TW201826290A - Test socket and conductive particle - Google Patents

Abstract

The present invention relates to a test socket. The test socket includes: a plurality of conductive portions arranged at positions corresponding to the terminals of the test-target device and spaced apart from each other in a surface direction of the test socket, each of the conductive portions including a plurality of conductive particles contained in an elastic insulative material and aligned in a thickness direction of the test socket; and an insulative support arranged between the conductive portions spaced apart from each other to support the conductive portions and insulate the conductive portions from each other in the surface direction, wherein each of the conductive particles includes: a body having a pillar shape; and at least two protrusions protruding from an upper end of the body, wherein a recess recessed toward the body is provided between the protrusions that are adjacent to each other, ends of the protrusions have a convex circular shape, and a center region of the recess has a concave circular shape.

Description

Test socket and conductive particles

The present invention relates to a test socket and conductive particles, and more particularly to a test socket and conductive particles configured to maintain electrical conductivity for a long time even when the test socket frequently contacts the test target device.

In general, test sockets are used during the test process to check for defects or errors in the manufactured device. For example, when performing an electrical test to check whether the manufactured device (test target device) has a defect or an error, the test target device is not directly in contact with the test device but is indirectly connected to the test socket through the test socket. each other. This is because the test equipment is relatively expensive and is worn or damaged due to frequent contact with the test target device, which in turn requires difficulty and high cost when replaced by new test equipment. Therefore, the test socket can be detachably attached to the upper side of the test device, and then the test target device to be tested can be electrically connected by bringing the test target device into contact with the test socket instead of bringing the test target device into contact with the test device. Connect to the test device. Thereafter, the electrical signal generated by the self-test device can be transmitted to the test target device via the test socket.

Referring to FIGS. 1 and 2 , the test socket 100 can be placed between the test target device 130 and the test device 140 to electrically connect the terminal 131 of the test target device 130 to the pad 141 of the test device 140 . The test socket 100 includes a conductive portion 110 arranged at a position corresponding to the terminal 131 of the test target device 130 and having conductivity in the thickness direction of the test socket 100, each of the conductive portions 110 being passed through the test socket 100 The plurality of conductive particles 111 are arranged in the elastic insulating material 112 in the thickness direction; and the insulating support 120 supports the conductive portions 110 and insulates the conductive portions 110 from each other. When the test socket 100 is mounted on the test device 140, the conductive portion 110 of the test socket 100 contacts the pad 141 of the test device 140, and the test target device 130 can contact the conductive portion 110 of the test socket 100.

The test target device 130 can be transferred using an insert and can be placed on the test socket 100 while contacting the conductive portion 110 of the test socket 100. Thereafter, the electrical signal can be transmitted from the test device 140 to the test target device 130 via the test socket 100 to electrically test the test target device 130.

The conductive portion 110 of the test socket 100 is formed by arranging the conductive particles 111 in the elastic insulating material 112, and the terminal 131 of the test target device 130 can be frequently contacted with the conductive portion 110. As described above, when the terminal 131 of the test target device 130 frequently contacts the conductive portion 110, the conductive particles 111 distributed in the elastic insulating material 112 can be easily separated from the elastic insulating material 112. In particular, since the conductive particles 111 have a spherical shape, the conductive particles 111 can be more easily separated from the elastic insulating material 112. As described above, if the conductive particles 111 are separated, the conductivity of the test socket 100 may be lowered, and thus may have a negative influence on the test reliability.

One of the Korean Patent No. 1019721, entitled "Test Socket with Conductive Pillar Particles", filed by the applicant of the present application, discloses a method for solving the above-mentioned spherical conductive particles. The technology of the problem. As shown in FIG. 3, the test socket 200 includes: a conductive portion 210 respectively including a plurality of conductive pillar particles 211, the plurality of conductive pillar particles 211 are placed in the elastic insulating material; and an insulating support 220 supporting the conductive Part 210. Since the conductive pillar particles 211 are distributed in the conductive portion 210 of the test socket 200, the contact area between the adjacent conductive pillar particles 211 can be relatively large, and thus the resistance of the test socket 200 can be reduced, thereby providing stable Electrical connection. In addition, since the conductive pillar particles 211 have a relatively large contact area with the elastic insulating material compared to the prior art spherical conductive particles, the adhesion between the conductive pillar particles 211 and the elastic insulating material is strong, and thus even when When the test is repeatedly performed, the conductive pillar particles 211 may still not be easily separated from the elastic insulating material.

Although the conductive pillar particles have higher conductivity than the spherical conductive particles, if the conductive pillar particles closely arranged in the conductive portion are not aligned with each other in the vertical direction, the upper conductive pillar particles and the lower conductive pillar particles Contact may or may not occur between the upper conductive pillar particles and the lower conductive pillar particles while the conductive portion is compressed. In particular, this problem has become more severe due to the recent trend in technology tending to reduce the distance between the conductive portions.

[Technical Problem] The present invention has been made to solve the above problems. More specifically, it is an object of the present invention to provide a test socket configured to prevent separation of conductive particles from conductive portions during frequent contact to ensure a secure electrical connection between conductive particles while the conductive portions are compressed and expanded. And providing a conductive particle. [Technical Solutions]

To achieve the above object, embodiments of the present invention provide a test socket configured to be placed between a test target device and a test device to electrically connect terminals of the test target device to the test device The test socket includes: a plurality of conductive portions arranged at positions corresponding to the terminals of the test target device and spaced apart from each other in a surface direction of the test socket, in the conductive portion Each of the plurality of electrically conductive particles, the plurality of electrically conductive particles being contained in the elastic insulating material and aligned in a thickness direction of the test socket; and an insulating support disposed between the electrically conductive portions spaced apart from each other To support the conductive portions and to insulate the conductive portions from each other in the surface direction, wherein each of the conductive particles includes: a body having a column shape; and at least two protrusions from An upper end portion of the body protrudes, wherein a recess portion recessed toward the body is disposed between the protrusions adjacent to each other, and an end portion of the protrusion has a convex circle Shape, and the center region of the recessed portion having a circular concave shape.

The protrusion and the recess may have corresponding shapes.

When the conductive particles and another conductive particle adjacent to the conductive particles are coupled to each other by a magnetic field, a protrusion having a convex circular shape of the conductive particles may be inserted into the other conductive particles having a concave shape In the recessed portion of the circular shape.

The body is shaped and sized such that when the conductive particles are aligned in the elastic insulating material using a magnetic field, the conductive particles may stand in the thickness direction.

Each of the bodies may have a h/w ratio greater than 1, wherein h refers to a vertical length measured from the upper end to the lower end of the body, and w is perpendicular to the vertical length The horizontal length of the body.

Each of the bodies can have a w/d ratio greater than 1, where d refers to the thickness of the body.

A pair of lateral surfaces may be disposed between the upper end and the lower end of the body, and the pair of lateral surfaces may be from the upper end and the lower end of the body toward the body The center portions are recessed toward each other.

A plurality of concavo-convex portions may be disposed on a lateral surface of the body.

At least two protrusions may protrude from a lower end of the body.

The upper end portion of the body and the protrusion on the lower end portion may be symmetrical with respect to the body.

In order to achieve the above object, embodiments of the present invention provide a conductive particle for testing a socket, the test socket being configured to be placed between a test target device and a test device to electrically connect a terminal of the test target device a pad connected to the test device, wherein the conductive particles comprise a plurality of conductive particles aligned in a conductive portion of the test socket in a thickness direction of the test socket, the conductive particles being arranged in an elastic insulating material And when the terminal of the test target device presses the conductive portion, the conductive particles arranged in the conductive portion contact each other to make the conductive portion become conductive, wherein the conductive portion Each of the particles includes: a body having a column shape; and at least two protrusions protruding from an upper end portion of the body, wherein a recess toward the body is disposed between the protrusions adjacent to each other The depressed portion has an end portion having a circular shape, and a central portion of the depressed portion has a circular shape.

The end of the protrusion may have a semicircular shape.

The recess may have a width greater than a diameter of the protrusion such that the protrusion may be easily inserted into the recess.

At least two protrusions may protrude from a lower end of the body. [Effect of the invention]

According to the test socket of the present invention, the protruding portion and the recessed portion have a circular shape, so that even when the conductive portion is compressed, the conductive particles coupled to each other can maintain a large contact area therebetween to achieve stable contact and conduction. Sex.

Hereinafter, a test socket will be described in detail in accordance with an embodiment of the present invention with reference to the accompanying drawings.

According to a preferred embodiment of the present invention, the test socket 10 is in the form of a sheet having a predetermined thickness and is configured to block current in the surface direction of the test socket 10 and conduct current in the thickness direction of the test socket 10 to be vertical The terminal 131 of the test target device 130 is electrically connected to the pad 141 of the test device 140 in the direction. The test socket 10 can be used to perform an electrical test on the test target device 130.

The test socket 10 includes a conductive portion 20 and an insulating support 30. The conductive portion 20 extends in the thickness direction, and when the conductive portion 20 is pressed in the thickness direction, the conductive portion 20 can be compressed and can conduct a current in the thickness direction. The conductive portions 20 are spaced apart from each other in the surface direction and the insulating support 30 is arranged between the conductive portions 20 such that current may not flow between the conductive portions 20. The conductive portion 20 and the insulating support 30 will now be described in detail.

The upper end portion of the conductive portion 20 may contact the terminal 131 of the test target device 130, and the lower end portion of the conductive portion 20 may contact the pad 141 of the test device 140. In the elastic insulating material, a plurality of conductive particles 21 are vertically arranged between the upper end portion and the lower end portion of each of the conductive portions 20. When the conductive portion 20 is pressed by the test target device 130, the conductive particles 21 may contact each other and conduct a current. That is, when the conductive portion 20 is not pressed by the test target device 130, the conductive particles 21 are slightly spaced apart from each other or in contact with each other, and when the conductive portion 20 is pressed and compressed by the test target device 130, the conductive particles 21 can be firmly contacted with each other. And thus can conduct current.

Specifically, the conductive portion 20 is formed by closely arranging the conductive particles 21 vertically at a position approximately corresponding to the terminal 131 of the test target device 130 in the elastic insulating material.

Preferably, the elastic insulating material may comprise an insulating polymer substance having a crosslinked structure. Various curable polymer forming materials can be used to obtain such crosslinked polymeric materials. Specific examples of the crosslinked polymer material include: conjugated diene rubber, such as polybutadiene rubber, natural rubber, polyisoprene rubber, styrene - styrene-butadiene copolymer rubber, or acrylonitrile-butadiene copolymer rubber; hydrogenated product of conjugated diene rubber; block copolymer rubber Rubber), such as styrene-butadiene-diene block copolymer rubber or styrene-isoprene block copolymer rubber; a hydrogenated product of a block copolymer rubber; a chloroprene rubber; a urethane rubber; a polyester rubber; an epichlorohydrin rubber; an anthrone rubber (silicone rubber); ethylene-propylene copolymer rubber; and ethylene - an ethylene-propylene-diene copolymer rubber. Since an anthrone rubber has a good formability and electrical properties, an anthrone rubber can be used.

Preferably, the fluorenone rubber is obtainable from liquid fluorenone rubber by crosslinking or condensation. The liquid fluorenone rubber may preferably have a viscosity of not more than 10 ⁵ poise when measured at a shear rate of 10 ^-1 second. The liquid fluorenone rubber may be one of a condensation curing silicone rubber, an addition curing silicone rubber, and an anthrone rubber having a vinyl group or a hydroxyl group. Specific examples of the liquid fluorenone rubber may include dimethyl silicone raw rubber, methyl vinyl silicone raw rubber, and methyl phenyl vinyl fluorenone raw rubber. (methyl phenyl vinyl silicon raw rubber).

Each of the conductive particles 21 includes a body 22 having a column shape as a whole and a protrusion 23 protruding from an upper end portion and a lower end portion of the body 22.

The body 22 has an approximately cylindrical shape, specifically a thin quadrangular prism shape. Although the body 22 is illustrated as having a quadrangular prism shape in the above examples, the body 22 is not limited thereto. For example, body 22 can have a polygonal prism shape.

The shape and size of the body 22 are determined such that the conductive particles 21 can stand in the thickness direction by aligning the body 22 in the elastic insulating material with a magnetic field. That is, when the test socket 10 is manufactured, the mold is filled with the liquid fluorenone rubber in which the conductive particles 21 are distributed, and a magnetic field is applied in one direction to linearly arrange the conductive particles 21 at positions corresponding to the conductive portion 20. . For this process, it is important to determine the size of the body 22 such that the conductive particles 21 can stand in one direction. To this end, the body 22 may have a long column shape extending in one direction.

In particular, each of the bodies 22 can have a h/w ratio greater than one, where h refers to the vertical length from the upper end to the lower end of the body 22, and w refers to the body that is perpendicular to the vertical length The horizontal length of 22. When the h/w ratio is greater than 1, the vertical length of the body 22 is greater than the horizontal length of the body 22, and thus the body 22 can easily stand in a direction parallel to the thickness direction. Therefore, when the conductive particles 21 are aligned in the thickness direction, the protrusions 23 extending from the adjacent body 22 can be easily coupled to each other. However, if the h/w ratio is less than 1, the conductive particles 21 may be oriented differently, and thus, the protrusions 23 may not be easily coupled to each other.

Additionally, body 22 can have a w/d ratio greater than one, where d refers to the thickness of body 22. That is, the body 22 can have a rectangular horizontal cross section rather than a square horizontal cross section. When the body 22 has a w/d ratio greater than 1, the conductive particles 21 can be oriented in a particular direction by a magnetic field. That is, the conductive particles 21 may not be rotated to a random angle but may be oriented in a particular direction relative to the central axis of the body 22 (through the center of the body 22 in parallel with the vertical length of the body 22), and thus the upper conductive The protrusions 23 of the particles and the lower conductive particles 21 can be easily coupled to each other. However, if the w/d ratio is less than 1, the conductive particles 21 may be rotated to different angles, and thus, the protrusions 23 of the conductive particles 21 may not be easily coupled to each other. The w/d ratio may preferably be greater than 1, more preferably 2 or greater than 2, and even more preferably 5 or greater than 5.

If the size of the body 22 is determined as described above, the protrusions 23 of the conductive particles 21 can be easily coupled to each other when the conductive particles 21 are aligned with each other.

In addition, a pair of lateral surfaces 221 for connecting the upper end surface and the lower end surface are formed between the upper end portion and the lower end portion of each of the bodies 22, and the pair of lateral surfaces 221 are from the upper end of the body 22. The lower portion and the lower end portion are recessed toward each other toward the center portion of the body 22. That is, the elastic insulating material may even be filled in the concave central portion of the lateral surface 221, and thus the separation of the conductive particles 21 from the conductive portion 20 may be minimized.

At least two protrusions 23 may protrude from the upper end of each of the bodies 22. In addition, the protrusion 23 protruding from the lower end portion of the body 22 may have a shape or a form corresponding to the shape or form of the protrusion 23 protruding from the upper end portion of the body 22. A recessed portion 231 recessed toward the body 22 is formed between the adjacent protruding portions 23. The depressed portion 231 has a width larger than the diameter of the protruding portion 23, so that the protruding portion 23 can be easily inserted into the depressed portion 231.

The end of the protrusion 23 may have a convex circular shape. Specifically, the protruding portion 23 may have a semicircular shape, and the depressed portion 231 may have a central portion of a concave circular shape. For example, the recess 231 may have an approximately semi-circular shape. In this case, since the protruding portion 23 and the depressed portion 231 have corresponding shapes, after the protruding portion 23 of the conductive particle 21 is coupled to the depressed portion 231 of the other conductive particle 21, the protruding portion 23 and the depressed portion 231 can be maintained The surface contact therebetween is easily rotated relative to each other.

In detail, when the adjacent conductive particles 21 are coupled to each other by a magnetic field during the process of manufacturing the test socket 10, the protrusion 23 having a convex circular shape of one conductive particle 21 may be as shown in FIG. The recess 231 of the other conductive particle 21 is inserted.

After the conductive particles 21 are coupled to each other as described above, if the terminal 131 of the test target device 130 presses the upper side of the conductive portion 20, the relatively upper conductive particles 21 in the conductive particles 21 are rotated to some as shown in FIG. The coupling between the conductive particles 21 is maintained while the angle is being maintained. Since the protruding portion 23 of the relatively upper conductive particle 21 is rotated into a state of being inserted and contacting the depressed portion 231 of the relatively lower conductive particle 21, the protruding portion 23 of the relatively upper conductive particle 21 is relatively lower than the contact The contact area between the depressed portions 231 of the conductive particles 21 may not be significantly reduced by the rotation.

In addition, when the conductive portion 20 is returned to its original state as the pressing force from the test target device 130 is released, the relatively upper conductive particles 21 return to their original while rotating relative to the relatively lower conductive particles 21. Position (refer to Figure 7).

In addition to the shape of the conductive particles 21, materials which can be used to form the conductive particles 21 will also be explained.

The conductive particles 21 may be formed of a magnetic material to easily align the conductive particles 21 along the magnetic lines of force in the vertical direction. For example, the conductive particles 21 may be particles of a magnetic metal such as nickel, iron, or cobalt; particles of an alloy of the magnetic metal; particles containing such a magnetic metal; or The particles are used as core particles and are plated with particles of a conductive metal such as gold, silver, palladium, or rhodium which are difficult to oxidize. However, the conductive particles 21 are not always required to include magnetic core particles.

For example, the conductive particles 21 may include: core particles formed of an inorganic material such as non-magnetic metal, glass, or carbon; formed of a polymer such as polystyrene or polystyrene crosslinked with divinylbenzene. a core particle; or a core particle formed by breaking an elastic fiber filament or a glass fiber filament into particles having a length equal to or less than a certain value, wherein the core particle may be plated with, for example, nickel or cobalt Or a conductive magnetic substance such as a nickel-cobalt alloy, or a conductive metal which can be coated with a conductive magnetic substance and which is difficult to oxidize.

The insulating support 30 insulates the conductive portions 20 from each other and supports the conductive portion 20. Preferably, the insulating support 30 may be formed of the same fluorenone rubber as the elastic insulating material for forming the conductive portion 20. However, the insulating support 30 is not limited to this. That is, the insulating support 30 may be formed of an insulating material different from that used to form the elastic insulating material.

According to an embodiment of the invention, the test socket 10 can be fabricated as follows.

First, a forming material (i.e., a flowable elastic material in which the conductive particles 21 are distributed) is prepared, and a mold (not shown) is filled with the forming material. Thereafter, a magnetic field is applied to the forming material in the vertical direction to align the conductive particles 21 in the vertical direction in parallel with the magnetic lines of force. Next, the forming material is cured, thereby completing the manufacture of the test socket 10.

The test target device 130 can be tested using the test socket 10 in accordance with a preferred embodiment of the present invention as follows.

First, the test socket 10 is placed over the test equipment 140. In detail, the test socket 10 is placed such that the lower end portion of the conductive portion 20 contacts the pad 141 of the test apparatus 140. Thereafter, the test target device 130 is moved downward to bring the terminal 131 of the test target device 130 into contact with the conductive portion 20. At this time, if the test target device 130 is further lowered, the test target device 130 starts pressing the conductive portion 20, and the ends of the conductive particles 21 of the conductive portion 20 are in contact with each other and thus electrically connected to each other. At this time, if the test device 140 generates a predetermined electrical signal, the electrical signal is transmitted to the test target device 130 via the test socket 10.

According to a preferred embodiment of the present invention, the test socket 10 has the following effects.

First, since the protruding portion 23 and the recessed portion 232 have a circular shape, when the conductive portion 20 is compressed by the terminal of the test target device, the conductive particles 21 coupled to each other rotate while maintaining a large contact area therebetween, and Therefore, contact stability can be maintained.

In addition, since the body 22 has a column shape with an h/w ratio of more than 1, the body 22 can be easily aligned vertically when the test socket 10 is manufactured.

In addition, the protrusions 23 that allow the conductive particles 21 to be easily coupled to each other are disposed on the upper end and the lower end of the body 22 that can be easily stood, and the conductive particles 21 are coupled to each other in the conductive portion 20. This coupling structure enables a large contact area to be maintained between the conductive particles 21 even when the conductive portion 20 is compressed by the test target device 130, and therefore, the conductivity of the conductive particles 21 can be maintained.

In addition, since the body 22 is concave at its central portion, the contact area between the body 22 and the elastic insulating material is increased, and thus the body 22 may not be easily separated from the conductive portion 20.

In addition, since the thickness (d) of the body 22 of the conductive particles 21 is smaller than the width (w) of the body 22, the conductive particles 21 can be easily aligned in the vertical direction, and thus the conductive particles 21 can be easily coupled to each other.

In addition, since the protruding portion 23 is coupled to the depressed portion 231 formed between the protruding portions 23, when the test socket 10 is used, the contact area between the conductive particles 21 and the depressed portion 231 may not be significantly reduced, and the conductive particles 21 and The surface contact between the depressed portions 231 can be maintained, thereby ensuring high contact stability.

The test socket 10 in accordance with a preferred embodiment of the present invention can be modified as described below.

In the embodiment described above, the lateral surface 221 is linearly inclined. However, as shown in FIG. 9, the lateral surface of the conductive particles 21' may be provided with the uneven portion 222 having a constant width in the vertical direction.

In addition, as shown in FIG. 10, the uneven surface portion 223 may be disposed on the lateral surface of the concave central portion of the conductive particles 21". If a plurality of uneven portions are provided on the lateral surface as described above, the elastic insulating material can be filled between the uneven portions, and thus the separation of the conductive particles can be reliably prevented.

While the preferred embodiments of the present invention have been shown and described, the invention is not limited to the embodiments of the invention or the modified examples, and various other modifications and changes can be made without departing from the scope of the invention. .

10‧‧‧Test socket

20‧‧‧Electrical Department

21, 21', 21'', 111‧‧‧ conductive particles

22‧‧‧Ontology

23‧‧‧Protruding

30, 120‧‧‧Insulated support

100, 200‧‧‧ test socket

110‧‧‧Electrical Department

112‧‧‧elastic insulation

130‧‧‧Test target device

131‧‧‧terminal

140‧‧‧Test equipment

141‧‧‧ pads

210‧‧‧Electrical Department

211‧‧‧conductive column particles

220‧‧‧Insulation support

221‧‧‧ lateral surface

222, 223‧‧‧

231‧‧‧Depression

D‧‧‧thickness

h‧‧‧Vertical length

W‧‧‧ horizontal length/width

1 is a diagram illustrating a test socket of the prior art. Figure 2 is a diagram illustrating the operation of the test socket shown in Figure 1. 3 is a diagram illustrating another test socket of the prior art. 4 is a diagram illustrating a test socket in accordance with an embodiment of the present invention. Figure 5 is a diagram for explaining the operation of the test socket shown in Figure 4. Figure 6 is a perspective view illustrating one of the conductive particles located in the conductive portion of the test socket shown in Figure 4. FIG. 7 is a view illustrating an example in which such conductive particles as shown in FIG. 6 are coupled to each other in a conductive portion. Figure 8 is a diagram illustrating an exemplary operation of such conductive particles as shown in Figure 6 in a conductive portion. Figure 9 is a diagram illustrating conductive particles in accordance with another embodiment of the present invention. Figure 10 is a diagram illustrating conductive particles in accordance with another embodiment of the present invention.

Claims (14)

A test socket configured to be placed between a test target device and a test device to electrically connect a terminal of the test target device to a pad of the test device, the test socket comprising: a plurality of conductive portions, Arranging at positions corresponding to the terminals of the test target device and spaced apart from each other in a surface direction of the test socket, each of the conductive portions including a plurality of conductive particles, the plurality of conductive particles Included in the elastic insulating material and aligned in the thickness direction of the test socket; and an insulating support disposed between the conductive portions spaced apart from each other to support the conductive portion and to allow the conductive portion to be Each of the conductive particles includes: a body having a column shape; and at least two protrusions protruding from an upper end portion of the body, wherein the protrusions adjacent to each other A recessed portion recessed toward the body is disposed between the portions, the end portion of the protruding portion has a convex circular shape, and a central portion of the depressed portion has a concave circular shape Like. The test socket of claim 1, wherein the protrusion has a corresponding shape with the recess. The test socket of claim 1, wherein when the conductive particles and another conductive particle adjacent to the conductive particles are coupled to each other by a magnetic field, the conductive particles have a convex circular shape. The protrusion is inserted into the recess of the other conductive particle having a concave circular shape. The test socket of claim 1, wherein the body is shaped and sized such that when the conductive particles are aligned in the elastic insulating material by a magnetic field, the conductive particles stand in the thickness direction on. The test socket of claim 4, wherein each of the bodies has a h/w ratio greater than 1, wherein h is measured from the upper end to the lower end of the body Vertical length, and w refers to the horizontal length of the body perpendicular to the vertical length. The test socket of claim 5, wherein each of the bodies has a w/d ratio greater than 1, wherein d is the thickness of the body. The test socket of claim 1, wherein a pair of lateral surfaces are disposed between the upper end and the lower end of the body, and the pair of lateral surfaces are from the body The upper end portion and the lower end portion are recessed toward each other toward a central portion of the body. The test socket according to any one of claims 1 to 7, wherein a plurality of concave and convex portions are provided on a lateral surface of the body. The test socket of claim 1, wherein at least two protrusions protrude from a lower end of the body. The test socket of claim 9, wherein the upper end portion of the body and the protrusion on the lower end portion are symmetrical with respect to the body. a conductive particle for testing a socket, the test socket being configured to be placed between a test target device and a test device to electrically connect a terminal of the test target device to a pad of the test device, wherein The conductive particles include a plurality of conductive particles aligned in a conductive portion of the test socket in a thickness direction of the test socket, the conductive particles being arranged in an elastic insulating material, and when the test target device is When the terminal presses the conductive portion, the conductive particles arranged in the conductive portion contact each other to make the conductive portion conductive, wherein each of the conductive particles includes: a body having a column shape; and at least two protrusions projecting from an upper end portion of the body, wherein a recess portion recessed toward the body is disposed between the protrusions adjacent to each other, the end portion of the protrusion having A circular shape, and a central portion of the depressed portion has a circular shape. The conductive particle of claim 11, wherein the end of the protrusion has a semicircular shape. The conductive particle according to claim 11, wherein the depressed portion has a width larger than a diameter of the protruding portion, so that the protruding portion can be easily inserted into the depressed portion. The conductive particles of claim 11, wherein at least two protrusions protrude from a lower end portion of the body.