Probe unit, probe head, probe card, and probe system

Abstract

The invention relates to a probe unit, which comprises a first probe and a second probe, the length of the first probe and the length of the second probe are the same, the probe body is provided with at least one through slit extending along the lengthwise direction of the probe body and is hollow, at least two sheet bodies are defined by the slit, and the total cross sectional area of the sheet body of the first probe is larger than the total cross sectional area of the sheet body of the second probe; or, the needle body of the second probe is not provided with a slit and is in a solid shape, and the total cross sectional area of the sheet body of the first probe is larger than the cross sectional area of the needle body of the second probe. The shape of the sheet body is selected to enable the contact force of the first probe to be larger than the contact force of the second probe, so that the test requirements of probe test contact blocks with different sizes on an electronic tested device are met, and meanwhile, the problems of different needle point abrasion rates and overlarge needle mark area ratio difference can be avoided.

Description

Technical Field

[0001] This invention relates to probes in probe cards, and more particularly to a probe unit comprising probes of different shapes, as well as a probe head, probe card, and probe system employing said probe unit. Background Technology

[0002] During current wafer testing, devices typically utilize probe cards to transmit signals between the device under test (DUT) and the testing equipment. A probe card is equipped with multiple probes that contact various contact areas on the DUT, such as pads or bumps. Some DUT contact areas have different current requirements and sizes; generally, higher current requires larger contact areas with greater spacing, while lower current requires smaller contact areas with less spacing. Therefore, if the probe card uses only thin probes, the contact force and current carrying capacity may be insufficient for large-sized contact areas with high current requirements. Conversely, if the probe card uses only coarse probes, the probe pressure may be excessive, potentially damaging the contact areas for small-sized contact areas with low current requirements.

[0003] Patent TWI695549 discloses a scheme that uses probes with different cross-sectional areas simultaneously, i.e., both coarse and fine probes. While this solves the aforementioned problem, the probes have the same bending stiffness, thus generating the same contact force. In other words, the probes contact different sized probe contact areas on the tested device with the same contact force, which will lead to inconsistent tip wear rates and / or excessively large differences in the area ratio of the needle marks.

[0004] In detail, the tip wear rate depends on the contact force per unit area. When a coarse probe and a fine probe contact the large and small probe contact areas with the same contact force, respectively, the tip wear rate of the fine probe will be higher than that of the coarse probe. The needle mark area ratio refers to the ratio of the area of ​​the mark left by the probe pressing down on the top of a bump to the cross-sectional area of ​​the bottom of the bump, when the probe contact area of ​​the device under test is a bump. When a coarse probe and a fine probe contact the large and small bumps with the same contact force, respectively, the needle mark area ratio produced by the fine probe will be greater than that produced by the coarse probe, resulting in a difference in height between the large and small bumps after testing. Summary of the Invention

[0005] This invention discloses a probe unit, probe head, probe card, and probe system that can use probes with different cross-sectional areas and can suppress the adverse effects caused by differences in the wear rate of the probe tip, and can also control the difference in the area ratio of the probe marks within an acceptable range.

[0006] According to a specific embodiment of the present invention, a probe unit is provided for contacting multiple probe contact blocks of an electronic test device integrated on a semiconductor wafer. The probe unit includes multiple probes having the same length. Each probe includes a tail and a tip located at its two ends, and a body located between the tail and the tip. The body includes at least one slit extending along its longitudinal direction. The slit penetrates the body along a first transverse axis, making the body hollow and defining at least two sheets by the at least one slit. The at least two sheets are separated from each other along a second transverse axis and can be elastically bent under load. Each sheet can define a cross-sectional area on an imaginary plane parallel to the first and second transverse axes. The sum of the cross-sectional areas of the at least two sheets of each probe is defined as the total cross-sectional area.

[0007] The plurality of probes includes a first probe and a second probe. The total cross-sectional area of ​​the sheet of the first probe is greater than the total cross-sectional area of ​​the sheet of the second probe. The shapes of the sheet of the first probe and the sheet of the second probe are different from each other, and the shapes of the sheet are selected such that the contact force of the first probe is greater than the contact force of the second probe.

[0008] Therefore, this invention employs a hybrid probe approach, simultaneously using at least two probe types: a first probe and a second probe. The width and thickness of the first and second probes are designed to match the size and spacing of the probe contact areas of the electronic device under test (DUT) they are required to contact. Furthermore, the rigidity of the probes can be appropriately reduced through the design of the slits in the probe body (design width, number, etc.), thereby appropriately reducing the contact force and ensuring that the first and second probes meet the testing requirements of their respective probe contact areas in various aspects. Specifically, the first probe has a larger total cross-sectional area, which can meet the high current requirements of larger probe contact areas, while the larger probe contact areas can withstand the larger contact force of the first probe without easily being damaged. The second probe has a smaller total cross-sectional area, which can meet the low current requirements of smaller probe contact areas, while the smaller contact force of the second probe avoids damage to the smaller probe contact areas. More importantly, the first and second probes can contact larger and smaller probe contact areas with larger and smaller contact forces, respectively. Therefore, through size design, the ratio of contact force to contact area of ​​the first and second probes can be made consistent or similar, resulting in consistent or similar tip wear rates for the first and second probes, and consequently, consistent or similar lengths for the first and second probes. Furthermore, through size design, the first and second probes can produce consistent or similar probe mark area ratios for the large and small bumps of the electronic device under test they contact, ensuring that the large and small bumps have consistent or similar heights after testing.

[0009] In a preferred embodiment, the ratio of the contact force of the first probe to the contact force of the second probe is greater than 1 and less than 4.

[0010] This can meet the needs of most wafer testing.

[0011] In a preferred embodiment, the needle body of each probe can be defined in terms of thickness in the first transverse direction and width in the second transverse direction, and the width of the needle body of each probe is less than or equal to the thickness of the needle body of each probe.

[0012] In other words, the probe's cross-sectional shape can be square or rectangular, with the longer side of the rectangle pointing in the direction of the probe's thickness, i.e., the first transverse axis. Since the probe's slit extends through the probe body along the first transverse axis, the probe body bends along the second transverse axis (i.e., the axis defining the width) during use. A square-section probe not only better matches the shape of the probe contact area of ​​the electronic test device, but also, because the width of the probe body is no greater than its thickness, it facilitates elastic deformation when bending along the second transverse axis. A rectangular-section probe, with a width less than its thickness, exhibits even better elastic deformation when bending along the second transverse axis. Furthermore, the probe body's width being less than or equal to its thickness allows for sufficient thickness to maintain a certain current-carrying capacity.

[0013] In a preferred embodiment, the tip of the first probe includes a base connected to the needle body and an end connected to the base. The end is used to contact the probe contact area of ​​the electronic test device. The base and the end can define cross-sectional areas on imaginary planes parallel to the first transverse axis and the second transverse axis, respectively. The cross-sectional area of ​​the end is smaller than the cross-sectional area of ​​the base.

[0014] In other words, the tip of the first probe has a thinned and / or narrowed end. That is, the base may have the same outer contour dimensions as the body, while the end is further reduced in thickness and / or width compared to the base, so that the cross-sectional area of ​​the end is smaller than that of the base. Such a structural design also helps to adjust the tip wear rate of the first probe and the ratio of the resulting needle mark area, thereby making the tip wear rates of the first and second probes consistent or similar, and making the first and second probes produce consistent or similar needle mark area ratios.

[0015] In a preferred embodiment, the tip of the second probe can define a cross-sectional area on an imaginary plane parallel to the first transverse axis and the second transverse axis, and the cross-sectional area of ​​the end of the tip of the first probe is greater than or equal to the cross-sectional area of ​​the tip of the second probe.

[0016] Therefore, when the first and second probes contact the probe contact area of ​​the electronic test device, the contact area of ​​the first probe will be greater than or equal to the contact area of ​​the second probe. This structural design also helps to make the tip wear rate of the first and second probes consistent or similar, and to make the first and second probes produce consistent or similar needle mark area ratios.

[0017] In a preferred embodiment, the ratio of the cross-sectional area of ​​the tip of the first probe to the cross-sectional area of ​​the tip of the second probe is greater than 1 and less than 4.

[0018] This can meet the needs of most wafer testing.

[0019] In a preferred embodiment, the plurality of probe contact blocks of the electronic test device include a first protrusion and a second protrusion, wherein the maximum cross-sectional area of ​​the first protrusion is greater than the maximum cross-sectional area of ​​the second protrusion; when the tips of the first probe and the second probe press against the first protrusion and the second protrusion respectively, causing the needle bodies of the first probe and the second probe to bend elastically under load, the first probe forms a first needle mark area on the first protrusion, and the second probe forms a second needle mark area on the second protrusion, and the ratio of the first needle mark area to the maximum cross-sectional area of ​​the first protrusion and the ratio of the second needle mark area to the maximum cross-sectional area of ​​the second protrusion are substantially equal.

[0020] In this way, when the probe contact area of ​​the electronic device under test is a bump, the first and second probes produce substantially equal probe mark area ratios for the large bump (i.e., the first bump) and the small bump (i.e., the second bump) of the electronic device under test they contact. Substantially equal is defined as a difference of less than or equal to 20%, so that the first and second bumps have consistent or similar heights after testing.

[0021] In a preferred embodiment, the plurality of probe contact blocks of the electronic test device include a plurality of first bumps and a second bump, each of the first bumps and the second bump being substantially the same size; the tip of the first probe is used to simultaneously press against the plurality of first bumps, each of the plurality of first bumps being configured to transmit a first signal, the first signal being one of a power signal and a ground signal; the tip of the second probe is used to press against the second bump, the second bump being configured to transmit a second signal, the second signal being a test signal different from the first signal.

[0022] Therefore, even if the dimensions of the first and second protrusions are substantially the same, the first probe with a larger contact force is used to press against multiple first protrusions at the same time, while the second probe with a smaller contact force is used to press against a single second protrusion. Thus, the wear rate of the tips of the first and second probes can still be made consistent or similar through size design, and / or the first and second protrusions can be made to have consistent or similar needle mark area ratios.

[0023] In a preferred embodiment, the needle body of each probe can be defined with a thickness in the first transverse axis and a width in the second transverse axis, wherein the ratio of the width to the thickness of the needle body of the first probe is less than the ratio of the width to the thickness of the needle body of the second probe.

[0024] Therefore, the ratio of the width to the thickness of the first probe is relatively small, which helps to improve its elastic deformation effect when bending along the second transverse axis. This allows the first probe with a larger total cross-sectional area and the second probe with a smaller total cross-sectional area to produce the same or similar elastic deformation effect, thereby producing the same or similar probe measurement performance.

[0025] In a preferred embodiment, the first probe and the second probe are made of materials with different hardness.

[0026] Therefore, the first and second probes can be made of materials with different hardness. For example, the second probe, which has a smaller total cross-sectional area, can be made of a harder material to slow down its tip wear rate. This also helps to make the tip wear rates of the first and second probes consistent or similar.

[0027] In a preferred embodiment, the material hardness of the second probe is greater than that of the first probe.

[0028] Therefore, the use of a harder material for the second probe with a smaller total cross-sectional area can slow down its tip wear rate, which helps to make the tip wear rates of the first and second probes consistent or similar.

[0029] In a preferred embodiment, at least one bump group is provided in the slit of the first probe (meaning that at least one bump group may also be provided in the slit of the second probe, or there may be no bump group in the slit of the second probe), the bump group comprising two bumps, the two bumps protruding from the two adjacent pieces facing each other.

[0030] In this way, when the probe body is subjected to load and bends elastically, the two protrusions facing each other within the slit will abut against each other, thus preventing adjacent pieces from contacting each other and wearing out, thereby extending the probe's lifespan. Moreover, by having the two protrusions facing each other abut against each other, the pieces can maintain a consistent yaw direction and a certain distance, which is beneficial for the electrical performance of high-frequency and high-speed tests.

[0031] To overcome at least one aspect of the aforementioned defects and problems in the prior art, the present invention provides a probe unit for contacting multiple probe contact blocks of an electronic test device integrated on a semiconductor wafer; the probe unit includes:

[0032] A plurality of probes having the same length, each probe including a tail and a tip located at its two ends, and a body located between the tail and the tip, wherein the plurality of probes include:

[0033] A first probe, the probe body including at least one slit extending along its longitudinal direction, the slit penetrating the probe body along a first transverse axis, such that the probe body is hollowed out and defined by the at least one slit as at least two plates, the at least two plates being separated from each other along a second transverse axis and capable of elastic bending under load; and

[0034] The second probe has a solid body that can be elastically bent under load;

[0035] The tail and tip of each probe, each of the plates of the first probe, and the body of the second probe can each have a cross-sectional area defined on an imaginary plane parallel to the first transverse axis and the second transverse axis. The sum of the cross-sectional areas of the at least two plates of the first probe is defined as the total cross-sectional area. The total cross-sectional area of ​​the plates of the first probe is greater than the cross-sectional area of ​​the body of the second probe. The cross-sectional area of ​​the body of the second probe is less than the cross-sectional area of ​​the tail of the second probe and less than the cross-sectional area of ​​the tip of the second probe. The shape of the plates of the first probe is selected such that the contact force of the first probe is greater than the contact force of the second probe.

[0036] Therefore, this invention employs a mixed-probe approach, simultaneously using at least two probe types: a first probe and a second probe. The width and thickness of the first and second probes can be designed to match the size and spacing of the probe contact areas of the electronic device under test (DUT) to be contacted. Furthermore, the rigidity of the first probe can be appropriately reduced by designing the width of the slit in its body, thereby appropriately reducing the contact force. Similarly, the rigidity of the second probe can be appropriately reduced by reducing the cross-sectional area of ​​its body relative to its tail and tip, thereby appropriately reducing the contact force. In other words, although the body of the first probe is hollow and the body of the second probe is solid, the cross-sectional area of ​​both probes can be designed to ensure that the first and second probes meet the testing requirements of their corresponding probe contact areas in various aspects. Specifically, the first probe has a larger total cross-sectional area, which can meet the high current requirements of a larger probe contact area, while the larger probe contact area can withstand the larger contact force of the first probe without easily being damaged. The second probe has a smaller cross-sectional area, which can meet the low current requirements of a smaller probe contact area, while the smaller contact force of the second probe can avoid damaging the smaller probe contact area. More importantly, the first and second probes can contact the larger and smaller probe contact areas with larger and smaller contact forces, respectively. Therefore, through size design, the ratio of contact force to contact area of ​​the first and second probes can be made consistent or similar, so that the tip wear rate of the first and second probes is consistent or similar, thereby maintaining consistent or similar lengths of the first and second probes. Furthermore, through size design, the first and second probes can produce consistent or similar needle mark area ratios for the large and small bumps of the electronic device under test they contact, so that the large and small bumps have consistent or similar heights after testing.

[0037] In a preferred embodiment, the needle body of the first probe can be defined in terms of thickness in the first transverse direction and width in the second transverse direction, wherein the width of the needle body of the first probe is less than or equal to the thickness of the needle body of the first probe.

[0038] In other words, the cross-sectional shape of the first probe can be square or rectangular, with the longer side of the rectangle pointing in the direction of the probe's thickness, i.e., the first transverse axis. Since the slit of the first probe extends through the probe body along the first transverse axis, the probe body bends along the second transverse axis (i.e., the axis defining the width) during use. A probe with a square cross-section not only better matches the shape of the probe contact area of ​​the electronic test device, but also, because the width of the probe body is no greater than its thickness, it facilitates elastic deformation when bending along the second transverse axis. A probe with a rectangular cross-section, where the width of the probe body is less than its thickness, exhibits even better elastic deformation when bending along the second transverse axis. Furthermore, the width of the probe body being less than or equal to its thickness allows the probe body to have sufficient thickness to maintain a certain current-carrying capacity.

[0039] In a preferred embodiment, the first probe and the second probe are made of materials with different hardness. Therefore, the first probe and the second probe can be made of materials with different hardness; for example, the second probe, with its smaller cross-sectional area, can be made of a harder material to slow down its tip wear rate. This also helps to make the tip wear rates of the first and second probes consistent or similar.

[0040] In a preferred embodiment, the material hardness of the second probe is greater than that of the first probe.

[0041] Therefore, the use of a harder material for the second probe with a smaller total cross-sectional area can slow down its tip wear rate, which helps to make the tip wear rates of the first and second probes consistent or similar.

[0042] In a preferred embodiment, the slit is provided with at least one set of bumps, the set of bumps including two bumps that protrude from two adjacent pieces facing each other.

[0043] In this way, when the probe body of the first probe is subjected to load and bends elastically, the two protrusions facing each other within the slit will abut against each other, thus preventing adjacent probe bodies from contacting each other and wearing out, thereby extending the service life of the first probe. Moreover, by having the two protrusions facing each other abut against each other, the probe bodies can maintain a consistent yaw direction and a certain distance, which is beneficial to the electrical performance of high-frequency and high-speed testing.

[0044] In a preferred embodiment, the resistance values ​​of the first probe and the second probe are different.

[0045] Therefore, the first and second probes can be designed with different resistance values ​​by means of their materials, shapes, sizes, etc., so that they can be used for different currents to meet the testing requirements of different probe contact areas. At the same time, the first and second probes can still be designed so that their contact forces can make their tip wear rates consistent or similar, and / or produce consistent or similar needle mark area ratios for the probe contact areas they contact.

[0046] In a preferred embodiment, the resistance value of the first probe is less than the resistance value of the second probe.

[0047] In this way, the first probe can be used for larger currents, which can meet the high current requirements of the larger probe contact area, while the larger probe contact area can withstand the large contact force of the first probe without being easily damaged; the second probe can be used for smaller currents, which can meet the low current requirements of the smaller probe contact area, while the smaller contact force of the second probe can avoid damaging the smaller probe contact area.

[0048] In a preferred embodiment, the first probe and the second probe have different current withstand values.

[0049] Therefore, the first and second probes can be designed with different current withstand values ​​through their materials, shapes, sizes, etc., to meet the current requirements of different probe contact areas. At the same time, the first and second probes can still be designed so that their contact forces can make their tip wear rates consistent or similar, and / or produce consistent or similar needle mark area ratios for the probe contact areas they contact.

[0050] In a preferred embodiment, the resistivity of the first probe is different from that of the second probe.

[0051] Therefore, the first and second probes can be made of different materials with different resistivity, so as to achieve optimized design of the first and second probes under different current conditions through material differences. For example, probes with high current requirements use low resistivity materials to reduce Joule heat loss, while probes with low current requirements can use materials with better mechanical strength to improve lifespan and accuracy.

[0052] In a preferred embodiment, the first probe and the second probe have different electrical conductivities. Therefore, the first probe and the second probe can be made of different materials with different conductivity, allowing for optimized design of the first and second probes under different current conditions through material differences. Materials with higher conductivity conduct electricity more easily; probes requiring high current can use materials with high conductivity, while probes requiring low current can use materials with better mechanical strength to improve lifespan and accuracy.

[0053] To overcome at least one aspect of the aforementioned defects and problems in the prior art, the present invention provides a probe head applied to a probe system for testing electronic devices under test integrated on a semiconductor wafer. The probe head includes: an upper guide plate unit, a lower guide plate unit, and a probe unit as described above; the upper guide plate unit includes a plurality of upper guide holes; the lower guide plate unit includes a plurality of lower guide holes; wherein the tails of a plurality of probes of the probe unit pass through the plurality of upper guide holes, the tips of the plurality of probes pass through the plurality of lower guide holes, and the bodies of the plurality of probes are all bent along a second transverse axis.

[0054] To overcome at least one aspect of the aforementioned defects and problems in the prior art, the present invention provides a probe card for use in a probe system for testing electronic devices under test integrated on a semiconductor wafer; the probe card includes: a probe head, a space converter, and a main circuit board as described above. The space converter is disposed on the lower surface of the main circuit board, and includes a lower surface and a plurality of contact pads located on the lower surface of the space converter. The probe tails of the plurality of probes of the probe head mechanically and electrically contact the contact pads of the space converter.

[0055] To overcome at least one aspect of the aforementioned defects and problems in the prior art, the present invention provides a probe system for testing electronic devices under test integrated on a semiconductor wafer; the probe system includes: a fixture for supporting the electronic device under test, a testing machine, and a probe card as described above. The probe card is electrically connected to the testing machine for contacting the electronic device under test, thereby electrically connecting the testing machine and the electronic device under test for performing electrical testing procedures.

[0056] Therefore, the probe head, probe card and probe system provided by the present invention adopt the probe unit as described above, and thus have its advantages and functions. It can use probes with different cross-sectional areas to meet the testing requirements of probe contact blocks of different sizes of electronic devices under test, and at the same time avoid the problems of different tip wear rates and excessive differences in the area ratio of the needle marks.

[0057] Detailed descriptions of the structure, features, assembly, and usage of the probe unit, probe head, probe card, and probe system provided by this invention 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

[0058] The probe unit, probe head, probe card, and probe system provided by the present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0059] Figure 1 This is a schematic diagram of the probe system and semiconductor wafer provided in the first preferred embodiment of the present invention;

[0060] Figure 2 This is a top view schematic diagram of an electronic test device on a semiconductor wafer.

[0061] Figure 3 This is a partial cross-sectional schematic diagram of the probe head and space converter of the probe system provided in the first preferred embodiment of the present invention;

[0062] Figure 4 This is a cross-sectional view of the needle body of the first and second probes of the probe head;

[0063] Figure 5 This is a partial schematic diagram of the first and second probes and the electronic test device;

[0064] Figure 6 This is a partial schematic diagram of the electronic test device, showing the state of the first and second protrusions of the electronic test device after being pressed against by the first and second probes, respectively.

[0065] Figure 7 Similar to Figure 4 However, the first and second probes showed different states;

[0066] Figure 8 A schematic diagram of a different type of first probe;

[0067] Figure 9 for Figure 8 A sectional view along section line 9-9;

[0068] Figure 10 This is a partial cross-sectional schematic diagram of the probe head provided in the second preferred embodiment of the present invention;

[0069] Figure 11 This is a partial cross-sectional schematic diagram of the probe head provided in the third preferred embodiment of the present invention;

[0070] Figure 12 A cross-sectional view of the needle body of the first and second probes of the probe head provided in the third preferred embodiment of the present invention;

[0071] Figure 13 This is a schematic diagram of the first and second probes used to contact the first and second protrusions, which are substantially the same size.

[0072] Explanation of reference numerals in the attached figures:

[0073] 10: Probe system; 11: Fixture; 12: Tester; 13: Probe card; 14: Main circuit board; 141: Lower surface; 15: Space converter; 151: Lower surface; 152: Upper surface; 153: Contact pad; 16: Probe head; 20: Semiconductor wafer; 22: Electronic device under test; 221, 222: Probe contact area; 223: Central area; 224: Peripheral area; 31: Upper guide plate unit; 311: Upper guide hole; 32: Lower guide plate unit; 321: Lower guide hole; 33: Probe unit; 34 : Accommodation space; 35, 36: Probe unit; 40A, 40A': First probe; 40B, 40B': Second probe; 41: Needle tail; 42: Needle tip; 421: Base; 422: End; 43: Needle body; 431: Slit; 432: Sheet; 433: Bump group; 434: Bump; 51: First bump; 511: Bottom; 513: Needle mark; 52: Second bump; 521: Bottom; 523: Needle mark; W1, W2, W3, W4: Width; T1, T2, T3, T4: Thickness Detailed Implementation

[0074] 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 an 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.

[0075] The terms “including,” “comprising,” and “having” used in this invention are all open-ended terms, meaning “including but not limited to.”

[0076] 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.

[0077] Please refer to the following first. Figure 1 A first preferred embodiment of the present invention provides a probe system 10 for testing a plurality of electronic test devices 22 integrated on a semiconductor wafer 20. For example... Figure 2As shown, each electronic test device 22 includes multiple probe contact blocks 221 and 222. The probe contact blocks 221 and 222 can be bumps or contact pads. In the embodiments of the present invention, they are bumps. The probe contact blocks 221 and 222 are quite small in size and very numerous. To simplify the diagram and facilitate explanation, Figure 1 The needle contact areas 221 and 222 are not shown in the data. Figure 2 The diagram schematically shows one configuration of probe contact blocks 221 and 222, wherein probe contact block 221 has a larger area and spacing and is configured in the central region 223 of the electronic device under test 22, and probe contact block 222 has a smaller area and spacing and is configured in the peripheral region 224 of the electronic device under test 22.

[0078] The probe system 10 includes a fixture 11 for supporting the electronic device under test 22, a tester 12, and a probe card 13. The probe card 13 includes a main circuit board 14, a space transformer 15 (ST), and a probe head 16 (PH). The probe head 16 includes multiple probes (detailed below) for contacting the probe contact blocks 221 and 222 of the electronic device under test 22. For simplicity of diagrams and ease of explanation, [details omitted]. Figure 1 The probe is not shown in the figure and is only schematically represented by a rectangle. The internal structure of the probe head 16 is shown in other figures. The main circuit board 14 is used for electrical connection to the tester 12. The space converter 15 is located between the probe head 16 and the lower surface 141 of the main circuit board 14. It is used to perform spatial conversion between the probe of the probe head 16 and the conductive contacts (not shown) on the lower surface 141 of the main circuit board 14. That is, the lower surface 151 of the space converter 15 is provided with a plurality of contact pads 153 for electrical contact of the probe (e.g., ...). Figure 3 As shown in the figure, the spacing between them is smaller than the spacing of the contact pads (not shown) on the upper surface 152 of the space converter 15 for electrical connection to the main circuit board 14. Therefore, when the probes of the probe card 13 contact the probe contact blocks 221 and 222 of the electronic test device 22, the tester 12 is electrically connected to the electronic test device 22 through the probe card 13, thus enabling the electrical testing procedure to test the electrical properties of the electronic test device 22. More specifically, the present invention provides a method for testing the electronic test device 22, comprising:

[0079] (a) Provide the probe system 10 as described above;

[0080] (b) Positioning the probe tip 16 relative to the electronic test device 22; and

[0081] (c) Press the probe head 16 against the electronic test device 22 so that the probe of the probe head 16 contacts the probe contact blocks 221, 222 of the electronic test device 22 and detect the electrical characteristics of the electronic test device 22.

[0082] like Figure 3 As shown, the probe head 16 includes an upper guide plate unit 31, a lower guide plate unit 32, and a probe unit 33 disposed within the upper and lower guide plate units 31 and 32. The probe unit described in this invention refers to a collection of probes used to contact the probe contact areas 221 and 222 of the electronic test device 22. This includes multiple first probes 40A for contacting the probe contact area 221 and multiple second probes 40B for contacting the probe contact area 222. For simplicity and ease of explanation, only one first probe 40A and one second probe 40B are schematically shown in the drawings of this invention. Hereinafter, the first and second probes 40A and 40B will be used to represent all probes in the probe unit 33 for description. However, the probe unit of this invention is not limited to all probes having the structural features of the first and second probes described below.

[0083] In this embodiment, the upper and lower guide plate units 31 and 32 each include only one plate body. However, the upper guide plate unit 31 and / or the lower guide plate unit 32 may also be composed of multiple stacked plates. The edges of the upper and lower guide plate units 31 and 32 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 31 and 32. The upper guide plate unit 31 includes multiple upper guide holes 311, and the lower guide plate unit 32 includes multiple lower guide holes 321. The first and second probes 40A and 40B have the same length and each includes a needle tail 41 and a needle tip 42 located at their respective ends, and an elongated needle body 43 extending between the needle tail 41 and the needle tip 42. The needle tail 41 is used to mechanically and electrically contact the contact pad 153 of the space converter 15, and the needle tip 42 is used to mechanically and electrically contact the probe contact blocks 221 and 222 of the electronic test device 22. The needle tails 41 of the first and second probes 40A and 40B pass through the upper guide hole 311, the needle tips 42 pass through the lower guide hole 321, and the needle body 43 is located in the accommodating space 34 between the upper and lower guide plate units 31 and 32.

[0084] In this embodiment, the first and second probes 40A and 40B are both targets, meaning that the cross-sectional shape of each part of them is square, for example... Figure 4The cross-sectional outline of the needle body 43 of the first and second probes 40A and 40B is square. Furthermore, the thickness of each part of the first and second probes 40A and 40B can be defined along the first transverse axis (X-axis), the width along the second transverse axis (Y-axis), and the cross-sectional area can be defined on an imaginary plane (XY plane) parallel to the first and second transverse axes, for example... Figure 4 The widths W1 and W2 and the thicknesses T1 and T2 of the needle body 43 of the first and second probes 40A and 40B are shown. In this embodiment, W1 = T1 and W2 = T2. Furthermore, the needle bodies 43 of the first and second probes 40A and 40B in this embodiment are both lamellar-shaped; such probes are commonly referred to as comb-shaped needles. Specifically, the needle body 43 includes sections along its longitudinal direction (in... Figure 3 At least one slit 431 extends parallel to the Z-axis (in the middle part of the needle body 43) and penetrates the needle body 43 along a first transverse axis (X-axis), making the needle body 43 hollow and defining at least two pieces 432 by the at least one slit 431. The at least two pieces 432 are separated from each other along a second transverse axis (Y-axis), that is, the at least two pieces 432 are spaced apart along the second transverse axis (Y-axis). The sum of the cross-sectional areas of the at least two pieces 432 is defined as the total cross-sectional area. In this embodiment, each probe needle body 43 has only a single slit 431, thus defining two pieces 432, and the total cross-sectional area is the sum of the cross-sectional areas of the two pieces 432. If the needle body 43 has two slits 431, then three pieces 432 will be defined, and the total cross-sectional area will be the sum of the cross-sectional areas of the three pieces 432, and so on.

[0085] During the assembly of the probe head 16, the upper and lower guide plate units 31 and 32 are initially positioned relative to each other but not yet fixed. At this time, the upper guide hole 311 is coaxially aligned with the lower guide hole 321, and the first and second probes 40A and 40B pass through the coaxially aligned upper guide hole 311 and lower guide hole 321 in a straight line. Figure 3 The state shown is as follows. After the probes are inserted, the upper and lower guide plate units 31 and 32 will move relative to each other along the second transverse axis (Y-axis), causing the upper guide hole 311 and the lower guide hole 321 to be offset from each other along the Y-axis, thereby causing the needle bodies 43 of the first and second probes 40A and 40B to bend along the second transverse axis (Y-axis). After the upper and lower guide plate units 31 and 32 have moved relative to each other, they will be fixed together. Therefore, when the probe head 16 is assembled, each piece 432 of the needle body 43 of the first and second probes 40A and 40B will remain bent. The needle body 43 has good elasticity. When the tips 42 of the first and second probes 40A and 40B contact the probe contact blocks 221 and 222 of the electronic test device 22, each piece 432 will be elastically bent under the load.

[0086] In detail, when the first and second probes 40A and 40B are used to test the electronic device under test 22, the probe tips 42 will come into contact with the probe contact areas 221 and 222 of the electronic device under test 22, and then move closer to each other relative to each other for a test stroke (overdrive, or overtravel, or OT). This causes the probe bodies 43 of the first and second probes 40A and 40B to be compressed and elastically bent, and the probe tips 42 of the first and second probes 40A and 40B to press against the probe contact areas 221 and 222 of the electronic device under test 22. During this period, the force exerted by the probe tips 42 of the first and second probes 40A and 40B on the probe contact areas 221 and 222 of the electronic device under test 22 is defined in this invention as the contact force of the first and second probes 40A and 40B. The greater the contact force, the smaller the contact resistance between the probe tips 42 and the probe contact areas 221 and 222 of the electronic device under test 22. The contact force is measured by applying OD / OT to the first and second probes 40A and 40B, and measuring the force value of each probe tip 42 acting on the force sensor at this time.

[0087] Furthermore, the aforementioned contact forces include probe deformation force and probe friction force. Probe deformation force refers to the force required for the probe to undergo elastic deformation during the aforementioned test stroke. Probe deformation force depends on many factors, such as the probe's material properties (e.g., Young's modulus, elastic modulus), the probe's final geometry and dimensions (e.g., length, thickness, width, etc.). Probe friction force is the frictional force exerted on the probe by the guide plate, such as the frictional force exerted on the probe by the wall of the aforementioned upper guide hole 311 and / or the wall of the lower guide hole 321. The aforementioned contact forces stably push the needle tails 41 of the first and second probes 40A and 40B against the contact pad 153 of the aforementioned space converter 15, and subsequently buckle / buckle the needle bodies 43 of the first and second probes 40A and 40B. This enables an electrical connection to be established between the first and second probes 40A and 40B and the probe contact blocks 221 and 222 of the electronic device under test 22, and thus an electrical connection is established between the probe contact blocks 221 and 222 of the electronic device under test 22 and the first and second probes 40A and 40B to the test machine 12.

[0088] Depend on Figures 3 to 5As can be seen, the first probe 40A and the second probe 40B are a coarse probe and a fine probe, respectively. The first probe 40A is used for the probe contact area 221 with a larger contact area and spacing, while the second probe 40B is used for the probe contact area 222 with a smaller contact area and spacing. More specifically, the total cross-sectional area of ​​the sheet 432 of the first probe 40A is greater than that of the sheet 432 of the second probe 40B. The shapes of the sheet 432 of the first probe 40A and the sheet 432 of the second probe 40B are different from each other (although the cross-sectional shapes are both rectangular, the dimensions are different, so they are considered to be different shapes). The shape of the sheet 432 is selected such that the contact force of the first probe 40A is greater than that of the second probe 40B. Preferably, the ratio of the contact force of the first probe 40A to the contact force of the second probe 40B is greater than 1 and less than 4. When the ratio is less than or equal to 1, i.e., the contact force of the first probe 40A is less than or equal to the contact force of the second probe 40B, it is easy to cause insufficient contact force of the first probe 40A, which is used to contact the larger probe contact area 221, thus affecting test stability; or it may cause excessive contact force of the second probe 40B, which is used to contact the smaller probe contact area 222, thus easily damaging the second probe 40B and / or the probe contact area 222. Furthermore, it is impossible to avoid a higher tip wear rate. The problem is that the ratio of the needle marks is too large. Secondly, when the ratio is greater than or equal to 4, that is, when the contact force of the first probe 40A is greater than or equal to four times the contact force of the second probe 40B, not only is the difference between the contact force of the first probe 40A and the contact force of the second probe 40B too large, which can easily affect the wear consistency of the first probe 40A and the second probe 40B, it can also easily cause damage to the central area and the outer area of ​​the space converter 15 due to the extremely uneven force, or require additional reinforcement structure design. Moreover, the excessive contact force of the first probe 40A can also easily cause damage to the first probe 40A and / or the probe contact block 221.

[0089] In other words, this embodiment uses a combination of different comb-shaped needles, namely the first and second probes 40A and 40B. The outer contour of the cross-section of the needle body 43 is square, but the length and width are different, so they are considered to be different shapes. Specifically, the width W1, thickness T1 and total cross-sectional area of ​​the needle body 43 of the first probe 40A are greater than the width W2, thickness T2 and total cross-sectional area of ​​the needle body 43 of the second probe 40B. Furthermore, the contact force of the first probe 40A on the needle contact area 221 is greater than the contact force of the second probe 40B on the needle contact area 222. The combination of different comb-shaped needles can be such that the first and second probes 40A and 40B each have a single slit 431 and two sheet bodies 432 (as provided in this embodiment); or, the second probe 40B has a single slit 431 and two sheet bodies 432, and the first probe 40A has two slits 431 and three sheet bodies 432, or more than two slits 431 and more than three sheet bodies 432; or, the second probe 40B has two slits 431 and three sheet bodies 432, and the first probe 40A has a single slit 431 and two sheet bodies 432, or two slits 431 and three sheet bodies 432, or more than two slits 431 and more than three sheet bodies 432; and so on.

[0090] Therefore, the width and thickness of the first and second probes 40A and 40B can be designed to match the size and spacing of the probe contact areas 221 and 222 they need to contact. Furthermore, the rigidity of the probes can be appropriately reduced through the design of the slits 431 in the probe body 43 (design width, number, etc.), thereby appropriately reducing the contact force of the probes. This allows the first and second probes 40A and 40B to meet the testing requirements of their corresponding probe contact areas 221 and 222 in various aspects. Specifically, the first probe 40A has a larger total cross-sectional area of ​​sheet 432, which can meet the high current requirements of the larger probe contact area 221, while the larger probe contact area 221 can withstand the larger contact force of the first probe 40A without easily being damaged. Conversely, the second probe 40B has a smaller total cross-sectional area of ​​sheet 432, which can meet the low current requirements of the smaller probe contact area 222, while the smaller contact force of the second probe 40B can avoid damaging the smaller probe contact area 222. In other words, the sheet bodies 432 of the first probe 40A and the second probe 40B have different thickness-to-width ratios in geometry. This difference in shape results in different total cross-sectional areas, and further causes different contact force performance. Specifically, the sheet bodies 432 of the first probe 40A and the second probe 40B may be formed with different lengths, and / or the sheet bodies 432 of the first probe 40A and the second probe 40B may be formed with different thicknesses, and / or the sheet bodies 432 of the first probe 40A and the second probe 40B may be formed with different widths.

[0091] More importantly, this invention can, through the dimensional design of the first and second probes 40A and 40B—such as width, thickness, slit width 431, and total cross-sectional area of ​​the sheet 432—make the first and second probes 40A and 40B substantially equal in tip abrasion rate and / or produce substantially equal needle mark area ratios. In this invention, "substantially equal" is defined as a difference of less than or equal to 20%. In other words, by designing the dimensions of the first and second probes 40A and 40B, the ratio of contact force to contact area of ​​the first and second probes 40A and 40B is made consistent or similar, so that the tip wear rate of the first and second probes 40A and 40B is consistent or similar, thereby making the first and second probes 40A and 40B maintain consistent or similar lengths; and / or making the first and second probes 40A and 40B produce consistent or similar needle mark area ratios for the large protrusions (i.e., probe contact area 221) and small protrusions (i.e., probe contact area 222) they contact, so that the large protrusions and small protrusions have consistent or similar heights after testing.

[0092] In detail, since the probe contact areas 221 and 222 in the embodiments of the present invention are protrusions, the probe contact areas 221 and 222 are respectively defined as the first protrusion 51 and the second protrusion 52. The maximum cross-sectional area of ​​the first protrusion 51 (i.e., the cross-sectional area of ​​its bottom 511) is greater than the maximum cross-sectional area of ​​the second protrusion 52 (i.e., the cross-sectional area of ​​its bottom 521). When the tip 42 of the first probe 40A and the tip 42 of the second probe 40B press against the first protrusion 51 and the second protrusion 52 respectively, causing the needle body 43 of the first probe 40A and the needle body 43 of the second probe 40B to bend elastically under load, the tips 42 of the first and second probes 40A and 40B will respectively locally flatten the first and second protrusions 51 and 52, producing planar needle marks 513 and 523, such as... Figure 6As shown in the side view, the area of ​​the needle mark 513 formed by the first probe 40A on the first protrusion 51 is defined as the first needle mark area, and the area of ​​the needle mark 523 formed by the second probe 40B on the second protrusion 52 is defined as the second needle mark area. The needle mark area ratio generated by the first probe 40A is the ratio of the first needle mark area (i.e., the area of ​​needle mark 513) to the maximum cross-sectional area of ​​the first protrusion 51 (i.e., the cross-sectional area of ​​the bottom 511), and the needle mark area ratio generated by the second probe 40B is the ratio of the second needle mark area (i.e., the area of ​​needle mark 523) to the maximum cross-sectional area of ​​the second protrusion 52 (i.e., the cross-sectional area of ​​the bottom 521). In this embodiment, the "needle mark area ratio" refers to the ratio of the probe contact area (needle mark area) formed by the needle mark at the top of the protrusion when observed from the top view (top view) of the electronic test device 22, to the maximum cross-sectional area of ​​the protrusion. In other words, the needle mark area ratio is a parameter that measures the degree of indentation of the probe corresponding to the protrusion, to compare the deformation range produced by different needle marks corresponding to protrusions of different sizes. Generally, the maximum cross-sectional area of ​​a protrusion is defined based on its size, i.e., the nominal size (specification) set during protrusion design. For example, if the protrusion is a circular protrusion with a diameter of 20 micrometers, its maximum cross-sectional area can be considered as the area of ​​the circle, calculated using the diameter. That is, in this embodiment, the maximum cross-sectional area of ​​the protrusion is defined by its diameter, width, or equivalent geometric dimensions (e.g., projected area), and is used as a reference benchmark for the pin mark area ratio. In some embodiments, the pin mark area can also be inferred from the collapse height of the protrusion after probe contact. Generally, the ratio of the first pin mark area to the maximum cross-sectional area of ​​the first protrusion 51 and / or the ratio of the second pin mark area to the maximum cross-sectional area of ​​the second protrusion 52 is preferably less than 25%.

[0093] It is worth mentioning that the first and second probes 40A and 40B can also be used to contact the first protrusion 51 and the second protrusion 52, which have essentially the same contact size, such as... Figure 13 As shown, the tip 42 of the first probe 40A is used to simultaneously press against multiple first protrusions 51, for example, four first protrusions 51 arranged in a matrix. Figure 13Only two of the first protrusions 51 are shown. All of the first protrusions 51 are configured to transmit a first signal, which can be a power signal or a ground signal. The tip 42 of the second probe 40B is used to press against a single second protrusion 52, which is configured to transmit a second signal. The second signal is a test signal different from the first signal, i.e., neither a power signal nor a ground signal. Therefore, even though the first protrusions 51 and second protrusions 52 are substantially the same size, the first probe 40A with a larger contact force is used to press against multiple first protrusions 51 simultaneously, while the second probe 40B with a smaller contact force is used to press against a single second protrusion 52. Thus, the tip wear rates of the first and second probes 40A and 40B can still be made consistent or similar through size design, and / or the needle mark area ratio of the first protrusions 51 and the second protrusions 52 can be made consistent or similar.

[0094] Furthermore, the first probe 40A and the second probe 40B can also be made of materials with different hardness. The difference in hardness between the first probe 40A and the second probe 40B helps to harmonize the tip wear rates of the first and second probes 40A and 40B to be substantially equal. For example, the second probe 40B, with its smaller total cross-sectional area, can be made of a harder material to slow down its tip wear rate. In this embodiment, the "different hardness" of the first probe 40A and the second probe 40B refers to the fact that their probe bodies are made of materials with different hardnesses. The hardness can be measured according to Vickers hardness (HV) or other standard hardness testing methods and will have certain differences. By configuring materials with different hardnesses, the wear rates of probes of different sizes can be coordinated, maintaining consistency and long-term stability during testing.

[0095] Furthermore, the first probe 40A and the second probe 40B may have different resistance values, and / or different current-carrying capacity values, and / or different resistivity, and / or different conductivity, to meet the testing requirements of different probe contact areas. At the same time, the first probe 40A and the second probe 40B may still be designed such that their contact forces can make their tip wear rates consistent or similar, and / or produce consistent or similar needle mark area ratios for the probe contact areas they contact.

[0096] In this embodiment, the probe resistance refers to the electrical impedance generated by the conductive material constituting the probe under its designed length and cross-sectional area, when current flows through it, typically expressed in ohms (Ω). In other words, the resistance value is a comprehensive representation of the probe's geometry and its material properties (resistivity), suitable for comparing the conductivity of probes of different sizes or materials. The probe resistance value can be calculated using the formula R = ρ(L / A), where R is the probe resistance value, L is the probe length, A is the probe cross-sectional area, and ρ is the resistivity of the probe material. For example, when the first probe 40A and the second probe 40B are made of the same material but have different dimensions, their resistance values ​​will mainly be due to differences in geometry. Generally, the larger probe with a larger cross-sectional area (i.e., the first probe 40A) has a lower resistance value, while the smaller probe with a smaller cross-sectional area (i.e., the second probe 40B) has a higher resistance value.

[0097] In this embodiment, the current withstand value refers to the maximum current that a single probe can continuously withstand under stable operating conditions without overheating, structural damage, or material degradation, typically measured in milliamperes (mA). In other words, the current withstand value is a comprehensive indicator of structural dimensions, material thermal conductivity, and heat dissipation environment conditions. In this embodiment, the current withstand capability of the probe is affected by factors such as its cross-sectional area, length, material melting point, and thermal conductivity. Generally, a thicker probe with a larger cross-sectional area has better heat dissipation efficiency and current carrying capacity, so its current withstand value is usually higher than that of a thinner probe. For example, if the first probe 40A is a thicker probe and the second probe 40B is a thinner probe, then under the same material and testing conditions, the current withstand capability of the first probe 40A is expected to be higher than that of the second probe 40B, meaning that the first probe 40A can withstand a larger current flow without thermal damage.

[0098] In this embodiment, resistivity refers to a material's ability to impede the conduction of current; it is an inherent physical property of the material and is usually measured in ohm-meters (Ω·m). Higher resistivity means the material significantly impedes current flow, while lower resistivity indicates better conductivity. Conversely, conductivity is the reciprocal of resistivity and also represents a material's ability to conduct current, usually measured in Siemens per meter (S / m). Higher conductivity indicates a more readily conductive material. In this invention, if the first probe 40A and the second probe 40B have different resistivities or conductivities, it means that the first and second probes 40A and 40B are made of different conductive materials. This material difference can be used to optimize the design of the probes under different current conditions. For example, probes with high current requirements can use low-resistivity materials to reduce Joule heat loss, while probes with low current requirements can use materials with better mechanical strength to improve lifespan and accuracy.

[0099] The first probe 40A and the second probe 40B in the present invention are not limited to a square shape, that is, the cross-sectional shape of each part thereof is not limited to a square. For example, Figure 7 The outer contour of the cross-section of the shanks 43 of the first and second probes 40A and 40B is shown as a rectangle. The width of the shank 43 of each probe is less than the thickness, that is, W1 < T1, W2 < T2. That is, the long side direction of the rectangle is the thickness direction of the probe, that is, the first transverse axis (X-axis). Such a design can make the elastic deformation effect of the shank 43 bending along the second transverse axis (Y-axis) better, and can make the shank 43 have sufficient thickness to maintain a certain current-carrying capacity.

[0100] Furthermore, Figure 7 In the first and second probes 40A and 40B shown, since the total cross-sectional area of the sheet 432 of the first probe 40A is larger than the total cross-sectional area of the sheet 432 of the second probe 40B, it means that the first probe 40A is a probe with a thicker needle diameter, and the second probe 40B is a probe with a thinner needle diameter. Generally speaking, for a probe with a thinner needle diameter, the distance between the probes is relatively small. Therefore, it is impossible to arbitrarily expand its needle diameter size (width and / or thickness) to avoid problems such as the probes contacting each other and short-circuiting due to too small probe spacing, or insufficient wall thickness caused by too small hole spacing of the guide plate. Based on this design consideration, the ratio of the width W1 to the thickness T1 of the shank 43 of the first probe 40A is less than the ratio of the width W2 to the thickness T2 of the shank 43 of the second probe 40B, that is, W1 / T1 < W2 / T2. Alternatively, the outer contour of the cross-section of the first probe 40A can be a rectangle, and the outer contour of the cross-section of the second probe 40B can be a square, which can also achieve the structural characteristics of the above ratio relationship. Thereby, while the shank 43 of the first probe 40A maintains a larger cross-sectional area to withstand a higher current, due to the smaller width-to-thickness ratio, it has a better elastic deformation effect of bending along the second transverse axis, so that it can produce a consistent or similar elastic deformation reaction with the second probe 40B with a smaller cross-sectional area, thereby ensuring that both have a consistent or similar needle testing performance.

[0101] Moreover, the comb-shaped needle in the present invention can also have such as Figure 8 and Figure 9The structural features shown are illustrated here using the first probe 40A as an example. At least one bump group 433 may be provided within its slit 431. The bump group 433 includes two bumps 434, which protrude from adjacent plates 432 facing each other. Therefore, when the tip 42 of the first probe 40A presses against the probe contact block 221 of the electronic test device 22, causing the plates 432 of the probe body 43 to bend elastically under load, the two facing bumps 434 within the slit 431 will abut against each other. This prevents adjacent plates 432 from contacting each other and causing wear, thus extending the probe's lifespan. Furthermore, the abutment of the two facing bumps 434 helps maintain a consistent yaw direction and a certain distance between the plates 432, which is beneficial for high-frequency, high-speed electrical performance testing. The bump 434 is disposed between adjacent pieces 432 and is arranged face to face. When the probe is bent, the bump 434 will make contact first, thereby limiting the bending direction and angle of the piece 432. This can prevent the piece 432 from asymmetrically swaying under eccentric force, ensuring that the contact angle between the probe tip and the contact pad or bump is stable, which helps to ensure consistent needle marks and contact resistance.

[0102] Please see Figure 10 The probe unit 35 provided in the second preferred embodiment of the present invention is similar to the aforementioned probe unit 33, except that the difference lies in the shape of the tip 42 of the first probe 40A.

[0103] In detail, in this embodiment, the tip 42 of the first probe 40A includes a base 421 connected to the needle body 43 and an end portion 422 connected to the base 421. The cross-sectional shape of the base 421 is the same as or equivalent to the outer contour shape of the cross-section of the needle body 43; "equivalent" means that the area difference is ±20%. Compared to the base 421, the end portion 422 is reduced in width and / or thickness, such that the cross-sectional area of ​​the end portion 422 is smaller than that of the base 421. The cross-sectional area of ​​the end portion 422 is preferably 20-60% of the cross-sectional area of ​​the base 421, more preferably 50% of the cross-sectional area of ​​the base 421. This end portion 422 enables the tip 42 of the first probe 40A to actually contact the actual contact tip of the electronic test device, that is, the end portion 422 refers to the part actually used to contact the probe contact block 221 of the electronic test device 22. Figure 10 As shown, the end 422 is preferably eccentric relative to the center of the first probe 40A, or eccentric relative to the base 421. This end 422 can be obtained by removing material asymmetrically (unilaterally / unidirectionally) from one side of the tip 42 of the first probe 40A.

[0104] Under this structural design, the shapes of the sheet bodies 432 of the first and second probes 40A and 40B can still be selected such that the contact force of the first probe 40A, which has a larger total cross-sectional area, is greater than the contact force of the second probe 40B, which has a smaller total cross-sectional area. Preferably, the ratio of the contact force of the first probe 40A to the contact force of the second probe 40B is greater than 1 and less than 4. Furthermore, the tip 42 of the first probe 40A has a thinned and / or narrowed end 422, which helps to adjust the tip wear rate of the first probe 40A and the ratio of the resulting needle mark area, thereby making the tip wear rates of the first and second probes 40A and 40B consistent or similar, and / or making the first and second probes 40A and 40B produce consistent or similar needle mark area ratios. In particular, it is easier to harmonize the first and second probes 40A and 40B so that the ratios of the needle mark areas they produce are substantially equal.

[0105] Furthermore, even though the cross-sectional area of ​​the tip 422 of the first probe 40A is reduced, the cross-sectional area of ​​the tip 422 of the first probe 40A can still be made larger than the cross-sectional area of ​​the tip 42 of the second probe 40B. This not only allows for the corresponding larger needle contact area 221 and smaller needle contact area 222 respectively, but also helps to make the tip wear rates of the first and second probes 40A and 40B consistent or similar, and to make the needle mark area ratio of the first and second probes 40A and 40B consistent or similar. Preferably, the ratio of the cross-sectional area of ​​the tip 422 of the first probe 40A to the cross-sectional area of ​​the tip 42 of the second probe 40B is greater than 1 and less than 4. When the ratio is less than 1, that is, when the cross-sectional area of ​​the tip 422 of the first probe 40A is less than the cross-sectional area of ​​the tip 42 of the second probe 40B, it is impossible to avoid the problems of different tip wear rates and excessively large differences in the needle mark area ratio. Secondly, when the ratio is greater than or equal to 4, that is, when the cross-sectional area of ​​the tip 422 of the first probe 40A is greater than or equal to the cross-sectional area of ​​the tip 42 of the second probe 40B, the difference is too large, which not only easily affects the wear consistency of the first probe 40A and the second probe 40B, but also makes it difficult to avoid the problem of excessively large differences in the needle mark area ratio.

[0106] Please see Figure 11 and Figure 12 The main difference between the probe unit 36 ​​provided in the third preferred embodiment of the present invention and the aforementioned embodiments is that the first probe 40A' in this embodiment is also a comb-shaped needle, but the second probe 40B' is a non-comb-shaped needle, and the needle body 43 of the second probe 40B' is inwardly recessed, as detailed below.

[0107] In this embodiment, the first probe 40A' is similar in shape and size to the second probe 40B in the aforementioned embodiments. The needle body 43 of the first probe 40A' includes at least one slit 431 extending along its longitudinal direction. The slit 431 penetrates the needle body 43 of the first probe 40A' along a first transverse axis (X-axis), making the needle body 43 of the first probe 40A' hollow and defining at least two plates 432 by the at least one slit 431. The at least two plates 432 are separated from each other along a second transverse axis (Y-axis) and can be elastically bent under load. Similar to the comb-shaped needle in the first preferred embodiment, the width W3 of the needle body 43 of the first probe 40A' in this embodiment can be equal to the thickness T1 (i.e., the outer contour of the cross section is square), or the width W3 can be less than the thickness T1 (i.e., the outer contour of the cross section is rectangular) to improve the elastic deformation effect of the needle body 43 when bending along the second transverse axis and to make the needle body 43 have sufficient thickness to be less prone to breakage. In this embodiment, the first probe 40A' can also be configured as follows: Figure 8 and Figure 9 The bump group 433 shown is designed to improve the probe's lifespan and electrical performance in high-frequency and high-speed testing.

[0108] In this embodiment, the tail 41 and tip 42 of the second probe 40B' are similar in shape and size to the tail 41 and tip 42 of the first probe 40A'. However, the body 43 of the second probe 40B' is solid without a slit, and its width and / or thickness are reduced compared to the tail 41 and tip 42, so that the cross-sectional area of ​​the body 43 of the second probe 40B' is smaller than that of the tail 41 and smaller than that of the tip 42. The inward shrinkage of the body 43 of the second probe 40B' compared to the tail 41 and tip 42 can be a single-sided shrinkage, a double-sided shrinkage, or a four-sided shrinkage. The needle body 43 of the second probe 40B' can also be elastically bent between the upper and lower guide plate units 31 and 32, and has good elasticity. It can be elastically bent under load when the needle tip 42 is pressed against the electronic test device 22.

[0109] In other words, this embodiment uses a combination of comb-shaped needles and non-comb-shaped needles, namely the first and second probes 40A' and 40B'. The outer contour of the cross-section of their needle bodies 43 is square, but their lengths and widths are different, so they are also considered to be different shapes. Specifically, the width W3 and thickness T3 of the needle body 43 of the first probe 40A' are greater than the width W4 and thickness T4 of the needle body 43 of the second probe 40B', and the total cross-sectional area of ​​the sheet 432 of the first probe 40A' is greater than the cross-sectional area of ​​the needle body 43 of the second probe 40B'. Furthermore, the shape of the sheet 432 of the first probe 40A' is selected such that the contact force of the first probe 40A' is greater than the contact force of the second probe 40B'.

[0110] Therefore, the first and second probes 40A' and 40B' in this embodiment can also meet the testing requirements of their corresponding probe contact areas 221 and 222 in various aspects through their size design. Specifically, the first probe 40A' has a larger total cross-sectional area of ​​its body 432, which can meet the high current requirements of the larger probe contact area 221, while the larger probe contact area 221 can withstand the larger contact force of the first probe 40A' without being easily damaged. The second probe 40B' has a smaller cross-sectional area of ​​its needle body 43, which can meet the low current requirements of the smaller probe contact area 222, while the smaller contact force of the second probe 40B' can avoid damaging the smaller probe contact area 222. More importantly, this embodiment can also adjust the first and second probes 40A' and 40B' to achieve substantially equal needle tip wear rates and / or substantially equal needle mark area ratios through the size design of the first and second probes 40A' and 40B'. Furthermore, the first probe 40A' and the second probe 40B' can also be made of materials with different hardness. This difference in hardness helps to harmonize the first and second probes 40A' and 40B' to achieve substantially equal tip wear rates. In this embodiment, the "different hardness" of the first probe 40A' and the second probe 40B' refers to the fact that their probe bodies are composed of materials with different hardnesses. The hardness can be measured using Vickers hardness (HV) or other standard hardness testing methods and will have certain differences. By configuring materials with different hardnesses, the wear rates of probes of different sizes can be coordinated, maintaining consistency and long-term stability during testing.

[0111] In the embodiments described in this invention, "different shapes" refers to identifiable differences in the geometric shape, size ratio, or cross-sectional distribution of the first and second probes. For example, even if the cross-sections of the first and second probes are both rectangular, differences in their thickness and width (i.e., the dimensions defined by the first and second transverse axes) constitute "different shapes." Furthermore, if the number of probes is the same, but their distribution, number of slits, aspect ratio, and / or symmetrical configuration differ, this also falls under the category of "different shapes" as described in this specification. Such design differences help adjust the contact force distribution and elastic deformation behavior of each probe, ensuring testing accuracy and reliability for different probe contact areas (such as large bumps and small contact pads).

[0112] Finally, it must be stated again that the embodiments disclosed in this invention are merely illustrative examples and are not intended to limit the scope of this case. Substitutions or variations of other equivalent elements should also be covered by the patent protection scope of this case.

Claims

1. A probe unit for contacting a plurality of needle test contact pads of an electronic device under test integrated in a semiconductor wafer; characterized by: The probe unit comprises: a plurality of probes having the same length, each of the probes comprising a needle tail and a needle tip respectively at two ends thereof, and a needle body between the needle tail and the needle tip, the needle body comprising at least one slit extending along a longitudinal direction thereof, the slit penetrating through the needle body along a first lateral axis, such that the needle body is hollow and defined by the at least one slit into at least two pieces, the at least two pieces being separated from each other along a second lateral axis and elastically bendable under a load, each of the pieces being capable of defining a cross-sectional area on an imaginary plane parallel to the first lateral axis and the second lateral axis, and a total cross-sectional area being defined by a sum of the cross-sectional areas of the at least two pieces of each of the probes; wherein the plurality of probes comprises a first probe and a second probe, a total cross-sectional area of the pieces of the first probe being greater than a total cross-sectional area of the pieces of the second probe, shapes of the pieces of the first probe and the second probe being different from each other, and the shapes of the pieces being selected such that a contact force of the first probe is greater than a contact force of the second probe.

2. The probe unit of claim 1, wherein: a ratio of the contact force of the first probe to the contact force of the second probe is greater than 1 and less than 4.

3. The probe unit of claim 1, wherein: the needle body of each of the probes is capable of defining a thickness along the first lateral axis and a width along the second lateral axis, and the width of the needle body of each of the probes is less than or equal to the thickness of the needle body of each of the probes.

4. The probe unit of claim 1, wherein: the needle tip of the first probe comprises a base connected to the needle body, and an end connected to the base, the end being configured to contact a needle test contact region of the electronic device under test, the base and the end being capable of defining cross-sectional areas on imaginary planes parallel to the first lateral axis and the second lateral axis, respectively, and the cross-sectional area of the end being less than the cross-sectional area of the base.

5. The probe unit of claim 4, wherein: the needle tip of the second probe is capable of defining a cross-sectional area on an imaginary plane parallel to the first lateral axis and the second lateral axis, and the cross-sectional area of the end of the needle tip of the first probe is greater than or equal to the cross-sectional area of the needle tip of the second probe.

6. The probe unit of claim 5, wherein: a ratio of the cross-sectional area of the end of the needle tip of the first probe to the cross-sectional area of the needle tip of the second probe is greater than 1 and less than 4.

7. The probe unit of claim 1, wherein: The plurality of contact blocks of the electronic device under test includes a first bump and a second bump, a maximum cross-sectional area of the first bump is greater than a maximum cross-sectional area of the second bump; when a tip of the first probe and a tip of the second probe are pressed against the first bump and the second bump respectively, the shank of the first probe and the shank of the second probe are elastically bent under load, the first probe forms a first contact area on the first bump, the second probe forms a second contact area on the second bump, and a ratio of the first contact area to the maximum cross-sectional area of the first bump is substantially equal to a ratio of the second contact area to the maximum cross-sectional area of the second bump.

8. The probe unit of claim 1, wherein: the plurality of contact blocks of the electronic device under test includes a plurality of first bumps and a second bump, each of the first bumps and the second bump has substantially the same size; the tip of the first probe is configured to press against the plurality of first bumps simultaneously, the plurality of first bumps are configured to transmit a first signal, the first signal is one of a power signal and a ground signal; the tip of the second probe is configured to press against the second bump, the second bump is configured to transmit a second signal, the second signal is different from the first signal.

9. The probe unit of claim 1, wherein: the shank of each of the probes has a thickness defined along the first transverse axis and a width defined along the second transverse axis, a ratio of the width to the thickness of the shank of the first probe is less than a ratio of the width to the thickness of the shank of the second probe.

10. The probe unit of claim 1, wherein: the first probe and the second probe are made of different materials.

11. The probe unit of claim 10, wherein: the material of the second probe is harder than the material of the first probe.

12. The probe unit of claim 1, wherein: at least one bump group is disposed in the slit of at least the first probe, the bump group includes two bumps, the two bumps protrude from two adjacent ones of the pieces towards each other.

13. A probe unit for contacting a plurality of needle test contact pads integrated in an electronic device under test of a semiconductor wafer; characterized by: The probe unit includes: a plurality of probes having the same length, each of the probes includes a tail and a tip at two ends thereof respectively, and a shank between the tail and the tip, the plurality of probes includes: a first probe, the shank of the first probe includes at least one slit extending along a longitudinal direction of the first probe, the slit penetrates the shank of the first probe along a first transverse axis, so that the shank of the first probe is hollow and is defined by the at least one slit into at least two pieces separated from each other along a second transverse axis and elastically bendable under load; and a second probe, the shank of the second probe is solid and elastically bendable under load. Wherein, the needle tail and the needle tip of each of the probes, each of the pieces of the first probe, and the needle body of the second probe, respectively, can define a cross-sectional area on an imaginary plane parallel to the first lateral axis and the second lateral axis, and the sum of the cross-sectional areas of the at least two pieces of the first probe defines a total cross-sectional area, the total cross-sectional area of the pieces of the first probe is greater than the cross-sectional area of the needle body of the second probe, the cross-sectional area of the needle body of the second probe is less than the cross-sectional area of the needle tail of the second probe and less than the cross-sectional area of the needle tip of the second probe, and the shape of the pieces of the first probe is selected such that the contact force of the first probe is greater than the contact force of the second probe.

14. The probe unit of claim 13, wherein: the needle body of the first probe defines a thickness in the first lateral axis and a width in the second lateral axis, and the width of the needle body of the first probe is less than or equal to the thickness of the needle body of the first probe.

15. The probe unit of claim 13, wherein: the first probe and the second probe are made of different materials.

16. The probe unit of claim 15, wherein: the material of the second probe is harder than the material of the first probe.

17. The probe unit of claim 13, wherein: the slit is provided with at least one bump group, and the bump group includes two bumps that protrude from the adjacent two pieces of the second probe and face each other.

18. The probe unit of claim 1 or 13, wherein: the first probe and the second probe have different resistances.

19. The probe unit of claim 18, wherein: the resistance of the first probe is less than the resistance of the second probe.

20. The probe unit of claim 1 or 13, wherein: the first probe and the second probe have different current resistances.

21. The probe unit of claim 1 or 13, wherein: the first probe and the second probe have different resistivities.

22. The probe unit of claim 1 or 13, wherein: the first probe and the second probe have different conductivities.

23. A probe head, applied to a probe system, for testing electronic devices under test integrated on a semiconductor wafer; characterized in that: The probe head includes: an upper guide plate unit including a plurality of upper guide holes; a lower guide plate unit including a plurality of lower guide holes; and the probe unit of claim 1 or 13; wherein the needle tails of the plurality of probes pass through the plurality of upper guide holes, the needle tips of the plurality of probes pass through the plurality of lower guide holes, and the needle bodies of the plurality of probes are bent along the second lateral axis.

24. A probe card applied to a probe system for testing an electronic device under test integrated in a semiconductor wafer; wherein: The probe card includes: the probe head of claim 23; a space converter; and a main circuit board; wherein the space converter is disposed on the lower surface of the main circuit board, the space converter includes a lower surface and a plurality of contact pads on the lower surface of the space converter, and the needle tails of the plurality of probes of the probe head mechanically and electrically contact the contact pads of the space converter.

25. 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 electronic device under test; a test machine; and a probe card as claimed in claim 24 electrically connected to the test machine for contacting the electronic device under test to electrically connect the test machine to the electronic device under test for performing an electrical test procedure.

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