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KR-20260066200-A - Contact Probe for Probe Heads of Electronic Devices

KR20260066200AKR 20260066200 AKR20260066200 AKR 20260066200AKR-20260066200-A

Abstract

A contact probe (20) is described herein, comprising a first end portion (20A) that can be in contact with a contact pad of a test element, a second end portion (20B) that can be in contact with a contact pad of a PCB board of a test device, and a rod-shaped probe body (20C) that extends along the length-extended direction (z) between the ends (20A, 20B), wherein the probe body (20C) extends along the length-extended direction (z) and has at least one opening (22) that defines at least one pair of arms (21a, 21b) in the probe body (20C). Appropriately, each arm (21a, 21b) of the at least one pair of arms has a cross-section perpendicular to the length development direction (z) and has different areas at different points (A, B, C) along the probe body (20C), thereby ensuring that stress is distributed along the probe body (20C) while the contact probe (20) is bent during a test operation of the device to be tested using the contact probe (20).

Inventors

  • 베토리, 리카르도

Assignees

  • 테크노프로브 에스.피.에이.

Dates

Publication Date
20260512
Application Date
20210803
Priority Date
20200804

Claims (20)

  1. A contact probe (20) comprising a first end portion (20A) capable of contacting a contact pad of a test element, a second end portion (20B) capable of contacting a contact pad of a PCB board of a test device, and a probe body (20C) extended along a lengthwise development direction (z) between the first end portion (20A) and the second end portion (20B), wherein the probe body (20C) is extended along the lengthwise development direction (z) and has at least one opening (22) defining at least one pair of arms (21a, 21b) in the probe body (20C). Each of the arms (21a, 21b) of the at least one pair of arms is characterized by having a non-uniform cross-section perpendicular to the length development direction (z) and having different areas at different points (A, B, C) along the probe body (20C). Contact probe (20).
  2. In paragraph 1, In a rest condition in which the contact probe (20) is not in pressurized contact with the contact pad of the element under test, the probe body (20C) is characterized by having a pre-deformed shape in a curvilinear configuration. Contact probe (20).
  3. In paragraph 2, The above pre-deformed shape includes at least one bend and a curvature change point (B), and the arms (21a, 21b) are characterized by having a cross-section of maximum value at the curvature change point (B). Contact probe (20).
  4. In paragraph 3, The above arms (21a, 21b) are characterized by having a cross section that continuously increases from the first end of the arms (21a, 21b) to the curvature change point (B) and then continuously decreases from the curvature change point (B) to the second end of the arms (21a, 21b). Contact probe (20).
  5. In paragraph 3, The above arms (21a, 21b) have a cross-section that is variable only in the portion of the probe body (20C) that includes the curvature change point (B) and is defined between the first intermediate point (A) and the second intermediate point (C). The above cross-section is characterized by being constant from the first end of the arms (21a, 21b) to the first intermediate point (A), continuously increasing from the first intermediate point (A) to the curvature change point (B), continuously decreasing from the curvature change point (B) to the second intermediate point (C), and being constant from the second intermediate point (C) to the second end of the arms (21a, 21b). Contact probe (20).
  6. In paragraph 1, It further includes at least one bending neck (26, 26A, 26B) formed at the end of the probe body (20C) by a portion having a reduced cross-section, and The above-mentioned reduced cross-section preferably has a cross-section reduced by 30-60% compared to the cross-section (Sez 20C) of the probe body (20C), and more preferably has a cross-section corresponding to 50% of the cross-section of the probe body (20C). Contact probe (20).
  7. In paragraph 1, It further includes at least one stopper (27) formed by an opening (27A) provided in the contact head portion (20B), and The above opening (27A) is preferably teardrop-shaped and defines two opposite portions in the contact head portion (20B) that can move closer and further apart when transversal compression forces are applied, and The above stopper (27) is characterized as being an elastic stopper, Contact probe (20).
  8. In paragraph 2, The above pre-deformed shape comprises at least one pair of bends arranged with opposite curvatures with respect to the length development direction (z), wherein the first bend has a curvature change at a first point (A') and is connected to a second bend at a second point (B'), and the second bend has a curvature change at a third point (C'). Contact probe (20).
  9. In paragraph 8, The above arms (21a, 21b) have a cross section that continuously increases from the first end of the arms (21a, 21b) to the first curvature change point (A') and then continuously decreases from the first point (A') to the second point (B'). The above cross section is characterized by increasing again to the third point (C') and then decreasing again to the second end of the arms (21a, 21b). Contact probe (20).
  10. In paragraph 8, The arms (21a, 21b) have a continuously increasing cross-section along the probe body (20C) including the first bend and the second bend, wherein the continuously increasing cross-section starts from the first end of the arms (21a, 21b), passes through the first point (A'), the second point (B'), and the third point (C'), and extends to the second end of the arms (21a, 21b). Contact probe (20).
  11. In paragraph 8, The above arms (21a, 21b) have a cross-section that is variable only along the portion of the probe body (20C) including the second point (B') and is defined between the first point (A') and the third point (C'), The above cross section is characterized by being constant from the first end of the arms (21a, 21b) to the first point (A'), continuously increasing from the first point (A') to the second point (B') and from the second point (B') to the third point (C'), and being constant from the third point (C') to the second end of the arms (21a, 21b). Contact probe (20).
  12. In paragraph 8, It includes a first bending neck (26A) and a second bending neck (26B) formed by a portion having a reduced cross-section, wherein the first bending neck (26A) is formed at the first end of the probe body (20C) in the contact tip portion (20A), and the second bending neck (26B) is formed at the second end of the probe body (20C) in the contact head portion (20B). The above-mentioned reduced cross-section preferably has a cross-section reduced by 30-60% relative to the cross-section of the probe body (20C), and more preferably has a cross-section corresponding to 30% of the cross-section of the probe body (20C). Contact probe (20).
  13. In Paragraph 12, The first bending neck (26A) and the second bending neck (26B) have symmetrically arranged concave portions, and preferably, each of the concave portions is arranged oppositely to the concave shape of an adjacent bend among the bends. Contact probe (20).
  14. In Paragraph 12, It includes a strengthening portion (28) located at the end of the opening (22), and In the above reinforcing part (28), at least one of the arms (21a, 21b), preferably the arm (21a) located opposite to the concave shape of the bending neck (26A) adjacent to the reinforcing part (28), is characterized by having a portion (28A) having a cross-section larger than that of the arm at the end of the opening (22). Contact probe (20).
  15. In paragraph 1, It has rectangular cross-sections, The above cross-sections of the variability are characterized by being obtained through variations in the base dimensions of the above rectangular cross-sections. Contact probe (20).
  16. In paragraph 1, It includes a contact tip portion (23A) having a thinned configuration and comprising a base portion (23A) and a terminal tip (24A) with a reduced cross-section, and The base portion (23A) has a cross-section that is identical or equivalent to the cross-section of the probe body (20C), wherein equivalent means that the difference between the two cross-sections is ±20%. The reduced cross-section of the terminal tip (24A) is preferably 20-60% of the cross-section of the probe body (20C), and more preferably 50% of the cross-section of the probe body (20C). Contact probe (20).
  17. In paragraph 1, It includes a contact head portion (20B) having a thinned shape and comprising a base portion (23B) and a terminal tip (24B) with a reduced cross-section, and The base portion (23B) has a cross-section that is identical or equivalent to the cross-section of the probe body (20C), wherein equivalent means that the difference between the two cross-sections is ±20%. The reduced cross-section of the terminal tip (24B) is preferably 20-60% of the cross-section of the probe body (20C), and more preferably 50% of the cross-section of the probe body (20C). Contact probe (20).
  18. In paragraph 1, The above contact head portion (20B) is characterized by including an enlarged portion (25) that defines an undercut wall of the contact head portion (20B) by having a cross-section larger than the cross-section of the probe body (20C). Contact probe (20).
  19. In paragraph 1, Characterized by having an overall longitudinal extension (Ls) of 2 mm to 5 mm, preferably 3.8 mm to 4.6 mm, more preferably 2.1 mm, in a dormant state where the above contact probe (20) is not in contact with the contact pad of the element to be tested. Contact probe (20).
  20. A probe head (30) for testing the functionality of a test device, comprising at least one upper guide (31) having upper guide holes (31A) and a lower guide (32) having lower guide holes (32A) to accommodate a plurality of contact probes, The above contact probes (20) are characterized by being manufactured according to any one of claims 1 to 19. Probe head (30).

Description

Contact Probe for Probe Heads of Electronic Devices The present invention, in its more general sense, relates to a contact probe for a probe head of an electronic device, and below the invention is described with reference to this application field solely for the purpose of simplifying the description. As is well known, essentially, a probe head is a device capable of electrically connecting multiple contact pads of a microstructure, particularly an electronic device integrated on a wafer, to corresponding channels of a test device. The test device performs functional testing of the electronic device, particularly electrical testing, or general testing. The above tests performed on integrated devices are particularly useful for detecting and isolating defective devices as early as possible, such as during the production stage. Therefore, probe heads are typically used to perform electrical tests on integrated devices before they are cut from the wafer and assembled into a chip containment package. The probe head is typically formed of a special alloy wire having excellent electrical and mechanical properties and comprises a plurality of contact elements or contact probes having at least one contact portion for one of the contact pads of the element under test. A probe head of the type generally referred to as a "vertical probe head" comprises a plurality of contact probes that are substantially plate-shaped and are typically held by at least one pair of plates or guides that are parallel to each other. The guides are provided with appropriate guide holes and are spaced apart from each other by a certain distance so that a free space or air gap can be provided for the movement and possible deformation of the contact probes. The pair of guides includes an upper guide and a lower guide, wherein the upper guide is positioned closer to a test device containing the probe head and the lower guide is positioned closer to a wafer containing a test element, and both guides are provided with respective guide holes within which the contact probes slide axially. By applying pressure to the probe head itself, a good connection is ensured between the contact probes of the probe head and the contact pads of the probe head, and the contact probes, which are movable within the guide holes formed in the upper and lower guides, are bent in the air gap between the two guides during the pressure contact and slide within the corresponding guide holes. Additionally, the bending of contact probes in an air gap can be implemented through the appropriate shape of the probes themselves or the appropriate shape of their guides, as schematically illustrated in FIG. 1, where only one contact probe among the multiple probes typically included in a probe head is illustrated for the sake of simplification of the example, and the illustrated probe head is a type of probe head having a so-called shifted plate. In particular, FIG. 1 schematically illustrates a probe head (10) comprising at least one upper plate or die (2) and one lower plate or die (3), wherein the dies (2, 3) each have upper guide holes (2A) and lower guide holes (3A), and at least one contact probe (1) slides within these holes (12A, 13A), and the contact probe (1) has a probe body (1C) that is basically extended in a longitudinal direction along the HH axis shown in the drawing. A plurality of contact probes (1) are typically arranged in a longitudinal direction that is perpendicular to the test element and the guides within the probe head (10), that is, substantially perpendicular along the x-axis of the local reference in the drawing. The above contact probe (1) has at least one end or contact tip (1A). Hereinafter, the term end or tip refers to an end portion, which does not necessarily have to be sharp. In particular, the contact tip (1A) makes mechanical and electrical contact between the test element (4) and a test device (not shown) by contacting the contact pad (4A) of the test element (4), and the probe head (10) is an end element of the test device. In some cases, the contact probes are immovably fixed to the probe head, for example, the upper guide: such probe heads are referred to as "blocked probe heads". Alternatively, a probe head is used in which the contact probes are not fixed in place but are held in a connected state on the PCB board of the test device: such a probe head is referred to as a "non-blocking probe head." In this case, the probe head typically includes a so-called "space transformer," which is interposed between the probe head and the test device and can spatially redistribute the contact pads implemented thereon to the contact pads on the device under test, and in particular can relax the distance constraint between the centers of the pads themselves; that is, it can relax the distance constraint between the centers by causing a space transformation in terms of the distance between the centers of adjacent pads, commonly referred to as pitche