position the test tool assembly to align with the interconnect bonding portion;

During testing, applying a push force to a first portion of the interconnect bond with the first test tool and applying a pull force to a second portion of the interconnect bond with the second test tool;

performing a self-monitoring machine force test by moving the test tool assembly with a positioning mechanism so that the test tool assembly is positioned to engage a force sensing element mounted on a fixture; and

A reaction force applied to the test tool assembly is determined by the force sensing element.

17. The method according to claim 16, wherein the steps of applying a pushing force and applying a pulling force include: moving the test tool assembly with the positioning mechanism so that after a pulling force is applied to the second part of the interconnect bonding part by the second test tool, a pushing force is applied to the first part of the interconnect bonding part by the first test tool.

18. The method of claim 17, wherein when applying the push force and the pull force, further comprising the step of determining a reaction force applied to the first test tool and the second test tool using at least one sensor connected to the first test tool and the second test tool.