Probe head, probe card, probe system and probe thereof

Abstract

The present application relates to a probe head, a probe card, a probe system and a probe, the probe head comprising at least one guide plate and a plurality of probes respectively penetrating a plurality of guide holes of the guide plate, wherein at least one probe pair is included, the probe pair being composed of two probes, the needle head and / or the needle tail of each probe of the probe pair having a cross-section reduction section and at least one adjacent section adjacent to the cross-section reduction section, the cross-sectional area of the cross-section reduction section being smaller than that of the adjacent section, so that each probe of the probe pair has at least one recess formed by the cross-section reduction section, and the cross-section reduction section is at least partially located in the guide hole; thereby, the present application can effectively improve the impedance matching between the whole probe head and the device under test, reduce the reflection loss during the transmission of test signals, and ensure the test accuracy.

Description

Technical Field

[0001] This invention relates to the testing of semiconductor wafers or packaged devices, and particularly to a probe head, probe card, probe system and probe thereof for testing. Background Technology

[0002] A probe card is a tool used to test the electrical properties of semiconductor wafers or packaged devices. Generally, a probe card includes at least a probe head, a space transformer mounted on the probe head, and a main circuit board (also known as a wiring substrate) mounted on the space transformer. The probe head may include multiple probes, each used to contact the device under test (DUT) integrated on the semiconductor wafer to test the electrical performance of the DUT.

[0003] In recent years, the demand for high-frequency / high-speed testing of electronic devices under test (DUTs) has been increasing. As data transmission rates during testing increase (e.g., from 100Gbps to over 200Gbps), the impedance matching between the probe tip and the DUT has a more significant impact on high-speed signal transmission. When there is an impedance mismatch in the test path (i.e., the signal transmission path), the effect of return loss becomes significant.

[0004] However, since probe tips are not solely composed of electronic components but also include non-electronic components (e.g., probes and guide plates), the impedance matching design of probe tips must take into account the mechanical characteristics of these non-electronic components. Therefore, impedance matching design of probe tips is more challenging than that of space converters and wiring boards (PCBs) because it involves different types of components and requires consideration of the mechanical structure's influence in the electrical design. In view of this, improving the impedance matching between the overall probe tip and the device under test is a pressing technical problem that needs to be solved in the field of this invention. Summary of the Invention

[0005] Therefore, the present invention provides a probe head for high-frequency / high-speed testing, which can effectively improve the impedance matching between the probe head and the device under test, reduce reflection loss during test signal transmission, and ensure test accuracy.

[0006] The probe head provided by this invention is used in a probe card to test electronic devices under test. The probe head includes at least one guide plate and a plurality of probes. The guide plate includes a plurality of guide holes, and the plurality of probes are respectively disposed in each of the guide holes. Each probe includes a needle tip, a needle tail, and a needle body connecting the needle tip and the needle tail, the needle tip being used to contact the electronic device under test. The plurality of probes includes at least one probe pair, the probe pair consisting of two probes. At least one of the needle tip and needle tail of each probe in the probe pair has a cross-sectional reduction section, and at least one adjacent section adjacent to the cross-sectional reduction section. The cross-sectional area of ​​the cross-sectional reduction section is smaller than the cross-sectional area of ​​the adjacent section, such that each probe in the probe pair includes at least one recess formed by the cross-sectional reduction section, the cross-sectional reduction section being at least partially located in the guide hole of the guide plate.

[0007] Therefore, in the probe head provided by this invention, the section of each probe constituting a probe pair (e.g., (but not limited to) a differential pair) disposed in the guide hole of the guide plate has a reduced cross-sectional area compared to other sections (at least compared to the adjacent sections). For the section of the two probes constituting the probe pair disposed in the guide hole of the guide plate, the smaller the cross-sectional area of ​​the probe itself, the greater the characteristic impedance of the two probes in that section. Therefore, by forming a cross-sectional reduction section on the probe and having the cross-sectional reduction section at least partially located in the guide hole of the guide plate, this invention optimizes the structural proportions and electromagnetic behavior between the probe and the guide plate, thereby improving the characteristic impedance performance in that section. This effectively reduces the impedance fluctuations caused by the guide plate between the two probes, thereby reducing the reflection loss between the probe head as a whole and the electronic device under test, and further improving the impedance matching between the probe head (and even the probe card to which it belongs) and the electronic device under test. Therefore, this invention can effectively improve the reliability and accuracy of high-speed signal testing and enhance the overall performance of the probe card in high-frequency applications. Furthermore, through the above structural design, this invention can effectively control the impedance between probes even without specifically selecting a low dielectric constant material as the guide plate material. This design increases the overall design freedom of the guide plate and probe head, making the selection of guide plate materials and mechanical design more flexible, thereby balancing the required electrical characteristics and mechanical strength, and achieving overall performance optimization.

[0008] Preferably, the at least one guide plate includes a lower guide plate, and the tips of each probe of the probe pair pass through the guide hole of the lower guide plate and have the cross-sectional reduction section, wherein the cross-sectional reduction section of each probe is at least partially located in the guide hole of the lower guide plate.

[0009] Therefore, in the probe head provided by the present invention, the section of each probe constituting the probe pair has a reduced cross-sectional area in which the probe tip is disposed in the guide hole of the lower guide plate. Since the probe head usually has upper and lower guide plates for the needle tail and the needle tip to pass through respectively, and the needle tip will move slightly up and down during testing, the thickness of the lower guide plate is usually greater than the thickness of the upper guide plate. By forming the cross-sectional reduction section in the needle tip and disposing it in the guide hole of the lower guide plate, the effect achieved by the aforementioned cross-sectional reduction section can be improved.

[0010] More preferably, the at least one guide plate further includes an upper guide plate, wherein the tail of each probe of the probe pair passes through a guide hole in the upper guide plate and has the cross-sectional reduction section, wherein the cross-sectional reduction section of each tail is at least partially located in the guide hole of the upper guide plate.

[0011] Therefore, in the probe head provided by the present invention, the section of the probe head disposed in the guide hole of the lower guide plate and the section of the probe tail disposed in the guide hole of the upper guide plate are both reduced in cross-sectional area. That is, each probe of the probe pair has two reduced cross-sectional sections, located in the guide holes of the upper and lower guide plates respectively, which can further improve the aforementioned effects.

[0012] Preferably, the plurality of probes includes at least one general probe that does not have the cross-sectional reduction section, and the air gap between the cross-sectional reduction section and the guide hole is larger than the air gap between the general probe and the guide hole.

[0013] This results in a smaller impedance variation between the two probes of the probe pair due to the guide plate, effectively reducing reflection loss during signal transmission and thus improving the reliability and accuracy of high-frequency / high-speed testing.

[0014] Preferably, each of the probes is one of a straight probe and a pre-bent probe, and the probe pair is a differential pair for transmitting a set of differential signals.

[0015] Therefore, the present invention is applicable to vertical probes, which generally extend along the longitudinal development axis, but the probe body is bent so that it can be slightly elastically deformed when the probe tip touches the electronic test device. The vertical probe can be a straight probe that is straight when it is manufactured, and the bending of the probe body is generated by the lateral misalignment of the upper and lower guide plates when it is installed. The vertical probe can also be a pre-bent probe that is bent when it is manufactured. The present invention can use straight probes or bent probes according to the application requirements.

[0016] Preferably, the section reduction zone is located entirely within the guide hole of the guide plate.

[0017] This more effectively reduces impedance fluctuations between the two probes of the probe pair caused by the guide plate, thereby further enhancing the efficiency of the aforementioned cross-section reduction section.

[0018] Preferably, the at least one guide plate includes a lower guide plate, and the tips of each probe of the probe pair pass through the guide hole of the lower guide plate and include the cross-sectional reduction section, wherein the cross-sectional reduction section of each probe extends from the guide hole of the lower guide plate to below the lower surface of the lower guide plate.

[0019] During the test, after the probe tip contacts the electronic device under test (DUT), the probe tip and the DUT move relative to each other overdrive, causing the probe tip to press further against the DUT. At this time, the probe tip moves upward relative to the lower guide plate. Since the cross-sectional area reduction section extends below the lower surface of the lower guide plate, when the probe tip moves upward relative to the lower guide plate, the portion of the cross-sectional area reduction section that was originally located below the lower surface of the lower guide plate enters the guide hole of the lower guide plate. This ensures that a considerable length of the cross-sectional area reduction section is maintained within the guide hole of the lower guide plate, or even that the guide hole of the lower guide plate is entirely composed of the cross-sectional area reduction section. This maintains stable impedance control capability throughout the entire test stroke, making the performance of the aforementioned cross-sectional area reduction section even better.

[0020] More preferably, the cross-sectional reduction section of each needle extends downward from the lower surface of the lower guide plate by a predetermined length, the length being substantially greater than or equal to the maximum upward movement of each needle relative to the lower guide plate during testing.

[0021] Therefore, the length design ensures that during the test stroke, the section of the needle entering the guide hole from below the lower guide plate is a section with a reduced cross-sectional area. This avoids the section with a larger cross-sectional area of ​​the needle entering the guide hole and causing problems such as pressure on the inner wall of the guide hole or changes in contact impedance. Thus, the length design can further improve the consistency and repeatability of the test.

[0022] More preferably, after each of the probes moves upward by the maximum amount relative to the lower guide plate during testing, only the cross-sectional reduction section of each probe of the probe pair is located in the guide hole of the lower guide plate.

[0023] In other words, the guide hole of the lower guide plate only contains the cross-sectional reduction section and not other sections of the probe, thus maintaining stable impedance control capability throughout the entire test stroke, making the aforementioned cross-sectional reduction section more effective.

[0024] Preferably, the adjacent segment can define a central axis, and the recess formed by the cross-section reduction segment has a uniform depth and completely surrounds the circumference of the cross-section reduction segment with the central axis as the center.

[0025] Therefore, the cross-sectional shape of the section with reduced cross-section is circular, thus possessing the circumference. The cross-sectional shape of other sections of the probe can also be circular. That is to say, the section with reduced cross-section has a smaller overall diameter compared to other sections (at least compared to the adjacent sections), making the section with reduced cross-section uniformly thinner throughout the circumference while still being coaxial with the adjacent sections. This structure is suitable for probes whose original cross-sectional shape is circular, facilitating the formation of the section with reduced cross-section through turning, thereby achieving the aforementioned effects produced by the section with reduced cross-section.

[0026] Preferably, the cross-section reduction section includes a minimum cross-section area and a transition area, wherein the transition area gradually shrinks from the diameter of the adjacent section to the minimum cross-section area in a continuous manner, such that the transition area has a conical surface.

[0027] Therefore, the cross-sectional shape of the section reduction segment is circular, and its diameter is not abruptly reduced to the minimum diameter from the diameter of the adjacent segment, but is continuously reduced without obvious step difference in the transition zone. This can also reduce the problem of weakening the probe structure strength due to the reduction of the cross-sectional area of ​​the section reduction segment.

[0028] Preferably, the recess formed by the cross-section reduction section is located only on one side of the cross-section reduction section, rather than completely surrounding the outer contour of the cross-section reduction section.

[0029] Therefore, the cross-sectional shape of the section reduction segment (i.e., the shape of the outer contour) can be any shape, and the cross-sectional shape of other segments of the probe can also be circular, rectangular or other shapes. The section reduction segment has a reduced cross-sectional area on one side compared to other segments (at least compared to the adjacent segments), and can be formed by cutting a general probe on one side, thereby achieving the effect that the aforementioned section reduction segment can produce. Furthermore, since the cross-sectional area of ​​the section reduction segment is reduced on only one side, it is asymmetrical relative to the central axis of the adjacent segment. In other words, the central axis of the section reduction segment is offset from the central axis of the adjacent segment. As a result, the two probes of the probe pair can be configured such that the recesses formed by their section reduction segments face each other across the guide plate, causing the central axes of the section reduction segments of the two probes to be offset away from the central axis of the adjacent segment. That is, the center-to-center distance between the section reduction segments of the two probes is greater than the center-to-center distance between the adjacent segments. This further increases the characteristic impedance of the section reduction segments of the two probes disposed in the guide holes of the guide plate, making the performance of the aforementioned section reduction segment even better.

[0030] Preferably, two recesses are formed in the same cross-sectional reduction section, and the two recesses are located on opposite sides of the cross-sectional reduction section and are symmetrical to each other, so that the cross-sectional reduction section has a narrow and elongated cross-section.

[0031] Therefore, the cross-sectional shape of the section reduction segment can be any shape, and the cross-sectional shapes of other segments of the probe can also be circular, rectangular, or other shapes. The section reduction segment has a reduced cross-sectional area on opposite sides compared to other segments (at least compared to the adjacent segments). This can be achieved by symmetrically cutting a general probe on opposite sides, thereby achieving the aforementioned effect of the section reduction segment. Because this section reduction segment has a reduced cross-sectional area on opposite sides, its cross-section will be elongated, for example, flat on both sides with rounded ends, rectangular, elliptical, or other shapes with clearly defined major and minor axes.

[0032] Preferably, the recess formed by the cross-section reduction section completely surrounds the outer contour of the cross-section reduction section at the same depth.

[0033] Therefore, the cross-sectional shape of the section reduction segment (i.e., the shape of the outer contour) can be circular, elliptical, rectangular, or other non-circular, and the cross-sectional shape of other segments of the probe can be the same shape with larger dimensions. In other words, the section reduction segment is uniformly thinned across the entire outer contour in a coaxial or equivalent manner compared to other segments (at least compared to the adjacent segments), thereby achieving the effect that the aforementioned section reduction segment can produce.

[0034] Preferably, the cross-sectional reduction section has a minimum cross-sectional area and a transition area, wherein the transition area gradually shrinks from the cross-sectional area of ​​the adjacent section to the minimum cross-sectional area in a continuous manner.

[0035] Therefore, the cross-sectional shape of the section reduction segment can be any shape, and its cross-sectional area is not abruptly reduced from the cross-sectional area of ​​the adjacent segment to the minimum cross-sectional area, but is continuously reduced without obvious step difference in the transition zone. For example, it can be a cone, a tapered ellipse, or an asymmetrical polygon or other non-circular tapered structure. This can also reduce the problem of weakening the strength of the probe structure due to the reduction of the cross-sectional area of ​​the section reduction segment.

[0036] Preferably, the recesses of the two probes of the probe pair face each other at least partially separated by the guide plate.

[0037] Therefore, when the cross-sectional reduction section is a reduction of the entire circumference or the entire outer contour, the two probes of the probe pair do not need a specific arrangement direction. As long as the height positions of their cross-sectional reduction sections are approximately equal, the recesses formed by their cross-sectional reduction sections will face each other partially across the guide plate within the guide hole. When the cross-sectional reduction section is a unilateral reduction, the two probes of the probe pair are configured such that the recesses formed by their cross-sectional reduction sections face each other across the guide plate. That is, the cross-sectional reduction sections of the two probes are reduced in a direction away from each other. This allows the center-to-center distance between the cross-sectional reduction sections of the two probes to be greater than the center-to-center distance between the probes, thereby further increasing the characteristic impedance of the cross-sectional reduction sections of the two probes positioned in the guide hole of the guide plate, and making the aforementioned cross-sectional reduction section more effective.

[0038] The present invention further provides a probe card for testing electronic devices under test integrated on a semiconductor wafer in a probe system. The probe card includes a main circuit board, a space converter, and probe heads as described above. The main circuit board and the probe heads are respectively disposed on opposite sides of the space converter, and the tails of each probe of the probe head are electrically connected to the space converter.

[0039] Therefore, the probe card achieves its function by using the probe head as described above. The impedance matching between the probe head (or even the probe card as a whole) and the device under test can be effectively improved, reducing reflection loss during test signal transmission and ensuring the accuracy of high-frequency / high-speed testing. Thus, the probe card has good overall performance in high-frequency applications.

[0040] The present invention also provides a probe system for testing electronic devices under test integrated on a semiconductor wafer. The probe system includes a fixture for supporting the semiconductor wafer, a probe card as described above, and a testing device. The probe card is disposed on the testing device, and the testing device is used to electrically connect to the electronic device under test via the probe card to perform electrical testing on the electronic device under test.

[0041] Therefore, the probe system achieves its function by using the probe card as described above. The impedance matching between the probe tip (or even the probe card) and the device under test can be effectively improved, reducing reflection loss during test signal transmission and ensuring the accuracy of high-frequency / high-speed testing. Thus, the probe system has good overall performance in high-frequency applications.

[0042] The present invention also provides a probe for testing electronic devices under test in a probe card. The probe includes a needle tip, a needle tail, and a needle body connected between the needle tip and the needle tail. The needle tip is used to pass through a guide hole in a guide plate and to physically contact the contact pad of the electronic device under test during testing. The needle tip has a cross-sectional reduction section and an adjacent section adjacent to the cross-sectional reduction section. The cross-sectional area of ​​the cross-sectional reduction section is smaller than the cross-sectional area of ​​the adjacent section, such that the needle tip has a recess formed by the cross-sectional reduction section, and the cross-sectional reduction section is at least partially located in the guide hole.

[0043] In this way, the section of the probe tip disposed in the guide hole of the guide plate has a reduced cross-sectional area compared to other sections (at least compared to the adjacent sections). This optimizes the structural proportions and electromagnetic behavior between the probe and the guide plate, thereby improving the characteristic impedance performance of the section of the probe disposed in the guide hole, and further enhancing the impedance matching between the probe tip (or even the probe card to which it belongs) and the device under test.

[0044] Preferably, the adjacent segment can define a central axis, and the recess formed by the cross-section reduction segment completely surrounds the outer contour of the cross-section reduction segment with the central axis as the center.

[0045] Therefore, the cross-sectional shape of the section reduction segment (i.e., the shape of the outer contour) can be circular, elliptical, rectangular, or other non-circular, and the cross-sectional shape of other segments of the probe can be the same shape with larger dimensions. In other words, the section reduction segment is uniformly thinned across the entire outer contour in a coaxial or equivalent manner compared to other segments (at least compared to the adjacent segments), thereby achieving the effect that the aforementioned section reduction segment can produce.

[0046] Preferably, the recess formed by the cross-section reduction section is located only on one side of the cross-section reduction section, rather than completely surrounding the outer contour of the cross-section reduction section.

[0047] Therefore, the cross-sectional shape of the section reduction segment (i.e., the shape of the outer contour) can be any shape, and the cross-sectional shape of other segments of the probe can also be circular, rectangular, or other shapes. The section reduction segment reduces the cross-sectional area on one side compared to other segments (at least compared to the adjacent segments), and can be formed by machining a general probe on one side, thereby achieving the effect produced by the aforementioned section reduction segment. Furthermore, since the section reduction segment only reduces the cross-sectional area on one side, when two probes form a probe pair, the two probes can be arranged such that the center-to-center distance of the section reduction segment is greater than the center-to-center distance of the probes. This can further increase the characteristic impedance of the section reduction segment in which the two probes are disposed in the guide hole of the guide plate, making the effect produced by the aforementioned section reduction segment even better.

[0048] Preferably, the cross-sectional reduction section has a minimum cross-sectional area and a transition area, wherein the transition area gradually shrinks from the cross-sectional area of ​​the adjacent section to the minimum cross-sectional area in a continuous manner, such that the transition area has a conical surface.

[0049] Therefore, the cross-sectional shape of the section reduction segment can be any shape, and its cross-sectional area is not abruptly reduced from the cross-sectional area of ​​the adjacent segment to the minimum cross-sectional area, but is continuously reduced without obvious step difference in the transition zone. For example, it can be a cone, a tapered ellipse, or an asymmetrical polygon or other non-circular tapered structure. This can also reduce the problem of weakening the strength of the probe structure due to the reduction of the cross-sectional area of ​​the section reduction segment.

[0050] Preferably, the cross-section of the section reduction segment is non-circular.

[0051] Therefore, the present invention is not limited to reducing the diameter of a probe with a circular cross-section in a coaxial manner to form the cross-section reduction section. Rather, it can reduce the cross-sectional area of ​​a probe with a circular cross-section on one side, both sides, or in other ways. It can also reduce the cross-sectional area of ​​a probe with a non-circular cross-section in various ways. Thus, the cross-section of the resulting cross-section reduction section is non-circular, such as elliptical, rectangular, or other directional cross-sections.

[0052] Preferably, the cross-sectional reduction section extends to the portion of the probe that is exposed outside the guide plate during use.

[0053] Therefore, during the test, when the probe tip moves relative to the guide plate, the portion of the cross-sectional reduction section that was originally exposed outside the guide plate can enter the guide hole of the guide plate, so that the guide hole of the guide plate will still maintain a considerable length of cross-sectional reduction section, or even the guide hole of the guide plate can be completely filled with cross-sectional reduction section, thereby maintaining stable impedance control capability throughout the entire test stroke, making the aforementioned cross-sectional reduction section more effective.

[0054] Preferably, the needle body has a multi-layer structure, the multi-layer structure including a plurality of layers and at least one slit formed between each of the layers, the cross-section of the needle body having a wide side and a thick side, the slit penetrating the needle body along the direction of the thick side, each of the layers being separated from each other along the direction of the wide side, and the length of the thick side being greater than or equal to the length of the wide side.

[0055] In this way, the slit weakens the rigidity of the probe body, thereby reducing the contact force exerted by the probe on the contact pads of the electronic device under test, and preventing damage to the contact pads due to excessive contact force. Especially for high-frequency and high-speed testing requirements, shorter probes are usually used to obtain good electrical transmission characteristics. However, shorter probes have higher rigidity and contact force, which can be reduced by the slit. In addition, the slit also enhances the elasticity of the probe body, ensuring the elastic deformation effect when the probe body bends along the wide side. Furthermore, the length of the thick side of the probe body is greater than or equal to the length of the wide side; that is, the width of the probe body is not greater than the thickness, or even less than the thickness. This allows for better elastic deformation effect when the probe body bends along the wide side and provides sufficient thickness to make the probe body less prone to breakage.

[0056] The present invention also provides a probe head for testing electronic devices under test in a probe card. The probe head includes at least one guide plate and a plurality of probes. The guide plate has a plurality of guide holes, and the plurality of probes are respectively disposed in the plurality of guide holes. Each probe has a needle tip, a needle tail, and a needle body connecting the needle tip and the needle tail. The plurality of probes includes at least one cross-section reduction probe and at least one general probe. The cross-section reduction probe has a cross-section reduction section located within the guide hole, the cross-sectional area of ​​the cross-section reduction section being smaller than the cross-sectional area of ​​the guide hole section of the general probe located within the guide hole, such that the air gap between the cross-section reduction section of the cross-section reduction probe and the guide hole is larger than the air gap between the guide hole section of the general probe and the guide hole.

[0057] Therefore, the section of the probe head provided by this invention where a portion of the probes (i.e., the reduced-section probes) is disposed in the guide hole of the guide plate (i.e., the reduced-section section) has a reduced cross-sectional area compared to the section where another portion of the probes (i.e., the general probes) is disposed in the guide hole of the guide plate (i.e., the guide hole section). This optimizes the structural proportions and electromagnetic behavior between the reduced-section probes and the guide plate, thereby improving the characteristic impedance performance in this section. This effectively reduces the impedance fluctuations caused by the guide plate to the reduced-section probes, thereby reducing reflection losses between the probe head as a whole and the electronic device under test, and further improving the impedance matching between the probe head (and even the probe card as a whole) and the electronic device under test. Therefore, this invention can effectively improve the reliability and accuracy of high-speed signal testing and enhance the overall performance of the probe card in high-frequency applications. Furthermore, through the above structural design, this invention can effectively control the impedance between probes even without specifically selecting a low relative permittivity material as the guide plate material. This design increases the overall design freedom of the guide plate and probe head, making the selection of materials and the design of the mechanism of the guide plate more flexible, thereby taking into account the required electrical characteristics and mechanical strength, and achieving overall performance optimization.

[0058] Detailed descriptions of the probe head, probe card, probe system, and probes provided by this invention, including their structure, features, assembly, and usage, will be provided in the subsequent detailed descriptions of the embodiments. However, those skilled in the art will understand that the detailed descriptions and specific embodiments listed for implementing this invention are for illustrative purposes only and are not intended to limit the scope of patent protection of this invention. Attached Figure Description

[0059] The following embodiments, in conjunction with the accompanying drawings, further illustrate the present invention, wherein:

[0060] Figure 1 This is a schematic diagram of the probe system provided in the first preferred embodiment of the present invention; Figure 2 and Figure 3 This is a cross-sectional schematic diagram of the probe head of the probe system; Figure 4 Generally similar to Figure 3 However, it also shows more of a typical probe; Figure 5 for Figure 3 A sectional view along section line 5-5; Figure 6 and Figure 7 Similar to Figure 5 However, it shows cross-sectional reduction sections with different patterns; Figure 8 Similar to Figure 3 ,but Figure 8 The cross-sectional reduction section of the probe corresponds to Figure 6 The state shown; Figure 9 This is a cross-sectional schematic diagram of the probe head provided in the second preferred embodiment of the present invention; Figure 10 for Figure 9 A cross-sectional view along section line 10-10; Figure 11 and Figure 12 Similar to Figure 10 However, it shows cross-sectional reduction sections with different patterns; Figure 13 Similar to Figure 9 ,but Figure 13 The cross-sectional reduction section of the probe corresponds to Figure 11 The state shown; Figure 14 This is a cross-sectional schematic diagram of the probe head provided in the third preferred embodiment of the present invention; Figure 15 for Figure 14 A cross-sectional view along section line 15-15; Figure 16 and Figure 17 Generally speaking Figure 2 It is a magnified view of a section, but it shows the reduced section with different appearances.

[0061] Explanation of reference numerals in the attached figures: 10: Probe system; 11: Fixture; 12: Probe card; 121: Main circuit board; 122: Space converter; 13: Test equipment; 14: Semiconductor wafer; 15: Electronic device under test; 151: Contact pad; 20: Probe tip; 21: Upper guide plate unit; 211: Upper guide plate; 212: Guide hole; 22: Lower guide plate unit; 221: Lower guide plate; 222: Guide hole; 223: Lower surface; 23: Probe; 24: Space; 25: Probe pair; 30A, 30B, 30C: Probe; 30A': General probe; 31: Needle tip; 32 1: Guide hole section; 32: Needle tail; 321: Guide hole section; 33: Needle body; 331: Cross section; 332: Wide side; 333: Thick side; 34: Section reduction section; 341: Circumference; 342: Outer contour; 343: Cross section; 35: Adjacent section; 36: Recess; 37: Multi-layer structure; 371: Layer; 372: Slit; 38: Minimum cross section area; 39: Transition zone; 391: Stepped surface; 392: Conical surface; A1, A2: Central axis; G1, G2: Air gap; L: Length; T: Thickness; W: Width. Detailed Implementation

[0062] The following description provides detailed examples and accompanying drawings, but these examples are not intended to limit the scope of this disclosure. For ease of understanding, in the embodiments and drawings described below, the same reference numerals denote the same or similar elements or structural features thereof. It should be noted that the elements and structures in the drawings are for illustrative purposes and are not drawn to scale or in quantity, and features of different embodiments may be used interchangeably if feasible. Furthermore, when it is stated that one element is disposed on another element, it means that the aforementioned element is directly disposed on the other element, or the aforementioned element is indirectly disposed on the other element; that is, one or more other elements are disposed between the two elements.

[0063] The terms “including,” “comprising,” and “having” used in this invention are all open-ended terms, meaning “including but not limited to.”

[0064] In the description of the various embodiments, when the terms "first," "second," "third," "fourth," etc. are used to describe elements, they are only used to distinguish these elements from each other and do not limit the order or importance of these elements.

[0065] Please refer to the following first. Figure 1The probe system 10 provided in the first preferred embodiment of the present invention includes a fixture 11, a probe card 12, and a testing device 13. The fixture 11 is used to support a semiconductor wafer 14, on which a plurality of electronic devices under test 15 are formed, each electronic device under test 15 including a plurality of contact pads 151. The probe card 12 is disposed on the testing device 13, and the testing device 13 is used to electrically connect to the electronic device under test 15 through the probe card 12 to perform electrical testing on the electronic device under test 15.

[0066] The probe card 12 includes a main circuit board 121, a space converter 122, and a probe head 20. The main circuit board 121 and the probe head 20 are respectively disposed on opposite sides of the space converter 122. The probe head 20 includes an upper guide plate unit 21, a lower guide plate unit 22, and a plurality of probes 23 passing through the upper and lower guide plate units 21 and 22. The probes 23 used in this invention can be pre-bent probes (e.g., probe 30A in the first preferred embodiment and general probe 30A', such as...). Figure 4 (as shown), or a straight probe (e.g., probes 30B and 30C in the second and third preferred embodiments, such as...). Figure 9 and Figure 14 As shown in the figure, its structure will be described in detail below.

[0067] Please see Figures 1 to 3 The probe head 20 of this invention includes at least one guide plate. In this embodiment, the at least one guide plate includes an upper guide plate 211 of an upper guide plate unit 21 and a lower guide plate 221 of a lower guide plate unit 22. The upper guide plate 211 includes a plurality of guide holes 212, and the lower guide plate 221 includes a plurality of guide holes 222. The upper guide plate unit 21 may also include a plurality of stacked upper guide plates 211, and the lower guide plate unit 22 may also include a plurality of stacked lower guide plates 221. The edges of the upper and lower guide plate units 21 and 22 may have protruding structures and be directly connected to each other, or a hollow middle guide plate (not shown in the figure) may be connected between the upper and lower guide plate units 21 and 22.

[0068] The various probes 30A, 30B, 30C and general probe 30A' in this invention all include a needle tip 31 at one end, a needle tail 32 at the other end, and a needle body 33 connecting the needle tip 31 and the needle tail 32. The needle tip 31 passes through the guide hole 222 of the lower guide plate 221 and extends below the lower surface 223 of the lower guide plate 221, for physically contacting the contact pad 151 of the electronic test device 15. The needle tail 32 passes through the guide hole 212 of the upper guide plate 211, for abutting against the contact pad (not shown) on the lower surface of the space converter 122 and electrically connecting with the space converter 122, so that the probes 30A, 30B, 30C and general probe 30A' are electrically connected to the test equipment 13 through the space converter 122 and the main circuit board 121. The test equipment 13 provides test signals to the electronic device under test 15 and / or receives result signals from the electronic device under test 15 via the probe card 12 to test the electronic device under test 15. The needle body 33 is located between the upper and lower guide plate units 21 and 22, and the needle body 33 is generally designed to be slightly elastically deformable when the needle tip 31 contacts the contact pad 151 of the electronic device under test 15, as detailed below.

[0069] It should be noted here that Figure 3 The needle body 33 of the two probes 30A shown is shaped as follows when viewed from the X-axis direction: Figure 2 As shown in the curved shape, the two probes 30A are arranged along the X-axis, therefore Figure 2 You will only see one of the probes, 30A. Figure 9 The probe head shown is in the state where the upper guide plate unit 21 and the lower guide plate unit 22 are not laterally misaligned with each other in the horizontal direction (i.e., the X-axis and / or Y-axis direction). At this time, the needle body 33 of the two probes 30B is in a straight line, so the shape of the probe 30B as seen from the X-axis direction is no longer drawn.

[0070] In this invention, for the sake of simplicity, all figures only depict a portion of the multiple vertical probes typically included in the probe head 20. In reality, the vertical probes are configured in accordance with the contact pads 151 of the electronic test device 15, and are typically located in the central region of the probe head 20. A vertical probe is defined as having an elongated shape and extending approximately along a vertical axis (Z-axis) when applied to a probe card, but is not limited to extending completely in a straight line along the vertical axis. The probes applicable to this invention may include at least straight probes or pre-bent probes. Straight probes may be, for example, forming wires (FW) or MEMS wires (MW). Pre-bent probes may be, for example, cobra probes or MEMS wires with pre-bent forming probes. Furthermore, the space 24 within the guide plate (e.g., a space between the probe and the guide plate) through which the probe itself (e.g., a pre-bent probe) or the probe (e.g., a forming probe or a MEMS probe among straight probes) passes can be appropriately configured to allow the probe to pass through the space 24 within the guide plate. Figure 2 (As shown) bending. Specifically, a straight probe refers to a probe that is straight when manufactured, such as probes 30B and 30C in the second and third preferred embodiments. The bending of the needle body 33 is generated when the upper and lower guide plate units 21 and 22 are installed, through the lateral misalignment of the upper and lower guide plate units 21 and 22. The diagrams of the second and third preferred embodiments show the state before the lateral misalignment of the upper and lower guide plate units 21 and 22 and before the bending of the needle body 33. A pre-bent probe refers to a probe that is bent when manufactured, such as probe 30A in the first preferred embodiment and general probe 30A'. The needle body 33 is originally bent and does not need to be generated through the lateral misalignment of the upper and lower guide plate units 21 and 22.

[0071] When the probe head 20 is a so-called offset plate type (applicable to shaped probes or MEMS probes in straight probes, such as probes 30B and 30C in the second and third preferred embodiments), specifically, the centers of the guide holes 212 and 222 in the upper and lower guide plates 211 and 221 through which the same probe passes can be misaligned, that is, the line connecting the centers of the guide holes 212 and 222 is not parallel to the vertical axis. The vertical axis can be a direction parallel to the Z-axis and perpendicular to the reference plane in the local reference system of the diagram, and the reference plane can correspond to the lateral development plane of each guide plate. Accordingly, the probe housed in the guide holes 212 and 222 of the upper and lower guide plates 211 and 221 is deformed relative to its longitudinal development axis (corresponding to the Z-axis direction of the local reference system of the diagram), and the longitudinal development axis is set to be perpendicular to the reference plane. The upper and lower guide plates 211 and 221 may be parallel to each other and extend along the reference plane, and the plates of the semiconductor wafer 14, the electronic test device 15, and the space converter 122 may also extend along the reference plane. When the probe in the probe head 20 is a pre-bent probe type, such as the cobra probe in the first preferred embodiment, the probe has a pre-deformed configuration that is offset between the tip 31 and the tail 32, which are already defined in the placement conditions of the probe head. In particular, in this example, the probe includes a pre-deformed portion that can assist in the proper bending of the probe, even when the probe is not in contact with the electronic test device 15. The probe further deforms during its operation, i.e., when it is in pressure contact with the electronic test device 15. It should be noted that for proper probe head operation, the probe may have appropriate axial movement freedom within the guide hole. In this way, these probes can also be extracted and replaced in the event of a single probe failure, without having to be forced to replace the entire probe head. The axial movement freedom (especially when the probe slides inside the guide hole) contrasts with the normal safety requirements of the probe head during its operation.

[0072] When the aforementioned probes 30A, 30B, 30C and general probe 30A' are used to test the electronic device under test 15, after the probe tip 31 comes into contact with the contact pad 151 of the electronic device under test 15, the probe holder 12 and the clamp 11 will move closer to each other and shift relative to each other by a test drive (OD; or overtravel, OT), so that the probe tip 31 moves upward relative to the guide plate by the test drive and presses against the contact pad 151 of the electronic device under test 15, while the probe body 33 will be compressed and deformed.

[0073] Furthermore, it should be emphasized that the probes in this invention can have cross-sectional shapes of different shapes. Specifically, in the first preferred embodiment, the tip 31 and tail 32 of probe 30A and general probe 30A' are originally cylindrical, i.e., their cross-section is circular. Subsequently, probe 30A is machined to form at least one cross-sectional reduction section 34 (detailed below). The body 33 of probe 30A and general probe 30A' in the first preferred embodiment is a curved flat plate, with a generally rectangular cross-section. In the second and third preferred embodiments, the sections of probes 30B and 30C are originally square prisms, i.e., their cross-section is square. Subsequently, at least one cross-sectional reduction section 34 is machined to form (detailed below). In addition to being circular or square, the aforementioned cross-sections can also be rectangular, elliptical, triangular, arbitrary polygonal, or any other shape. Considering that probes are usually polished on sandpaper to make their ends rounded, such as the uppermost tail of the second and third preferred embodiments, the cross-section of the probe is preferably circular or square, because these shapes are easier to polish into a rounded shape. Those skilled in the art to which this invention pertains should understand that the cross-section of the probe actually manufactured may still have certain tolerances or manufacturing errors, and may not be geometrically perfect in the aforementioned shape.

[0074] In this embodiment, the probe head 20 includes at least one probe pair 25 among its multiple probes. Each probe pair 25 can be used to transmit a set of differential signals, i.e., a differential pair. In a preferred embodiment of the invention, the differential pair is used to transmit differential signals, that is, two single-ended signal lines (e.g., referred to as P-line and N-line) are used to connect two connection points (i.e., TX+ and RX+ hereinafter) and two other connection points (i.e., TX- and RX- hereinafter) to transmit signals simultaneously. These two signals have the same voltage amplitude but opposite phases, i.e., one positive and one negative. In other words, these two signal lines are mutually referenced, with the P-line referencing the N-line and the N-line referencing the P-line, ideally forming a mutual reference loop. The differential pair is connected to the transmitting end (typically referred to as TX) and the receiving end (typically referred to as RX) of the electronic device under test 15. The transmitting end (TX) includes two connection points (typically referred to as TX+ and TX-). The receiving end (RX) also includes two connection points (typically referred to as RX+ and RX-). The transmitting end (TX) is connected to a high-frequency signal source. The receiver (RX) is connected to an error detector. For example... Figure 3As shown, in the first preferred embodiment, two probes 30A constitute a probe pair 25. The tip 31 and tail 32 of each probe 30A respectively include a cross-sectional reduction section 34 and two adjacent sections 35 respectively adjacent to the upper and lower ends of the cross-sectional reduction section 34. More specifically, the adjacent section 35 at the upper end of the tip 31 is adjacent to the needle body 33, but this adjacent section 35 may be absent, or this adjacent section 35 may be the needle body 33; the adjacent section 35 at the lower end of the tip 31 is a contact end for contacting the contact pad 151 of the electronic test device 15. Similarly, the adjacent section 35 at the lower end of the tail 32 is adjacent to the needle body 33, but this adjacent section 35 may be absent, or this adjacent section 35 may be the needle body 33; the adjacent section 35 at the upper end of the tail 32 is a contact end for contacting the contact pad of the space converter 122. The cross-sectional area of ​​each section reduction segment 34 is smaller than the cross-sectional area of ​​its adjacent section 35, such that each probe 30A includes at least one recess 36 formed by the section reduction segment 34, such as Figure 4 and Figure 5 As shown. Furthermore, the cross-sectional reduction section 34 is at least partially located within the guide hole of the guide plate. That is, the cross-sectional reduction section 34 of the needle tip 31 may be completely located within the guide hole 222 of the lower guide plate 221, or it may be partially exposed outside the guide hole 222. Similarly, the cross-sectional reduction section 34 of the needle tail 32 may be completely located within the guide hole 212 of the upper guide plate 211, or it may be partially exposed outside the guide hole 212. The accompanying drawings of this invention clearly depict the degree of reduction of the cross-sectional reduction section 34. In reality, the diameter or length of the cross-section 343 of the cross-sectional reduction section 34 is reduced to approximately 50-95% of the diameter or length of the cross-section of the adjacent section 35, preferably 70-90%.

[0075] The recessed portion 36 mentioned in this invention refers to the space formed by the cross-sectional reduction section 34 being recessed from the outer surface of the probe towards the center. Furthermore, in addition to the probes 30A constituting the probe pair 25, the probe head 20 may also include at least one general probe 30A' without a cross-sectional reduction section, such as... Figure 4As shown, probe 30A can be formed by machining a cross-section reduction section 34 from a general probe 30A'. The probe with the cross-section reduction section 34 is also referred to as a cross-section reduction probe in this invention. Because probe 30A has the space (i.e., recess 36) formed by the cross-section reduction section 34, the air gap G2 between the cross-section reduction section 34 and the guide holes 222 and 212 is larger than the air gap G1 between the tip 31 and tail 32 of a general probe 30A' and their respective guide holes 222 and 212. This results in a smaller impedance variation between the two probes 30A of probe 25 due to the guide plate. More specifically, the tip 31 and tail 32 of a general probe 30A' respectively include guide hole sections 311 and 321 located within guide holes 222 and 212. The cross-sectional area of ​​the cross-section reduction section 34 of the cross-section reduction probe is smaller than the cross-sectional area of ​​the guide hole sections 311 and 321 of a general probe 30A', making the air gap G2 larger than the air gap G1.

[0076] In detail, for the section of the probe pair disposed in the via of the guide plate, the smaller the cross-sectional area of ​​the probe itself and / or the larger the center-to-center distance between the two probes, the greater the characteristic impedance of the section of the two probes in the via of the guide plate. Therefore, by forming a cross-sectional reduction section 34 in probe 30A and placing the cross-sectional reduction section 34 at least partially in the via of the guide plate, the present invention optimizes the structural proportions and electromagnetic behavior between probe 30A and the guide plate, thereby improving the characteristic impedance performance of the section of probe 30A in the via of the guide plate. This effectively reduces the impedance fluctuations between the probes 30A and the guide plate, thereby reducing the reflection loss between the probe head 20 as a whole and the electronic device under test 15, and further improving the impedance matching between the probe head 20 (or even the probe card 12) as a whole and the electronic device under test 15. Therefore, the present invention can effectively improve the reliability and accuracy of high-speed signal testing and improve the overall performance of the probe card 12 in high-frequency applications. Furthermore, through the above structural design, this invention can effectively control the impedance between probes even without specifically selecting a low dielectric constant material as the guide plate material. This design increases the overall design freedom of the guide plate and probe head, making the selection of guide plate materials and mechanical design more flexible, thereby balancing the required electrical characteristics and mechanical strength, and achieving overall performance optimization.

[0077] exist Figures 2 to 5 In the illustrated configuration, the cross-sectional reduction section 34 reduces the overall diameter coaxially, ensuring that the cross-sectional reduction section 34 tapers uniformly across the entire circumference while remaining coaxial with the adjacent section 35. Specifically, the adjacent section 35 defines a central axis A1 (e.g., Figure 3As shown), the recess 36 formed by the cross-section reduction section 34 has a uniform depth and completely surrounds the circumference 341 of the cross-section reduction section 34 with the central axis A1 as the center (as shown). Figure 5 As shown), that is, the depth of the recess 36 is the same at all angular positions. However, the cross-sectional reduction section 34 may not taper uniformly across the entire circumference. For example... Figure 6 and Figure 8 As shown, the cross-sectional reduction section 34 reduces its cross-sectional area only on one side, for example, by machining a general probe 30A' on one side. Therefore, the recess 36 formed by the cross-sectional reduction section 34 is only located on one side of the cross-sectional reduction section 34 and does not completely surround the outer contour 342 of the cross-sectional reduction section 34. For example... Figure 7 As shown, the cross-sectional reduction section 34 reduces the cross-sectional area on both sides, for example, by symmetrically cutting a general probe 30A' on both sides. Therefore, the same cross-sectional reduction section 34 forms two recesses 36, which are located on opposite sides of the cross-sectional reduction section 34 and are symmetrical to each other, so that the cross-sectional reduction section 34 has a narrow and elongated cross-section 343.

[0078] Furthermore, in Figure 6 and Figure 8 In the illustrated configuration, the cross-sectional area reduction section 34 is reduced on only one side. Therefore, relative to the central axis A1 of the adjacent section 35, the cross-sectional area reduction section 34 is an asymmetrical structure. That is, the central axis A2 of the cross-sectional area reduction section 34 is offset from the central axis A1 of the adjacent section 35. Furthermore, the two probes 30A are configured such that the recesses 36 formed by their cross-sectional area reduction sections 34 face each other across the guide plate, causing the central axes A2 of the cross-sectional area reduction sections 34 of the two probes 30A to be offset away from each other from the central axis A1 of the adjacent section 35. In other words, the center-to-center distance between the cross-sectional area reduction sections 34 of the two probes 30A is greater than the center-to-center distance between the adjacent sections 35. This further increases the characteristic impedance of the cross-sectional area reduction sections 34 of the two probes 30A disposed in the guide holes of the guide plate, making the aforementioned cross-sectional area reduction section 34 more effective. The recess 36 formed by the cross-sectional reduction section 34 is radially reduced in size along the X-axis direction, making the lateral cross-sectional area of ​​the cross-sectional reduction section 34 smaller than that of the adjacent section 35. Furthermore, when the probe card is actually assembled, the cross-sectional reduction section 34 rests against the guide holes 212 and 222 along the Y-axis direction; therefore, the reduction direction of the recess 36 formed by the cross-sectional reduction section 34 is perpendicular to the bearing direction of the cross-sectional reduction section 34 in the guide holes.

[0079] In addition, such as Figure 2As shown, the cross-sectional reduction section 34 of the probe tip 31 of the probe 30A is not only located within the guide hole 222 of the lower guide plate 221, but also extends downward from the lower surface 223 of the lower guide plate 221 by a predetermined length L. This length L is substantially greater than or equal to the maximum upward movement of the probe tip 31 relative to the lower guide plate 221 during testing (i.e., the aforementioned test stroke). Furthermore, after the probe tip 31 has moved upward by the maximum amount relative to the lower guide plate 221 during testing, only the cross-sectional reduction section 34 of the probe 30A remains within the guide hole 222 of the lower guide plate 221. In other words, only the cross-sectional reduction section 34 is present in the guide hole 222 of the lower guide plate 221, without any other sections of the probe 30A. This ensures stable impedance control throughout the entire test stroke, resulting in better performance from the aforementioned cross-sectional reduction section 34.

[0080] Please see Figure 9 and Figure 10 The second preferred embodiment of the present invention is similar to the first preferred embodiment, but this embodiment uses a straight probe with a square cross-sectional shape. It should be noted that... Figure 9 and Figure 10 The display shows the state where the upper guide plate 211 and the lower guide plate 221 have not yet been misaligned (for example, they have not yet been misaligned along the X-axis direction, or they have not yet been misaligned along both the X-axis and Y-axis directions). Figure 9 and Figure 10 The two probes 30B constitute a probe pair 25, such as a differential pair. Each probe 30B has a reduced cross-section section 34 at its tip 31 and tail 32. The recesses 36 formed by these reduced cross-section sections 34 completely surround the outer contour 342 of the reduced cross-section section 34 at equal depths, thus making the outer contour 342 of the reduced cross-section section 34 square. Other structural features and functions of this embodiment are similar to those of the first preferred embodiment and will not be repeated here.

[0081] In the second preferred embodiment, the cross-sectional reduction section 34 may not be uniformly thinned across the entire outer contour. For example... Figure 11 and Figure 13 As shown, the cross-sectional reduction section 34 only reduces its cross-sectional area on one side. Therefore, the recess 36 formed by the cross-sectional reduction section 34 is located only on one side of the cross-sectional reduction section 34 and does not completely surround the outer contour 342 of the cross-sectional reduction section 34. Specifically, the recess 36 formed by the cross-sectional reduction section 34 exhibits radial dimensional reduction along the X-axis, making the lateral cross-sectional area of ​​the cross-sectional reduction section 34 smaller than that of the adjacent section 35. Furthermore, when the probe card is actually assembled, the cross-sectional reduction section 34 rests against the guide holes 212 and 222 along the Y-axis. Therefore, the reduction direction of the recess 36 formed by the cross-sectional reduction section 34 is perpendicular to the resting direction of the cross-sectional reduction section 34 in the guide holes. For example... Figure 12As shown, the cross-sectional reduction section 34 reduces its cross-sectional area on opposite sides, thus forming two recesses 36 within the same cross-sectional reduction section 34. These two recesses 36 are located on opposite sides of the cross-sectional reduction section 34 and are symmetrical to each other, resulting in the cross-sectional reduction section 34 having an elongated cross-section 343. In fact, the recesses 36 of the cross-sectional reduction section 34 in this invention can not only surround the entire circumference, be located on one side or on opposite sides, but can also be located on three sides, four sides, or other variations.

[0082] Please see Figure 14 The third preferred embodiment of the present invention is similar to the second preferred embodiment, but in this embodiment, the probe body 33 of the probe 30C includes a multilayer structure 37, the multilayer structure 37 including a plurality of layers 371, and at least one slit 372 formed between the layers 371. Figure 15 As shown, the cross-section 331 of the needle body 33 has a wide side 332 and a thick side 333. The slit 372 extends through the needle body 33 along the direction of the thick side 333 (i.e., along the Y-axis) and extends into an elongated shape along the longitudinal direction of the needle body 33. That is, before the needle body 33 is bent or deformed, the slit 372 extends along the vertical axis (Z-axis). In addition, the sheets 371 are separated from each other along the direction of the wide side 332 (i.e., along the X-axis). This slit 372 can weaken the rigidity of the needle body 33 to reduce the probe contact force, thereby preventing the contact pad 151 of the electronic test device 15 from being damaged due to excessive probe contact force. Furthermore, the needle body 33 originally extends linearly along the Z-axis. When the upper and lower guide plate units 21 and 22 are misaligned along the X-axis, the needle body 33 bends along the X-axis and appears curved on the XZ plane. When the needle tip 31 contacts the electronic test device 15 and is subjected to force, the needle body 33 can bend elastically along the X-axis again. The aforementioned slit 372 can enhance the elasticity of the needle body 33 bending along the X-axis, ensuring the elastic deformation effect of the needle body 33 bending along the X-axis. In addition, the length of the thick side 333 of the needle body 33 (i.e., the thickness T) is greater than or equal to the length of the wide side 332 (i.e., the width W). This allows the needle body 33 to produce a better elastic deformation effect and allows the needle body 33 to have sufficient thickness T to be less prone to breakage.

[0083] The cross-sectional reduction sections 34 in the aforementioned embodiments can also be reduced in a gradual manner. The following description takes the needle 31 of the pre-bent probe in the first preferred embodiment as an example. Any type of probe can adopt a similar design for the cross-sectional reduction sections 34 at any location.

[0084] like Figure 16As shown, the cross-sectional reduction section 34 may include a minimum cross-sectional area 38 and at least one transition section 39. The transition section 39 gradually shrinks in diameter from the adjacent section 35 to the minimum cross-sectional area 38 in a stepped manner, such that the transition section 39 has a clearly identifiable stepped surface 391 with a diameter change. Even when the cross-sectional shape of the cross-sectional reduction section 34 is non-circular, the transition section 39 can still gradually shrink in cross-sectional area from the adjacent section 35 to the minimum cross-sectional area 38 in a stepped manner, producing a stepped surface 391. Thus, the cross-sectional area of ​​the cross-sectional reduction section 34 does not abruptly shrink to the minimum diameter from the cross-sectional area of ​​the adjacent section 35, but rather shrinks in a stepped manner within the transition section 39, thereby reducing the problem of weakening the probe structure strength due to the reduction in the cross-sectional area of ​​the cross-sectional reduction section 34.

[0085] Or, such as Figure 17 As shown, the cross-sectional reduction section 34 may include a minimum cross-sectional area 38 and a transition section 39. The transition section 39 gradually shrinks in diameter from the adjacent section 35 to the minimum cross-sectional area 38, resulting in a conical surface 392. Even when the cross-sectional shape of the cross-sectional reduction section 34 is non-circular, the transition section 39 can still gradually shrink in cross-sectional area from the adjacent section 35 to the minimum cross-sectional area 38, creating a conical inclined plane or curved surface. Thus, the cross-sectional area of ​​the cross-sectional reduction section 34 does not abruptly shrink from the cross-sectional area of ​​the adjacent section 35 to the minimum cross-sectional area, but rather shrinks continuously within the transition section 39 without significant step differences. This also reduces the problem of weakening the probe structure strength due to the reduction in the cross-sectional area of ​​the cross-sectional reduction section.

[0086] Finally, it must be stated again that the constituent elements disclosed in the foregoing embodiments of the present invention are merely illustrative examples and are not intended to limit the scope of this application. Substitutions or variations of other equivalent elements should also be covered by the scope of this application.

[0087] For example, the present invention is not limited to applications of differential signals. In other embodiments, the probe pair can also be used to transmit single-ended signals. In a single-ended signal configuration, the signal line transmits the signal using only one signal probe (e.g., S) and uses an adjacent ground probe (e.g., G) as a reference loop, such as a GS or GSG configuration. In this case, the signal line is referenced relative to ground (GND), rather than using another signal line as a reference, as in a differential signal. A single-ended signal can be connected to a single signal connection point at the transmitting (TX) or receiving (RX) end of the electronic device under test 15.

Claims

1. A probe head used in a probe card to test an electronic device under test; characterized in that: The probe head includes: At least one guide plate, the guide plate including a plurality of guide holes; Multiple probes are respectively inserted into each of the guide holes. Each probe includes a needle tip, a needle tail, and a needle body connected between the needle tip and the needle tail. The needle tip is used to contact the electronic test device. The plurality of probes includes at least one probe pair, which consists of two probes. At least one of the tips and tails of each probe in the probe pair has a cross-sectional reduction section, and at least one adjacent section adjacent to the cross-sectional reduction section. The cross-sectional area of ​​the cross-sectional reduction section is smaller than the cross-sectional area of ​​the adjacent section, such that each probe in the probe pair includes at least one recess formed by the cross-sectional reduction section, which is at least partially located in the guide hole of the guide plate.

2. The probe head according to claim 1, characterized in that: The at least one guide plate includes a lower guide plate, and the tips of each probe of the probe pair pass through the guide holes of the lower guide plate and have the cross-sectional reduction section, wherein the cross-sectional reduction section of each probe is at least partially located in the guide holes of the lower guide plate.

3. The probe head according to claim 2, characterized in that: The at least one guide plate further includes an upper guide plate, wherein the tail of each probe of the probe pair passes through a guide hole in the upper guide plate and has the cross-sectional reduction section, and the cross-sectional reduction section of each tail is at least partially located in the guide hole of the upper guide plate.

4. The probe head according to claim 1, characterized in that: The plurality of probes includes at least one general probe that does not have the cross-sectional reduction section. The air gap between the cross-sectional reduction section and the guide hole is larger than that between the general probe and the guide hole.

5. The probe head according to claim 1, characterized in that: Each probe is either a straight probe or a pre-bent probe, and the probe pair is a differential pair used to transmit a set of differential signals.

6. The probe head according to claim 1, characterized in that: The section reduction zone is entirely located within the guide hole of the guide plate.

7. The probe head according to claim 1, characterized in that: The at least one guide plate includes a lower guide plate, and the tips of each probe of the probe pair pass through a guide hole in the lower guide plate and have the cross-sectional reduction section, the cross-sectional reduction section of each probe extending from the guide hole in the lower guide plate to below the lower surface of the lower guide plate.

8. The probe head according to claim 7, characterized in that: The cross-sectional reduction section of each of the needles extends downward from the lower surface of the lower guide plate by a predetermined length, the length being substantially greater than or equal to the maximum upward movement of each of the needles relative to the lower guide plate during testing.

9. The probe head according to claim 8, characterized in that: After each of the probes moves upward by the maximum amount relative to the lower guide plate during testing, only the cross-sectional reduction section of each probe in the probe pair is located in the guide hole of the lower guide plate.

10. The probe head according to claim 1, characterized in that: The adjacent section can define a central axis, and the recess formed by the section reduction section is of equal depth and completely surrounds the circumference of the section reduction section with the central axis as the center.

11. The probe head according to claim 1, characterized in that: The cross-section reduction section includes a minimum cross-section area and a transition area. The transition area gradually shrinks from the diameter of the adjacent section to the minimum cross-section area in a continuous manner, so that the transition area has a conical surface.

12. The probe head according to claim 1, characterized in that: The recess formed by the section reduction segment is located only on one side of the section reduction segment, rather than completely surrounding the outer contour of the section reduction segment.

13. The probe head according to claim 1, characterized in that: Two recesses are formed in the same cross-sectional reduction section. The two recesses are located on opposite sides of the cross-sectional reduction section and are symmetrical to each other, so that the cross-sectional reduction section has a narrow and elongated cross-section.

14. The probe head according to claim 1, characterized in that: The recess formed by the cross-section reduction section completely surrounds the outer contour of the cross-section reduction section at the same depth.

15. The probe head according to claim 1, characterized in that: The cross-sectional reduction section has a minimum cross-sectional area and a transition area, wherein the transition area gradually shrinks from the cross-sectional area of ​​the adjacent section to the minimum cross-sectional area in a continuous manner.

16. The probe head according to claim 1, characterized in that: The recesses of the two probes of the probe pair face each other at least partially separated by the guide plate.

17. A probe card, used in a probe system to test electronic devices under test integrated on a semiconductor wafer; characterized in that: The probe card includes: Main circuit board; Space converter; The probe head as described in any one of claims 1 to 16; The main circuit board and the probe head are respectively disposed on opposite sides of the space converter, and the tail of each probe of the probe head is electrically connected to the space converter.

18. A probe system for testing electronic devices under test integrated on a semiconductor wafer; characterized in that: The probe system includes: A fixture for supporting the semiconductor wafer; The probe card as described in claim 17; Test equipment; The probe card is disposed on the test equipment, and the test equipment is used to electrically connect with the electronic device under test through the probe card to perform electrical tests on the electronic device under test.

19. A probe for testing an electronic device under test in a probe card, the probe comprising a tip, a tail, and a body connected between the tip and the tail, the tip being for passing through a guide hole in a guide plate and for physically contacting the contact pad of the electronic device under test during testing; characterized in that: The needle has a reduced cross-section section and an adjacent section adjacent to the reduced cross-section section, the cross-sectional area of ​​the reduced cross-section section being smaller than the cross-sectional area of ​​the adjacent section, such that the needle has a recess formed by the reduced cross-section section, the reduced cross-section section being at least partially located in the guide hole.

20. The probe according to claim 19, characterized in that: The adjacent segment can define a central axis, and the recess formed by the cross-section reduction segment completely surrounds the outer contour of the cross-section reduction segment with the central axis as the center.

21. The probe according to claim 19, characterized in that: The recess formed by the section reduction segment is located only on one side of the section reduction segment, rather than completely surrounding the outer contour of the section reduction segment.

22. The probe according to claim 19, characterized in that: The cross-sectional reduction section has a minimum cross-sectional area and a transition area. The transition area gradually shrinks from the cross-sectional area of ​​the adjacent section to the minimum cross-sectional area in a continuous manner, such that the transition area has a conical surface.

23. The probe according to claim 19, characterized in that: The cross-section of the section reduction zone is non-circular.

24. The probe according to claim 19, characterized in that: The section reduction zone extends to the portion of the probe that is exposed outside the guide plate during use.

25. The probe according to claim 19, characterized in that: The needle body has a multi-layer structure, which includes multiple layers and at least one slit formed between each layer. The cross-section of the needle body has a wide side and a thick side. The slit penetrates the needle body along the direction of the thick side. Each layer is separated from each other along the direction of the wide side. The length of the thick side is greater than or equal to the length of the wide side.

26. A probe head for testing electronic devices under test in a probe card, the probe head comprising: At least one guide plate having a plurality of guide holes; Multiple probes are respectively inserted into each of the guide holes, and each probe has a needle head, a needle tail, and a needle body connected between the needle head and the needle tail; The feature is that: the plurality of probes includes at least one cross-section reduction probe and at least one general probe, the cross-section reduction probe having a cross-section reduction section located within the guide hole, the cross-sectional area of ​​the cross-section reduction section being smaller than the cross-sectional area of ​​the guide hole section of the general probe located within the guide hole, such that the air gap between the cross-section reduction section of the cross-section reduction probe and the guide hole is larger than the air gap between the guide hole section of the general probe and the guide hole.

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