Test probe and method of manufacturing the same

Abstract

Disclosed is a method of manufacturing a test probe. The method includes: forming a terminal body portion by stacking a lower dry film on a substrate and filling a predetermined material into a molding groove of the lower dry film; forming a tip portion by stacking an upper dry film on the lower dry film and filling a predetermined material in a molding groove of the upper dry film; forming at least one tip by machining an upper portion of the tip portion; and removing the upper dry film and the lower dry film from the tip portion formed with the tip and the terminal body portion.

Description

TEST PROBE AND METHOD OF MANUFACTURING THE SAME

[0001] The disclosure relates to a test probe for testing the electrical characteristics of a subject-to-be-tested, such as a semiconductor, and a method of manufacturing the test probe based on a micro electro-mechanical system (MEMS) process.

[0002] A test probe includes a barrel shaped like a cylinder, a terminal partially inserted in a first end portion of the barrel, a plunger partially inserted in a second end portion of the barrel, and a spring interposed between the terminal and the plunger within the barrel. At least one of the terminal and the plunger is partially inserted slidably in the barrel. The terminal comes into contact with a hemispherical bump terminal of a subject-to-be-tested, and the plunger comes into contact with a pad terminal of a test circuit board. The terminal includes a contact portion having a sharp tip to come into contact with the hemispherical bump terminal, and a body portion inserted in the first end portion of the barrel. The terminal may be manufactured by machining or micro electro-mechanical system (MEMS) processes.

[0003] In the MEMS processes for manufacturing the terminal, the contact portion is formed by filling and flattening hard metal in a groove corresponding to the sharp tip, e.g., a V-shaped groove on a sacrificial substrate; the body portion is formed by repeating dry film stacking, pattern exposure, development, and metal filling on the sacrificial substrate; and the dry films and the sacrificial substrate are removed to finally complete the terminal. In this case, the sacrificial substrate to be ultimately removed is used as a base substrate for a MEMS stacking process to form a horn-shaped tip. Such a conventional MEMS process for manufacturing the terminal has a problem of increasing manufacturing costs because the sacrificial substrate to be ultimately removed is expensive.

[0004] An aspect of the disclosure is to provide a test probe capable of stably testing a subject-to-be-tested.

[0005] Another aspect of the disclosure is to provide a method of manufacturing a test probe, by which manufacturing costs are reduced.

[0006] According to an embodiment of the disclosure, there is provided a method of manufacturing a test probe. The method includes: forming a terminal body portion by stacking a lower dry film on a substrate and filling a predetermined material into a molding groove of the lower dry film; forming a tip portion by stacking an upper dry film on the lower dry film and filling a predetermined material in a molding groove of the upper dry film; forming at least one tip by machining an upper portion of the tip portion; and removing the upper dry film and the lower dry film from the tip portion formed with the tip and the terminal body portion.

[0007] The substrate may include an insulating substrate coated with a conductive film, or a conductive substrate. Thus, a reusable glass substrate or conductive substrate is applied to the MEMS process without using the consumable and expensive sacrificial substrate, thereby reducing manufacturing costs.

[0008] The forming the tip portion may include forming a plurality of tip portions by filling a predetermined material in a plurality of molding grooves of the upper dry film, which are provided to be spaced apart along a circumferential direction. Thus, the plurality of tip portions can be in stable contact with a hemispherical bump terminal (i.e., the counterpart terminal) of the subject-to-be-tested, thereby improving the reliability of the test.

[0009] The forming the at least one tip comprises forming a plurality of tips provided on the tip portions at the same distance from a center of a spherical surface of a counterpart terminal so that the plurality of tip portions can be in contact with the spherical surface of the counterpart terminal while partially accommodating the spherical surface. Thus, when the terminal is manufactured through the MEMS process, it is easy and inexpensive to form a plurality of tips suitable for coming into contact with the hemispherical bump terminal of the subject-to-be-tested.

[0010] The plurality of tip portions may be shaped like pillars extending in a stacking direction and having side edges facing each other, and the forming the plurality of tips comprises forming recessed portions having a predetermined width and depth extending toward the side edges on the tip portions. Thus, it is easier and less expensive to form the plurality of tips suitable for coming into contact with the hemispherical bump terminal of the subject-to-be-tested.

[0011] According to an embodiment of the disclosure, a method of manufacturing a test probe may use a glass substrate or a conductive substrate instead of a sacrificial substrate, thereby reducing manufacturing costs.

[0012] FIG. 1 is a perspective view showing a test probe according to a first embodiment of the disclosure.

[0013] FIG. 2 is an exploded perspective view of the test probe of FIG. 1.

[0014] FIG. 3 is a cross-sectional view taken along line A-A of FIG. 1.

[0015] FIG. 4 illustrates a contact state between a bump terminal of a subject-to-be-tested and a tip.

[0016] FIG. 5 is a flowchart showing a method of manufacturing a terminal of FIG. 1.

[0017] FIGS. 6 and 7 schematically illustrate the method of manufacturing the terminal of FIG. 5.

[0018] FIG. 8 is a flowchart showing a method of manufacturing a terminal according to a second embodiment of the disclosure.

[0019] FIGS. 9 and 10 schematically illustrate the method of manufacturing the terminal of FIG. 8.

[0020] Below, a test probe 1 and a method of manufacturing the same will be described in detail with reference to the accompanying drawings.

[0021] FIG. 1 is a perspective view showing a test probe 1 according to a first embodiment of the disclosure, FIG. 2 is an exploded perspective view of the test probe 1 of FIG. 1, FIG. 3 is a cross-sectional view taken along line A-A of FIG. 1, and FIG. 4 illustrates a contact state between a bump terminal 110 of a subject-to-be-tested 100 and a tip 32c.

[0022] Referring to FIGS. 1 to 3, the test probe 1 includes a barrel 2 shaped like a cylinder, a terminal 3 partially inserted in a first end portion of the barrel 2, a plunger 4 partially inserted in a second end portion of the barrel 2, and a spring 5 interposed between the terminal 3 and the plunger 4 within the barrel 2. The terminal 3 is secured to the first end portion of the barrel 2, and the plunger 4 is slidable within the barrel 2 while compressing and restoring the spring 5.

[0023] The barrel 2 is shaped like a tube, and made of conductive metal such as brass.

[0024] The terminal 3 includes a terminal body portion 31 partially inserted in the first end portion of the barrel 2, and three tip portions 32 stacked on the terminal body portion 31 to come into contact with a counterpart terminal (hereinafter referred to as 'the bump terminal 110 of the subject-to-be-tested 100'). The number of tip portions 32 is not limited to three but may be two or four or more.

[0025] The terminal body portion 31 includes a barrel insertion portion 31a having a diameter corresponding to the inner diameter of the barrel 2, a spring supporting portion 31b accommodated in and supported on a first side of the spring 5 provided in an end portion of the barrel insertion portion 31a inserted inside the barrel 2, a barrel supporting portion 31c fastening the terminal body portion 31 to the barrel 2, and a tip supporting portion 31d facing an end portion of the barrel 2 from the outer side of the barrel 2 and supporting the three tip portions 32 on the other side thereof.

[0026] The barrel insertion portion 31a is shaped like a cylinder, is in contact with the inner surface of the barrel 2, and has a diameter corresponding to the inner diameter of the barrel 2.

[0027] The spring supporting portion 31b is shaped like a cylinder, has a diameter smaller than the inner diameter of the barrel 2, and is in contact with the first side of the spring 5.

[0028] The barrel supporting portion 31c is recessed along a circumferential direction on the outer circumferential surface of the barrel insertion portion 31a so as to accommodate a protrusion formed by pressing and deforming the barrel 2 inward through dimpling.

[0029] The tip supporting portion 31d is shaped like a cylinder, and has a diameter equal to or smaller than the outer diameter of the barrel 2 and larger than the inner diameter of the barrel 2. The tip supporting portion 31d may include, for example, the three tip portions 32 stacked on the top surface thereof.

[0030] The three tip portions 32 are arranged at predetermined intervals in the circumferential direction with respect to the central axis O of the barrel 2. The three tip portions 32 have fanwise cross-sections along the axial direction. Each upper portion of the three tip portions 32 includes a tip stepped portion 32a provided at a predetermined depth on a side edge facing toward the central axis O, and a recessed portion 32b radially extending toward the central axis O by a predetermined width. Each of the three tip portions 32 is divided into a lower tip portion 321 having a fanwise cross-section along the axial direction on the tip supporting portion 31d, and two upper tip portions 322 divided into two by the recessed portion 32b on the lower tip portion 321 and having fanwise cross-sections along the axial direction. One lower tip portion 321 may be formed with one lower tip 32c on a side edge portion facing toward the central axis O, and two upper tip portions 322 may be formed with two upper tips 32c on the side edge portions facing toward the central axis O. Thus, the lower tip 32c and the upper tip 32c may be spaced apart in the stacking direction and provided at different distances from the central axis O.

[0031] Referring to FIG. 4, substantially, the hemispherical bump terminal 110 presses the test probe 1 placed between the three tip portions 32 during a test. Three lower tips 32c provided on the lower tip portion 321 and six upper tips 32c provided on the upper tip portion 322 are in contact with a curved surface of the hemispherical bump terminal 110 at the same distance from the central axis O while partially accommodating the spherical surface. As a result, nine tips 32c respectively provided in the three tip portions 32 may stick in the bump terminal 110, thereby ensuring the stability of the contact.

[0032] FIG. 5 is a flowchart showing a method of manufacturing the terminal 3 of FIG. 1, and FIGS. 6 and 7 schematically illustrate the method of manufacturing the terminal 3 of FIG. 5. Although a plurality of terminals 3 are manufactured on one glass substrate 61 by the MEMS process simultaneously, only one terminal 3 is shown in FIGS. 6 and 7 for the convenience of descriptions.

[0033] At operation S1, a flat insulating substrate having a predetermined thickness, for example, the glass substrate 61 is prepared. The insulating substrate may be replaced by a conductive substrate.

[0034] At operation S2, a conductive film 62, for example, a gold (Au) film is formed on one surface of the glass substrate 61 by sputtering. If the conductive substrate is used, the operation S2 will be omitted.

[0035] At operation S3, a first layer 65 (corresponding to the spring supporting portion 31b of FIG. 2) is formed by stacking a first dry film 63 on the conductive film 62 of the glass substrate 61, forming a plurality of first molding grooves 64, which are spaced apart from each other, by pattern exposure and development, and filling first metal, e.g., nickel (Ni) into the plurality of first molding grooves 64 by electroplating or electroless plating and grinding a portion of the first metal protruding from the top surface of the first dry film 63. By the electroplating, nickel (Ni) is dissolved and precipitated on the conductive film 62 as an electric current flows between a positive electrode plate made of nickel (Ni) and the conductive film (i.e., a negative electrode) 62 on the glass substrate 61 in an aqueous solution. By the electroless plating, metal ions in a plating solution is precipitated as metal on the conductive film 62 of the glass substrate 61 based on a chemical reaction with a reducing agent.

[0036] At operation S4, a second layer 65 (corresponding to a portion of the barrel insertion portion 31a of FIG. 2) is formed by stacking a second dry film 66 on the first dry film 63, forming a plurality of second molding grooves 67, each of which is wider than each first molding groove 64, by pattern exposure and development, and filling the first metal, e.g., nickel (Ni) into the plurality of second molding grooves 67 by the electroplating and grinding a portion of the first metal protruding from the top surface of the second dry film 66.

[0037] At operation S5, a third layer 71 (corresponding to the barrel supporting portion 31c of FIG. 2) is formed by stacking a third dry film 69 on the second dry film 66, forming a plurality of third molding grooves 70, each of which is narrower than each second molding groove 67, by pattern exposure and development, and filling the first metal, e.g., nickel (Ni) into the plurality of third molding grooves 70 by the electroplating and grinding a portion of the first metal protruding from the top surface of the third dry film 69.

[0038] At operation S6, a fourth layer 74 (corresponding to a portion of the barrel insertion portion 31a of FIG. 2) is formed by stacking a fourth dry film 72 on the third dry film 69, forming a plurality of fourth molding grooves 73, each of which is wider than each third molding groove 70, by pattern exposure and development, and filling the first metal, e.g., nickel (Ni) into the plurality of fourth molding grooves 73 by the electroplating and grinding a portion of the first metal protruding from the top surface of the fourth dry film 72.

[0039] At operation S7, a fifth layer 77 (corresponding to the tip supporting portion 31d of FIG. 2) is formed by stacking a fifth dry film 75 on the fourth dry film 72, forming a plurality of fifth molding grooves 76, each of which is wider than each fourth molding groove 73, by pattern exposure and development, and filling the first metal, e.g., nickel (Ni) into the plurality of fifth molding grooves 76 by the electroplating and grinding a portion of the first metal protruding from the top surface of the fifth dry film 75.

[0040] By the foregoing process, the first to fifth layers 65, 68, 71, 74 and 77 are stacked to form the terminal body portion 31.

[0041] At operation S8, a sixth layer 80 (corresponding to the tip portion 32 of FIG. 2) is formed by stacking a sixth dry film 78 is stacked on the fifth dry film 75, forming a plurality of sixth molding grooves 79, which are arranged to be spaced part along the circumferential direction with respect to the stacking directional central axis, on the fifth layer 77 by pattern exposure and development, and filling second metal harder than the first metal, e.g., nickel boride (NiB) into the plurality of sixth molding grooves 79 by the electroplating and grinding a portion of the second metal protruding from the top surface of the sixth dry film 78. Each of the sixth molding groove 79 and the sixth layer 80 has a fanwise cross-section in a direction transverse to the stacking direction.

[0042] At operation S9, the recessed portion 12b having a predetermined width and depth extending toward the center O of the circumference in the direction transverse to the stacking direction is formed by, for example, a drill on the sixth layer 80 (corresponding to the tip portion 32 of FIG. 2) exposed to the top surface of the sixth dry film 78. Thus, two upper tip portions 322 divided by the recessed portion 12b to have two small fanwise shapes are formed on the sixth layer 80 (corresponding to the tip portion 32 of FIG. 1). In this case, one tip 32c provided in the lower tip portion 321 and two tips 32c provided in the upper tip portion 322 are spaced part in the stacking direction and positioned at different distances from the central axis O. In other words, three lower tips 32c provided on the three lower tip portions 321 are positioned at the same distance from the central axis O, and six upper tips 32c provided on the three upper tip portions 322 are positioned at the same distance from the central axis O.

[0043] At operation S10, the first to sixth dry films 63, 66, 69, 72, 75 and 78 are removed to complete the terminal 3.

[0044] FIG. 8 is a flowchart showing a method of manufacturing a terminal 3 according to a second embodiment of the disclosure, and FIGS. 9 and 10 schematically illustrate the method of manufacturing the terminal 3 of FIG. 8. Operation S11 to S17 in FIG. 8 is similar to the operation S1 to S7 in FIG. 5, and thus repetitive descriptions thereof will be omitted.

[0045] At operation S18, a sixth layer 80 (corresponding to the lower tip portion 321 of FIG. 2) is formed by stacking a sixth dry film 78 on the fifth dry film 75, forming a plurality of sixth molding grooves 79, which are arranged to be spaced part along the circumferential direction with respect to the stacking directional central axis, on the fifth layer 77 by pattern exposure and development, and filling second metal harder than the first metal, e.g., nickel boride (NiB) into the plurality of sixth molding grooves 79 by the electroplating and grinding a portion of the second metal protruding from the top surface of the sixth dry film 78. Each of the sixth molding groove 79 and the sixth layer 80 has a fanwise cross-section in a direction transverse to the stacking direction.

[0046] At operation S19, a seventh layer 83 (corresponding to the upper tip portion 322 of FIG. 2) is formed by stacking a seventh dry film 81 on the sixth dry film 78, forming a plurality of seventh molding grooves 82, which are arranged to be spaced part along the circumferential direction with respect to the stacking directional central axis, on the sixth layer 80 by pattern exposure and development, and filling the second metal harder, e.g., nickel boride (NiB) into the plurality of seventh molding grooves 82 by the electroplating and grinding a portion of the second metal protruding from the top surface of the seventh dry film 81. The seventh molding groove 82 and the seventh layer 83 have fanwise cross-sections divided into two in the circumferential direction on the sixth molding groove 79 and the sixth layer 80, respectively. In this way, one lower tip 32c, with which the bump terminal 110 of the subject-to-be-tested 100 will be in contact, may be formed on the top of the side edge of the sixth layer 80 (or 321) facing toward the stacking directional central axis O, and the upper tip 32, with which the bump terminal 110 of the the subject-to-be-tested 100 will be in contact, may be formed on the top of the side edge of the seventh layer 83 (or 322) facing toward the stacking directional central axis O.

[0047] At operation S20, the first to seventh dry films 63, 66, 69, 72, 75, 78 and 81 are removed to complete the terminal 3.

[0048] Although a few embodiments of the disclosure have been illustrated and described above, the disclosure is not limited to the foregoing specific embodiments. Various modifications can be made in the embodiments by those skilled in the art without departing from the scope of the disclosure as claimed in Claims, and these modified embodiments should not be understood separately from the technical spirits or prospects of the disclosure.

Claims

1.A method of manufacturing a test probe, comprising:forming a terminal body portion by stacking a lower dry film on a substrate and filling a predetermined material into a molding groove of the lower dry film;forming a tip portion by stacking an upper dry film on the lower dry film and filling a predetermined material in a molding groove of the upper dry film;forming at least one tip by machining an upper portion of the tip portion; andremoving the upper dry film and the lower dry film from the tip portion formed with the tip and the terminal body portion.2.The method of claim 1, wherein the substrate comprises an insulating substrate coated with a conductive film, or a conductive substrate.3.The method of claim 1, wherein the forming the tip portion comprises forming a plurality of tip portions by filling a predetermined material in a plurality of molding grooves of the upper dry film, which are provided to be spaced apart along a circumferential direction.4.The method of claim 3, wherein the forming the at least one tip comprises forming a plurality of tips provided on the tip portions at the same distance from a center of a spherical surface of a counterpart terminal so that the plurality of tip portions can be in contact with the spherical surface of the counterpart terminal while partially accommodating the spherical surface.5.The method of claim 4, whereinthe plurality of tip portions are shaped like pillars extending in a stacking direction and having side edges facing each other, andthe forming the plurality of tips comprises forming recessed portions having a predetermined width and depth extending toward the side edges on the tip portions.

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