Test connector and conductive ball for test connector

Abstract

Provided are: a test connector disposed between a test device and a device to be tested; and a conductive ball for a test connector. The test connector comprises an insulation housing, a conductive ball disposed in a through-hole of the insulation housing, and a lower insulating sheet bonded to the lower surface of the insulation housing. The conductive ball includes multiple conductive particles and an elastic material, and the multiple conductive particles and the elastic material are formed integrally in a spherical shape. The lower insulating sheet has a lower-side hole smaller than the through-hole of the insulation housing. When the conductive ball is under an unpressurized condition, a space surrounding the conductive ball is formed between the conductive ball and the through-hole. The conductive ball is elastically deformable by means of a pressing force such that the space shrinks in the horizontal direction.

Description

Test connector and conductive ball for test connector

[0001] The present disclosure relates to a test connector used for testing a device under test, and a conductive component used in the test connector.

[0002] Test connectors are used when testing devices under test, such as semiconductor devices. The test connector is positioned between a test device and a device under test to electrically connect the two. The test connector transmits electrical test signals from the test device to the device under test and transmits electrical response signals from the device under test to the test device. As an example of a test connector, a conductive rubber connector is known in the art.

[0003] A conductive rubber connector comprises a plurality of conductive parts that perform signal transmission between an inspection device and a device under inspection, and an insulating part that maintains the plurality of conductive parts in an up-and-down direction. The conductive parts contact the terminals of the device under inspection and consist of a plurality of metal particles assembled in a cylindrical shape and an elastic material. The insulating part is made of the same elastic material as the elastic material of the conductive parts.

[0004] The conductive part and the insulating part can be molded together from a liquid molding material in which a plurality of metal particles are mixed with liquid silicone rubber. The conductive part can be formed by applying a magnetic field to the liquid molding material to aggregate the metal particles into a cylindrical shape. During the process of molding the conductive part and the insulating part together, adjacent conductive parts may be connected to each other by the metal particles, and as a result, insulation between the conductive parts is not achieved.

[0005] A manufacturing technique has been proposed in the art field to insulate adjacent conductive parts by forming multiple through holes in an insulating part and fitting a cylindrical conductive part, pre-molded, into each through hole. The aforementioned manufacturing technique requires the manufacturing of individual conductive parts and the assembly of the individual conductive parts and the insulating part. Consequently, the aforementioned manufacturing technique is complex and reduces the manufacturing efficiency of conductive rubber connectors. Furthermore, since the individual conductive parts fitted into the through holes have low operability, they degrade the conductivity characteristics of the conductive rubber connector.

[0006] In inspections using conductive rubber connectors, for the conductive part to exhibit conductivity (low resistance) above a certain level, the indentation depth (e.g., stroke) of the conductive part must exceed a predetermined level due to the pressure applied through the device under inspection. However, since cylindrical conductive parts formed integrally with the insulating part or fitted into the through-hole of the insulating part are constrained by the insulating part, the conductive part cannot undergo elastic deformation to the desired degree and exhibits a low stroke. The strong pressure applied to achieve a high stroke of the conductive part damages the device under inspection and the conductive part, and reduces the service life of the conductive part. To prevent damage to the conductive part and increase its service life, a conductive part with a larger diameter may be considered. However, such a conductive part exhibits a low stroke and requires a stronger pressure. As such, the conductive part of the conventional conductive rubber connector cannot exhibit a high stroke under low pressure and cannot undergo smooth elastic deformation.

[0007] Embodiments of the present disclosure provide a test connector and a conductive component used in the test connector that solve the problems of the prior art described above. At least one embodiment of the present disclosure provides a test connector comprising a conductive component that elastically deforms smoothly under pressure. At least one embodiment of the present disclosure provides a test connector comprising a conductive component that exhibits a high stroke under low pressure.

[0008] One aspect of the embodiments of the present disclosure relates to a test connector that is disposed between a test device and a device under test and can be used to test the device under test. A test connector according to one embodiment comprises an insulating housing, a conductive ball, and a lower insulating sheet. The insulating housing has a through hole that is perforated in the vertical direction. A conductive ball is separated from the through hole and disposed within the through hole, and is configured to conductively connect the test device and the device under test. The conductive ball comprises a plurality of conductive particles and an elastic material filled between each of the plurality of conductive particles, and the plurality of conductive particles and the elastic material are integrally formed in a spherical shape. The lower insulating sheet is coupled to the lower surface of the insulating housing and has a lower hole disposed below the through hole and having an inner diameter smaller than the inner diameter of the through hole. In the non-pressurized state of the conductive ball, a space surrounding the conductive ball is formed between the conductive ball and the through hole. The conductive ball is elastically deformable by a downward pressure applied to reduce the space in the horizontal direction.

[0009] In one embodiment, the conductive ball has a diameter smaller than the inner diameter of the through hole in a non-pressurized state and can move or rotate through the space formed between the conductive ball and the through hole.

[0010] In one embodiment, the conductive ball can be elastically deformed by a pressure so as to reduce the distance formed between some of the plurality of conductive particles forming the side end of the conductive ball and the inner surface of the through hole in the horizontal direction.

[0011] In one embodiment, the conductive ball is configured to be compressed in the vertical direction by an applied pressure and expanded in the horizontal direction. The horizontal expansion of the conductive ball is constrained by the inner circumference of the through hole, thereby deforming the conductive ball from a spherical shape toward a cylindrical shape.

[0012] A connector according to one embodiment may include an upper insulating sheet coupled to the upper surface of an insulating housing. The upper insulating sheet has an upper hole positioned above a through hole and having an inner diameter smaller than the inner diameter of the through hole. Each of the lower hole and the upper hole may have a circumferential surface capable of contacting a conductive ball and inclined toward the conductive ball.

[0013] In one embodiment, the lower insulating sheet includes a lower conductive portion that is coupled and fixed to a lower hole and makes conductive contact with a conductive ball, and the upper insulating sheet includes an upper conductive portion that is coupled and fixed to an upper hole and makes conductive contact with a conductive ball. The conductive ball is capable of moving and rotating between the lower conductive portion and the upper conductive portion in a non-pressurized state and is capable of elastic deformation by a pressure applied through the upper conductive portion. The lower conductive portion may be configured identically to the conductive ball and may have a spherical shape. The upper conductive portion may be configured identically to the lower hemisphere of the conductive ball and may have a hemispherical shape. A plurality of conductive balls may be disposed between the lower conductive portion and the upper conductive portion.

[0014] In one embodiment, at least two conductive balls are in conductive contact within a through hole, and a space is formed between each of the conductive balls and the through hole in a non-pressurized state. Each of the conductive balls is elastically deformable by pressure so as to expand in a horizontal direction and contract the space in a horizontal direction.

[0015] In one embodiment, the conductive balls comprise a plurality of conductive balls having different diameters, and the through holes comprise a plurality of through holes having different inner diameters. Each of the plurality of conductive balls or at least two of the plurality of conductive balls are disposed in one of the plurality of through holes.

[0016] In one embodiment, the conductive ball comprises a first conductive ball configured to conductively connect a signal terminal of a device under test and a test device, and a second conductive ball configured to conductively connect a power terminal or ground terminal of a device under test and a test device, having a diameter larger than the diameter of the first conductive ball. The through hole comprises a first through hole in which the first conductive ball is disposed, and a second through hole having an inner diameter larger than the inner diameter of the first through hole and in which the second conductive ball is disposed. At least two first conductive balls may be disposed within the first through hole, and a number of second conductive balls less than the number of first conductive balls may be disposed within the second through hole.

[0017] In one embodiment, the conductive ball comprises a first conductive ball and a second conductive ball having a diameter smaller than the diameter of the first conductive ball. The through hole comprises a first through hole in which at least two first conductive balls are disposed, and a second through hole in which at least one first conductive ball and at least two second conductive balls are disposed. The second conductive ball disposed at the uppermost position in the second through hole is positioned higher than the first conductive ball disposed at the uppermost position in the first through hole. The conductive ball may comprise a third conductive ball having a diameter larger than the diameter of the first conductive ball, and the through hole may comprise a third through hole in which the second conductive ball and the third conductive ball are disposed. The second conductive ball disposed at the uppermost position in the second through hole may be positioned higher than the third conductive ball disposed at the uppermost position in the third through hole.

[0018] In one embodiment, the conductive ball comprises a first conductive ball, a second conductive ball having a diameter smaller than the diameter of the first conductive ball, and a third conductive ball having a diameter larger than the diameter of the first conductive ball. The through hole comprises a first through hole in which at least three first conductive balls are disposed, a second through hole in which at least two second conductive balls and at least one third conductive ball are disposed, and a third through hole in which at least two third conductive balls are disposed. The first conductive ball disposed at the uppermost position in the first through hole is positioned higher than the second conductive ball disposed at the uppermost position in the second through hole, and the second conductive ball disposed at the uppermost position in the second through hole is positioned higher than the third conductive ball disposed at the uppermost position in the third through hole.

[0019] Another aspect of the embodiments of the present disclosure relates to a conductive ball for a test connector configured to be disposed in a through hole of the test connector to conductively connect a test device and a device under test. A conductive ball according to one embodiment comprises a plurality of conductive particles assembled in a spherical shape and an elastic material filled between each of the plurality of conductive particles. The plurality of conductive particles and the elastic material are integrally formed in a spherical shape to form a conductive ball. In a non-pressurized state of the conductive ball, the conductive ball is configured to be disposed within the through hole while forming a space surrounding the conductive ball. The conductive ball is elastically deformable by a downward pressure applied to reduce the space in the horizontal direction.

[0020] In one embodiment, among a plurality of conductive particles, two conductive particles adjacent to each other form the outer surface of a conductive ball and are conductively contacted along the circumference of a sphere.

[0021] In one embodiment, the conductive ball is formed such that some of the plurality of conductive particles protrude from the surface of the elastic material.

[0022] In one embodiment, the mass ratio of the mass of the elastic material to the mass of the majority of conductive particles may be at least 1:7.

[0023] According to at least one embodiment of the present disclosure, a conductive ball comprising a plurality of conductive particles and an elastic material can smoothly undergo elastic deformation in response to applied pressure within a through hole of an insulating housing. Accordingly, the conductive ball and the test connector can exhibit a high stroke under low applied pressure and can exhibit uniform operating characteristics.

[0024] According to at least one embodiment of the present disclosure, a spherical conductive ball is disposed in a through hole of an insulating housing and elastically deformed by an applied pressure. Accordingly, a large space allowing for the deformation of the conductive ball can be formed between the conductive ball and the through hole. Furthermore, it is unnecessary to adjust the distance between the conductive ball and the through hole to control the elasticity of the conductive ball. Additionally, metal particles constituting the conductive ball can be included in the conductive ball at a high density without considering the deformation of the conductive ball. Therefore, a conductive ball containing high-density conductive particles can function like a spherical metal conductor while possessing elasticity, and can overcome the low density of conductive particles for low pressure and high stroke.

[0025] According to at least one embodiment of the present disclosure, the entire spherical outer surface of the conductive ball may serve as a contact surface for a conductive connection. Accordingly, the conductive ball may be placed in a through hole of an insulating housing without directionality, may have an increased service life, and may increase the manufacturing efficiency of the test connector.

[0026] According to at least one embodiment of the present disclosure, one or more conductive balls having different diameters may be disposed in a through hole of an insulating housing. Accordingly, by distributing the conductive balls according to the application or difference in protrusion length of the terminals of the device under test, the test connector can reliably contact the device under test.

[0027] FIG. 1 schematically illustrates an example in which a test connector according to embodiments of the present disclosure is used.

[0028] FIG. 2 is a cross-sectional view illustrating a part of a test connector according to a first embodiment of the present disclosure.

[0029] Figure 3 is a cross-sectional view illustrating the challenge ball shown in Figure 2.

[0030] FIG. 4 is a cross-sectional perspective view showing a part of the test connector shown in FIG. 2.

[0031] FIG. 5 is a cross-sectional view schematically illustrating the non-pressurized and pressurized states of the conductive ball shown in FIG. 2.

[0032] FIG. 6 is a cross-sectional view schematically illustrating an example of a conductive ball employed in a test connector according to one embodiment.

[0033] FIG. 7 is a cross-sectional view schematically illustrating another example of a conductive ball employed in a test connector according to one embodiment.

[0034] FIG. 8 is a cross-sectional view illustrating a part of a test connector according to a second embodiment of the present disclosure.

[0035] FIG. 9 is a cross-sectional view illustrating a part of a test connector according to a third embodiment of the present disclosure.

[0036] FIG. 10 is a cross-sectional view illustrating a part of a test connector according to a fourth embodiment of the present disclosure.

[0037] FIG. 11 is a cross-sectional view illustrating a part of a test connector according to a fifth embodiment of the present disclosure.

[0038] FIG. 12 is a cross-sectional view schematically illustrating the pressurized state of the conductive ball shown in FIG. 11.

[0039] FIG. 13 is a cross-sectional view illustrating a part of a test connector according to the sixth embodiment of the present disclosure.

[0040] FIG. 14 is a cross-sectional view illustrating the pressurized state of the conductive ball shown in FIG. 13.

[0041] FIG. 15 is a cross-sectional view illustrating a part of a test connector according to the seventh embodiment of the present disclosure.

[0042] FIG. 16 is a cross-sectional view illustrating a part of a test connector according to the eighth embodiment of the present disclosure.

[0043] FIG. 17 is a cross-sectional view illustrating a part of a test connector according to the ninth embodiment of the present disclosure.

[0044] The embodiments of the present disclosure are illustrative for the purpose of explaining the technical concept of the present disclosure. The scope of rights according to the present disclosure is not limited to the embodiments presented below or the specific description thereof.

[0045] All technical and scientific terms used in this disclosure, unless otherwise defined, have the meaning generally understood by those skilled in the art to which this disclosure pertains. All terms used in this disclosure are selected for the purpose of further clarifying this disclosure and are not selected to limit the scope of the rights under this disclosure.

[0046] Expressions such as 'comprising', 'having', 'having', etc. used in this disclosure should be understood as open-ended terms implying the possibility of including other embodiments, unless otherwise stated in the phrase or sentence containing such expressions.

[0047] Unless otherwise stated, singular expressions described in this disclosure may include a plural meaning, and this applies likewise to singular expressions described in the claims.

[0048] Expressions such as 'first', 'second', etc. used in this disclosure are used to distinguish multiple components from one another and do not limit the order or importance of said components.

[0049] In the present disclosure, where it is stated that a component is 'connected' or 'combined' to another component, it should be understood that the component may be directly connected or combined to the other component, or connected or combined through a new component.

[0050] As used in this disclosure, the direction indicator 'upward' is based on the direction in which the test connector is positioned relative to the test device, and the direction indicator 'downward' means the opposite direction of upward. It should be understood that the direction indicator 'upward and downward direction' used in this disclosure includes both upward and downward directions, but does not mean a specific direction between the upward and downward directions. As used in this disclosure, the horizontal direction is a direction orthogonal to the upward and downward direction. If the upward and downward direction is assumed to be the Y-axis, the horizontal direction may be a direction located in the X-axis plane.

[0051] Embodiments are described with reference to the examples illustrated in the attached drawings. In the attached drawings, identical or corresponding components are given the same reference numerals. Additionally, in the description of the following embodiments, the description of identical or corresponding components may be omitted. However, even if a description of a component is omitted, it is not intended that such component is not included in any embodiment.

[0052] The embodiments described below and the examples illustrated in the attached drawings relate to a test connector used for testing a device under test and a conductive component used in the test connector. For example, the test connector may be used for final testing of a semiconductor device in a post-process during the manufacturing process of a semiconductor device. However, the examples of testing to which the test connector is applied are not limited to the aforementioned testing.

[0053] Refer to FIG. 1, which illustrates an example in which a test connector according to embodiments of the present disclosure is used. FIG. 1 schematically illustrates the shapes of a test connector, a component to which the test connector is attached, a test device, and a device to be tested. The shapes shown in FIG. 1 are one example selected for understanding the embodiments.

[0054] The test connector (10) is a sheet-shaped structure and is positioned between the inspection device (20) and the device to be inspected (30). The test connector (10) may be a component of a test socket. For example, the test connector (10) may be attached to a socket housing (40) and positioned on the inspection device (20) by the socket housing (40). The socket housing (40) may have a socket guide (41), and a receiving hole (42) may be formed in the socket guide (41) in the vertical direction (VD). The socket housing (40) may be removablely mounted to the inspection device (20) at the socket guide (41), and the test connector (10) may be removablely coupled to the socket guide (41). A device to be tested (30), which is transported to the inspection device (20) by hand or by a transport device, is received in the receiving hole (42) of the socket housing, and the socket housing (40) aligns the device to be tested (30) with respect to the test connector (10). When the device to be tested (30) is inspected, the test connector (10) contacts the inspection device (20) and the device to be tested (30) in the vertical direction (VD), thereby electrically connecting the inspection device (20) and the device to be tested (30).

[0055] The device to be tested (30) may be a semiconductor device manufactured by packaging a semiconductor IC chip and a plurality of terminals in a cuboid shape using a resin material. The device to be tested (30) may include a substrate (31) and a plurality of terminals (32) protruding from the lower surface of the substrate (31). The terminals (32) shown in FIG. 1 are of the ball type, but are not limited to the ball type.

[0056] The terminal (32) may include a signal terminal used for signal transmission, a power terminal for receiving power, and a ground terminal for grounding. The arrangement of terminals of the device under test shown in FIG. 1 is merely exemplary. In some areas of the lower surface of the substrate (31), only the signal terminal may be placed. In another area of ​​the lower surface of the substrate (31), the signal terminal and the power terminal may be placed. In yet another area of ​​the lower surface of the substrate (31), the signal terminal, the power terminal, and the ground terminal may be placed.

[0057] The inspection device (20) can inspect the electrical characteristics and operational characteristics of the device under inspection (30). The inspection device (20) may have a board on which the inspection is performed, and the board may be equipped with an inspection circuit (21) for inspecting the device under inspection. The inspection circuit (21) has a plurality of pads (22) that are conductively connected to the terminals of the device under inspection through a test connector (10). Some of the pads (22) can transmit an electrical test signal and receive a response signal from the device under inspection. Other of the pads (22) can apply power to the device under inspection and function as ground.

[0058] A test connector (10) according to one embodiment comprises an insulating housing (100), at least one conductive ball (200) disposed in the insulating housing and comprising an elastic material and a conductive material, and a lower insulating sheet (300) coupled to the lower surface of the insulating housing (100). The insulating housing (100) constitutes the main body of the test connector and has a through hole (120) that accommodates the conductive ball (200). The insulating housing (100) may be attached to a socket guide (41) of a socket housing (40) and positioned in a horizontal direction (HD). The conductive ball (200) is accommodated and disposed within the through hole (120) of the insulating housing and is configured to conductively connect the test device (20) and the device to be tested (30). The lower insulating sheet (300) supports the conductive ball (200) and insulates the adjacent conductive ball (200).

[0059] When inspecting a device to be inspected, a test connector (10) is placed on a test device (20), and a device to be inspected (30) is positioned on the test connector (10). A conductive ball (200) contacts the terminal (32) of the device to be inspected and the pad (22) of the test device in an up-and-down direction (VD). The conductive ball (200) contacts the terminal (32) at its upper end and contacts the pad (22) at its lower end. Accordingly, the conductive ball (200) forms an up-and-down conductive path between the corresponding terminal (32) and the pad (22).

[0060] When terminal (32) is a signal terminal, the conductive ball (200) transmits a test signal from the inspection device to the device under inspection and transmits a response signal from the device under inspection to the inspection device, thereby performing signal transmission between the inspection device (20) and the device under inspection (30). When terminal (32) is a power terminal, the conductive ball (200) supplies power from the inspection device to the device under inspection. When terminal (32) is a ground terminal, the device under inspection (30) is grounded through the conductive ball (200).

[0061] The insulating housing (100) may include a plurality of through holes (120), and at least one conductive ball (200) may be received in each through hole (120). The plurality of through holes (120) may be arranged in a matrix form or in a matrix form of one or more pairs within the insulating housing (100), and the arrangement of the through holes may vary depending on the arrangement of the terminals of the device under test. The arrangement of the through holes shown in FIG. 1 is one example, and the arrangement of the through holes may vary depending on the area of ​​the insulating housing (100). Depending on the area of ​​the insulating housing (100), only through holes receiving conductive balls for signal terminals may be arranged, conductive balls for signal terminals and conductive balls for power terminals may be arranged side by side, or conductive balls for signal terminals and conductive balls for ground terminals may be arranged side by side. Accordingly, the test connector may include only a conductive ball for the signal terminal, or may include a conductive ball for the signal terminal and a conductive ball for the power terminal, or may include a conductive ball for the signal terminal, a power terminal, and a ground terminal, depending on the area of ​​the insulating housing.

[0062] When inspecting the device under test, a pressure (PF) is applied to the device under test (30) by a mechanical device or manually. The terminal (32) of the device under test receiving the pressure (PF) presses the conductive ball (200) of the test connector downward. As the terminal of the device under test presses the conductive ball (200) downward, the conductive ball (200) is compressed downward by the downward pressure (PF) and can be elastically deformed to expand in the horizontal direction (HD). When the pressure (PF) is removed from the device under test, the conductive ball (200) can be restored to its original shape.

[0063] Reference is made to FIGS. 2 through 17 for the description of embodiments of a test connector. FIGS. 2 through 17 schematically illustrate the shape and number of components of a test connector, which are examples selected for understanding embodiments of the test connector.

[0064] FIG. 2 is a cross-sectional view illustrating a part of a test connector according to a first embodiment of the present disclosure. FIG. 3 is a cross-sectional view illustrating a conductive ball illustrated in FIG. 2. FIG. 4 is a cross-sectional perspective view illustrating a part of the test connector illustrated in FIG. 2. In the following description, reference will be made to FIG. 2 to FIG. 4.

[0065] The test connector (10) illustrated in FIG. 2 includes an insulating housing (100), a conductive ball (200), and a lower insulating sheet (300). A portion of the test connector illustrated in FIG. 2 includes a conductive ball (200) that can contact a signal terminal of a device to be tested. Depending on the area of ​​the insulating housing, the test connector (10) may include a conductive ball that can contact a power terminal and a conductive ball that can contact a ground terminal, and the conductive ball that can contact the signal terminal, the power terminal, and the ground terminal may have the same structure.

[0066] A conductive ball (200) is received in an insulating housing (100). The insulating housing (100) may be made of an insulating material. The insulating material of the insulating housing (100) may include, for example, silicone rubber, polyimide resin, etc., but is not limited thereto. The insulating housing (100) has a plurality of through holes (120) that penetrate in the vertical direction (VD), and a conductive ball (200) is received and arranged within each through hole. The through holes (120) may have a circular cross-sectional shape and have a cylindrical inner surface (121). The insulating housing (100) separates the conductive balls received in each through hole (120) adjacent in the horizontal direction (HD) and insulates them from each other in the horizontal direction (HD).

[0067] For example, liquid silicone rubber may be injected into a molding die and cured to form a sheet corresponding to an insulating housing. Through holes (120) may be formed in this sheet by laser irradiation to form an insulating housing (100). For another example, the molding die may have a plurality of pillars corresponding to each of the through holes within the molding space, and as the liquid silicone rubber is cured, an insulating housing (100) having a plurality of through holes may be formed.

[0068] The lower insulating sheet (300) is bonded to the lower surface (111) of the insulating housing (100) and, for example, can be adhered to the lower surface (111). As an example, the lower insulating sheet (300) may include a film made of polyimide resin. The lower insulating sheet (300) can prevent short circuits between adjacent conductive balls and can protect the lower surface of the insulating housing (100).

[0069] The lower insulating sheet (300) has a lower hole (310) positioned to correspond to the through hole (120) and the conductive ball (200). The lower hole (310) penetrates the lower insulating sheet in the vertical direction (VD). The lower hole (310) is positioned below the through hole (120) and has an inner diameter that is smaller than the inner diameter (DH) of the through hole (120) and the diameter (DB) of the conductive ball (200) in at least a portion thereof. A portion of the conductive ball (200) may protrude beyond the lower surface of the lower insulating sheet (300) through the lower hole (310), and the lower hole (310), which is smaller than the through hole (120), may prevent the conductive ball (200) from being separated from the through hole (120).

[0070] According to one embodiment of the test connector, the lower hole (310) has a circumferential surface (311) that slopes toward the conductive ball (200). The circumferential surface (311) is formed along the circumference of the lower hole (310) so as to be in contact with the conductive ball (200). The circumferential surface (311) slopes toward the conductive ball (200) with respect to the inner circumferential surface (121) of the through hole. The circumferential surface (311) slopes toward the conductive ball (200) so that the lower hole (310) expands upward.

[0071] The conductive ball (200) is placed within the through hole (120) of the insulating housing and is separated from the through hole (120) (e.g., from the inner surface (121) of the through hole). The conductive ball (200) is independent from the insulating housing (100) and the lower insulating sheet (300). The conductive ball (200) includes a conductive material and an elastic material, functions as an electrical conductor, and functions to elastically deform in response to the pressure applied by the device under test.

[0072] The conductive ball (200) comprises a plurality of conductive particles (211) and an elastic material (212). The conductive particles (211) of the conductive ball may be metal powder made of a highly conductive metal material and having dimensions of several micrometers. Alternatively, the conductive particles (211) may be metal powder in which a highly conductive metal material is coated onto a core made of an elastic resin material or a metal material. The conductive ball (200), comprising a plurality of conductive particles (211) assembled or clustered in a predetermined shape, functions as an electrical conductor between the pad of the inspection device and the device to be inspected.

[0073] The elastic material (212) of the conductive ball is in a hardened state and imparts elasticity to the conductive ball. For example, the elastic material (212) may be hardened silicone rubber, but is not limited thereto. Within the conductive ball (200), the elastic material (212) is filled between each of the plurality of conductive particles (211).

[0074] A plurality of conductive particles (211) and an elastic material (212) are integrally formed to form a conductive ball (200). According to an embodiment of the present disclosure, the plurality of conductive particles (211) and the elastic material (212) are integrally formed in a spherical shape, so that the conductive ball (200) is formed in a spherical shape. The plurality of conductive particles (211) are gathered in a spherical shape, and the elastic material (212) maintains the plurality of conductive particles (211) in a spherical shape. Therefore, the conductive ball (200) has a spherical shape and can function as an elastically deformable conductor.

[0075] A conductive ball (200) can be manufactured by molding using a mold. For example, a liquid molding material may be prepared comprising a liquid material of an elastic material (212) and a plurality of conductive particles (211) dispersed within the liquid material. Additionally, an upper mold having a molding cavity corresponding to the upper hemispherical shape of the conductive ball and a lower mold having a molding cavity corresponding to the lower hemispherical shape of the conductive ball may be prepared. When the upper mold and the lower mold are joined, a spherical molding cavity is formed by the upper mold and the lower mold. The liquid molding material is injected into the spherical molding cavity and cured to manufacture the conductive ball (200). Accordingly, the conductive ball (200) may be composed of an upper hemispherical portion (221) corresponding to the upper hemispherical shape of the conductive ball and a lower hemispherical portion (222) corresponding to the lower hemispherical shape of the conductive ball, and the upper hemispherical portion (221) and the lower hemispherical portion (222) are integrally combined to form the conductive ball (200).

[0076] In the conductive ball (200) that can be manufactured as described above, a plurality of conductive particles (211) constituting the conductive ball (200) are assembled in a nearly uniform spherical shape without a specific orientation, and an elastic material (212) is filled between each of the plurality of conductive particles. Inside the conductive ball (200), one conductive particle can be in contact with another conductive particle in all directions. For example, inside the conductive ball (200), two adjacent conductive particles (211) among the plurality of conductive particles can be conductively contacted in the vertical direction (VD), the horizontal direction (HD), or in an inclined direction between the vertical direction (VD) and the horizontal direction (HD). Additionally, conductive particles (211) that form the outer surface of the spherical shape of the conductive ball (200) and are adjacent to each other can be conductively contacted along the perimeter of the spherical shape of the conductive ball (200). For example, adjacent conductive particles (211) can be conductively contacted along the circumference of the circular cross-section of the conductive ball. Additionally, a plurality of conductive particles (211) are uniformly arranged on the spherical outer surface of the conductive ball (200) to form the spherical outer surface of the conductive ball (200). Thus, the entire spherical outer surface of the conductive ball (200) can function to contact the terminal of the device under test, the pad of the test device, or another conductive ball. Furthermore, since the conductive ball (200) can be arranged without directionality within the through hole (120) of the insulating housing, the manufacturing efficiency of the test connector is increased.

[0077] According to an embodiment of the test connector, the conductive ball (200) may be formed such that the conductive particles (211) forming the outer surface of the conductive ball protrude from the surface of the elastic material (212) without being separated from the surface of the elastic material (212) forming the outer surface of the conductive ball. Alternatively, according to an embodiment of the test connector, the conductive ball (200) may be formed such that the surface of the conductive particles (211) forming the outer surface of the conductive ball and the surface of the elastic material (212) are positioned at nearly the same level, in which case a portion of the conductive particles (211) may be exposed from the surface of the elastic material (212). For example, by processing the conductive ball in which the surface of the conductive particles and the surface of the elastic material are positioned at nearly the same level to remove the elastic material, a conductive ball in which the conductive particles protrude from the surface of the elastic material may be formed. A conductive ball in which the conductive particles protrude from the surface of the elastic material may improve contact performance with the terminals of the device under test, the pads of the test device, or other conductive balls.

[0078] A conductive ball (200) comprising a plurality of spherically assembled conductive particles (211) and an elastic material (212) is elastically deformable in the vertical direction (VD) and the horizontal direction (HD). When inspecting a device under inspection, a terminal of the device under inspection, which receives a pressure (pressure indicated by the symbol PF in FIG. 1), presses the conductive ball (200) downward. The conductive ball (200) is configured to be elastically deformed by the pressure applied downward, and can be elastically deformed to be compressed in the vertical direction (VD) and expanded in the horizontal direction (HD). Hereinafter, the state in which the conductive ball (200) is elastically deformed by the pressure as described above is referred to as the pressure state of the conductive ball. When the inspection of the device under inspection is completed and the pressure is removed from the device under inspection, each conductive ball (200) can be elastically restored from the pressure state to its original shape. Hereinafter, the state of the conductive ball (200) in which no pressure is applied to the conductive ball is referred to as the non-pressure state of the conductive ball. In this way, each conductive ball can be elastically deformed into a non-pressure state and a pressure state.

[0079] A spherical conductive ball (200) has a diameter (DB). For example, the diameter (DB) of the conductive ball can be defined as the maximum distance measured between conductive particles that are furthest apart from each other in a direction passing through the center of the spherical conductive ball. The conductive ball (200) placed within the through hole (120) has a diameter (DB) smaller than the inner diameter (DH) of the through hole (120) in a non-pressurized state.

[0080] A spherical conductive ball (200) smaller than the through hole (120) is placed within a cylindrical through hole (120). Thus, in a non-pressurized state, a space (130) is formed between the conductive ball (200) and the through hole (120), specifically between the outer surface of the conductive ball (200) and the inner surface (121) of the through hole (120). The space (130) is an empty space or gap formed between the conductive ball and the through hole. The space (130) functions to allow elastic deformation of the conductive ball (200) under pressure.

[0081] In the non-pressurized state of the conductive ball, the space (130) is formed to surround the conductive ball (200) between the inner surface (121) of the through hole and the outer surface of the conductive ball (200). The space (130) is formed to surround the outer surface of the conductive ball (200) in the circumferential direction of the central axis (CA) of the through hole (120). For example, the space (130) can be defined by subtracting the spherical space occupied by the conductive ball (200) from the cylindrical space that can be defined by the upper and lower ends of the conductive ball (200) and the inner surface (121) of the through hole. Since the conductive ball (200) has a spherical shape, the size of the space (130) that allows for deformation of the conductive ball can be increased.

[0082] Since the conductive ball (200) is smaller than the through hole (120) in the non-pressurized state, the conductive ball (200) can be moved or rotated through the space (130) within the through hole (120) in the non-pressurized state. Thus, the conductive ball (200) can be easily placed in the through hole (120) of the insulating housing without directionality. Additionally, after using the test connector for a predetermined period of time, the damaged conductive ball can be easily replaced. Alternatively, instead of replacing the damaged conductive ball, the test connector or test socket can be shaken. Accordingly, the damaged conductive ball can be moved or rotated within the through hole (120), unused conductive particles can be positioned for use on the outer surface of the damaged conductive ball, and the service life of the test connector can be increased.

[0083] FIG. 5 is a cross-sectional view schematically illustrating the non-pressurized and pressurized states of the conductive ball illustrated in FIG. 2. With reference to FIG. 2 to FIG. 5, the deformation of the conductive ball under pressure and the operation of a part of the test connector will be described.

[0084] As a pressure (PF) is applied downward to the conductive ball (200) through the device under test, the conductive ball (200) changes from the non-pressurized state exemplified on the left side of FIG. 5 to the pressured state exemplified on the right side of FIG. 5. The conductive ball (200) is pressed by the terminal (32) of the device under test, and the conductive ball (200) is compressed downward by the pressure (PF) and elastically deformed to expand in the horizontal direction (HD).

[0085] While the conductive ball (200) is changing to a pressurized state, the conductive ball (200) is elastically deformed to contract the space (130) in the horizontal direction (HD). As the pressurizing force (PF) is applied downward to the conductive ball (200), when viewed from a cross-section, the conductive ball (200) deforms from a circular shape toward an elliptical shape, thereby contracting the space (130) in the horizontal direction (HD). For example, the upper hemisphere (221) of the conductive ball and the lower hemisphere (222) of the conductive ball expand simultaneously in the horizontal direction (HD) through the space (130) toward the inner surface (121) of the through hole, and the space (130) contracts in the horizontal direction (HD) between the outer surface of the conductive ball (200) and the inner surface (121) of the through hole.

[0086] Since the diameter of the conductive ball (200) is smaller than the inner diameter of the through hole (120), in the non-pressurized state of the conductive ball, a separation distance (SD) is formed in the horizontal direction (HD) between some of the plurality of conductive particles forming the side end of the conductive ball (200) and the inner surface (121) of the through hole. The separation distance (SD) may be a distance measured in the horizontal direction (HD) between the conductive particles located at the side end of the conductive ball in the horizontal direction (HD) and the inner surface (121) of the through hole, and may be the thickness of a part of the space (130) in the horizontal direction (HD). The side end of the conductive ball may refer to the end of the conductive ball corresponding to the spherical equator of the conductive ball, and may be the boundary between the upper hemisphere (221) and the lower hemisphere (222). While the conductive ball (200) is changing to a pressurized state, the conductive ball (200) is deformed by the pressurizing force (PF) to reduce the separation distance (SD) in the horizontal direction (HD). When viewed in a cross-sectional view of the conductive ball in the vertical direction, the conductive ball may have two ends. Since the conductive ball can move within the through hole in a non-pressurized state, either of the two ends of the conductive ball (200) may come into contact with the inner surface (121) of the through hole. Accordingly, the separation distance (SD) may be formed between the end of the conductive ball that does not come into contact with the inner surface (121) and the inner surface (121).

[0087] While the conductive ball is changing to a pressurized state, the side end of the conductive ball (200) comes into contact with the inner surface (121) of the through hole, and accordingly, the horizontal expansion of the equator of the conductive ball (200) is constrained and stopped by the inner surface (121). As the conductive ball continues to be pressed through the terminal (32) by the pressurizing force (PF), the horizontal expansion of the equator of the conductive ball (200) is constrained by the inner surface (121) of the through hole (120), but the upper and lower parts of the equator of the conductive ball (200) continue to expand in the horizontal direction (HD), thereby shrinking the space (130) in the horizontal direction (HD). For example, while the expansion of the equator of the conductive ball is constrained by the inner surface (121), the upper hemisphere (221) and the lower hemisphere (222) expand through the space (130) in the horizontal direction toward the inner surface (121). As a result, the conductive ball (200) can be deformed from a spherical shape in a non-pressurized state toward a roughly cylindrical shape, and the inner surface (121) of the through hole deforms the conductive ball from a spherical shape in a non-pressurized state toward a cylindrical shape in a pressurized state. The cylindrical shape in the pressurized state may be a spatial shape defined by the inner surface (121) of the through hole. The cylindrical shape may be a shape consisting of a cylindrical shape formed by the part of the conductive ball in contact with the inner surface (121), and a roughly disc shape formed on the upper and lower sides of the cylindrical shape and having a round circumference.

[0088] As the conductive ball (200) is constrained by the inner surface (121) and elastically deformed from a spherical shape toward a cylindrical shape by the applied force (PF), the distance between the top and bottom of the conductive ball (200) (height of the conductive ball) is reduced, and the upper hemisphere (221) and the lower hemisphere (222) are each deformed toward a cylindrical shape. As the conductive ball (200) is deformed from a spherical shape toward a cylindrical shape by the applied force (PF), the top of the conductive ball (200) in contact with the terminal can be deformed to be slightly concave and approximately flat, and the bottom of the conductive ball (200) can be deformed to be approximately flat. Additionally, compared to the non-pressurized state, the number of conductive particles placed at the top and bottom of the conductive ball can be increased, and the relative height in the vertical direction (VD) between adjacent conductive particles in the horizontal direction (HD) at the top and bottom of the conductive ball can be reduced.

[0089] A conductive ball (200) that is deformed from a spherical shape into a cylindrical shape by applying pressure causes a plurality of conductive particles to be uniformly arranged in the vertical direction and causes the contact pressure between the conductive particles generated by the pressure to act in the vertical direction. Accordingly, the conductive ball (200) can exhibit low contact resistance and uniform operating characteristics under pressure, and does not cause problems such as bending of the conductive parts under pressure.

[0090] Assuming the vertical length of the conductive ball in a non-pressurized state is the first length, the conductive ball (200) deformed into a cylindrical shape has a second length that is shorter than the first length. The difference between the first length and the second length is the indentation depth of the conductive ball and can be referenced as a stroke. As the conductive ball (200) deforms from a spherical shape to a cylindrical shape, the conductive ball (200) can exhibit a high stroke. Accordingly, the conductive ball (200) can be elastically deformed smoothly under low pressure, and the device under inspection can be inspected using even lower pressure. In addition, the conductive ball (200) deformed from a spherical shape to a cylindrical shape can exhibit an impedance that is well matched to the impedance of the device under inspection and the impedance of the inspection device.

[0091] FIG. 6 is a cross-sectional view schematically illustrating one example of a conductive ball employed in a test connector according to one embodiment, and FIG. 7 is a cross-sectional view schematically illustrating another example of a conductive ball employed in a test connector according to one embodiment. FIG. 6 and FIG. 7 illustrate the non-pressurized state and the pressurized state of the conductive ball side by side. In the following description, reference will be made to FIG. 6 and FIG. 7.

[0092] The conductive ball (200) may be formed such that the conductive particles (211) forming the outer surface of the conductive ball protrude from the surface of the elastic material (212) (see FIG. 6). The conductive ball (200) may be formed such that the conductive particles (211) forming the outer surface of the conductive ball and the surface of the elastic material (212) are positioned at approximately the same level (see FIG. 7). The conductive particles (211) may be formed in a roughly spherical shape, but the spherical shape of the conductive particles (211) is merely exemplary. The conductive particles (211) may have a shape, for example, a star shape or a shape with spikes protruding from the sphere. Conductive particles with a star shape or a shape with protruding spikes can improve the bonding force between the conductive particles and reduce the contact resistance between the terminals of the device under test and the conductive particles.

[0093] As the conductive ball (200) is deformed into a cylindrical shape through the space (130) by the applied pressure (PF), the conductive ball (200) can achieve a high stroke while absorbing the applied pressure (PF). This deformed shape of the conductive ball can realize a short separation distance between the conductive ball and the inner surface of the through hole. In addition, by adjusting the ratio of multiple conductive particles included in the conductive ball, the resistance characteristics or elastic characteristics of the conductive ball can be appropriately selected to suit various devices under inspection. Furthermore, conductive balls having various diameters can be appropriately selected according to the applied pressure required for inspection of the device under inspection or the terminal arrangement of the device under inspection.

[0094] For example, a single conductive ball may contain multiple conductive particles (211) and an elastic material (212) such that the mass ratio of the mass of the elastic material (212) to the mass of multiple conductive particles (211) is at least 1:7. The mass ratio is not limited to the example described above. The mass ratio may have a minimum value and a maximum value within a range that enables the molding of a conductive ball in which the multiple conductive particles (211) and the elastic material (212) are integrally formed in a spherical shape, deformed into a cylindrical shape by pressure, and restored to a spherical shape. Therefore, the conductive ball (200) contains conductive particles at a high density, thereby simultaneously realizing low resistance and appropriate elastic deformation.

[0095] FIGS. 8 to 17 are cross-sectional views illustrating various embodiments of a test connector. The test connectors illustrated in FIGS. 8 to 17 have a structure and configuration identical or similar to the structure and configuration of the test connector according to the aforementioned embodiment, and include the aforementioned conductive ball.

[0096] FIG. 8 is a cross-sectional view illustrating a portion of a test connector according to a second embodiment of the present disclosure. Referring to FIG. 8, the test connector (10) according to the second embodiment includes an upper insulating sheet (400) coupled to an insulating housing (100). The upper insulating sheet (400) is coupled to an upper surface (112) of the insulating housing (100) and, for example, may be adhered to the upper surface (112). As an example, the upper insulating sheet (400) may include a film made of polyimide resin. The upper insulating sheet (400) can prevent short circuits between adjacent conductive balls and can protect the upper surface of the insulating housing (100).

[0097] The upper insulating sheet (400) has an upper hole (410) positioned to correspond to the through hole (120) and the conductive ball (200). The upper hole (410) penetrates the upper insulating sheet in the vertical direction (VD). The upper hole (410) is positioned above the through hole (120). The upper hole (410) may have an inner diameter that is smaller than the inner diameter of the through hole (120) and the diameter of the conductive ball (200) in at least a portion thereof. A terminal of the device under test may contact the conductive ball (200) through the upper hole (410). Alternatively, a portion of the conductive ball (200) may protrude above the upper surface of the upper insulating sheet (400) through the upper hole (410).

[0098] According to one embodiment of the test connector, the upper hole (410) has a circumferential surface (411) that slopes toward the conductive ball (200). The circumferential surface (411) is formed along the circumference of the upper hole (410) so as to be able to contact the conductive ball (200). The circumferential surface (411) slopes toward the conductive ball (200) with respect to the inner circumferential surface (121) of the through hole. The circumferential surface (411) slopes toward the conductive ball (200) so that the upper hole (410) expands downward. The circumferential surface (411) can prevent the conductive ball (200) from separating from the through hole (120). Additionally, since the circumferential surface (411) has a slope toward the conductive ball (200), the deformation and rotation space of the conductive ball within the through hole (120) can be expanded.

[0099] FIG. 9 is a cross-sectional view illustrating a portion of a test connector according to a third embodiment of the present disclosure. Referring to FIG. 9, the test connector according to the third embodiment includes a conductive portion fixed in a hole of an insulating sheet.

[0100] The lower insulating sheet (300) includes a lower conductive portion (320) that is coupled and fixed to the lower hole (310), and the upper insulating sheet (400) includes an upper conductive portion (420) that is coupled and fixed to the upper hole (410). The lower conductive portion (320) and the upper conductive portion (420) are configured to be conductive in the vertical direction (VD). The lower conductive portion (320) is in contact with the conductive ball (200) so as to be conductive in the vertical direction (VD). The upper conductive portion (420) can be in contact with the conductive ball (200) so as to be conductive in the vertical direction (VD).

[0101] In a non-pressurized state, the upper conductive portion (420) may not come into contact with the conductive ball (200). In a non-pressurized state, the conductive ball (200) is not fixed between the lower conductive portion (320) and the upper conductive portion (420) and is movable and rotatable through the space (130). The movable and rotatable conductive ball (200) can come into contact with the upper conductive portion (420) and the lower conductive portion (320) on its entire outer surface. The terminal of the device under inspection presses the upper conductive portion (420) downward by a pressure, and the conductive ball (200) can be deformed to reduce the space (130) in the horizontal direction (HD) by the pressure applied through the upper conductive portion (420).

[0102] The lower conductive portion (320) and the upper conductive portion (420) are configured to include a conductive material and an elastic material. The lower conductive portion (320) and the upper conductive portion (420) are configured in the same way as the conductive ball (200). Accordingly, the lower conductive portion (320) and the upper conductive portion (420), like the conductive ball (200), are composed of a plurality of conductive particles assembled in a spherical shape and an elastic material filled between each of the conductive particles, and have a spherical shape in a non-pressurized state. The hemispherical upper hemisphere of the lower conductive portion (320) can be inserted into the through hole (120), and the hemispherical lower hemisphere of the upper conductive portion (420) is inserted into the through hole (120). Thus, the test connector according to the third embodiment may have a structure in which two conductive balls are placed within the through hole (120), and may be applied to arrange two conductive balls vertically.

[0103] Since the fixed upper conductive portion (420) can contact the terminal of the device under test at the top of the upper hemisphere, the terminal of the device under test and the upper conductive portion (420) can be in stable contact. In addition, since the upper conductive portion (420) is fixed to the upper insulating sheet (400), a damaged upper conductive portion (420) can be easily replaced together with the upper insulating sheet (400).

[0104] FIG. 10 is a cross-sectional view illustrating a portion of a test connector according to a fourth embodiment of the present disclosure. Referring to FIG. 10, in the test connector according to the fourth embodiment, the upper conductive portion of the upper insulating sheet has a hemispherical shape compared to the test connector according to the third embodiment.

[0105] The upper conductive portion (420) may be configured similarly to the lower hemispherical portion (222) of the conductive ball (200) and may be formed in a hemispherical shape. The upper conductive portion (420) may be fixed to the upper hole (410) of the upper insulating sheet so that the hemispherical flat upper surface (421) faces upward. The upper surface (421) of the upper conductive portion (420) may come into contact with the ball-type terminal of the device under test with a wide contact surface. For example, as pressure is applied from the terminal to the upper conductive portion (420) while the ball-type terminal is in contact with the upper surface (421) of the upper conductive portion, the upper surface (421) may be deformed to be concave downward, partially covering the surface of the ball-type terminal and coming into contact with the ball-type terminal.

[0106] In some of the through holes among the plurality of through holes, a plurality of conductive balls (200) may be disposed between the lower conductive portion (320) and the upper conductive portion (420). For example, as shown in the rightmost through hole in FIG. 10, four conductive balls (200) may be disposed in a two-layer structure between the lower conductive portion (320) and the upper conductive portion (420). The conductive balls (200) in the rightmost through hole may have a diameter corresponding to half the diameter of the conductive balls disposed in the other through holes. A test connector in which a plurality of conductive balls are disposed between the lower conductive portion (320) and the upper conductive portion (420) may be used for testing a device under test that requires low pressure. The structure of a test connector having a plurality of conductive balls disposed between the lower conductive portion and the upper conductive portion is illustrated exemplarily in FIG. 10 and may be adopted in the through holes depending on the area of ​​the insulating housing.

[0107] FIG. 11 is a cross-sectional view illustrating a part of a test connector according to a fifth embodiment of the present disclosure, and FIG. 12 is a cross-sectional view schematically illustrating the pressurized state of a conductive ball of a part of the test connector illustrated in FIG. 11. In the following description, reference will be made to FIG. 11 and FIG. 12.

[0108] According to an embodiment of the test connector, at least two conductive balls (200) may be placed within a single through hole (120) in a manner that allows them to be conductively contacted in an up-and-down direction. In a non-pressurized state, a space (130) is formed between each conductive ball (200) and the inner surface (121) of the through hole.

[0109] When changing from a non-pressurized state to a pressurized state, each conductive ball (200) is elastically deformable by a pressure (PF) to reduce the space (130) in the horizontal direction (HD). Each conductive ball (200) is constrained by the inner circumference of the through hole (120) and deforms from a spherical shape toward a cylindrical shape. The upper hemisphere and the lower hemisphere of each conductive ball (200) simultaneously expand in the horizontal direction (HD) by the pressure (PF), thereby reducing the space (130) in the horizontal direction (HD).

[0110] The conductive balls (200) in contact from above and below are elastically deformed independently by a pressure (PF), and can achieve a high stroke corresponding to the sum of the indentation depths of each conductive ball. When the conductive balls (200) in contact from above and below change to a pressure state, the conductive ball (200) located on the lower side may exhibit a greater indentation depth than the conductive ball (200) located on the upper side. If the conductive balls (200) have conductive particles protruding from the surface of the elastic material, the contact performance between the upper and lower conductive balls may be improved. For example, the conductive ball shown in FIG. 11 may have the same diameter as the conductive ball shown in FIG. 2, and the insulating housing shown in FIG. 11 may have a thickness equal to twice the thickness of the insulating housing shown in FIG. 2. The two conductive balls (200) within the through hole (120) can move and rotate independently within the through hole (120), and the contact position between the two conductive balls (200) can be varied.

[0111] According to an embodiment of the present disclosure, the conductive balls employed in the test connector may include a plurality of conductive balls having different diameters. The through holes of the insulating housing may include a plurality of through holes having different inner diameters to correspond to the conductive balls having different diameters. The number of different diameters of the conductive balls and the number of different inner diameters of the through holes in the embodiment are exemplary. For example, depending on the application and protrusion length of the terminals of the device under test, conductive balls having various diameters and through holes having various inner diameters may be employed in the test connector.

[0112] According to an embodiment of the present disclosure, each of the plurality of conductive balls may be disposed in one of the plurality of through holes. Alternatively, at least two of the plurality of conductive balls may be disposed in one of the plurality of through holes. Since the plurality of conductive balls have different inner diameters, the conductive height formed by the conductive balls in each of the plurality of through holes may differ. In this regard, the conductive height may refer to the distance between the top and bottom of a single conductive ball disposed within a single through hole, the distance between the top and bottom of a combination of two or more conductive balls disposed within a single through hole, or the distance between the top and bottom of a combination of two or more different conductive balls disposed within a single through hole.

[0113] FIG. 13 is a cross-sectional view illustrating a part of a test connector according to a sixth embodiment of the present disclosure, showing the part of the test connector and the part of the device under test together. FIG. 14 is a cross-sectional view illustrating the pressurized state of the conductive ball shown in FIG. 13. In the following description, reference will be made to FIG. 13 and FIG. 14.

[0114] The device under test may include a signal terminal (33), a power terminal (34), and a ground terminal (35) depending on the area of ​​the substrate (31). The signal terminal (33) and the power terminal (34) may be arranged adjacently, and the signal terminal (33) and the ground terminal (35) may be arranged adjacently. FIG. 13 illustrates, by way of example, that the signal terminal (33), the power terminal (34), and the ground terminal (35) are arranged side by side. The test connector (10) may include conductive balls having different diameters according to the use of each terminal.

[0115] The power terminal (34) and the ground terminal (35) are not used for signal transmission. In order for the conductive ball for the power terminal or the ground terminal to exhibit low resistance, the conductive ball for the power terminal or the conductive ball for the ground terminal needs to be subjected to a stronger pressing force and needs to be pressed to a greater pressing depth. However, the conductive ball for the signal terminal needs to be pressed to a smaller pressing depth than the pressing depth required for the conductive ball for the power terminal or the ground terminal to prevent excessive deformation, and needs to be subjected to a smaller pressing force. To correspond to the pressing depth required for the signal terminal, power terminal, or ground terminal, a test connector according to one embodiment includes conductive balls having different diameters, and the conductive ball placed in the through hole for the signal terminal is positioned lower than the conductive ball for the power terminal or the ground terminal.

[0116] In a test connector according to an embodiment illustrated in FIG. 13, the conductive ball comprises a first conductive ball (201) and a second conductive ball (202) having a diameter larger than the diameter of the first conductive ball (201). For example, the first conductive ball (201) may have the same diameter as the conductive ball illustrated in FIG. 2. The first conductive ball (201) is configured to conductively connect a signal terminal (33) of a device under test and a test device (20). The second conductive ball (202) is configured to conductively connect a power terminal (34) or a ground terminal (35) of a device under test and a test device (20).

[0117] The through hole of the insulating housing (100) includes a first through hole (1201) in which a first conductive ball (201) is disposed and a second through hole (1202) in which a second conductive ball (202) is disposed. The second through hole (1202) has an inner diameter larger than the inner diameter of the first through hole (1201). The first through hole (1201) is disposed to correspond to a signal terminal (33). The second through hole (1202) is disposed to correspond to a power terminal (34) or a ground terminal (35).

[0118] At least two first conductive balls (201) are placed within the first through hole (1201). In the example illustrated in FIG. 13, three first conductive balls (201) are placed within the first through hole (1201). A number of second conductive balls (202) fewer than the number of first conductive balls placed within the first through hole (1201) is placed within the second through hole (1202). In the example illustrated in FIG. 13, two second conductive balls (202) are placed within the second through hole (1202). As another example, the first conductive balls (201) and the second conductive balls (202) may be employed in a test connector according to the embodiment illustrated in FIG. 2.

[0119] In the non-pressurized state, the first conductive height (CH1) in the first through hole (1201) is smaller than the second conductive height (CH2) in the second through hole (1202). The first conductive ball (201) positioned at the top of the first through hole (1201) is positioned lower than the second conductive ball (202) positioned at the top of the second through hole (1202). When the conductive ball is switched from the non-pressurized state to the pressurized state shown in FIG. 14, the power terminal (34) or the ground terminal (35) contacts the conductive ball before the signal terminal (33).

[0120] FIG. 15 is a cross-sectional view illustrating a part of a test connector according to the seventh embodiment of the present disclosure, and illustrates a part of the test connector and a part of the device under test together. In the following description, reference will be made to FIG. 15.

[0121] The device under test may include terminals (32) with different protrusion lengths depending on the area of ​​the substrate (31). The protrusion length may refer to the distance from the lower surface of the substrate (31) of the device under test to the bottom of the terminal (32). For example, in FIG. 15, the terminal (32) located on the right side has a shorter protrusion length than the terminal (32) located in the middle. Terminals (32) having different protrusion lengths do not come into contact with the conductive ball simultaneously. A test connector according to one embodiment shown in FIG. 15 has different conductivity heights in each through hole so that terminals (32) having different protrusion lengths and the conductive ball can come into contact simultaneously.

[0122] In a test connector according to an embodiment illustrated in FIG. 15, the conductive balls of the test connector include a first conductive ball (201) and a second conductive ball (202) having a diameter smaller than the diameter of the first conductive ball (201). For example, the first conductive ball (201) may have the same diameter as the conductive ball illustrated in FIG. 2. The through hole of the insulating housing (100) includes a first through hole (1201) in which the first conductive ball (201) is disposed and a second through hole (1202) in which the first conductive ball (201) and the second conductive ball (202) are disposed.

[0123] One first conductive ball (201) may be placed in the first through hole (1201), and two second conductive balls (202) may be placed in the second through hole (1202). In the example illustrated in FIG. 15, at least two first conductive balls (201) are placed within the first through hole (1201) by being in contact conductively in the vertical direction (VD). Additionally, at least one first conductive ball (201) and at least two second conductive balls (202) are placed within the second through hole (1202) by being in contact conductively in succession in the vertical direction (VD). The second conductive ball (202) placed at the uppermost position in the second through hole (1202) is positioned higher than the first conductive ball (201) placed at the uppermost position in the first through hole (1201). Therefore, the first conductive height (CH1) in the first through hole (1201) is smaller than the second conductive height (CH2) in the second through hole (1202), and the first conductive ball (201) of the first through hole and the second conductive ball (202) of the second through hole can simultaneously come into contact with terminals (32) having different protrusion lengths.

[0124] A through hole (e.g., a second through hole (1202)) that accommodates a conductive ball having a different diameter may include a partial through hole having a different inner diameter to correspond to a different diameter of the conductive ball. For example, referring to FIG. 15, the second through hole (1202) includes a first partial through hole (1221) in which a first conductive ball (201) can be placed together with the aforementioned space, and a second partial through hole (1222) in which a second conductive ball (202) can be placed together with the aforementioned space.

[0125] FIG. 16 is a cross-sectional view illustrating a part of a test connector according to the eighth embodiment of the present disclosure, and illustrates the part of the test connector and the part of the device under test together. In the following description, reference will be made to FIG. 16.

[0126] The device under test may include terminals (32) with different protrusion lengths depending on the area of ​​the substrate (31). For example, in FIG. 16, the terminal (32) located in the middle has a shorter protrusion length than the terminal (32) located on the left, and the terminal (32) located on the right has a shorter protrusion length than the terminal (32) located in the middle. A test connector according to one embodiment shown in FIG. 16 is configured similarly to a test connector according to an embodiment shown in FIG. 15, and has different conductivity heights in each through hole so that three terminals (32) having different protrusion lengths and a conductive ball can be in contact simultaneously.

[0127] The conductive ball of the test connector (10) includes a third conductive ball (203) having a diameter larger than that of the first conductive ball (201). The through hole of the insulating housing (100) includes a first through hole (1201) in which the first conductive ball (201) is disposed, a second through hole (1202) in which the first conductive ball (201) and the second conductive ball (202) are disposed in contact so as to be conductive in the vertical direction, and a third through hole (1203) in which the second conductive ball (202) and the third conductive ball (203) are disposed in contact so as to be conductive in the vertical direction. The second conductive ball (202) disposed at the uppermost side of the second through hole (1202) is positioned higher than the third conductive ball (203) disposed at the uppermost side of the third through hole (1203). Therefore, the third conductive height (CH3) in the third through hole (1203) is smaller than the second conductive height (CH2) in the second through hole (1202). The first conductive ball (201) of the first through hole, the second conductive ball (202) of the second through hole, and the third conductive ball (203) of the third through hole can simultaneously come into contact with terminals (32) having different protrusion lengths. The third through hole (1203) accommodating conductive balls having different diameters may include partial through holes having different inner diameters to correspond to different diameters of the conductive balls. The third through hole (1203) includes a first partial through hole (1221) in which the second conductive ball (202) can be disposed together with the aforementioned space, and a second partial through hole (1222) in which the third conductive ball (203) can be disposed together with the aforementioned space.

[0128] FIG. 17 is a cross-sectional view illustrating a part of a test connector according to the ninth embodiment of the present disclosure, and illustrates the part of the test connector and the part of the device under test together. In the following description, reference will be made to FIG. 17.

[0129] When the substrate (31) of the device under test (30) has a large surface area, the substrate (31) can be bent into an arch shape. Accordingly, the distance between the terminal (32) of the substrate and the upper surface of the test connector is not constant depending on the bent shape of the substrate (31). The test connector (10) according to one embodiment shown in FIG. 17 has different conductivity heights in each through hole so that the terminal (32) of the substrate (31) having a bent shape and the conductive ball can come into contact simultaneously. Therefore, the test connector (10) can stably come into contact with the device under test having the substrate (31) having a bent shape.

[0130] The conductive balls of the test connector (10) include a first conductive ball (201), a second conductive ball (202) having a diameter smaller than the diameter of the first conductive ball (201), and a third conductive ball (203) having a diameter larger than the diameter of the first conductive ball (201). For example, the first conductive ball (201) may have the same diameter as the conductive ball shown in FIG. 2. The through holes of the insulating housing (100) include a first through hole (1201) in which the first conductive ball (201) is disposed, a second through hole (1202) in which the second conductive ball (202) and the third conductive ball (203) are disposed, and a third through hole (1203) in which the third conductive ball (203) is disposed.

[0131] At least three first conductive balls (201) may be placed in the first through hole (1201) by being in contact with each other in the vertical direction (VD) so as to be conductive. At least two second conductive balls (202) and at least one third conductive ball (203) may be placed in the second through hole (1202) by being in contact with each other in the vertical direction (VD) so as to be conductive. At least two third conductive balls (203) may be placed in the third through hole (1203) by being in contact with each other in the vertical direction (VD) so as to be conductive. The first conductive ball (201) placed at the uppermost position in the first through hole (1201) is positioned higher than the second conductive ball (202) placed at the uppermost position in the second through hole (1202). Additionally, the second conductive ball (202) positioned at the uppermost side of the second through hole (1202) is positioned higher than the third conductive ball (203) positioned at the uppermost side of the third through hole (1203). Therefore, the first conductive height (CH1) in the first through hole (1201) is greater than the second conductive height (CH2) in the second through hole (1202), and the second conductive height (CH2) is greater than the third conductive height (CH3) in the third through hole (1203). The conductive balls positioned in the first through hole (1201), the second through hole (1202), and the third through hole (1203) can simultaneously come into contact with the terminal (32) of the substrate (31) having a curved shape. The second through hole (1202) that accommodates conductive balls having different diameters includes a partial through hole having a different inner diameter to correspond to the different diameters of the conductive balls. The second through hole (1202) includes a first partial through hole (1221) in which the third conductive ball (203) can be disposed together with the aforementioned space, and a second partial through hole (1222) in which the second conductive ball (202) can be disposed together with the aforementioned space.

[0132] Although the technical concept of the present disclosure has been described by some embodiments and examples illustrated in the accompanying drawings, it should be understood that various substitutions, modifications, and changes may be made without departing from the technical concept and scope of the present disclosure as understood by those skilled in the art to which the present disclosure pertains. Furthermore, such substitutions, modifications, and changes should be considered to fall within the scope of the appended claims.

Claims

1. It is a test connector placed between a test device and a device under test, and An insulating housing having a through hole penetrating in the vertical direction, and A conductive ball that is separated from the through hole and disposed within the through hole, configured to conductively connect the inspection device and the device to be inspected, and comprises a plurality of conductive particles and an elastic material filled between each of the plurality of conductive particles, wherein the plurality of conductive particles and the elastic material are integrally formed in a spherical shape, and It includes a lower insulating sheet that is positioned below the through hole and has a lower hole having an inner diameter smaller than the inner diameter of the through hole, and is coupled to the lower surface of the insulating housing. In a non-pressurized state of the conductive ball, a space surrounding the conductive ball is formed between the conductive ball and the through hole, and The above-mentioned conductive ball is elastically deformable by a downward pressure applied to reduce the space in the horizontal direction. Test connector.

2. In Paragraph 1, The above-mentioned conductive ball has a diameter smaller than the inner diameter of the through hole in the above-mentioned non-pressurized state and is movable or rotatable through the space, Test connector.

3. In Paragraph 1, The conductive ball is elastically deformable by the pressure to reduce the spacing distance formed between some of the plurality of conductive particles forming the side end of the conductive ball and the inner surface of the through hole in the horizontal direction. Test connector.

4. In Paragraph 1, The above-mentioned conductive ball is configured to be compressed in the vertical direction and expanded in the horizontal direction by the above-mentioned pressure, and The horizontal expansion of the above-mentioned conductive ball is constrained by the inner circumference of the above-mentioned through hole, thereby deforming the above-mentioned conductive ball from a spherical shape toward a cylindrical shape. Test connector.

5. In Paragraph 1, It further includes an upper insulating sheet that is positioned above the through hole and has an upper hole having an inner diameter smaller than the inner diameter of the through hole, and is coupled to the upper surface of the insulating housing. Each of the lower hole and the upper hole has a circumferential surface that is capable of contacting the conductive ball and inclined toward the conductive ball. Test connector.

6. In Paragraph 1, It further includes an upper insulating sheet that is positioned above the through hole and has an upper hole having an inner diameter smaller than the inner diameter of the through hole, and is coupled to the upper surface of the insulating housing. The lower insulating sheet includes a lower conductive portion that is coupled and fixed to the lower hole and makes conductive contact with the conductive ball. The upper insulating sheet includes an upper conductive portion that is coupled and fixed to the upper hole and makes conductive contact with the conductive ball. The above conductive ball is capable of moving and rotating between the lower conductive part and the upper conductive part in the above non-pressurized state, and is capable of elastic deformation by the pressure applied through the upper conductive part. Test connector.

7. In Paragraph 6, The lower conductive portion is configured identically to the conductive ball and has a spherical shape, and the upper conductive portion is configured identically to the lower hemisphere of the conductive ball and has a hemispherical shape. Test connector.

8. In Paragraph 7, A plurality of the above-mentioned conductive balls are disposed between the lower conductive part and the upper conductive part, Test connector.

9. In Paragraph 1, At least two of the above-mentioned conductive balls are conductively contacted within the through hole, and In the above non-pressurized state, the space is formed between each of the conductive balls and the through hole, and Each of the above-mentioned conductive balls is elastically deformable by the pressure so as to expand in the horizontal direction and contract the space in the horizontal direction. Test connector.

10. In Paragraph 1, The above-mentioned conductive ball comprises a plurality of conductive balls having different diameters, and The above through hole includes a plurality of through holes having different inner diameters, and Each of the plurality of conductive balls or at least two of the plurality of conductive balls are disposed in one of the plurality of through holes. Test connector.

11. In Paragraph 1, The conductive ball comprises a first conductive ball configured to conductively connect a signal terminal of the device under test and the test device, and a second conductive ball configured to conductively connect a power terminal or ground terminal of the device under test and the test device and having a diameter larger than the diameter of the first conductive ball. The above through hole comprises a first through hole in which the first conductive ball is disposed, and a second through hole having an inner diameter larger than the inner diameter of the first through hole and in which the second conductive ball is disposed. Test connector.

12. In Paragraph 11, At least two of the first conductive balls are disposed within the first through hole, and A number of the second conductive balls less than the number of the first conductive balls is disposed within the second through hole, Test connector.

13. In Paragraph 1, The above-mentioned conductive ball comprises a first conductive ball and a second conductive ball having a diameter smaller than the diameter of the first conductive ball, and The above through hole includes a first through hole in which at least two of the first conductive balls are disposed, and a second through hole in which at least one of the first conductive balls and at least two of the second conductive balls are disposed. The second conductive ball positioned at the uppermost side of the second through hole is positioned higher than the first conductive ball positioned at the uppermost side of the first through hole. Test connector.

14. In Paragraph 13, The above-mentioned challenge ball further includes a third challenge ball having a diameter larger than the diameter of the first challenge ball, and The above through hole further includes a third through hole in which the second conductive ball and the third conductive ball are disposed, and The second conductive ball positioned at the uppermost side of the second through hole is positioned higher than the third conductive ball positioned at the uppermost side of the third through hole. Test connector.

15. In Paragraph 1, The above-mentioned conductive ball comprises a first conductive ball, a second conductive ball having a diameter smaller than the diameter of the first conductive ball, and a third conductive ball having a diameter larger than the diameter of the first conductive ball. The above through hole comprises a first through hole in which at least three of the first conductive balls are disposed, a second through hole in which at least two of the second conductive balls and at least one of the third conductive balls are disposed, and a third through hole in which at least two of the third conductive balls are disposed. The first conductive ball positioned at the uppermost side of the first through hole is positioned higher than the second conductive ball positioned at the uppermost side of the second through hole, and the second conductive ball positioned at the uppermost side of the second through hole is positioned higher than the third conductive ball positioned at the uppermost side of the third through hole. Test connector.

16. A conductive ball for a test connector configured to be placed in the through hole of the test connector to conductively connect the test device and the device under test, and It comprises a plurality of conductive particles assembled in a spherical shape and an elastic material filled between each of the plurality of conductive particles, The plurality of conductive particles and the elastic material are integrally formed into the spherical shape to form the conductive ball, and In a non-pressurized state of the conductive ball, the conductive ball is configured to be disposed within the through hole while forming a space surrounding the conductive ball, and The above-mentioned conductive ball is elastically deformable by a downward pressure applied to reduce the space in the horizontal direction. Conductive ball for test connector.

17. In Paragraph 16, Among the plurality of conductive particles, two conductive particles adjacent to each other form the outer surface of the conductive ball and are conductively in contact along the circumference of the sphere. Conductive ball for test connector.

18. In Paragraph 16, The conductive ball is formed such that some of the plurality of conductive particles forming the outer surface of the conductive ball protrude from the surface of the elastic material. Conductive ball for test connector.

19. In Paragraph 16, The mass ratio of the mass of the elastic material to the mass of the plurality of conductive particles is at least 1:7, Conductive ball for test connector.

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