Probe card, multi-probe channel resistance measuring system and method

Abstract

The invention discloses a probe card and a multi-probe channel resistance measuring system and method.The probe card comprises a substrate and a probe bonding pad area located in the middle of the substrate, the probe bonding pad area comprises a plurality of bonding pads arranged in a plurality of rows and columns, the bonding pads are used for welding sleeves of a plurality of elastic probes, and the elastic probes are arranged in the bonding pads. The plurality of rows and the plurality of columns of bonding pads are connected to the corresponding wires in a one-to-one correspondence manner, so that the elastic probes of any four bonding pads form a group of test terminals. According to the probe card and the multi-probe channel resistance measurement system and method provided by the invention, any N of the M elastic probes are selected to form a group through the channel selection device to realize resistance measurement of the to-be-measured sample, and different N elastic probes are selected during multiple times of measurement, so that resistance test of any area of the to-be-measured sample can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of resistivity measurement, and in particular to a probe card, a multi-probe channel resistance measurement system and a method. Background Art

[0002] Superconducting technology is known as a high-tech with great economic and strategic significance in the 21st century, and has broad application prospects in many fields of the national economy. Superconductivity is one of the most notable features of superconducting technology. It refers to the phenomenon that the resistance of certain materials suddenly drops to zero below a certain temperature (critical temperature). Superconductivity can be used to manufacture devices with high sensitivity, low noise, fast response speed and low loss, such as superconducting quantum interferometers and single-photon detectors; it can also be used to manufacture powerful superconducting magnets for particle accelerators and magnetic levitation vehicles. The most direct way to evaluate the superconductivity of a material is to measure the superconducting transition temperature (Tc) of the material. At present, the mainstream method for measuring superconducting transition temperature at home and abroad is to use the comprehensive physical property measurement system (PPMS). This method requires cutting the sample into small pieces (less than 10*10 mm2), using silver glue or soldering indium and tin to prepare four electrodes in the sample area to be tested, and using the four-wire method or Van der Pauw method to measure the current and voltage in the sample area to be tested, and then calculate the resistance, change the sample ambient temperature and repeat the test, and obtain the temperature dependence of the resistance of the test sample, that is, the R (resistance)-T (temperature) curve, and finally obtain the superconducting transition temperature of the test sample. This method requires the sample to be cut before measurement, and can only measure 3 samples at a time, and the single measurement cycle is several or even more than ten hours, and the measurement cycle is long.

[0003] An existing elastic probe array multi-channel resistivity measurement method is to directly and tightly press an n*n elastic probe array onto a sample, place it on a temperature measurement platform, and use the Van der Pauw method. Each group of four elastic probes can simultaneously obtain the local resistivity curves of 2n regions with temperature or magnetic field. This method effectively solves the multi-region non-destructive testing of samples and improves measurement efficiency.

[0004] However, this method cannot measure all areas on the sample. The local test area selected for the sample to be tested has been fixed with the determined four probes, that is, the n*n elastic probe array can only measure the 2n determined samples. It cannot realize the resistance measurement of any selected area on the sample and traverse all areas of the sample. It can only realize the resistance measurement of the interval area, and the middle area between any two adjacent measurement areas cannot be measured, resulting in the inability to obtain the Tc value of all areas on the sample. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide a probe card, a multi-probe channel resistance measurement system and method, by which a channel selection device selects any N of the M probes to form a group to measure the resistance of a sample to be tested, thereby realizing resistance testing of any area of ​​the sample to be tested.

[0006] According to one aspect of the present invention, a probe card is provided, which includes: a substrate, and a probe pad area located in the middle of the substrate, the probe pad area includes a plurality of pads arranged in a plurality of rows and columns, the plurality of pads are used to weld sleeves of a plurality of elastic probes, the plurality of pads in the plurality of rows and the plurality of columns are respectively connected to corresponding wires one by one, so that the elastic probes of any four pads constitute a group of test terminals.

[0007] Optionally, the probe pad area is located on the first surface of the substrate, including a plurality of through holes located in the center and penetrating the substrate, and a conductive contact area surrounding the through holes on the first surface of the substrate. A portion of the elastic probe passes through a sleeve in the through hole and engages with the sleeve to achieve electrical connection between the elastic probe and the wire.

[0008] Optionally, in the probe pad area, the number of pads arranged in rows in the edge area is greater than or less than or equal to the number of pads arranged in rows in the middle area; and / or the number of pads arranged in columns in the edge area is greater than or less than or equal to the number of pads arranged in columns in the middle area.

[0009] According to another aspect of the present invention, there is provided a multi-probe channel resistance measurement system, comprising: a multi-probe sample device, comprising a probe card, M elastic probes and a sample base, the sample base being used to fix a sample to be tested, the elastic probe being connected to the probe card via a sleeve, the M elastic probes all being in elastic contact with and electrically connected to the surface of the sample to be tested to provide an excitation signal and obtain a detection signal, M being an integer greater than or equal to 4; a multi-channel selection device, connected to the multi-probe sample device, comprising a plurality of conductive channels that can be independently controlled to be turned on and off, the number of the conductive channels being not less than M, wherein among the plurality of conductive channels of the multi-channel selection device, M conductive channels correspond one-to-one to and are electrically connected to the M elastic probes, and the multi-channel selection device selects any N conductive channels from the M conductive channels to be turned on to perform resistance measurement on the sample to be tested, N being an integer less than or equal to M.

[0010] Optionally, the multi-channel selection device selects any 4 conductive channels from the M conductive channels to be turned on to measure the resistance of the sample to be measured, and M is an integer greater than or equal to 4.

[0011] Optionally, the M elastic probes are in uniform contact with the surface of the sample to be tested.

[0012] Optionally, the same N conductive channels are used to perform multiple resistance measurements on the sample to be tested.

[0013] Optionally, after performing a resistance measurement on the sample to be tested, the multi-channel selection device first closes the N conductive channels that are currently opened, and then reselects N conductive channels to be opened to perform resistance measurement again.

[0014] Optionally, the reselected N conductive channels are the same as the N conductive channels before the reselection.

[0015] Optionally, at least one of the reselected N conductive channels is different from the N conductive channels before the reselection.

[0016] Optionally, the multi-channel selection device includes: a multi-channel board card, used to provide a plurality of mutually independent conductive channels, and a multimeter, connected to the multi-channel board card, used to control the on and off of the plurality of conductive channels.

[0017] Optionally, the multi-probe sample device also includes: a base for fixing the probe card; a temperature controller, which matches the shape of the third groove on the second surface of the sample base and is located in the third groove, for providing a predetermined temperature for the sample to be tested; wherein an internal space is defined between the surfaces of the sample base and the base that are relatively arranged, and the probe card and the sample to be tested are fixed in the internal space.

[0018] Optionally, the probe card includes a substrate and a probe pad area located in the middle of the substrate; the base includes a main surface in contact with a second surface of the substrate, and a plurality of grooves located in the main surface, the plurality of grooves corresponding to the probe pad area, elastic probes and a second pressure ring for fixing the probe card, and providing wiring space for the probe pad area and the elastic probes.

[0019] Optionally, the multi-probe sample device also includes: a first groove and a second groove located on the first surface of the sample base, the first groove is used to provide a space for accommodating the sample to be tested, the second groove is used to provide a space for fixing the first pressure ring of the sample to be tested, and the first surface of the sample to be tested fixed in the sample base is electrically connected to the elastic probe; a fourth groove, a fifth groove and a sixth groove are located on the main surface of the base, the fourth groove is used to accommodate a wire connecting the elastic probe to an external electrical connection, the fifth groove is used to accommodate the probe card, and the sixth groove is used to accommodate the second pressure ring to fix the probe card.

[0020] Optionally, it also includes: a low-temperature constant temperature device, connected to the multi-probe sample device, providing an ambient temperature for the sample to be tested and connecting the pins of the probe card to the multiple conductive channels of the multi-channel selection device one by one through the wiring ports inside and outside the chamber of the low-temperature constant temperature device; a power supply device, connected to the multi-channel selection device, providing voltage and current to the sample to be tested; and a display device, connected to the multi-channel selection device, displaying the resistance measurement result of the sample to be tested.

[0021] According to another aspect of the present invention, a multi-probe channel resistance measurement method is provided, which includes: connecting a sample to be tested with a multi-probe channel resistance measurement system; selecting N of M elastic probes as sampling positions, M being an integer greater than or equal to 4, and N being an integer less than or equal to M; providing a predetermined temperature and an ambient temperature for the sample to be tested; measuring the resistance of the sample to be tested via the N elastic probes; judging whether the resistance measurement of the sample to be tested is completed at the temperature; if not, reselecting N elastic probes and measuring the resistance of the sample to be tested again; if yes, changing the predetermined temperature and ambient temperature for the sample to be tested and executing the step of measuring the resistance of the sample to be tested via the N elastic probes again.

[0022] Optionally, 4 of the M elastic probes are selected as sampling locations, where M is an integer greater than or equal to 4.

[0023] Optionally, in the step of measuring the resistance of the sample to be tested via N elastic probes, the resistance of the sample to be tested is measured at least once.

[0024] Optionally, at least one of the reselected N elastic probes is different from the N elastic probes before the reselection.

[0025] Optionally, the reselected N conductive channels are the same as the N conductive channels before the reselection.

[0026] The probe card, multi-probe channel resistance measurement system and method provided by the present invention have no requirements for the positional relationship of the elastic probes used for sampling during resistance measurement, that is, N elastic probes can form a quadrilateral shape, or a straight line or any other shape surrounded by four points, so that there are no requirements for the shape of the sample to be tested, and the shape of the pad area of ​​the probe card used to fix the elastic probes can also be changed with the shape of the sample to be tested. Therefore, the present application changes the pad area of ​​the probe card for samples of different shapes to be tested, which not only reduces the shape requirements for the sample to be tested, but also improves the test efficiency.

[0027] Furthermore, the probe card, multi-probe channel resistance measurement system and method provided by the present invention use a sample device with multiple probe channels in conjunction with a channel selection device. Multiple probes in the sample device are evenly in contact with the surface of the sample to be tested. The channel selection device selects any N of the M elastic probes to form a group, and the N elastic probes are used to measure the resistance of the area of ​​the sample to be tested corresponding to the N elastic probes. Different elastic probe selections represent regional resistance measurements of different samples to be tested, so that the multi-probe channel resistance measurement system of the present application can realize resistance testing of any area of ​​the sample to be tested. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0029] Figure 1 A schematic structural diagram of a multi-probe channel resistance measurement system according to an embodiment of the present invention is shown;

[0030] Figure 2 A schematic structural diagram of a sample device in a multi-probe channel resistance measurement system according to an embodiment of the present invention is shown;

[0031] Figure 3a and Figure 3b Shows an overall structural schematic diagram and a partial structural schematic diagram of a probe card in a sample device according to an embodiment of the present invention;

[0032] Figure 4 A schematic diagram of the structure of a temperature controller in a sample device according to an embodiment of the present invention is shown;

[0033] Figure 5a and Figure 5b A schematic structural diagram of a sample base in a sample device according to an embodiment of the present invention is shown;

[0034] Figure 6a and Figure 6b A schematic diagram showing the structure of a probe and a probe sleeve in a sample device according to an embodiment of the present invention is shown;

[0035] Figure 7a and Figure 7b The schematic structural diagrams of the front and back sides of the base in the sample device according to the embodiment of the present invention are respectively shown;

[0036] Figure 8 A flow chart of a multi-probe channel resistance measurement method according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0037] Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, the same elements are represented by the same or similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale.

[0038] The specific implementation of the present invention is further described in detail below in conjunction with the drawings and examples.

[0039] Superconducting technology is known as a high-tech with great economic and strategic significance in the 21st century, and has broad application prospects in many fields of the national economy. Superconductivity is one of the most notable features of superconducting technology. Superconductivity refers to the special electrical transport properties exhibited in superconducting materials, specifically when the superconducting material drops below the superconducting transition temperature (Tc), its resistance suddenly becomes zero. Tc refers to the superconducting transition temperature, Superconducting Transition Temperature. When the temperature of some substances is lower than a certain value (Tc), their resistance suddenly changes to zero. This state is called the superconducting state, and this type of substance is called a superconductor. Tc is called the transition temperature of the superconductor.

[0040] Furthermore, for superconducting materials, the four-wire method or the Vander Pauw method is usually used to measure the resistance of superconducting materials. Among them, the four-wire method is an experimental technique for measuring resistance by preparing two pairs of electrodes on the material, applying a current of known magnitude to one pair of electrodes, and then measuring the voltage between the other pair of electrodes to calculate the resistance of the material. The Vander Pauw method refers to an experimental technique for measuring resistance by applying current and measuring the corresponding voltage through the four edges of a thin sheet of material, and measuring the voltage at the edge of the sample to calculate the resistance.

[0041] In this application, the Van der Pauw method is used to measure the resistance of the sample to be tested.

[0042] Figure 1 A schematic structural diagram of a multi-probe channel resistance measurement system according to an embodiment of the present invention is shown.

[0043] refer to Figure 1 The multi-probe channel resistance measurement system 100 of the present application includes: a multi-probe sample device 110, a low temperature constant temperature device 120, a channel selection device 130, a power supply device 140 and a display device 150.

[0044] The multi-probe sample device 110 is used to fix the sample to be tested and provide a predetermined temperature to the sample to be tested. In addition, the multi-probe sample device 110 is also connected to the surface of the sample to be tested through M elastic probes to achieve electrical connection. The multi-probe sample device 110 with the sample to be tested fixed is fixed in the chamber of the cryostat 120 via screws, and the cryostat 120 provides a stable ambient temperature for the measurement process of the sample to be tested. Specifically, the ambient temperature provided by the cryostat 120 is, for example, 4-300K. The channel selection device 130 is connected to multiple probes in the multi-probe sample device 110 via the cryostat 120. At the same time, in one resistance measurement, the electrical connection paths of N (N≤M) elastic probes among M (M is an integer greater than or equal to 4) elastic probes can be selected by the channel selection device 130 to be turned on, while the electrical connection paths of other probes are disconnected, so as to achieve resistance measurement of any area (including any shape formed by N points and a straight line) of the sample to be tested.

[0045] In one embodiment, N=4, that is, the channel selection device 130 selects 4 electrically connected paths among the M elastic probes to be turned on as sampling positions in the resistance measurement process.

[0046] Furthermore, in this embodiment, the channel selection device 130 includes a plurality of conductive paths (the number of which is not less than M) that can be independently controlled to be turned on and off, wherein the M conductive channels are connected one-to-one via the cryostat 120 and the plurality of elastic probes in the multi-probe sample device 110, that is, each elastic probe has an independently connected conductive channel in the channel selection device 130.

[0047] Furthermore, the channel selection device 130 is also connected to the power supply device 140 and the display device 150. The power supply device 140 provides an excitation signal to the sample to be tested via the multi-channel selection device 130, for example, and the display device 150 is used to display the test result of the sample to be tested.

[0048] The channel selection device 130 selects N conductive paths to be turned on among the M conductive paths connected to the elastic probes, so that N of the M elastic probes are used as sampling positions in the resistance measurement. If the channel selection device 130 selects different N conductive paths to be turned on, it means that different areas of the sample to be tested are selected as sampling positions for resistance measurement.

[0049] In this embodiment, the channel selection device 130 is, for example, a combination of a multi-channel board and a multimeter, the multi-channel board has multiple independent conductive paths, and the multimeter is used to control the on and off of multiple conductive paths in the multi-channel board, thereby forming a resistance test loop. The power supply device 140 is, for example, an ammeter and a voltmeter, which are connected to the multi-channel board and are used to provide current and voltage input to the elastic probe. The display device 150 is used to display the resistance measurement result.

[0050] In the present application, the multi-channel board and the multimeter are used together to realize the function of connecting any test point on the sample to be tested to the ammeter and the voltmeter via the multi-probe sample device 110, the wire and the connection port on the low temperature constant temperature device 120, and can arbitrarily control the opening and closing of the channel corresponding to any test point. The realization of this function is not necessarily completed by the use of a multi-channel board and a multimeter, and can also be replaced by other multi-channel acquisition systems with free switching of channel switch states.

[0051] Furthermore, the multi-probe sample device 110 is an important component for fixing the sample 113 to be tested and establishing electrical connection between the sample 113 to be tested and the measurement system. Figures 2 to 7b shown.

[0052] Specifically, the overall structure of the multi-probe sample device 110 is as follows: Figure 2 As shown, it includes: a temperature controller 111, a sample base 112, a probe card 114, a base 115 and an elastic probe 116. An internal space is formed between the surfaces of the sample base 112 and the base 115 that are arranged opposite to each other, for accommodating the sample 113 to be tested, and the probe card 114 is also installed in the internal space. Specifically, the sample 113 to be tested is fixed in the internal space on the sample base 112 via a first pressing ring 117a, and the probe card 114 is fixed in the internal space on the base 115 via a second pressing ring 117b. Figure 2 Only the position of one elastic probe 116 in the multi-probe sample device 110 is shown, but it can be understood that in actual resistance measurement, the number of elastic probes 116 is M, M ≥ 4. In addition, the number and position of the elastic probes can be set according to the size and shape of the sample 113 to be tested.

[0053] Furthermore, during the use of the multi-probe sample device 110, it is also necessary to be used together with the fixing device 160. Specifically, the multi-probe sample device 110 is cylindrical in shape as a whole. After placing the sample 113 to be tested, the probe card 114, the elastic probe 116, etc. at corresponding positions in the multi-probe sample device 110, it is also necessary to use the fixing device 160 to surround the edge of the multi-probe sample device 110, and then fix the opening of the fixing device 160 by a fixing member. At the same time, the probe head of the elastic probe 116 in the multi-probe sample device 110 surrounded by the fixing device 160 is in contact with the sample 113 to be tested, but the elastic probe 116 also has a certain elastic expansion range.

[0054] Among them, the fixing device 160, for example, includes two movably connected semicircular rings. When the two semicircular rings are opened, the multi-probe sample device 110 can be placed in the area between the two semicircular rings, and then the two semicircular rings are merged. When the positions correspond, the openings of the two semicircular rings are fixed by bolts and nuts, so that the multi-probe sample device 110 is confined to the area defined by the two semicircular rings of the fixing device 160.

[0055] In order to achieve better fixation, in the vertical cross-sectional shape of the multi-probe sample device 110, the middle lateral dimension is larger than the lateral dimensions of the upper and lower sides. At the same time, the fixing device 160 has a shape that matches the shape of the edge portion of the multi-probe sample device 110, so that after the fixing device 160 fixes the multi-probe sample device 110 via the fixing piece, problems such as position movement will not occur.

[0056] The probe card 114 is one of the most important components for establishing electrical connection between the sample to be tested 113 and the multi-probe sample device 110. Figure 3a As shown. The probe card 114 includes a substrate 1141, a probe pad area 1142 located in the middle of the substrate 1141, and a plurality of pads 1145 located in the probe pad area. The overall shape of the substrate 1141 is substantially the same as the shape of the internal space in the multi-probe sample device 110 for accommodating the probe card 114 and the sample to be tested 113, for example, a circle. The plurality of pads 1145 in the probe pad area 1142 are arranged in a pattern of multiple rows and columns, and the plurality of pads 1145 are used to weld a plurality of elastic probes 116. Among them, the plurality of elastic probes 116 are connected to the corresponding pins in the cryostat 120 via corresponding wires one by one, and then the plurality of elastic probes 116 are connected to the conductive paths of the channel selection device 130 via the cryostat 120 one by one, so that the elastic probes 116 of any four pads 1145 constitute a group of test terminals. Among them, the wire that realizes the electrical connection between the elastic probe 116 and the cryostat 120 is, for example, a phosphor copper wire.

[0057] In one embodiment, the probe pad area 1142 is a circular area, and the number of pads in the outermost row and / or the outermost column is less than the number of pads in the middle row and / or the middle column. In other embodiments, the shape of the probe pad area 1142 can also be a triangle, a trapezoid or other irregular shapes, and according to the different shapes of the probe pad area 1142, the number of pads in the outermost row and / or the outermost column can also be set to be greater than, less than or equal to the number of pads in the middle row and / or the middle column. Specifically, the shape of the probe pad area 1142 is related to the shape of the sample to be tested 113, and the number of pads in the row or column in the probe pad area 1142 is related to the shape of the probe pad area 1142. In this embodiment, due to the use of a multi-channel board and a multimeter, there is no restriction on the shape of the sample to be tested 113 and the shape of the probe pad area 1142 in the present application.

[0058] Further, the probe pad area 1142 is located on the first surface of the substrate 1141, and each pad includes a through hole 1145a located in the center and penetrating the substrate 1141, and a conductive contact area 1145b surrounding the through hole 1145a on the first surface of the substrate 1141, such as Figure 3b A portion of the elastic probe 116 passes through the through hole 1145a, and another portion is welded to the conductive contact area 1145b to achieve fixation between the elastic probe 116 and the pad.

[0059] In addition, a plurality of fifth through holes 1144 are provided at the edge region of the probe card 114. Figure 3a As shown, the fifth through hole 1144 can be used to fix the probe card 114 and the base 115 .

[0060] The temperature controller 111 is also one of the core components of the multi-probe sample device 110. Its specific structure is as follows: Figure 2 and Figure 4 As shown, the temperature controller 111 includes a first part located above the sample base 112 and a second part that matches the groove shape of the sample base 112, and the second part is a step-like structure formed by overlapping and stacking a plurality of cylinders with different diameters. The first part of the temperature controller 111 also has a plurality of first through holes 1111, and screws pass through the first through holes 1111 to be tightly fixedly connected to the sample base 112. The temperature controller 111 has power output and temperature control functions, and can quickly heat the sample 113 to be tested to a set temperature point, thereby reducing the waiting time for temperature drift. In this embodiment, the first part of the temperature controller 111 can be circular or square. Figure 4 An embodiment is shown where the first portion is square.

[0061] The structure of the sample base 112 is as follows: Figure 5a and Figure 5bAs shown, specifically, the sample base 112 is a circular shape with missing corners, and the center of the first surface thereof has a first groove 1121 and a second groove 1125 (refer to Figure 5b ), used to place the sample 113 to be tested, the shapes of the first groove 1121 and the second groove 1125 can be designed into any shape according to the shape and size of the sample 113 to be tested, that is, the shape and size of the first groove 1121 match the shape and size of the sample 113 to be tested. Further, the specification size of the first groove 1121 needs to be slightly larger than the specification size of the sample 113 to be tested, so that the sample 113 to be tested can be placed in the first groove 1121 without the problem of displacement. The depth of the second groove 1125 is less than the depth of the first groove 1121, but the width of the second groove 1125 is greater than the width of the first groove 1121, so that after the sample 113 to be tested is placed in the first groove 1121, the first pressing ring 117a can limit the position of the sample 113 to be tested. Therefore, the second groove 1125 has a second through hole 1122 for fixing the first pressing ring 117a, for example, the first pressing ring 117a is fixed to the sample base 112 by a threaded bolt. In addition, the second surface of the sample base 112 (reference Figure 2 and Figure 5a ) The area corresponding to the first groove 1121 of the first surface has a third groove 1124 matching the shape of the second part of the temperature controller 111, and the periphery of the third groove 1124 has a third through hole 1123 corresponding to the first through hole 1111 in the temperature controller 111, which is used for fixed connection with the temperature controller 111.

[0062] The elastic probe 116 is located on the probe card 114. When in use, the elastic probe 116 needs to be matched with a sleeve 1164, which is made of conductive material. That is, on the probe card 114, the probe as a whole includes two movable parts, one is the elastic probe 116 with elastic expansion function, and the other is the sleeve 1164 used for welding with the probe card 114 and engaging with the elastic probe 116. Specifically, the shape of the sleeve 1164 is as follows: Figure 6bAs shown, the sleeve 1164 passes through the through hole of the pad in the probe card 114, and then is soldered to the contact area around the through hole of the pad, and further, the elastic probe 116 is snapped into the sleeve 1164. In one embodiment, for example, the sleeve 1164 is connected to the corresponding pins in the cryostat 120 one by one through phosphor copper wire, so that after the elastic probe 116 is snapped into the sleeve 1164, the elastic probe 116 is electrically connected to the conductive path of the channel selection device 130 one by one. Such a connection structure is adopted because after the elastic probe 116 is used many times, the elastic telescopic part may be worn, the elastic function fails, and other problems may occur. By making an electrical connection through the sleeve 1164, the elastic probe 116 can be quickly replaced after there is a problem, thereby ensuring the test efficiency and accuracy.

[0063] Specifically, the structure of the elastic probe 116 is as follows: Figure 6a As shown, it includes a first part 1161, a second part 1162 and a third part 1163, the first part 1161 is an elastic part, along Figure 6a The second part 1162 and the third part 1163 are used to fix the elastic probe 116 and the sleeve 1164. Multiple elastic probes 116 are distributed in the area corresponding to the first groove 1121 of the sample base 112 on the probe card 116, and the sum of the first part 1161 and the second part 1162 of the elastic probe 116 is greater than the distance between the probe card 114 and the first surface of the sample base 112, so that the elastic probe 116 can tightly press the sample 113 to be tested on the sample base 112, and at the same time, due to the setting of the first groove 1121 on the sample base 112, the sample 113 to be tested will not be displaced. Furthermore, the elastic probe 116 is made of a highly conductive material as the part in contact with the sample 113 to be tested in the test circuit.

[0064] The structure of the base 115 is as follows Figure 7a and Figure 7bAs shown, the base 115 is located on the side of the probe card 114 away from the sample 113 to be tested, and is used to support and fix the probe card 114 and the sample base 112 and other components. The base 115 includes a fourth groove 1151, a fifth groove 1152, a sixth groove 1153 and a sixth through hole 1154. The fourth groove 1151, the fifth groove 1152 and the sixth groove 1153 are located on the main surface of the base 115 opposite to the first surface of the sample base 112. The fourth groove 1151 corresponds to the pad area where the elastic probe 116 is set in the probe card 114, and is used to accommodate the phosphor copper wire connecting the sleeve 1164 and the low-temperature thermostat 120; the fifth groove 1152 surrounds the fourth groove 1151 and matches the position and shape of the probe card 114. The depth of the fifth groove 1152 in the base is less than the fourth groove 1151, and is used to accommodate the probe card 114; the sixth groove 1153 surrounds the fifth groove 1152, and the depth of the sixth groove 1153 in the base 115 is less than the fourth groove 1151. The fifth groove 1152 and the sixth groove 1153 are used to place the second pressing ring 117b to fix the probe card 114; the sixth through hole 1154 includes a plurality of through holes located at the edge of the fifth groove 1152 corresponding to the fifth through hole 1144 of the probe card 114 and a plurality of through holes located at the edge of the sixth groove 1153 corresponding to the through holes of the second pressing ring 117b, which are respectively used to fix the probe card 114 and the base 115 via screws and fix the second pressing ring 117b and the base 115. On the other side surface of the base 115 opposite to its main surface, its structure is as follows Figure 7b shown.

[0065] In this embodiment, the base 115 is usually made of copper material with good thermal conductivity. The base 115 is in direct contact with the low temperature thermostat 120 and is fixed by screws, so that the heat of the sample 113 to be tested is easily transferred to the low temperature thermostat 120.

[0066] In addition, structures for fixing the sample base 112 and the base 115 are provided at the corresponding edge positions of the base 115 and the sample base 112, such as through holes for bolt fixing. In other embodiments, any structure that can achieve fixing of the two can also be used.

[0067] Further, Figure 8 FIG. 4 is a flow chart showing a method for measuring resistance of a multi-probe channel according to an embodiment of the present invention. Figure 8 The specific steps of the multi-probe channel resistance measurement method of the present application include the following contents.

[0068] Step S10: Connect the sample to be tested to the multi-probe channel resistance measurement system.

[0069] In this step, firstly, the sample 113 to be tested is assembled onto the multi-probe sample device 110, and the sleeve 1164 is welded onto the probe card 114 by soldering, and then the elastic probe 116 is clamped into the sleeve 1164, and the elastic probe 116 on the probe card 114 is connected to the phosphor copper wire one by one. Then the probe card 114 is fixed to the base 115 by screws or the second pressing ring 117b. The temperature controller 111 is fixed to the sample base 112 by screws to ensure close contact between the two. The sample 113 to be tested is placed on the sample base 112, and the sample 113 to be tested is fixed by the first pressing ring 117, and the base 115 equipped with the probe card 114 is turned upside down 180 degrees and assembled onto the sample base 112. Then, after using the fixing device 160 to surround the side edge of the multi-probe sample device 110, adjust the position of the nut on the bolt of the fixing device 160, and carefully press the elastic probe 116 tightly onto the sample to be tested 113, while ensuring that the movement length of the elastic probe 116 during the compaction process is always within its elastic deformation range. When all the elastic probes 116 are evenly pressed against the sample to be tested 113, the process of loading the sample to be tested 113 onto the multi-probe sample device 110 is completed.

[0070] Further, the connection of the resistance measurement loop is completed. The multiple elastic probes 116 on the probe card 114 are connected to the wiring port in the chamber of the cryostat 120 through low-temperature phosphor copper wires, and the multiple elastic probes 116 on the probe card 114 are connected to the wiring port in the chamber of the cryostat 120 in a one-to-one correspondence, and the wiring port in the chamber of the cryostat 120 is also connected to the wiring port outside the chamber in a one-to-one correspondence. Further, the shielded wire is connected to the channel selection device 130 from the wiring port outside the chamber of the cryostat 120, so that the test point / sampling point on the sample 130 to be tested (the contact point where the elastic probe 116 is pressed tightly) is one-to-one corresponded and electrically connected to the multiple conductive channels of the channel selection device 130. The power supply device 140 provides an excitation signal to the elastic probe 116 via the channel selection device 130, and the excitation signal includes an excitation voltage and an excitation current.

[0071] Step S20: Select N of the M elastic probes as sampling locations.

[0072] In this step, N conductive channels are selected from the M conductive channels connected to the elastic probes 116 in the channel selection device 130 as conductive channels for the resistance measurement, and the elastic probes 116 connected to the N conductive channels serve as sampling positions in the resistance measurement.

[0073] Step S30: providing a predetermined temperature and an ambient temperature to the sample to be tested.

[0074] In this step, the temperature controller 111 and the cryostat 120 in the multi-probe sample device 110 provide a predetermined temperature to the sample to be tested 113, and the cryostat 120 provides a suitable ambient temperature to the sample to be tested 113. When the temperature controller 111 and the cryostat 120 jointly control the predetermined temperature of the sample to be tested 113, the temperature controller 111 has a fast temperature control speed, while the cryostat 120 has a slow temperature control speed.

[0075] Step S40: measuring the resistance of the sample to be tested via N elastic probes.

[0076] In this step, the power supply device 140 provides voltage and current to the sample 116 to be tested via the conductive channels of the channel selection device 130 , and returns the test results via the selected N conductive channels, which are displayed on the display device 150 .

[0077] In this embodiment, the test result is, for example, the resistance measurement results of N sampling positions of the sample to be tested.

[0078] Furthermore, in this step, it also includes using the same N elastic probes as sampling positions to perform multiple samplings.

[0079] Step S50: Determine whether the measurement of the sample to be tested is completed at the temperature.

[0080] In this step, it is determined whether the entire resistance measurement of the sample 113 is completed at the same predetermined temperature and ambient temperature, that is, whether any N elastic probes of the M elastic probes 116 have measured the sample 113 according to the set procedure. If completed, step S70 is executed, and if not, step S60 is executed.

[0081] Step S60: reselecting N elastic probes to perform resistance measurement again.

[0082] In this step, since all possible electronic measurements of the sample 113 to be tested have not been completed, it is necessary to reselect the N conductive channels selected in the channel selection device 130 and remeasure the sample 113 to be tested multiple times to achieve resistance measurement of other areas of the sample 113 to be tested. Then, step S50 is performed again.

[0083] In this embodiment, the reselected N elastic probes may be identical to the N elastic probes before reselection, or at least one of them may be different. In the process of repeatedly reselecting the N elastic probes, if the N elastic probes before and after selection are identical, it is for multiple measurements to improve accuracy, and if the N elastic probes before and after selection are different, it is for measuring the resistance of different regions. Furthermore, in the probe reselection for measuring different regions, at least one of the N elastic probes selected twice in the multiple reselections is different.

[0084] Step S70: changing the predetermined temperature and the ambient temperature of the sample to be tested.

[0085] In this step, since the resistance measurement of the sample 113 under the current temperature has been completed, it is necessary to change the predetermined temperature and the ambient temperature of the sample 113 under test and then measure the resistance again, thereby completing the resistance measurement of the sample under test at different temperatures.

[0086] The multi-probe channel resistance measurement system and method provided by the present invention use a sample device with multiple probe channels in conjunction with a channel selection device. Multiple probes in the sample device are evenly in contact with the surface of the sample to be tested. The channel selection device selects any N of the M probes to form a group. The N probes are used to measure the resistance of the area of ​​the sample to be tested corresponding to the N probes. Different probe selections represent different regional resistance measurements of the sample to be tested. Therefore, the multi-probe channel resistance measurement system of the present application can realize resistance testing of any area of ​​the sample to be tested.

[0087] According to the embodiments of the present invention as described above, these embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and the modified use based on the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A probe card, wherein: include: A substrate, and a probe pad area located in the middle of the substrate, the probe pad area includes a plurality of pads arranged in a plurality of rows and columns, the plurality of pads are used to weld sleeves of a plurality of elastic probes, the plurality of pads in the plurality of rows and the plurality of columns are respectively connected to corresponding wires one by one, so that the elastic probes of any four pads constitute a group of test terminals.

2. The probe card according to claim 1, wherein: The probe pad area is located on the first surface of the substrate, and includes a plurality of through holes located in the center and penetrating the substrate, and a conductive contact area surrounding the through holes on the first surface of the substrate. A portion of the elastic probe passes through a sleeve in the through hole and engages with the sleeve to achieve electrical connection between the elastic probe and the wire.

3. The probe card according to claim 1, wherein: In the probe pad area, the number of pads arranged in a row in the edge area is greater than or less than or equal to the number of pads arranged in a row in the middle area; and / or The number of the pads arranged in a row in the edge region is greater than or less than or equal to the number of the pads arranged in a row in the middle region.

4. A multi-probe channel resistance measurement system, characterized in that: include: A multi-probe sample device, comprising a probe card, M elastic probes and a sample base, wherein the sample base is used to fix a sample to be tested, the elastic probe is connected to the probe card via a sleeve, and the M elastic probes are all in elastic contact with the surface of the sample to be tested and electrically connected to provide an excitation signal and obtain a detection signal, wherein M is an integer greater than or equal to 4; A multi-channel selection device is connected to the multi-probe sample device, and includes a plurality of conductive channels that can be independently controlled to be turned on and off, and the number of the conductive channels is not less than M. Among them, among the multiple conductive channels of the multi-channel selection device, M conductive channels correspond one-to-one to and are electrically connected to the M elastic probes, and the multi-channel selection device selects any N conductive channels from the M conductive channels to be turned on to measure the resistance of the sample to be tested, and N is an integer less than or equal to M.

5. The multi-probe channel resistance measurement system according to claim 4, wherein: The multi-channel selection device selects any 4 conductive channels from the M conductive channels to be turned on to measure the resistance of the sample to be measured, where M is an integer greater than or equal to 4.

6. The multi-probe channel resistance measurement system according to claim 4, wherein: The M elastic probes are in uniform contact with the surface of the sample to be tested.

7. The multi-probe channel resistance measurement system according to claim 4, wherein: The same N conductive channels are used to perform multiple resistance measurements on the sample to be tested.

8. The multi-probe channel resistance measurement system according to claim 4, wherein: After performing a resistance measurement on the sample to be tested, the multi-channel selection device first closes the N conductive channels that are currently opened, and then reselects N conductive channels to be opened to perform resistance measurement again.

9. The multi-probe channel resistance measurement system according to claim 8, wherein: The reselected N conductive channels are the same as the N conductive channels before the reselection.

10. The multi-probe channel resistance measurement system according to claim 8, wherein: At least one of the reselected N conductive channels is different from the N conductive channels before the reselection.

11. The multi-probe channel resistance measurement system according to claim 4, wherein: The multi-channel selection device comprises: Multi-channel cards are used to provide multiple independent conductive channels. A multimeter is connected to the multi-channel board and is used to control the on and off of the multiple conductive channels.

12. The multi-probe channel resistance measurement system according to claim 10, wherein: The multi-probe sample device also includes: A base, used for fixing the probe card; A temperature controller, which matches the shape of the third groove on the second surface of the sample base and is located in the third groove, and is used to provide a predetermined temperature for the sample to be tested; There is an internal space between the surfaces of the sample base and the base that are arranged opposite to each other, and the probe card and the sample to be tested are fixed in the internal space.

13. The multi-probe channel resistance measurement system according to claim 12, wherein: The probe card includes a substrate and a probe pad area located in the middle of the substrate; The base includes a main surface in contact with the second surface of the substrate, and a plurality of grooves located in the main surface, the plurality of grooves corresponding to the probe pad area, the elastic probe and the second pressure ring for fixing the probe card, and providing wiring space for the probe pad area and the elastic probe.

14. The multi-probe channel resistance measurement system according to claim 13, wherein: The multi-probe sample device also includes: A first groove and a second groove are located on the first surface of the sample base, the first groove is used to provide a space for accommodating the sample to be tested, and the second groove is used to provide a space for fixing a first pressing ring of the sample to be tested, and the first surface of the sample to be tested fixed in the sample base is electrically connected to the elastic probe; The fourth groove, the fifth groove and the sixth groove are located on the main surface of the base, the fourth groove is used to accommodate the wire connecting the elastic probe with the external electrical connection, the fifth groove is used to accommodate the probe card, and the sixth groove is used to accommodate the second pressure ring to fix the probe card.

15. The multi-probe channel resistance measurement system according to claim 14, wherein: Also includes: A low temperature thermostat, connected to the multi-probe sample device, provides an ambient temperature for the sample to be tested and connects the pins of the probe card to the multiple conductive channels of the multi-channel selection device in a one-to-one correspondence through the wiring ports inside and outside the chamber of the low temperature thermostat; A power supply device, connected to the multi-channel selection device, and providing voltage and current to the sample to be tested; A display device is connected to the multi-channel selection device and displays the resistance measurement result of the sample to be tested.

16. A method for measuring resistance of a multi-probe channel, wherein: include: Connect the sample to be tested with the multi-probe channel resistance measurement system; Selecting N of the M elastic probes as sampling locations, where M is an integer greater than or equal to 4, and N is an integer less than or equal to M; Providing a predetermined temperature and an ambient temperature to the sample to be tested; Measuring the resistance of the sample to be tested via the N elastic probes; Determine whether the resistance measurement of the sample to be tested is completed at this temperature; If not, reselect N elastic probes and measure the resistance of the sample to be tested again; If yes, the predetermined temperature and the ambient temperature of the sample to be tested are changed and the step of measuring the resistance of the sample to be tested via the N elastic probes is performed again.

17. The multi-probe channel resistance measurement method according to claim 16, wherein: Four of the M elastic probes are selected as sampling locations, where M is an integer greater than or equal to four.

18. The multi-probe channel resistance measurement method according to claim 16, wherein: In the step of measuring the resistance of the sample to be tested via N elastic probes, the resistance of the sample to be tested is measured at least once.

19. The multi-probe channel resistance measurement method according to claim 16, wherein: At least one of the reselected N elastic probes is different from the N elastic probes before the reselection.

20. The multi-probe channel resistance measurement method according to claim 16, wherein: The reselected N conductive channels are the same as the N conductive channels before the reselection.

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