Test needle and four-wire test device
By designing test probes with test heads to expand the contact area, the problems of high manufacturing cost and low yield of four-wire test probes in miniaturized components under test are solved, achieving lower manufacturing cost and higher production yield while maintaining the same testing performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- UNIMICRON TECH CORP
- Filing Date
- 2025-05-09
- Publication Date
- 2026-05-05
AI Technical Summary
Existing four-wire test probes are costly and have low yield in miniaturized components under test, mainly because the width and spacing of the probes are too small to meet the miniaturization requirements.
Design a test probe in which the cross-sectional area of the test head is greater than the sum of the cross-sectional areas of the two probes. By combining the test head and the probes, the contact area is expanded to reduce width and spacing limitations. The coarser needle contacts the component under test first, and then contacts the finer needle, thereby improving production yield.
By expanding the contact area, manufacturing costs are reduced and the production yield of test probes is improved, resulting in better process adaptability while maintaining the same testing performance as traditional structures.
Smart Images
Figure CN224203277U_ABST
Abstract
Description
Technical Field
[0001] This work relates to a testing needle and a four-wire testing device. Background Technology
[0002] Current four-wire test probes connect two probes to two test pieces (e.g., solder balls) on opposite sides of the component under test (e.g., circuit board). Since the two probes on each side must simultaneously connect to the same test piece, there is a maximum width limitation on the two probes. Furthermore, according to the test instructions, the two probes must maintain an appropriate distance during testing to prevent contact, further restricting their width. Because the manufacturing cost and yield of the probes are directly proportional to the probe tip size and the minimum distance between the probes, the miniaturization of the components under test presents increasing challenges to probe manufacturing. Utility Model Content
[0003] To address the aforementioned issues, this invention provides a testing needle and a four-wire testing device.
[0004] One embodiment of the present invention discloses a test probe comprising: a first probe, a second probe, and a test head, wherein the second probe is arranged side-by-side with the first probe. The test head electrically contacts the first probe and the second probe along a contact direction, wherein at least a portion of the test head has a cross-sectional area in the contact direction that is greater than the sum of the cross-sectional areas of the first probe and the second probe in the contact direction.
[0005] According to one embodiment, the test head includes: a first segment having opposing first and second sides, wherein the first side electrically contacts the first probe and the second probe; and a second segment electrically contacts the second side of the first segment, wherein the cross-sectional area of the first segment in the contact direction is larger than the cross-sectional area of the second segment in the contact direction.
[0006] According to one embodiment, the first segment and the second segment are each cylindrical.
[0007] According to one embodiment, the diameter of the first segment is at least 20 micrometers larger than the sum of the diameters of the first probe and the second probe, and the diameter of the second segment is greater than either the diameter of the first probe or the diameter of the second probe.
[0008] According to one embodiment, the height of the first segment in the contact direction is 200 micrometers.
[0009] According to one embodiment, the test head includes two insertion holes for the first probe and the second probe to be inserted and electrically contact the first probe and the second probe.
[0010] According to one embodiment, the diameter of each of the two insertion holes is 30 micrometers.
[0011] According to one embodiment, the distance between the two insertion holes is 20 micrometers.
[0012] According to one embodiment, the test head is a cylinder.
[0013] One embodiment of this invention discloses a four-wire testing apparatus suitable for a component under test (DUT), and includes a test fixture and two test probes as described above. The test fixture has a support area for supporting the DUT. The two test probes are respectively disposed on opposite sides of the support area and are in electrical contact with the test fixture.
[0014] According to the test needle and four-wire test device disclosed in the above embodiments, a coarse needle can first electrically contact the test piece on the component under test, and then electrically contact the two fine needles originally used for testing. Compared with the traditional two needles directly contacting the test piece, the contact area of the test piece relative to the original test needles can be expanded, thereby reducing the width and / or spacing limitations of the original test needles, thereby reducing manufacturing costs and improving the production yield of test needles.
[0015] The above description of the content of this invention and the following description of the embodiments are used to demonstrate and explain the principles of this invention, and to provide a further explanation of the scope of the patent application for this invention. Attached Figure Description
[0016] Figure 1 This is a side view schematic diagram of a four-wire testing device illustrated according to an embodiment of the present invention.
[0017] Figure 2 This is a three-dimensional schematic diagram of a test needle drawn according to an embodiment of the present invention.
[0018] Figure 3 This is a three-dimensional schematic diagram of the first segment of the test head of a test needle, as illustrated in an embodiment of the present invention.
[0019] Figure 4 This is a three-dimensional schematic diagram of a test needle drawn according to another embodiment of the present invention. Detailed Implementation
[0020] The following detailed description of the features and advantages of this invention is sufficient to enable anyone skilled in the art to understand and implement the technical content of this invention. Furthermore, based on the disclosure, patent claims, and drawings in this specification, anyone skilled in the art can easily understand the related objectives and advantages of this invention. The following embodiments further illustrate the viewpoints of this invention, but are not intended to limit the scope of this invention in any way.
[0021] The four-wire test apparatus and test probes described below are applicable to circuit boards or other components under test that contain conductors.
[0022] Please refer to Figure 1 , Figure 1 This is a side view schematic diagram of a four-wire testing device illustrated according to an embodiment of the present invention.
[0023] like Figure 1 As shown, the four-wire testing device 1 includes two test probes 11 and a test fixture 12. Each test probe 11 includes a first probe 111, a second probe 112, and a test head 113, wherein the second probe 112 is arranged side by side with the first probe 111. The test head 113 may include a first segment 1131 and a second segment 1132. The test head 113 electrically contacts the first probe 111 and the second probe 112 along the contact direction D1, wherein at least a portion of the test head 113 has a cross-sectional area in the contact direction D1 that is greater than the sum of the cross-sectional areas of the first probe 111 and the second probe 112 in the contact direction D1. The test fixture 12 has a carrying area 121 for carrying the component under test 2. The two test probes 11 are respectively disposed on opposite sides of the carrying area 121 and electrically contact the test fixture 12.
[0024] The component under test 2 includes a substrate 21, a first test piece 22, and a second test piece 23, wherein the first test piece 22 and the second test piece 23 are respectively disposed on opposite sides of the substrate 21. The first test piece 22 and the second test piece 23 can each be, for example, a flattened bump, a ball grid array (BGA), or other type of conductor, and can make electrical contact with each other through conductive vias in the substrate 21. The test heads 113 of the two test probes 11 can make electrical contact with the first test piece 22 and the second test piece 23 respectively, and the test fixture 12 can perform electrical tests on the first test piece 22 and the second test piece 23 through the test probes 11. Figure 1 The four-wire test apparatus 1 is illustrated exemplarily as comprising a pair (two) test needles 11, while in other embodiments, the four-wire test apparatus 1 may comprise multiple pairs of test needles 11, electrical contact test fixtures 12, and each for testing multiple test pieces.
[0025] Please refer to the following: Figure 2 and Figure 3 . Figure 2 This is a three-dimensional schematic diagram of a test needle drawn according to an embodiment of the present invention. Figure 3 This is a three-dimensional schematic diagram of the first segment of the test head of a test needle, as illustrated in an embodiment of the present invention.
[0026] Figure 2 The test needle 11 shown can be used as Figure 1The test needle 11 includes a first probe 111, a second probe 112, and a test head 113, wherein the second probe 112 is arranged side-by-side with the first probe 111. The test head 113 includes a first segment 1131 and a second segment 1132. The first segment 1131 has opposing first sides 1131_1 and second sides 1131_2, and the first side 1131_1 of the first segment 1131 is in electrical contact with the first probe 111 and the second probe 112. The second segment 1132 is in electrical contact with the second side 1131_2 of the first segment 1131, and the cross-sectional area of the first segment 1131 in the contact direction D1 is larger than the cross-sectional area of the second segment 1132 in the contact direction D1.
[0027] In this embodiment, the first segment 1131 and the second segment 1132 can each be a cylinder, with the diameter d1 of the first segment 1131 being larger than the diameter d2 of the second segment 1132. Further, the diameter d1 of the first segment 1131 can be at least 20 micrometers larger than the sum of the diameters of the first probe 111 and the second probe 112, and the diameter d2 of the second segment 1132 can be larger than the diameter of either the first probe 111 or the second probe 112. For example, the diameters of the first probe 111 and the second probe 112 can be 30 micrometers, the diameter d1 of the first segment 1131 can be 120 micrometers, and the diameter d2 of the second segment 1132 can be 50 micrometers. Additionally, the diameter d2 of the second segment 1132 can be designed to be 10 to 20 micrometers smaller than the cross-sectional width of the test piece. For example, when the cross-sectional width of the test piece is 70 micrometers, the diameter d2 of the second segment 1132 can be designed to be 50 to 60 micrometers. In other embodiments, the first segment 1131 and the second segment 1132 can be implemented as other types of columnar or conical bodies.
[0028] like Figure 3 As shown, the first section 1131 of the test head 113 may include two insertion holes O1 and O2 for... Figure 2 The first probe 111 and the second probe 112 are inserted to make electrical contact with the first probe 111 and the second probe 112. In other embodiments, the first probe 111 and the second probe 112 may make electrical contact with the first segment 1131 by soldering.
[0029] In this embodiment, the diameters of the two insertion holes O1 and O2 can each be, for example, 30 micrometers, corresponding to the diameters of the first probe 111 and the second probe 112. The distances w1 between the insertion hole O1 and the edge of the first segment 1131, w2 between the two insertion holes O1 and O2, and w3 between the insertion hole O2 and the edge of the first segment 1131 can each be, for example, 20 micrometers. A probe spacing of 20 micrometers can accommodate high-density packaging and is suitable for high-density integrated circuit chip testing. In this embodiment, the height h1 of the first segment 1131 of the test head 113 in the contact direction D1 can be, for example, 200 micrometers.
[0030] Please refer to Figure 4 . Figure 4 This is a three-dimensional schematic diagram of a test needle drawn according to another embodiment of the present invention.
[0031] Figure 4 The test needle 11' shown can replace Figure 1 The test needle 11 is provided. The test needle 11' includes a first probe 111, a second probe 112, and a test head 113', wherein the second probe 112 is arranged side-by-side with the first probe 111. The test head 113' electrically contacts the first probe 111 and the second probe 112 along a contact direction D1, and at least a portion of the cross-sectional area of the test head 113' in the contact direction D1 is greater than the sum of the cross-sectional areas of the first probe 111 and the second probe 112 in the contact direction D1. In this embodiment, the test head 113' may be a cylinder. However, in other embodiments, the test head 113' may also be implemented as other types of cylindrical or conical shapes. In this embodiment, the electrical contact between the test head 113' and the first probe 111 and the second probe 112 can be achieved through the aforementioned insertion hole or soldering, wherein the specifications of the insertion hole are as described above and will not be repeated here.
[0032] Please refer to Table 1, which shows the resistance results of the first and second probes on one side of a current four-wire test probe under different current and voltage test conditions. As shown in Table 1, after 10 tests with different current and voltage conditions, the resistance results fell within 0.2%, indicating no significant difference. By changing the current and voltage test conditions of the first and second probes, it can be shown that the pins of the left and right probes are interchangeable. Therefore, it can be confirmed that the single-pin design of this invention can replace the traditional dual-pin structure and maintain the same testing performance.
[0033] Table 1. Results of the two-pin interchange test conditions on one side of the four-wire test probe (unit: mΩ)
[0034]
[0035]
[0036] According to the test probes and four-wire testing apparatus of the above embodiments, the coarse probe can first electrically contact the test piece on the component under test (DUT), and then electrically contact the two fine probes originally used for testing. Compared with the traditional two-prong direct connection structure, this expands the contact area of the DUT relative to the original test probes, thereby reducing the width and / or spacing limitations of the original test probes, thus reducing manufacturing costs and improving the yield of test probe production. Furthermore, by using a probe head with a cross-sectional area larger than the sum of the cross-sectional areas of the two original test probes to contact the DUT, compared with the traditional two-prong direct connection, the larger contact area results in more stable contact quality. In addition, with the continuous miniaturization of DUT dimensions, the structure design of this invention, which connects the probe and the DUT with the test head, is easier to implement than the structure design of directly connecting the probe to the DUT, and has better process adaptability. Moreover, there is no significant difference in results when the test conditions of the left and right probes are changed, proving that the structure design of this invention can maintain the same testing performance as the traditional two-prong structure.
[0037] Explanation of reference numerals in the attached figures:
[0038] 1: Four-wire testing device
[0039] 11, 11': Test needles
[0040] 111: First probe
[0041] 112: Second probe
[0042] 113, 113': Test header
[0043] 1131: First section
[0044] 1131_1: First side
[0045] 1131_2: Second side
[0046] 1132: Second section
[0047] 12: Test fixture
[0048] 121: Bearing Area
[0049] 2: Component under test
[0050] 21:Substrate
[0051] 22: First test piece
[0052] 23: Second test piece
[0053] D1: Contact direction
[0054] O1, O2: Insertion holes
[0055] d1, d2, d3, d4: diameter
[0056] w1, w2, w3: Distance
Claims
1. A testing needle, characterized in that, The test needle contains: First probe; The second probe is placed alongside the first probe; and The test head electrically contacts the first probe and the second probe along the contact direction, wherein at least a portion of the test head has a cross-sectional area in the contact direction that is greater than the sum of the cross-sectional areas of the first probe and the second probe in the contact direction.
2. The test needle according to claim 1, characterized in that, The test header contains: The first segment has opposing first and second sides, wherein the first side electrically contacts the first probe and the second probe; and The second segment electrically contacts the second side of the first segment, wherein the cross-sectional area of the first segment in the contact direction is larger than the cross-sectional area of the second segment in the contact direction.
3. The test needle according to claim 2, characterized in that, The first section and the second section are each cylindrical.
4. The test needle according to claim 3, characterized in that, The diameter of the first segment is at least 20 micrometers larger than the sum of the diameters of the first probe and the second probe, and the diameter of the second segment is greater than either the diameter of the first probe or the diameter of the second probe.
5. The test needle according to claim 2, characterized in that, The height of the first segment in the contact direction is 200 micrometers.
6. The test needle according to claim 1, characterized in that, The test head includes two insertion holes for the first probe and the second probe to be inserted and make electrical contact with each other.
7. The test needle according to claim 6, characterized in that, The diameter of each of the two insertion holes is 30 micrometers.
8. The test needle according to claim 6, characterized in that, The distance between the two insertion holes is 20 micrometers.
9. The test needle according to claim 1, characterized in that, The test head is cylindrical.
10. A four-wire testing device, characterized in that, This four-wire test setup is suitable for components under test and includes: The test fixture has a support area for supporting the component under test; and Two test needles according to any one of claims 1-9 are respectively disposed on opposite sides of the bearing area and are in electrical contact with the test fixture.