Chip bending test device, method and system

Abstract

The invention relates to the field of advanced packaging stress reliability verification, and provides a bending test device, method and system for a chip, and the device comprises a positioning column, a supporting member, a pedestal, a bearing block, an upper pressing block, and a limiting column. The at least two bearing blocks are located on the top end face of the base and used for abutting against the bottom end face of the chip; the base is used for applying upward supporting force to the bearing block and the chip; the bearing block is provided with a limiting groove facing the base. The limiting column is inserted into the inserting hole of the base and the limiting groove of the bearing block at the same time. The at least two upper pressing blocks are located on the bottom end face of the supporting piece and used for abutting against the top end face of the chip. Insertion holes are formed in the base and the supporting piece; the insertion holes in the base and the insertion holes in the supporting piece are arranged in a one-to-one correspondence manner; and the positioning column is simultaneously inserted into the insertion hole of the supporting piece and the insertion hole of the base in the vertical direction. The device is used for limiting the testing device in the horizontal direction so as to improve the calculation precision of the piezoresistive coefficient of the chip.

Description

Technical Field

[0001] The present invention relates to the field of advanced packaging stress reliability verification, and in particular to a chip bending test device, method and system. Background Art

[0002] As the integration of advanced packaging becomes higher and higher, the thermal expansion coefficients of different materials vary greatly. High-temperature processes and 3D stacking structures are more likely to produce greater stress, leading to mechanical problems such as solder ball cracking, chip breakage, and substrate warping. Stress sensors integrated on the chip can monitor stress changes in the packaging process and improve packaging reliability. Stress sensors need to be calibrated for piezoresistance before use.

[0003] In the related art, there is a four-point bending bracket used to support the chip and apply load to it to test its performance. The base of this bracket is provided with a horizontal axial cylindrical groove, and a movable cylinder is matched inside to support the bottom of the chip. The load is increased by placing a heavy object on the top of the chip. However, since the position of the movable cylinder is not fixed, the chip may be offset in the horizontal direction during the load application process. This not only affects the consistency and repeatability of the test conditions, but also causes the system to calculate the chip piezoresistance coefficient inaccurately. Therefore, there is an urgent need for a chip bending test device, method and system to improve the above problems. Summary of the invention

[0004] The object of the present invention is to provide a chip bending test device, method and system, which are used to provide horizontal limit for the test device to improve the calculation accuracy of the piezoresistance coefficient of the chip.

[0005] In the first aspect, the present invention provides a chip bending test device, comprising: a positioning column, a support member, a base, a limiting column, at least two bearing blocks and at least two upper pressure blocks; the at least two bearing blocks are located on the top end surface of the base, and the bearing block is used to abut the bottom end surface of the chip; the base is used to apply an upward supporting force to the bearing block and the chip; the bearing block is provided with a limiting groove facing the base; the limiting column is simultaneously inserted into the insertion hole of the base and the limiting groove of the bearing block, and is used to make the bearing block and the base relatively fixed in the horizontal direction. The support member is arranged directly above the base, and the at least two upper pressure blocks are located on the bottom end surface of the support member, and the upper pressure block is used to abut the top end surface of the chip; the support member is used to apply downward pressure to the upper pressure block and the chip; both the base and the support member are provided with sockets; the sockets located on the base and the sockets located on the support member are arranged one by one; the positioning column is simultaneously inserted into the sockets of the support member and the sockets of the base in the vertical direction; the positioning column is used to provide horizontal limitation for the base and the support member.

[0006] Optionally, the device also includes a flexible circuit board; the flexible circuit board has a solder pad; at least one stress sensor is integrated on the chip; the stress sensor is electrically connected to the solder pad; when the chip is subjected to force, the stress sensor is used to transmit an electrical signal through the flexible circuit board.

[0007] Optionally, the flexible circuit board has a wide end and a narrow end; the wide end is provided with a gold finger, and the gold finger is used to be plugged into a socket of a PCB board; the narrow end is provided with the soldering pad, and the stress sensor is bonded to the soldering pad through a wire.

[0008] Optionally, the height of the supporting block is greater than the height of the upper pressing block, so that an accommodation space is formed between the bottom side of the upper pressing block and the top surface of the base; the accommodation space is used to accommodate leads connected to the chip.

[0009] Optionally, the chip is arranged in a strip shape with a horizontally arranged length direction; the at least two supporting block positions include a first supporting block and a second supporting block; the at least two upper pressing block positions include a first upper pressing block and a second upper pressing block; the first upper pressing block and the second upper pressing block are symmetrically arranged with respect to the vertical section of the chip; the first supporting block and the second supporting block are symmetrically arranged with respect to the vertical section of the chip; the center point of the chip is located on the vertical section of the chip.

[0010] Optionally, the top end surface of the support member has a load-bearing area; the load-bearing area is used to apply a load.

[0011] Optionally, the upper pressing block is provided with a through hole; the positioning column passes through the through hole, so as to relatively fix the upper pressing block and the supporting member in a horizontal direction.

[0012] Optionally, the bottom end of the carrier block and the top end of the upper pressing block both have horizontally arranged edges, and the edges are used to provide a linear area contacting the chip.

[0013] In a second aspect, the present invention provides a bending test method for a chip, which is applied to building the device described in any one of the first aspects to obtain the piezoresistance coefficient of the chip, comprising: pasting the chip to a flexible printed circuit board, electrically connecting the stress sensor on the chip to the pad of the flexible circuit board, so that the stress sensor outputs an electrical signal through the flexible circuit board; selecting a socket for inserting a positioning column according to the size of the chip to build a test device corresponding to the size of the chip; recording the contact distance of two upper pressing blocks contacting the chip as the upper pressing block spacing L; recording the contact distance of two supporting blocks contacting the chip as the supporting block spacing d; applying a load to the support member to obtain the pressure F applied to the chip by each upper pressing block; calculating the stress exerted on the chip in its length direction according to the size of the chip, the pressure F, the upper pressing block spacing L and the supporting block spacing d; adjusting the load and recording the electrical signal of the stress sensor under different stresses; performing linear fitting based on the stress and the electrical signal to obtain the piezoresistance coefficient of the chip.

[0014] Optionally, the stress on the chip in the length direction satisfies:

[0015] in, is the stress in the length direction at the center of the upper surface of the chip, w is the dimension of the chip in the width direction; t is the dimension of the chip in the thickness direction; the thickness direction is along the vertical direction; the length direction, the width direction and the thickness direction are perpendicular to each other.

[0016] In a third aspect, the present invention provides a chip bending test system, comprising the device described in any one of the first aspects, and further comprising: a signal detection device and a host; the flexible circuit board, the signal detection device and the host are electrically connected in sequence; the signal detection device is used to detect the electrical signal output by the flexible circuit board, and convert the electrical signal into detection data; the host is used to calculate the piezoresistance coefficient of the chip based on the detection data.

[0017] Compared with the prior art, the beneficial effects of the present invention are: by simultaneously inserting the positioning column into the corresponding sockets on the support and the base, the base and the support are provided with horizontal limit; and the limiting column is simultaneously inserted into the socket of the base and the limiting groove of the bearing block, so that the bearing block and the base are relatively fixed in the horizontal direction, ensuring the horizontal limit of the entire test device. This effectively avoids the horizontal deviation of the chip when the load is applied, ensures the consistency and repeatability of the test conditions, and is conducive to improving the calculation accuracy of the system for the piezoresistance coefficient of the chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1A schematic diagram of the three-dimensional structure of a chip bending test device provided by the present invention; Figure 2 A structural schematic diagram of a bearing block provided by the present invention when viewed from the Y direction; Figure 3 A structural schematic diagram of a bearing block provided by the present invention when viewed from the Z direction; Figure 4 A schematic flow chart of a chip bending test method provided by the present invention; Figure 5 A schematic diagram of wafer dicing provided by the present invention; Figure 6 A schematic diagram of the structure of a chip for performing a bending test provided by the present invention; Figure 7 A schematic diagram of a support member provided by the present invention when viewed along the Z direction; Figure 8 A schematic structural diagram of a chip bending test system provided by the present invention.

[0019] Description of reference numerals in the figures: 1. Positioning column; 2. Support member; 3. Base; 4. Upper pressure block; 5. Chip; 6. Carrying block; 7. Socket; 8. Load; 9. Edge; 10. Flexible circuit board; 11. Lead; 12. Pad; 13. Gold finger; 14. Socket; 15. PCB board; 16. Pin; 17. Source meter; 18. Host; 19. Limiting column; 20. Limiting groove; 21. Gluing device; 22. Bonding device; 23. Curing device; 24. Vertical section. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be understood by people with general skills in the field to which the present invention belongs. "Including" and similar words used in this article mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0021] In the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. The term "plurality" refers to two or more than two, unless otherwise clearly defined.

[0022] In view of the problems existing in the existing technology, such as Figure 1 As shown, the first embodiment of the present invention provides a chip bending test device, comprising: a positioning column 1, a support member 2, a base 3, a limiting column 19, at least two bearing blocks 6 and at least two upper pressing blocks 4; the at least two bearing blocks 6 are located on the top surface of the base 3, and the bearing block 6 is used to abut the bottom surface of the chip 5; the base 3 is used to apply an upward supporting force to the bearing block 6 and the chip 5; the bearing block 6 is provided with a limiting groove 20 facing the base 3; the limiting column 19 is simultaneously inserted into the socket 7 of the base 3 and the limiting groove 20 of the bearing block 6, so as to make the bearing block 6 and the base 3 in the horizontal direction. The support member 2 is relatively fixed on the top; the support member is arranged directly above the base, and the at least two upper pressure blocks 4 are located on the bottom end surface of the support member 2, and the upper pressure blocks 4 are used to abut the top end surface of the chip 5; the support member 2 is used to apply downward pressure to the upper pressure blocks 4 and the chip 5; the base 3 and the support member 2 are both provided with a socket 7; the socket 7 located on the base 3 and the socket 7 located on the support member 2 are arranged one by one; the positioning column 1 is simultaneously inserted into the socket 7 of the support member 2 and the socket 7 of the base 3 in the vertical direction; the positioning column 1 is used to provide horizontal limitation for the base 3 and the support member 2.

[0023] It is worth noting that in this embodiment, the positioning column 1 is simultaneously inserted into the corresponding sockets 7 on the support member 2 and the base 3, providing horizontal limit for the base 3 and the support member 2; and the limit column 19 is simultaneously inserted into the socket 7 of the base 3 and the limit groove 20 of the bearing block 6, so that the bearing block 6 and the base 3 are relatively fixed in the horizontal direction, ensuring the horizontal limit of the entire test device. This effectively avoids the horizontal deviation of the chip 5 when the load 8 is applied, ensures the consistency and repeatability of the test conditions, and is conducive to improving the calculation accuracy of the system for the piezoresistance coefficient of the chip 5.

[0024] In some specific embodiments, the bottom end surface of the bearing block 6 is slidably connected to the top end surface of the base 3 ; the top end surface of the upper pressing block 4 is slidably connected to the bottom end surface of the support member 2 .

[0025] In some other specific embodiments, the bottom end surface of the bearing block 6 is detachably connected to the top end surface of the base 3 ; the top end surface of the upper pressing block 4 is detachably connected to the bottom end surface of the supporting member 2 .

[0026] In some further specific embodiments, the bottom end surface of the bearing block 6 abuts against the top end surface of the base 3 ; the top end surface of the upper pressing block 4 abuts against the bottom end surface of the supporting member 2 .

[0027] It is worth noting that this embodiment ensures the consistency of the length and position of the bent portion of the chip 5 during each calibration process by adopting the plug-in fixing method of the jack 7 and the positioning column 1, reduces the error during manual operation, and further reduces the measurement error of the piezoresistive coefficient.

[0028] like Figure 8 As shown, in some embodiments, the device also includes a flexible circuit board 10; the flexible circuit board 10 has a pad 12; at least one stress sensor is integrated on the chip 5; the stress sensor is electrically connected to the pad 12; when the chip 5 is subjected to force, the stress sensor is used to transmit an electrical signal through the flexible circuit board 10.

[0029] In some specific embodiments, the flexible circuit board 10 is configured as a flexible printed circuit board (FPC). It is worth noting that in this embodiment, by configuring the flexible circuit board 10, the influence of the circuit board on the bending of the chip 5 during the test is reduced, thereby improving the reliability of the test result.

[0030] In some other specific embodiments, an N*N stress sensor array is integrated on the chip 5 , where N is an odd number; the stress sensor located in the center of the chip 5 is electrically connected to the pad 12 .

[0031] In some embodiments, the flexible circuit board 10 has a wide end and a narrow end; the wide end is provided with a gold finger 13, and the gold finger 13 is used to be plugged into the socket 14 of the PCB board 15; the narrow end is provided with the soldering pad 12, and the stress sensor is bonded to the soldering pad 12 through the lead 11.

[0032] It is worth noting that in this embodiment, by introducing the use of the gold finger 13 and the socket 14 of the PCB board 15, the connection flexibility of the flexible circuit board 10 is significantly enhanced. This design makes the calibration of the stress sensor chip 5 no longer limited to a specific layout, and can flexibly respond to various installation requirements. In addition, it also eliminates the concerns about wiring compatibility during the design stage of the chip 5, simplifies the design process, and improves the adaptability and ease of use of the overall system.

[0033] In some specific embodiments, the number of the pads 12 is at least 4; two rows of pads 12 are distributed on both sides of the chip 5; and the spacing between the two rows of pads 12 is greater than the width of the chip 5. The pads 12 are connected to the pins of the stress sensor through bonding wires 11.

[0034] In some examples, an arrangement direction of each column of the two columns of pads 12 is parallel to a length direction of the chip 5 .

[0035] In some embodiments, the height of the supporting block 6 is greater than the height of the upper pressing block 4 so that an accommodation space is formed between the bottom side of the upper pressing block 4 and the top surface of the base 3; the accommodation space is used to accommodate the leads 11 connecting the chip 5.

[0036] In some specific embodiments, when the chip 5 is removed from between the upper pressing block 4 and the supporting block 6, the top end of the supporting block 6 abuts against the bottom end surface of the supporting member 2. In this embodiment, the bottom side of the upper pressing block 4 and the top end surface of the base 3 do not contact each other, thereby preventing the lead 11 from being damaged by pressure.

[0037] In some embodiments, the chip 5 is arranged in a strip shape with a horizontally arranged length direction; the at least two supporting blocks 6 include a first supporting block 6 and a second supporting block 6; the at least two upper pressing blocks 4 include a first upper pressing block 4 and a second upper pressing block 4; the first upper pressing block 4 and the second upper pressing block 4 are symmetrically arranged about the vertical section 24 of the chip 5; the first supporting block 6 and the second supporting block 6 are symmetrically arranged about the vertical section 24 of the chip 5; the center point of the chip 5 is located on the vertical section 24 of the chip 5.

[0038] In some examples, the first upper pressing block 4 , the first bearing block 6 , the second bearing block 6 , and the second upper pressing block 4 are sequentially arranged along the length direction.

[0039] In some embodiments, the top surface of the support member 2 has a bearing area; the bearing area is used to apply a load 8. In some specific embodiments, the load 8 is set as a weight or a push rod of a thrust meter.

[0040] In some examples, the support member 2 is configured as a support plate, and the force application direction of the push rod of the thrust meter is perpendicular to the support plate. In this example, the thrust meter is used to detect the thrust applied by the push rod to the support plate.

[0041] In some embodiments, the upper pressing block 4 is provided with a through hole; the positioning column 1 passes through the through hole, so as to relatively fix the upper pressing block 4 and the supporting member 2 in a horizontal direction.

[0042] In some specific embodiments, the through hole and the limiting groove 20 are consistent in shape and size with the insertion hole 7. The radial size of the insertion hole 7 is positively correlated with the radial size of the positioning column 1.

[0043] In some examples, the positioning column 1 is cylindrical, and the through hole, the limiting groove 20 and the insertion hole 7 are all cylindrical holes. In other examples, the positioning column 1 is prismatic, and the through hole and the insertion hole 7 are all prismatic holes. In still other examples, the limiting groove 20 passes through the bearing block 6.

[0044] In some embodiments, the bottom end of the carrier block 6 and the top end of the upper pressing block 4 both have horizontally arranged edges 9 , and the edges 9 are used to provide a linear area contacting the chip 5 .

[0045] In some specific embodiments, the linear region is parallel to the width direction of the chip 5 .

[0046] like Figure 2 As shown, in some examples, the bearing block 6 is arranged in a pentagonal prism shape, wherein one edge 9 is located at the top of the bearing block 6. In other examples, the bearing block 6 may be arranged in a triangular prism shape.

[0047] like Figure 3 and Figure 1 As shown, in some examples, the carrier block 6 is provided with four sockets 7. Among them, two sockets 7 are used to plug the positioning posts 1, and the chip 5 is located between the two positioning posts 1 plugged into the same carrier block 6. In other examples, the carrier block 6 is provided with six sockets 7.

[0048] like Figure 4 As shown, the second embodiment provides a bending test method for a chip, which is applied to build the device described in any one of the above embodiments to obtain the piezoresistance coefficient of the chip, including: pasting the chip to a flexible printed circuit board, electrically connecting the stress sensor on the chip to the pad of the flexible circuit board, so that the stress sensor outputs an electrical signal through the flexible circuit board; selecting a socket for inserting a positioning column according to the size of the chip to build a test device corresponding to the size of the chip; recording the contact distance of two upper pressing blocks contacting the chip as the upper pressing block spacing L; recording the contact distance of two supporting blocks contacting the chip as the supporting block spacing d; applying a load to the support member to obtain the pressure F applied by each upper pressing block to the chip; calculating the stress on the chip in its length direction according to the size of the chip, the pressure F, the upper pressing block spacing L and the supporting block spacing d; adjusting the load and recording the electrical signal of the stress sensor under different stresses; performing linear fitting based on the stress and the electrical signal to obtain the piezoresistance coefficient of the chip.

[0049] like Figure 5 As shown, in some specific embodiments, before the chip is pasted to the flexible printed circuit board, the method further includes: dicing the wafer with the integrated stress sensor to obtain a strip chip with the stress sensor.

[0050] In some examples, chips of different sizes can be cut out according to the size of the wafer. In some examples, the size of the strip chip cut out of an 8-inch wafer can be 7 cm*1 cm.

[0051] In other examples, according to different cutting directions, horizontal strip chips and vertical strip chips can be obtained. In some examples, the length direction of the horizontal strip chip is along the X direction, and the width direction of the horizontal strip chip is along the Y direction. The length direction of the vertical strip chip is along the Y direction, and the width direction of the vertical strip chip is along the X direction.

[0052] like Figure 6 As shown, in some embodiments, the stress on the transverse strip chip in its length direction satisfies:

[0053] in, is the stress in the X direction at the center of the upper surface of the chip, w is the dimension of the chip in the width direction; t is the dimension of the chip in the thickness direction; the thickness direction is along the vertical direction; the length direction, the width direction and the thickness direction are perpendicular to each other. In some examples, the length direction is along the X direction, the width direction is along the Y direction, and the thickness direction is along the Z direction.

[0054] Similarly, in some other embodiments, the stress on the longitudinal strip chip in its length direction satisfies:

[0055] in, is the stress in the Y direction at the center of the chip top surface.

[0056] like Figure 7 and Figure 1 As shown, in some embodiments, the sockets 7 are arranged in 4 rows on the support member 2. The first row of sockets 7, the second row of sockets 7, the third row of sockets 7 and the fourth row of sockets 7 are arranged along the Y direction. The arrangement direction of the sockets 7 in each row is along the X direction. When the positioning column 1 is plugged into the second row of sockets 7 and the third row of sockets 7, it is used to test the chip 5 with a smaller width. When the positioning column 1 is plugged into the first row of sockets 7 and the fourth row of sockets 7, it is used to test the chip 5 with a larger width.

[0057] like Figure 8 As shown, the third embodiment provides a bending test system for a chip, comprising the device described in any one of the above embodiments, and further comprising: a signal detection device and a host 18; the flexible circuit board 10, the signal detection device and the host 18 are electrically connected in sequence; the signal detection device is used to detect the electrical signal output by the flexible circuit board 10, and convert the electrical signal into detection data; the host 18 is used to calculate the piezoresistive coefficient of the chip 5 according to the detection data.

[0058] In some specific embodiments, the signal detection device includes a PCB board 15 and a source meter 17; the PCB board 15 has a socket and a pin 16; the socket 14 is used to electrically connect the flexible circuit board 10; the pin 16 is connected to a signal line, and the signal line is connected to the source meter 17; the source meter 17 is connected to the host 18 via a data line.

[0059] In some embodiments, the system further includes a glue coating device 21. The glue coating device 21 is used to coat glue on the bottom end of the chip 5 or the top end of the flexible printed circuit board 10, so that the bottom end of the chip 5 is attached to the top end of the flexible printed circuit board. It is worth noting that the glue coating area of ​​the glue coating device 21 is isolated from the position of the pad 12, and this setting is used to prevent the pad 12 from being covered by glue.

[0060] In some examples, the glue is configured as a non-conductive glue, including but not limited to UV curable glue, thermosetting epoxy resin, bottom filling glue, and acrylate glue.

[0061] In some other embodiments, the system further comprises a curing device 23, and the curing device 23 is used to cure the glue between the chip 5 and the flexible printed circuit board. The curing method adopted by the curing device 23 includes but is not limited to a method of curing the glue by heating or light.

[0062] In some other embodiments, the system further comprises a bonding device 22. The bonding device 22 is used to bond the lead 11 to the pin of the stress sensor. The bonding method used by the bonding device 22 includes but is not limited to thermal compression bonding, ultrasonic bonding and thermal ultrasonic bonding.

[0063] Although the embodiments of the present invention are described in detail above, it is obvious to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as described in the claims. Moreover, the present invention described herein may have other embodiments and may be implemented or realized in a variety of ways.

Claims

1. A chip bending test device, characterized in that: include: Positioning column, support member, base, limit column, at least 2 bearing blocks and at least 2 upper pressure blocks; The at least two bearing blocks are located on the top surface of the base, and the bearing block is used to abut against the bottom surface of the chip; the base is used to apply an upward supporting force to the bearing block and the chip; the bearing block is provided with a limiting groove facing the base; the limiting column is simultaneously inserted into the insertion hole of the base and the limiting groove of the bearing block, so as to relatively fix the bearing block and the base in the horizontal direction; The support member is arranged directly above the base, the at least two upper pressing blocks are located at the bottom end surface of the support member, and the upper pressing blocks are used to abut against the top end surface of the chip; the support member is used to apply downward pressure to the upper pressing blocks and the chip; Both the base and the support member are provided with sockets; the sockets located on the base are arranged in a one-to-one correspondence with the sockets located on the support member; the positioning column is simultaneously inserted into the sockets of the support member and the sockets of the base along the vertical direction; the positioning column is used to provide horizontal limitation for the base and the support member.

2. The device according to claim 1, characterized in that The device further comprises a flexible circuit board; the flexible circuit board has a solder pad; At least one stress sensor is integrated on the chip; the stress sensor is electrically connected to the pad; when the chip is subjected to force, the stress sensor is used to transmit an electrical signal through the flexible circuit board.

3. The device according to claim 2, characterized in that The flexible circuit board has a wide end and a narrow end; the wide end is provided with a gold finger, and the gold finger is used to be plugged into the socket of the PCB board; The narrow end is provided with the pad, and the stress sensor is bonded to the pad by wire bonding.

4. The device according to claim 2 or 3, characterized in that The height of the bearing block is greater than that of the upper pressing block, so that an accommodation space is formed between the bottom side of the upper pressing block and the top surface of the base; the accommodation space is used to accommodate leads connected to the chip.

5. The device according to claim 2, characterized in that The chip is arranged in a strip shape, and has a horizontal length direction; the at least two bearing block positions include a first bearing block and a second bearing block; the at least two upper pressing block positions include a first upper pressing block and a second upper pressing block; The first upper pressing block and the second upper pressing block are symmetrically arranged with respect to a vertical cross section of the chip; The first supporting block and the second supporting block are symmetrically arranged with respect to a vertical cross section of the chip; The center point of the chip is located on a vertical cross section of the chip.

6. The device according to claim 2, characterized in that The top end surface of the support member has a bearing area; the bearing area is used to apply a load.

7. The device according to claim 2, characterized in that The upper pressing block is provided with a perforation; The positioning column passes through the through hole and is used to relatively fix the upper pressing block and the supporting member in a horizontal direction.

8. The device according to claim 2, characterized in that The bottom end of the carrier block and the top end of the upper pressing block both have horizontally arranged edges, and the edges are used to provide a linear area contacting the chip.

9. A chip bending test method, applied to construct the device according to any one of claims 2 to 8 to obtain the piezoresistance coefficient of the chip, characterized in that: include: Pasting the chip to a flexible printed circuit board, and electrically connecting the stress sensor on the chip to a pad of the flexible circuit board, so that the stress sensor outputs an electrical signal through the flexible circuit board; Selecting a socket for inserting a positioning column according to the size of the chip to build a test device corresponding to the size of the chip; The distance between the contact points of the two upper pressing blocks contacting the chip is recorded as the upper pressing block spacing L; the distance between the contact points of the two supporting blocks contacting the chip is recorded as the supporting block spacing d; Applying a load on the support member to obtain a pressure F applied by each upper pressing block to the chip; Calculating the stress on the chip in its length direction according to the size of the chip, the pressure F, the upper pressure block spacing L and the carrier block spacing d; The load is adjusted, and the electrical signal of the stress sensor under different stresses is recorded; a linear fit is performed according to the stress and the electrical signal to obtain the piezoresistance coefficient of the chip.

10. The method according to claim 9, characterized in that The stress on the chip in its length direction satisfies: in, is the stress in the length direction at the center of the upper surface of the chip, w is the dimension of the chip in the width direction; t is the dimension of the chip in the thickness direction; the thickness direction is along the vertical direction; the length direction, the width direction and the thickness direction are perpendicular to each other.

11. A chip bending test system, comprising the device according to any one of claims 2 to 8, characterized in that: Also includes: a signal detection device and a host; The flexible circuit board, the signal detection device and the host are electrically connected in sequence; The signal detection device is used to detect the electrical signal output by the flexible circuit board and convert the electrical signal into detection data; The host is used to calculate the piezoresistance coefficient of the chip according to the detection data.

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