Probe and test head having the same

Abstract

The application discloses a probe and a test head with the probe, the probe comprises a deformation part which extends longitudinally along an up-down direction, when testing a measured element, the deformation part is bent and deformed towards a first direction which is perpendicular to the up-down direction, the deformation part has a first side surface and a second side surface which are oppositely arranged along a second direction, a third side surface and a fourth side surface which are oppositely arranged along the first direction, and the second direction is perpendicular to the first direction and the up-down direction; the deformation part has a first blind groove and a second blind groove, the first blind groove and the second blind groove respectively extend longitudinally along the up-down direction, the first blind groove is recessed from the first side surface to the second side surface; the second blind groove is recessed from the second side surface to the first side surface, the first blind groove and the second blind groove are both located between the third side surface and the fourth side surface, and the projection of the first blind groove and the second blind groove in the first direction is partially overlapped, so that stress concentration is avoided and the risk of breakage of the probe during bending and deformation is reduced.

Description

[Technical Field]

[0001] This invention relates to a probe and a test head having the probe, and more particularly to a probe that reduces stress and extends service life and a test head having the probe. [Background Technology]

[0002] A test head is used to perform electrical tests on a circuit before it is assembled into a chip package. A test head typically includes at least two guide plates separated by partitions and multiple probes passing through the guide plates. The probes are typically integral probes manufactured using MEMS processes or laser cutting. The guide plates have multiple through-holes corresponding to the probes. The probes bend within the partitions and slide axially within the through-holes during pressing contact. The upper end of the probe contacts the contact pad of a space converter, and the lower end contacts the contact pad of the chip under test. The test head achieves contact with the chip under test through the contact tip at the lower end of the probe. The test head is used for testing chip circuits. However, the test head is not a disposable item (it is not scrapped after one use), but a reusable product that can be used multiple times to test different or the same circuits. Therefore, long-term repeated use of the test head to test chips will cause a certain degree of wear on the probe. In order to extend the service life of the test head, part of the length at both ends of the probe will be worn off to continue to be used. However, this will result in a shorter overall length of the probe and a gradual increase in its rigidity. Consequently, the force applied by the probe to the chip under test will increase, increasing the risk of the chip under test being scratched and the contact probe itself being damaged.

[0003] Therefore, it is necessary to design a new probe and a test head with the probe to overcome the above problems. [Summary of the Invention]

[0004] To address the problems of the prior art, the present invention aims to provide a new probe and a test head having the probe, thereby reducing the contact stress of the probe.

[0005] To achieve the above objectives, the present invention provides a test head for abutting a mating element and a component under test. The test head includes: an upper guide plate having an upper receiving hole; a lower guide plate having a lower receiving hole; a receiving space located between the upper guide plate and the lower guide plate; and a probe correspondingly received in the upper and lower receiving holes. The probe includes a deformable portion extending longitudinally in the vertical direction, the deformable portion being received in the receiving space. When testing the component under test, the deformable portion bends and deforms in a first direction perpendicular to the vertical direction. The direction perpendicular to both the vertical and first directions is defined as a second direction. The deformable portion has a first side and a second side disposed opposite to each other along a second direction, and a third side and a fourth side disposed opposite to each other along a first direction; the deformable portion has a first blind groove and a second blind groove, the first blind groove and the second blind groove extending longitudinally along the vertical direction, the first blind groove being recessed from the first side to the second side; the second blind groove being recessed from the second side to the first side, the first blind groove and the second blind groove being located between the third side and the fourth side, and at least one first blind groove and at least one second blind groove overlapping in the projection portion in the first direction.

[0006] Furthermore, at least one of the first blind groove and the second blind groove has a depth in the second direction that is greater than one-half of the maximum size of the deformed part in the second direction and less than or equal to five-sixths of that maximum size.

[0007] Furthermore, there are two of each of the first and second blind grooves. The two first blind grooves are recessed to different depths in the second direction, and the two second blind grooves are also recessed to different depths in the second direction. The first blind groove with a larger recessed depth is defined as the first deep groove, and the other first blind groove is defined as the first shallow groove. The second blind groove with a larger recessed depth is defined as the second deep groove, and the other second blind groove is defined as the second shallow groove. The first shallow groove and the second shallow groove are arranged opposite each other in the second direction, and both are located between the first deep groove and the second deep groove in the first direction.

[0008] Furthermore, the projection portions of the first deep groove and the second shallow groove overlap in the first direction, and the projection portions of the second deep groove and the first shallow groove overlap in the first direction.

[0009] Furthermore, the probe includes a first portion located within an upper receiving hole and a second portion located within a lower receiving hole, the deformable portion being located between the first portion and the second portion in the vertical direction, and the minimum dimension of the deformable portion in the first direction being smaller than the maximum dimension of the first portion and the second portion in the first direction, respectively.

[0010] The present invention also provides a probe for contacting a device under test downwards, comprising a deformable portion extending longitudinally in the vertical direction. When testing the device under test, the deformable portion bends and deforms in a first direction perpendicular to the vertical direction. The direction perpendicular to the vertical direction and the first direction is defined as a second direction. The deformable portion has a first side surface and a second side surface disposed opposite to each other in the second direction, and a third side surface and a fourth side surface disposed opposite to each other in the first direction. The deformable portion has a first blind groove and a second blind groove, the first blind groove and the second blind groove extending longitudinally in the vertical direction respectively. The first blind groove is recessed from the first side surface to the second side surface. The second blind groove is recessed from the second side surface to the first side surface. The first blind groove and the second blind groove are both located between the third side surface and the fourth side surface, and at least one first blind groove and at least one second blind groove overlap in the projection portion in the first direction.

[0011] Furthermore, the depth of at least one of the first blind grooves and at least one of the second blind grooves in the second direction is greater than one-half of the maximum dimension of the deformed portion in the second direction and less than or equal to five-sixths of that maximum dimension.

[0012] Furthermore, there are two of each of the first and second blind grooves. The two first blind grooves are recessed to different depths in the second direction, and the two second blind grooves are also recessed to different depths in the second direction. The first blind groove with a larger recessed depth is defined as the first deep groove, and the other first blind groove is defined as the first shallow groove. The second blind groove with a larger recessed depth is defined as the second deep groove, and the other second blind groove is defined as the second shallow groove. The first shallow groove and the second shallow groove are arranged facing each other in the second direction, and both are located between the first deep groove and the second deep groove in the first direction.

[0013] Furthermore, the projection portions of the first deep groove and the second shallow groove overlap in the first direction, and the projection portions of the second deep groove and the first shallow groove overlap in the first direction.

[0014] Furthermore, the width of the first blind groove in the first direction is smaller than the depth of the first blind groove in the second direction.

[0015] The width of the first blind groove in the first direction is equal to the width of the second blind groove in the first direction.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] By recessing the first blind groove and the second blind groove in the deformed portion, and by overlapping the projected portions of at least one first blind groove and at least one second blind groove in the first direction (i.e., the depths of the first blind groove and the second blind groove at least intersect in the first direction), the design of the first blind groove and the second blind groove avoids the stress concentration problem caused by the through groove, reducing the risk of probe breakage during bending deformation; the specific layout and projected overlap design of the first blind groove and the second blind groove enable the probe to better recover its original shape after deformation, extending the service life of the probe; the optimized stress distribution and good elastic recovery force enable the probe to maintain good performance after multiple tests, improving the fatigue resistance of the probe. [Attached Image Description]

[0018] Figure 1 This is a partial cross-sectional view of the test head after assembly in a specific embodiment of the present invention;

[0019] Figure 2 for Figure 1 A partial cross-sectional view after the test head comes into contact with a mating component and a component under test;

[0020] Figure 3 for Figure 1 The test head displays a 3D view of only one probe;

[0021] Figure 4 for Figure 3 A partial schematic diagram of the deformed portion of the probe cut along the horizontal direction;

[0022] Figure 5 for Figure 3 Front view of the probe;

[0023] Figure 6 for Figure 5 A sectional view taken along the AA direction.

[0024]

[0025]

Detailed Implementation Methods

[0026] To facilitate a better understanding of the purpose, structure, and features of this invention, a first direction (X), a second direction (Y), and a vertical direction (Z) are defined, with these three directions being mutually perpendicular. The invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0027] like Figures 1 to 6The diagram illustrates a specific embodiment of the test head of the present invention. The test head 100 includes two upper guide plates 1, a lower guide plate 2 (of course, the number of upper guide plates 1 and lower guide plates 2 is not limited to this in other embodiments), a partition 3 located between the upper guide plates 1 and the lower guide plates 2, and a plurality of probes 4 housed in the partition 3. The test head 100 abuts upward against a docking element 200 and downward against a device under test 300, thereby realizing circuit testing of the device under test 300. In this embodiment, the docking element 200 is a circuit board, and the device under test 300 is a chip. The accompanying drawings only show three of the probes 4 for illustration; in reality, the test head 100 contains more than three probes 4.

[0028] like Figure 1 and Figure 2 As shown, each of the upper guide plates has multiple upper through holes 11 extending vertically. Of the two upper guide plates, the upper guide plate defined above is the first upper guide plate 1a, and the upper guide plate below is the second upper guide plate 1b. The lower guide plate 2 has multiple lower through holes 21 extending vertically. The multiple upper through holes 11 and the multiple lower through holes 21 are arranged opposite each other along the vertical direction Z. The multiple probes 4 pass through the multiple upper through holes 11 and the multiple lower through holes 21 respectively.

[0029] like Figure 1 and Figure 2 As shown, the partition 3 is located below the second upper guide plate 1b and above the lower guide plate 2. The partition 3 supports the second upper guide plate 1b upward and abuts against the lower guide plate 2 downward. The partition 3 has a receiving space 31 that extends vertically (in other embodiments, the receiving space 31 may also be a space surrounded by multiple support columns). The receiving space 31 communicates upward with multiple upper through holes 11 and downward with multiple lower through holes 21. Multiple probes 4 are received in the receiving space 31.

[0030] like Figure 1 and Figure 2 As shown, the probe 4 extends longitudinally along the vertical direction Z and has an upper extension section 41, a lower extension section 42, and a deformable portion 43 connecting the upper extension section 41 and the lower extension section 42. The upper end of the upper extension section 41 protrudes from the first upper guide plate 1a to abut against the docking element 200. The lower end of the lower extension section 42 protrudes downward from the lower through hole 21 corresponding to the lower guide plate 2 to abut against the tested element 300. When testing the tested element 300, the deformable portion 43 bends and deforms along a first direction X. The first direction X is perpendicular to the vertical direction Z. The direction perpendicular to the vertical direction Z and the first direction X is defined as the second direction Y. The dimension of the probe 4 in the second direction Y is a constant value.

[0031] like Figure 1 and Figure 5 As shown, the upper extension 41 includes a first portion 411 housed in the upper through hole 11, the lower extension 42 includes a second portion 421, and the deformable portion 43 is located between the first portion 411 and the second portion 421 in the vertical direction Z. The maximum dimension of the first portion 411 located in the upper through hole 11 in the first direction X is defined as the first dimension, and the maximum dimension of the second portion 421 located in the lower through hole 21 in the first direction X is defined as the second dimension. The minimum dimension of the deformable portion 43 in the first direction X is smaller than the first dimension and the second dimension, thereby reducing the contact stress of the probe 4. In this embodiment, the first dimension is equal to the second dimension.

[0032] like Figure 3 and Figure 4 As shown, the deformable portion 43 has a first side surface 431 and a second side surface 432 arranged opposite each other along the second direction Y, and a third side surface 433 and a fourth side surface 434 arranged opposite each other along the first direction X. The deformable portion 43 has two first blind grooves 435 and two second blind grooves 436. The first blind grooves 435 and the second blind grooves 436 extend longitudinally along the vertical direction Z and have the same height. The first blind grooves 435 are recessed from the first side surface 431 towards the second side surface 432, and the second blind grooves 436 are recessed from the second side surface 432 towards the first side surface 431. Compared with through grooves, the first blind grooves 435 and the second blind grooves 436 reduce the amount of material removed, simplify the processing technology, and reduce manufacturing difficulty and cost. The heights of the first blind grooves 435 and the second blind grooves 436 are not limited here and can be set according to actual needs.

[0033] like Figure 4 and Figure 6 As shown, the width of the first blind groove 435 in the first direction X is less than the depth of the first blind groove 435 in the second direction Y, and the width of the second blind groove 436 in the first direction X is less than the depth of the second blind groove 436 in the second direction Y. The width of the first blind groove 435 in the first direction X is equal to the width of the second blind groove 436 in the first direction X. This simplifies the processing technology and helps to improve product consistency and yield.

[0034] like Figure 4 and Figure 6As shown, the two first blind grooves 435 are recessed to different depths in the second direction Y. The first blind groove 435 with a larger recessed depth is defined as the first deep groove 435a, and the other first blind groove 435 is defined as the first shallow groove 435b. Similarly, the two second blind grooves 436 are recessed to different depths in the second direction Y. The second blind groove 436 with a larger recessed depth is defined as the second deep groove 436a, and the other second blind groove 436 is defined as the second shallow groove 436b. Both the two first blind grooves 435 and the two second blind grooves 436 are located between the third side surface 433 and the fourth side surface 434. By adjusting the depth and position of the two first blind grooves 435 and the two second blind grooves 436, the mechanical and electrical properties of the probe can be customized, thus improving design flexibility and meeting different testing requirements.

[0035] like Figure 4 and Figure 6 As shown, at least one first blind groove 435 and at least one second blind groove 436 partially overlap in the projection of the first blind groove 435 in the first direction X. Specifically, the projections of the first deep groove 435a and the second shallow groove 436b and the second deep groove 436a in the first direction X partially overlap, while the first shallow groove 435b only partially overlaps with the projection of the second deep groove 436a in the first direction X. In other embodiments, the number of the first blind groove 435 and the second blind groove 436 can be one or more, as long as at least one first blind groove 435 and at least one second blind groove 436 partially overlap in the projection of the first blind groove 436 in the first direction X. The specific number of the first blind groove 435 and the second blind groove 436 is not limited.

[0036] like Figure 4 and Figure 6 As shown, the first shallow groove 435b and the second shallow groove 436b are positioned opposite each other in the second direction Y, and are located between the first deep groove 435a and the second deep groove 436a along the first direction X. The first shallow groove 435b and the second shallow groove 436b have the same depth.

[0037] like Figure 4 and Figure 6As shown, the depths of the first deep groove 435a and the second deep groove 436a are both greater than half of the maximum dimension of the deformable part 43 in the second direction Y. In this embodiment, the depths of the first deep groove 435a and the second deep groove 436a are equal, and the depths of the first deep groove 435a and the second deep groove 436a are set to be equal to five-sixths of the maximum dimension. In other embodiments, the dimensions of the first deep groove 435a and the second deep groove 436a can be greater than half of the maximum dimension of the deformable part 43 in the second direction Y but less than five-sixths of the maximum dimension. That is, the groove depth can be adjusted according to the mechanical performance and current carrying capacity requirements of the probe 4.

[0038] In summary, the probe and test head having the probe of the present invention have the following beneficial effects:

[0039] 1. By recessing the first blind groove 435 and the second blind groove 436 in the deformable portion 43, and by overlapping the projection portions of at least one first blind groove 435 and at least one second blind groove 436 in the first direction X, the design of the first blind groove 435 and the second blind groove 436 avoids the stress concentration problem caused by the through groove, reducing the risk of breakage of the probe 4 during bending deformation; the specific layout and projection overlap design of the first blind groove 435 and the second blind groove 436 enable the probe 4 to better recover its original shape after deformation, extending the service life of the probe 4; the optimized stress distribution and good elastic recovery force enable the probe 4 to maintain good performance after multiple tests, improving the fatigue resistance of the probe 4.

[0040] 2. By setting the first deep groove 435a, the first shallow groove 435b, the second deep groove 436a and the second shallow groove 436b with different depths, the stress distribution when the probe 4 is bent and deformed can be controlled more precisely, avoiding excessive local stress. The combination design of the deep and shallow grooves allows the probe 4 to deform more evenly when under force, improving its resistance to deformation and service life.

[0041] 3. By setting the width of the first blind groove 435 in the first direction X to be less than the depth of the first blind groove 435 in the second direction Y, and the width of the first blind groove 435 in the first direction X being equal to the width of the second blind groove 436 in the first direction X, the specific width-to-depth ratio helps the probe 4 to better recover its original shape after deformation, reducing permanent deformation. In addition, the specific width-to-depth ratio helps the magnetic field distribution, reduces electromagnetic interference, and improves test accuracy. The uniform blind groove width design not only reduces manufacturing difficulty and cost, but also helps to improve product consistency and reduce the defect rate.

[0042] The above detailed description is only an illustration of a preferred embodiment of the present invention and is not intended to limit the patent scope of the present invention. Therefore, all equivalent technical changes made using the content of this invention's specification and illustrations are included within the patent scope of this invention.

Claims

1. A probe for downward contact with a test element, comprising a deformable portion extending longitudinally in a vertical direction, wherein when testing the test element, the deformable portion bends and deforms in a first direction perpendicular to the vertical direction, a second direction is defined as the direction perpendicular to both the vertical direction and the first direction, and the deformable portion has a first side surface and a second side surface disposed opposite to each other in the second direction, and a third side surface and a fourth side surface disposed opposite to each other in the first direction; characterized in that, The deformable portion has a first blind groove and a second blind groove, which extend longitudinally in the vertical direction. The first blind groove is recessed from the first side to the second side; the second blind groove is recessed from the second side to the first side. The first blind groove and the second blind groove are both located between the third side and the fourth side, and at least one of the first blind grooves and at least one of the second blind grooves overlap in the projection portion in the first direction.

2. The probe according to claim 1, characterized in that: The depth of at least one of the first blind grooves and at least one of the second blind grooves in the second direction is greater than one-half of the maximum dimension of the deformed portion in the second direction and less than or equal to five-sixths of that maximum dimension.

3. The probe according to claim 1, characterized in that: There are two first blind grooves and two second blind grooves. The two first blind grooves are recessed to different depths in the second direction. The two second blind grooves are also recessed to different depths in the second direction. The first blind groove with a larger recessed depth is defined as the first deep groove and the other first blind groove is defined as the first shallow groove. The second blind groove with a larger recessed depth is defined as the second deep groove and the other second blind groove is defined as the second shallow groove. The first shallow groove and the second shallow groove are arranged facing each other in the second direction, and both are located between the first deep groove and the second deep groove in the first direction.

4. The probe according to claim 3, characterized in that: The projection portions of the first deep groove and the second shallow groove overlap in the first direction, and the projection portions of the second deep groove and the first shallow groove overlap in the first direction.

5. The probe according to claim 1, characterized in that: The width of the first blind groove in the first direction is less than the depth of the first blind groove in the second direction, and the width of the first blind groove in the first direction is equal to the width of the second blind groove in the first direction.

6. A test head for contacting a mating element and a component under test, characterized in that, include: The upper guide plate is provided with an upper receiving hole; The lower guide plate is provided with a lower receiving hole; The receiving space is located between the upper guide plate and the lower guide plate; The probe is received in the upper receiving hole and the lower receiving hole respectively. The probe includes a deformable part that extends longitudinally in the vertical direction. The deformable part is received in the receiving space. When the tested element is tested, the deformable part bends and deforms in a first direction perpendicular to the vertical direction. The direction perpendicular to the vertical direction and the first direction is defined as the second direction. The deformable part has a first side and a second side arranged opposite to each other in the second direction, and a third side and a fourth side arranged opposite to each other in the first direction. The deformable portion has a first blind groove and a second blind groove, which extend longitudinally in the vertical direction. The first blind groove is recessed from the first side to the second side; the second blind groove is recessed from the second side to the first side. The first blind groove and the second blind groove are both located between the third side and the fourth side, and at least one of the first blind grooves and at least one of the second blind grooves overlap in the projection portion in the first direction.

7. The test head according to claim 6, characterized in that: At least one of the first blind groove and the second blind groove has a depth in the second direction that is greater than one-half of the maximum size of the deformed part in the second direction and less than or equal to five-sixths of that maximum size.

8. The test head according to claim 6, characterized in that: Two of each of the first and second blind grooves are provided. The two first blind grooves are recessed to different depths in the second direction. The two second blind grooves are also recessed to different depths in the second direction. The first blind groove with a larger recessed depth is defined as the first deep groove and the other first blind groove is defined as the first shallow groove. The second blind groove with a larger recessed depth is defined as the second deep groove and the other second blind groove is defined as the second shallow groove. The first shallow groove and the second shallow groove are arranged facing each other in the second direction, and both are located between the first deep groove and the second deep groove in the first direction.

9. The test head according to claim 8, characterized in that: The projection portions of the first deep groove and the second shallow groove overlap in the first direction, and the projection portions of the second deep groove and the first shallow groove overlap in the first direction.

10. The test head according to claim 6, characterized in that: The probe includes a first part located in the upper receiving hole and a second part located in the lower receiving hole. The deformable part is located between the first part and the second part in the vertical direction. The minimum size of the deformable part in the first direction is smaller than the maximum size of the first part and the second part in the first direction, respectively.

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