TWI859978B - Conductive particle, test connector, and method of manufacturing conductive particle - Google Patents

Abstract

There are provided a conductive particle used for a test connector disposed between a device to be tested and a testing apparatus to electrically connect a terminal of the device to be tested and a pad of the testing apparatus to each other, the conductive particles being distributed in an elastic insulating material and contacting each other when the device to be tested is in contact to thereby form a conductive path for electrical signal transmission, the conductive particle including: a body portion including a conductive material, the body portion having a flat lower surface disposed on a bottom and having a width decreasing toward an upper direction from the lower surface; and a protruding portion including a conductive material, the protruding portion protruding downward from the lower surface of the body portion, being integrally connected to the body portion, and having a width narrower than that of the lower surface of the body portion, wherein the body portion has a curved portion rounded from the bottom to an upper end of the body portion.

Description

Conductive particles, test connectors, and methods for making conductive particles

The present disclosure relates to a conductive particle for performing an electrical test by electrically connecting a device to be tested to a test device, an electrical test connector (i.e., a test connector), and a method for manufacturing the conductive particle.

For electrical testing of a device to be tested (i.e., a device under test), a connector that electrically connects the device under test to a test device is widely used in the relevant field. The connector transmits electrical signals from the test device to the device under test and transmits electrical signals from the device under test to the test device. As such a connector, a conductive rubber sheet is known in the art.

The conductive rubber sheet can be deformed in an elastic manner by applying an external force to the device under test. The conductive rubber sheet has a plurality of conductive parts that electrically connect the device under test to the test equipment and transmit electrical signals, and an insulating part that separates and insulates the plurality of conductive parts. The insulating part can be made of hardened silicone rubber. The insulating part can include hardened silicone rubber.

FIG1 shows a technique for a conventional conductive rubber sheet. The conductive rubber sheet 10 is composed of a conductive portion 11 and an insulating portion 12, and the conductive portion 11 is configured so that a plurality of spherical conductive particles 11a are disposed in the silicone rubber in the thickness direction.

Since the spherical conductive particles 11a are in almost point contact with other conductive particles or the terminals of the device under test, the contact area is small, and thus the electrical connection capability is reduced. In addition, since the bonding strength with the rubber is also low, there is a problem that the conductive particles 11a can easily separate from the conductive part 11 during repeated testing.

FIG. 2 shows a technique for another conventional conductive rubber sheet 20 in which a conductive portion 21 is configured such that a plurality of columnar conductive particles 21a (which include a diameter D and a length L) are disposed in the silicone rubber in the thickness direction.

The problem with columnar conductive particles 21a is that the elasticity of rubber sheets when made into connectors is generally reduced compared to sheets made of spherical particles. That is, since the conductive particles are formed into a columnar shape, they can make surface contact with other adjacent columnar particles or terminals of the device under test, and thus the contact area is increased and the electrical connection capability is better than that of spherical conductive particles. However, due to the property of columnar particles to stretch in one direction, the overall elasticity of the rubber sheet is reduced. Therefore, when an external force is applied, the elastic deformation of the conductive rubber sheet becomes somewhat difficult, and the external force (for example, the pressing force applied from the device under test) may not be fully absorbed.

FIG. 3 shows conductive particles used in other conventional conductive rubber sheets, and FIG. 4(a) to FIG. 4(d) show a method for manufacturing the conductive particles shown in FIG. 3.

The conductive particle 31a shown in FIG3 is formed into a ring shape with a central hole, and since the central hole is filled with silicone rubber, the conductive particle 31a has excellent bonding strength with the silicone rubber. In addition, due to the ring-shaped characteristics of the conductive particle 31a, in addition to point contact with another adjacent conductive particle or the terminal of the device to be tested, both line contact and surface contact can be performed, and thus the contact area is increased, and thus the electrical connection capability and durability are excellent.

The conductive particles 31a shown in FIG. 3 are manufactured into the shape desired by the designer using the microelectromechanical system (MEMS) manufacturing technology. As shown in FIG. 4 , in order to manufacture the conductive particles, the MEMS manufacturing technology includes: preparing a silicon wafer substrate 40 (see FIG. 4 (a)); applying a photoresist layer 41 on the substrate 40 (FIG. 4 (b)); forming a predetermined groove 42 by patterning the photoresist layer 41 (FIG. 4 (c)); and forming a coating layer 31a' in the groove 42 and then flattening the upper surface of the coating layer 31a' (FIG. 4 (d)). Thereafter, when the conductive particles are removed and separated from the photoresist layer 41, the predetermined conductive particles are obtained.

According to the conventional method of manufacturing ring-shaped conductive particles, the thickness of the photoresist layer must be greater than the thickness of the desired conductive particles, so the amount of photoresist consumed increases. In addition, the uniform shape and surface treatment of the conductive particles require a flattening process (chemical mechanical polishing (CMP)), which leads to an increase in total cost and low productivity.

In addition, since the surface of the particles is smooth and has no irregularities, there are disadvantages in terms of adhesion with silicone rubber.

In addition, in the case of conductive particles manufactured by MEMS manufacturing technology, a coating layer may be additionally formed on the upper and lower surfaces of the conductive particles using a highly conductive material, but even if the coating layer is formed on the upper and lower surfaces, the coating layer is not formed on the side surfaces. Therefore, metal materials with low conductivity such as the metal materials are generally exposed on the side surfaces of the conductive particles. Therefore, there is a problem in that when the side surface of the conductive particle contacts another conductive particle, the overall electrical connection capability of the conductive rubber sheet is reduced due to the increase in contact resistance.

In addition, in order to perform side plating of conductive particles, after separating the conductive particles to which MEMS technology is applied, the barrel plating method alone may be used. However, as the size of the conductive particles becomes smaller, there may be a phenomenon that the conductive particles agglomerate during the plating process, and thus the process difficulty may increase, and thus the total cost may increase.

The present disclosure is used to solve various problems including the above problems, and the purpose of the present disclosure is to provide an electrical test conductive particle that is easy to manufacture, can be manufactured at low cost, and has improved conductivity performance, and further provide an electrical test connector (i.e., a test connector) and a method for manufacturing conductive particles.

The present disclosure provides a conductive particle, which is used for a test connector. The test connector is arranged between a device to be tested and a test equipment to electrically connect the terminal of the device to be tested and the pad of the test equipment to each other. A plurality of conductive particles are distributed in an elastic insulating material and contact each other when the device to be tested is in contact, thereby forming a conductive path for transmitting electrical signals. The conductive particle includes: a body portion, which includes a conductive material, The main body portion has a flat lower surface disposed on the bottom and has a width that decreases from the lower surface toward the upper part; and a protruding portion, comprising a conductive material, the protruding portion protrudes downward from the lower surface of the main body portion, is integrally connected to the main body portion, and has a width narrower than the width of the lower surface of the main body portion, wherein the main body portion has a curved portion that becomes rounded from the bottom to the upper end of the main body portion.

In the conductive particles, the upper end of the body portion may be provided with a flat surface parallel to the bottom of the body portion.

In the conductive particles, the upper end portion of the body portion may have a convex curved shape, and thus the body portion as a whole may have a hemispherical shape.

In the conductive particles, the main body portion may have any one of a stripe shape, a grid shape, a triangle shape, a star shape, an S shape, and a double S shape.

In the conductive particles, the body portion may have any one of an H shape, an X shape, an O shape, a C shape, an S shape, an N shape, a V shape, a W shape, a Z shape, and a + shape, or a shape in which a plurality of each shape are continuously connected.

In the conductive particles, the body portion may be configured by stacking different materials into multiple layers.

In the conductive particles, the different materials may include any one of ferromagnetic metal materials, highly elastic metal materials and highly conductive metal materials.

In the conductive particles, a plurality of protrusions may be spaced apart from each other.

In the conductive particles, a plurality of protrusions may be spaced at equal intervals relative to the center of the bottom of the body portion.

In the conductive particles, the remaining outer surface of the body portion except the bottom may be coated with a high conductivity layer.

In the conductive particles, the bottom of the protruding portion may be coated with a high conductivity layer.

In the conductive particles, a concave portion may be formed inwardly between the main body portion and the protruding portion.

The present disclosure also provides a test connector, which is arranged between a plurality of terminals of a device to be tested and a plurality of pads of a test device to electrically connect the plurality of terminals to the plurality of pads, and the test connector comprises: a conductive portion, in which a plurality of conductive particles are distributed in a thickness direction in an elastic insulating material at a plurality of positions corresponding to the plurality of terminals of the device to be tested; and an insulating portion, which insulates and supports the conductive portion, wherein the plurality of conductive particles are electrically conductive to the conductive portion. Each of the particles includes: a body portion, comprising a conductive material, the body portion having a flat lower surface disposed on the bottom and having a width that decreases from the lower surface toward the upper portion; and a protruding portion, comprising a conductive material, the protruding portion protruding downward from the lower surface of the body portion, integrally connected to the body portion, and having a width narrower than the width of the lower surface of the body portion, wherein the body portion has a curved portion that becomes rounded from the bottom to the upper end of the body portion.

The present disclosure also provides a method for manufacturing conductive particles, wherein the conductive particles are used for a test connector, wherein the test connector is disposed between a device to be tested and a test equipment to electrically connect the terminal of the device to be tested and the pad of the test equipment to each other, and a plurality of conductive particles are distributed in an elastic insulating material and contact each other when the device to be tested contacts, thereby forming a conductive path for transmitting electrical signals, the method comprising: (a) ) preparing a substrate; (b) forming a molding layer on the substrate; (c) forming a groove for particle formation by removing at least a portion of the molding layer; (d) forming a first coating layer inside the groove for particle formation; and (e) forming a second coating layer in a protruding manner, the second coating layer being integrally connected to the first coating layer around the groove for particle formation and having a width that decreases in an upward direction.

The method may further include (f) removing the molding layer after operation (e).

In the method, in operation (a), a conductive coating may be formed on the substrate.

The method may further include (g) removing the conductive coating formed on the substrate after operation (f).

The method may further include (c-1) forming a third coating layer by coating a highly conductive material to a thickness smaller than the thickness of the molding layer between operations (c) and (d).

The method may further include (e-1) coating a highly conductive metal on the second coating layer after operation (e).

In the method, in operation (d), the first coating layer may be formed by coating with different metal materials and stacking the different metal materials into a plurality of layers.

In the method, in operation (e), the second coating layer may be formed by coating with different metal materials and stacking the different metal materials into a plurality of layers.

The conductive particles disclosed herein are provided with a main body portion having a flat bottom and a protruding portion protruding from the bottom of the main body portion, and thus surface contact can be made when the conductive particles contact another conductive particle, thereby improving conductivity due to an increase in the contact area.

In addition, since the conductive particles disclosed in the present invention are formed by plating a body portion with a higher photoresistance, the thickness of the photoresist used for particle generation can be smaller than the thickness of the photoresist in the prior art, and thus the overall manufacturing cost can be reduced.

In addition, since the conductive particles disclosed in the present invention are formed by stacking various materials in a plating process, conductive particles with various physical properties can be easily manufactured.

10: Conductive rubber sheet

11, 21, 110, 510: Conductive part

11a: Spherical conductive particles/conductive particles

12: Insulation part

20: Conventional conductive rubber sheet

21a: Columnar conductive particles

31a, 111, 211, 311, 411, 511, 611: Conductive particles

31a', 211': coating

40: Silicon wafer substrate/substrate

41: Photoresist layer

42, 132: Groove

100: Connector

112, 312, 412, 512: Main body

112a: Flat surface

112': Second coating

113, 313, 413, 513: protruding parts

113': First coating

114: Concave part

115, 515, 516: High conductivity layer

115': Highly conductive metal

116': Third coating

120: Insulation part/insulation body

130: Substrate

130a: Conductive coating

131: Molding layer

140:Testing equipment

141:Pad

150: Device to be tested

151: Terminal/hemispherical terminal/ball terminal

1121: Magnetic layer

1122: Highly conductive layer

D: Diameter

L: Length

FIG. 1 is a view showing a conventional connector used for testing.

FIG2 is a view showing a conventional connector used for testing.

FIG3 is a view showing conventional conductive particles.

FIG4 is a view showing a method of manufacturing the conductive particles shown in FIG3.

FIG5 is a view showing a connector for testing (i.e., a test connector) according to an embodiment of the present disclosure.

Figure 6 is an operation view of Figure 5.

FIG. 7 is a view showing another arrangement of a test connector according to an embodiment of the present disclosure.

FIG. 8 is a perspective view of the conductive particles used in the test connector shown in FIGS. 5 to 7.

FIG9 is a plan view, a side view and a rear view of the conductive particles shown in FIG8 .

FIG. 10 is a view showing various cross-sections of conductive particles.

FIG11 is a view showing a method of manufacturing the conductive particles shown in FIG8.

Figures 12 to 16 are views showing a state in which conductive particles according to the first embodiment of the present disclosure are in contact with each other in a test connector.

FIG17 is a cross-sectional view of the conductive particles according to the second embodiment of the present disclosure.

FIG18 is a view showing a method of manufacturing the conductive particles shown in FIG17.

FIG. 19 is a plan view, a side view, and a rear view of the conductive particles according to the third embodiment of the present disclosure.

FIG. 20 is a view showing conductive particles according to the fourth embodiment of the present disclosure.

FIG. 21 is a view showing conductive particles according to the fifth embodiment of the present disclosure.

FIG. 22 is a view showing a conductive portion provided with the conductive particles shown in FIG. 21.

FIG. 23 is a view showing various embodiments of the conductive particles disclosed herein.

The embodiments of the present disclosure are provided as examples to illustrate the technical ideas of the present disclosure. The scope of the present disclosure is not limited to the embodiments described below or the specific description of the embodiments.

Unless otherwise defined, the meanings of all technical and scientific terms used in this disclosure are the same as those commonly understood by those with ordinary knowledge in the art to which this disclosure belongs. All terms used in this disclosure are selected to more clearly explain this disclosure and are not intended to limit the scope of this disclosure.

Terms such as "comprising", "including", and "having" used in this disclosure should be understood as open-ended terms that imply the possibility of including other embodiments, unless otherwise stated in the phrase or sentence including the term.

Unless otherwise specifically mentioned, words in the singular may include plural forms, and the same applies to words in the singular in the patent claims.

Terms such as "first" and "second" are used in this disclosure to distinguish multiple components from each other, and the terms do not limit the order or importance of the components.

In the present disclosure, it should be understood that when an element is said to be "coupled" or "connected" to another element, the element may be directly coupled or directly connected to the other element, or any other element may be interposed between the two elements.

In the present disclosure, the directional term "upward" is based on the direction in which the test socket is positioned relative to the test board, and the directional term "downward" refers to the opposite direction of the upward direction. In the present disclosure, it should be understood that the directional term "vertical" includes the upward direction and the downward direction, and does not refer to only one of the upward direction and the downward direction.

The embodiments will be described with reference to the examples shown in the accompanying drawings. In the drawings, the same reference numerals represent the same elements. In addition, in the following description of the embodiments, the same elements or corresponding elements may not be described in detail. However, even when the description of some elements is omitted from the description of some embodiments, the elements are not intended to be excluded from the embodiments.

The embodiments described below and the examples shown in the accompanying drawings are related to a connector that is positioned between two electronic devices to electrically connect the two electronic devices. When the connector of the embodiment is applied, one of the two electronic devices may be a test device, and the other of the two electronic devices may be a device to be tested (i.e., a device to be tested) to be tested by the test device, but the application examples of the connector are not limited thereto. The connector of the embodiment can be used to achieve electrical connection by contacting any two electronic devices that need to be electrically connected. When the connector of the embodiment is used for the test device and the device to be tested, the connector of the embodiment can be used to electrically connect the test device and the device to be tested during electrical testing of the device to be tested. For example, the connector of the embodiment can be used during the manufacturing process of the device to be tested to perform final testing and timely testing on the device to be tested in post-processing. However, examples of testing of the connector to which the embodiment is applied are not limited to the above-mentioned tests.

FIG. 5 shows an example of a connector 100 applied according to an embodiment. To facilitate the description of the embodiment, FIG. 5 shows exemplary shapes of the connector 100, an electronic device on which the connector 100 is placed, and an electronic device in contact with the connector 100.

Referring to FIG. 5 , the connector 100 according to the embodiment is disposed between two electronic devices and electrically connects the two electronic devices by making contact. In the example shown in FIG. 5 , one of the two electronic devices may be a test device 140 and the other may be a device to be tested 150 to be tested by the test device 140. When the device to be tested 150 is electrically tested, the connector 100 contacts each of the test device 140 and the device to be tested 150 to electrically connect the test device 140 and the device to be tested 150 to each other.

The device to be tested 150 may be a semiconductor package, but is not limited thereto. A semiconductor package is a semiconductor device in which a semiconductor integrated circuit (IC) chip, a plurality of lead frames, and a plurality of terminals 151 are packaged into a hexahedral shape using a resin material. The semiconductor IC chip may be a memory IC chip or a non-memory IC chip. Pins, solder balls, or similar terminals may be used as the terminals 151. The device to be tested 150 shown in FIG. 5 has a plurality of hemispherical terminals 151 on the lower side of the device to be tested 150.

The test equipment 140 can test the electrical characteristics, functional characteristics, operating speed or similar characteristics of the device to be tested 150. The test equipment 140 can have a plurality of pads 141 capable of outputting electrical test signals and receiving response signals in the board to be tested. The connector 100 is disposed above the test equipment 140, and the conductive portion 110 can be disposed to contact the pads 141 of the test equipment 140. The terminals 151 of the device to be tested 150 are electrically connected to the corresponding pads 141 of the test equipment 140 via the connector 100. The connector 100 electrically connects the terminal 151 of the device under test 150 to the corresponding pad 141 of the test equipment 140 in the vertical direction, and thus the device under test 150 can be tested by the test equipment 140.

Most of the connector 100 may be made of an elastic insulating material, and the connector 100 may be elastic in the vertical direction and the horizontal direction. When an external force is applied downward to the connector 100 in the vertical direction, the connector 100 may be deformed in an elastic manner in the downward direction and the horizontal direction. The external force may be generated by pushing the device to be tested 150 toward the test equipment 140 using a pusher device (not shown). Due to this external force, the terminal 151 of the device to be tested 150 and the connector 100 may contact each other in the vertical direction, and the pad 141 of the connector 100 and the test equipment 140 may contact each other in the vertical direction. When the external force is removed, the connector 100 may return to the original shape of the connector 100.

The connector 100 for testing includes a conductive portion 110 and an insulating portion 120.

In the conductive part 110, a plurality of conductive particles 111 are distributed in the elastic insulating material in the thickness direction (vertical direction) at positions corresponding to the terminals 151 of the device to be tested 150. The conductive part 110 has a cylindrical shape, the number of the conductive parts 110 corresponds to the number of the terminals 151 of the device to be tested 150, and the plurality of conductive parts 110 are arranged spaced apart from each other in the horizontal direction.

The elastic insulating material constituting the conductive portion 110 is preferably a polymer material having a cross-linked structure. As the curable polymer forming material that can be used to obtain such a flexible insulating material, various materials can be used, and specific examples of the various materials include polybutadiene rubber, natural rubber, polyisoprene rubber, styrene-butadiene copolymer rubber, conjugated diene rubber (e.g., acrylonitrile-butadiene copolymer rubber) and hydrogenated products thereof, block copolymer rubber (e.g., styrene-butadiene-diene block copolymer rubber and styrene-isoprene block copolymer rubber), and styrene-butadiene copolymer rubber. copolymer) and its hydrogenation products, chloroprene rubber, urethane rubber, polyester type rubber, epichlorohydrin rubber, silicone rubber, ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, etc.

In the above content, when the connector 100 obtained for testing requires weather resistance, it is preferred to use a material other than the covalent diene rubber, and specifically, from the perspective of moldability property and electrical property, it is preferred to use silicone rubber.

A cross-linked liquid silicone rubber or a condensed liquid silicone rubber is preferably used as the silicone rubber. The liquid silicone rubber may be a condensed type, an added type, or a type containing a vinyl group or a hydroxyl group. Specifically, examples of the liquid silicone rubber include dimethyl silicone crude rubber, methylvinyl silicone crude rubber, methylphenylvinyl silicone crude rubber, and the like.

The conductive particles 111 are bonded to each other in the elastic insulating material. The plurality of conductive particles 111 contact each other in the conductive portion 110 to form a conductive path in the vertical direction. As shown in FIGS. 8 to 10 , each of the conductive particles 111 has a mushroom-like shape as a whole and includes a body portion 112 and a protruding portion 113.

The body portion 112 may be configured to have a shape in which a flat lower surface is provided on the bottom and the width decreases from the lower surface toward the upper portion, and is made of a conductive material. A flat surface 112a parallel to the bottom may be provided at the center of the upper portion as the top of the body portion 112.

The side surface of the body portion 112 may have a curved shape in which the width of the lower side is increased compared to the upper side. Therefore, when the conductive particles 111 contact the adjacent conductive particles 111, the elastic strain of the conductive portion 110 can be increased by easily sliding along the surface. That is, when an external force is applied by the device to be tested 150, the conductive portion 110 can be easily deformed in an elastic manner, and thus the pressure can be fully absorbed.

However, the shape of the body portion 112 is not limited thereto. For example, the body portion 112 may have a hemispherical shape as a whole, but may not have the flat surface 112a at the center of the upper portion.

The body portion 112 may be made of a magnetic metal material (such as iron, cobalt or nickel, alloys thereof or materials containing these metals), but is not limited thereto, and may use a material having excellent elasticity. A nickel-cobalt alloy material may be used as a material having excellent elasticity, but the present disclosure is not limited thereto.

The body portion 112 may be made entirely of one metal material or one alloy material or may be formed using various stacking methods. For example, the body portion 112 may be formed by alternately stacking a ferromagnetic metal material exhibiting magnetism with a high-conductivity metal material or a highly elastic metal material having excellent conductivity. Materials having excellent conductivity (such as gold, silver, palladium, rhodium, and copper) may be used as the high-conductivity material. FIG. 10(a) shows that the body portion 112 is made of one material, and FIG. 10(b) shows that the body portion 112 has a structure in which a magnetic layer 1121 and a high-conductivity layer 1122 are alternately stacked.

For example, in the body part 112 in FIG. 10( b ), magnetic layers 1121 such as nickel and highly conductive layers 1122 such as copper are alternately stacked. In this way, when different materials are stacked and arranged, only one body part 112 can be used to simultaneously implement the function of the magnetic body and the function of the highly conductive material, and thus there is an advantage that various electrical properties can be obtained. In this case, the magnetic layer 1121 can facilitate the assembly of the conductive particles 111 by magnetic force, and the highly conductive layer 1122 can reduce the resistance when in contact with other conductive particles 111.

A high conductivity layer 115 made of a material having excellent conductivity (such as gold, silver, palladium, rhodium or copper) may be coated on the outer surface of the body portion 112. The high conductivity layer 115 covers the upper surface and side surfaces of the body portion 112 and may not be disposed on the lower surface of the body portion 112.

When the high-conductivity layer 115 is coated on the outer surface of the body portion 112, when the high-conductivity layer 115 contacts the adjacent conductive particles 111, the contact resistance can be reduced and the conductivity can be improved. Specifically, since the high-conductivity layer 115 is electrically connected to the high-conductivity layer 1122 inside the body portion 112, the conductive performance can be further improved. In addition, the high-frequency signal can be transmitted well by reducing the eddy current when transmitting the high-frequency signal.

The protrusion 113 protrudes downward from the lower surface of the body 112, is integrally connected to the body 112, and may have a shape narrower than the lower surface of the body 112. The protrusion 113 is made of a conductive material. The protrusion 113 is preferably made of the same material as the body 112, but is not limited thereto. For example, the protrusion 113 may be made of a material different from that of the body 112 (e.g., various metal materials (e.g., magnetic materials, highly conductive materials, and elastic materials)).

The protruding portion 113 may have a cylindrical shape having a smaller diameter than the outer diameter of the bottom of the main body portion 112, and a concave portion 114 recessed inwardly may be formed between the protruding portion 113 and the main body portion 112. Since the concave portion 114 is filled with silicone rubber constituting the conductive portion 110, the bonding force between the conductive particles 111 and the silicone rubber may be further improved. Therefore, the conductive particles 111 will not be easily separated from the conductive portion 110.

The protruding portion 113 may be made entirely of one metal material or one alloy material or may be formed using various stacking methods. For example, the main body portion 112 may be formed by alternately stacking a metal material exhibiting magnetism and a high-conductivity material having excellent conductivity. Materials having excellent conductivity (such as gold, silver, palladium, rhodium, and copper) may be used as the high-conductivity material.

In addition, the body portion 112 is completely manufactured by plating and formed into a hemispherical shape, so there is no irregularity. However, the protruding portion 113 protruding from the bottom of the body portion 112 performs the function of irregularity, and thus can further increase the bonding force with the silicone rubber.

The length of the protruding portion 113 is not limited, but may have a smaller size than the main body portion 112. However, the present disclosure is not limited thereto, and the protruding portion 113 may have a thin columnar shape having a size longer than the main body portion 112 when necessary.

A high conductivity layer 115 made of a material having excellent conductivity (such as gold, silver, palladium, rhodium or copper) may be coated on the lower surface of the protrusion 113. In this way, the high conductivity layer 115 formed on the lower surface of the protrusion 113 reduces the contact resistance and improves the conductivity when contacting other adjacent conductive particles 111.

FIG. 10( c ) shows a form in which the high conductivity layer 115 is formed on the upper surface, the side surface, and the lower surface of the body portion 112 and completely covers the protruding portion 113. In this way, when the high conductivity layer 115 completely covers the body portion 112 and the protruding portion 113, the conductivity can be further improved.

The insulating portion 120 may form a rectangular elastic area in the connector 100. The plurality of conductive portions 110 are spaced apart from each other at equal or unequal intervals in the horizontal direction and insulated from each other by the insulating portion 120. The insulating portion 120 is formed as an elastic body, and the plurality of conductive portions 110 are embedded in the insulating portion 120 in the thickness direction (vertical direction) of the insulating portion 120. The insulating portion 120 is made of an elastic polymer material and is elastic in the vertical and horizontal directions. The insulating portion 120 not only maintains the shape of the conductive portion 110, but also maintains the conductive portion 110 in the vertical direction.

The insulator 120 may be made of a hardened silicone rubber material. For example, the insulating portion 120 may be formed by injecting liquid silicone rubber into a molding mold for molding the connector 100 and hardening the silicone rubber. Additive liquid silicone rubber, condensation liquid silicone rubber, liquid silicone rubber containing vinyl or hydroxyl groups, and similar rubbers may be used as the material of the liquid silicone rubber used to form the insulating portion 120. As a specific example, the material of the liquid silicone rubber may include dimethyl silicone raw rubber, methyl vinyl silicone raw rubber, methyl phenyl vinyl silicone raw rubber, or similar rubbers.

The following will describe the method of manufacturing the conductive particles 111 in the connector 100 for testing according to the present disclosure with reference to FIG. 11.

First, after preparing a substrate 130 made of a silicon wafer, silicon or ceramic, a thin conductive coating 130a (titanium, copper) for electroplating is formed on the surface of the substrate 130 (see FIG. 11(a)).

Next, a molding layer 131 is formed on one surface of the substrate 130 (see FIG. 11(b)). In this case, the molding layer 131 is a photoresist layer, and the photoresist layer having a thickness smaller than that of the conductive particles 111 is formed on one side of the substrate 130, and thus the consumption of the photoresist can be reduced and the cost can be reduced.

Thereafter, at least a portion of the molding layer 131 is removed to form a groove 132 for particle formation (see FIG. 11(c)). Specifically, the groove 132 having a desired shape is formed in the molding layer 131 using an exposure process and a development process.

Thereafter, a third coating layer 116' is formed inside the groove 132 for particle formation using a highly conductive material (see FIG. 11(d)). The third coating layer 116' is a high conductivity layer 115 formed on the lower surface of the protruding portion 113 and has a thickness smaller than that of the molding layer 131.

Thereafter, after forming the first coating layer 113' by coating, which becomes the protruding portion 113 after manufacturing the inside of the groove 132 for particle formation, additional coating is performed, thereby manufacturing the second coating layer 112' which protrudes more than the molding layer 131, and thus the protruding portion 113 is manufactured together with the body portion 112. In this case, the second coating layer 112' is a coating layer which becomes the body portion 112 and is disposed around the groove 132 for particle formation and is integrally connected to the first coating layer 113', and the second coating layer 112' has a substantially upper hemispherical shape in which the left and right width decreases in the upward direction (FIG. 11(e)).

In this case, the first coating layer 113' and the second coating layer 112' may be made of one material, but may be formed by sequentially or alternately coating a magnetic material and a highly conductive material (i.e., by stacking coating layers made of different materials).

Next, a high-conductivity metal 115' is plated on the second coating layer 112' (see FIG. 11(f)). In this case, the plated high-conductivity metal 115' becomes a high-conductivity layer 115 covering the outer surface of the body portion 112.

Next, after removing the mold layer 131, the conductive coating 130a formed on the surface of the substrate 130 is removed. Specifically, the conductive coating 130a formed on the substrate 130 is removed by etching so that the conductive particles 111 can be separated. Thereafter, the conductive particles 111 are separated from the substrate 130 (FIG. 11(g)).

The conductive particles 111 manufactured by this manufacturing method do not need to make the thickness of the molding layer 131 greater than the thickness of the conductive particles 111 as in the prior art, and therefore the amount of the molding layer 131 (photoresist layer) can be reduced overall and thus the manufacturing cost can be reduced.

In addition, since the conductive particles 111 are manufactured using the hemispherical portion protruding from the mold layer 131 without removing the hemispherical portion, there is an advantage that a planarization operation is not required after plating.

In addition, according to the present disclosure, a highly conductive metal is plated on the second plating layer 112' protruding from the substrate 130, and thus the side surface and the upper surface of the body portion 112 can be coated with a high conductivity layer 115. Therefore, unlike the prior art, since a highly conductive metal layer can be formed on the side surface without using a separate roller plating method, the manufacturing cost can be greatly reduced.

The conductive particles 111 disclosed herein have the following effects.

As shown in FIG. 5 , in a state where the connector 100 for testing is mounted on the testing equipment 140, the device to be tested 150 is transported by an insert or the like and is placed on the upper side of the connector 100.

Thereafter, as shown in FIG. 6 , the device to be tested 150 is lowered so that the terminal 151 of the device to be tested 150 is in contact with the connector 100. In this case, when the device to be tested 150 is pressed by a pusher (not shown), the conductive portion 110 expands in the horizontal direction while being compressed in the downward direction. Therefore, the conductive particles 111 in the conductive portion 110 contact each other to form an electrical conduction path. Thereafter, a predetermined electrical test is performed while applying an electrical signal from the test device 140.

Although FIG. 5 shows that the conductive particles are arranged in a constant shape in the vertical direction, the present disclosure is not limited thereto. For example, as shown in FIG. 7 , the conductive particles can be arranged in various shapes. That is, although FIG. 5 shows a form in which the body portion (the body portion is positioned on the upper side and the protruding portion is positioned on the lower side) is arranged in the vertical direction, the present disclosure is not limited thereto. For example, various arrangements can be made, such as some of the conductive particles standing upright and other conductive particles lying flat or tilted.

FIGS. 12 to 16 show examples of a state in which the conductive particles 111 according to the first embodiment come into contact with other conductive particles 111 or a ball-type terminal 151 of a device to be tested 150 during a test process.

First, as shown in FIG. 12 , when the conductive particles 111 contact the ball terminal 151 of the device to be tested 150, the sharp portion of the outer edge of the body portion 112 can contact the ball terminal, and thus can easily penetrate into the interior through the oxide film buried in the ball terminal 151, thereby helping to reduce resistance. When the sharp portion contacts the ball terminal 151, the contact pressure is greatly increased compared to the ball terminal.

In addition, as shown in FIG. 13 , when the conductive particles 111 contact the ball terminal 151 of the device to be tested 150, both the sharp portion of the outer edge of the body portion 112 and the sharp portion of the protrusion 113 can contact the ball terminal 151, and thus can easily penetrate into the interior through the oxide film buried in the ball terminal 151, thereby helping to reduce resistance. Therefore, the contact area can be increased and the electrical connection capability can be improved. Specifically, when the protrusion 113 provided on the bottom of the body portion 112 contacts the ball terminal 151, the contact area is enlarged.

As shown in FIG. 14 , when the conductive particles are in contact with each other (for example, when the side surfaces (for example, the upper curved surface portions) of the body portions 112 of the conductive particles 111 are in contact with each other), the conductive particles 111 are easy to slide on each other. Therefore, the elasticity of the conductive portion 110 can be improved, and thus the compressibility of the conductive portion 110 can be increased, and thus the pressure can be fully absorbed.

In addition, as shown in FIG. 15 , the flat bottom surfaces of the body portions 112 of the conductive particles 111 may contact each other. In this case, surface contact may be performed, and thus the contact area may be increased and the contact resistance may be reduced. Therefore, there is an effect of greatly improving the electrical connection capability.

In addition, as shown in FIG. 16, a high conductivity layer 115 may be coated on the surface of the protruding portion 113, and thus the internal material having high contact resistance may be exposed to the outside, thereby preventing contact with the curved surface of other particles. That is, since the protruding portion 113 of the conductive particle directly contacts the upper surface of the body portion 112 of another hemispherical particle without having a high conductivity layer, the contact resistance may be prevented from increasing.

Although examples of the conductive particles 111 have been described in the above embodiments, the conductive particles 111 are not limited thereto and may be modified as follows.

FIG. 17 shows a conductive particle 211 according to the second embodiment, and FIG. 18 shows a method of manufacturing the conductive particle 211 shown in FIG. 17 .

In the first embodiment, the surface of the conductive particle 111 is coated with a high conductivity layer 115. However, the present disclosure is not limited thereto, and there may also be a conductive particle 211 made of only a main body portion and a protruding portion.

As shown in FIG. 18 , the conductive particles 211 are obtained by sequentially performing the following steps: forming a conductive coating layer (not shown) by coating a conductive material on a substrate 130 such as a silicon wafer, silicon or ceramic (see FIG. 18 (a)); applying a molding layer 131 (photoresist layer) having a thickness less than that of the desired conductive particles 211 to the substrate 130 (see FIG. 18 (b)); and applying a conductive coating layer 131 (photoresist layer) to the substrate 130. An exposure process and a development process are performed to form a groove for particle formation (see FIG. 18(c)); a coating layer 211' is formed by a coating process to protrude upward around the groove inside the groove 132 for particle formation (see FIG. 18(d)); and the conductive particles 211 are separated from the substrate 130 after the mold layer 131 and the conductive coating layer are removed by etching (see FIG. 18(e)).

The conductive particles 211 according to the second embodiment can increase the elastic modulus of the conductive portion 110, increase the contact area by surface contact, increase the contact pressure on the ball terminal 151, and improve the bonding strength with the silicone rubber by the protruding portion as a simple manufacturing process.

FIG. 19 shows a conductive particle 311 according to the third embodiment, and the conductive particle 311 according to the third embodiment shows that a plurality of protrusions 313 are formed on the bottom of the body portion 312. FIG. 19 shows that the plurality of protrusions 313 are spaced at equal intervals. However, the present disclosure is not necessarily limited to this. In this way, when the plurality of protrusions 313 are formed on the bottom of the body portion 312, the silicone rubber can penetrate into the space between the protrusions 313 to further improve the bonding strength with the silicone rubber. In addition, the increase in contact resistance when contacting another conductive particle 311 can be prevented.

FIG. 20 shows a conductive particle 411 according to a fourth embodiment. The conductive particle 411 according to the fourth embodiment shows that a protruding portion 413 extending in one direction is formed on the bottom of a body portion 412, and the body portion 412 has a strip shape with a semicircular cross section and extends in one direction.

The conductive particles 411 according to the fourth embodiment can not only greatly increase the contact area with another conductive particle 411, but also increase the contact pressure when contacting the ball terminal. In addition, when the conductive particle 411 contacts another conductive particle 411, the conductive particle 411 slides on the curved portion of the side surface of the other conductive particle 411, thereby increasing the elastic modulus of the conductive portion and improving the bonding strength with the silicone rubber.

FIG. 21 is a conductive particle 511 according to the fifth embodiment. In the conductive particle 511 shown in FIG. 21 , a high conductivity layer 515 is provided on the upper surface and the side surface of the body portion 512, and a high conductivity layer 516 is provided on the bottom of the protruding portion 513. Even when the body portion 512 and the protruding portion 513 are made of a low conductivity material, the high conductivity layers 515 and 516 constituting the outer layer are in contact with other conductive particles 511, and thus the contact resistance can be prevented from being greatly increased.

FIG. 22 shows an example in which the conductive particles 511 shown in FIG. 21 are disposed inside the conductive portion 510. In this way, when the conductive particles 511 have a linear shape extending in one direction, the conductive particles 511 can be mixed in the conductive portion 510 in an irregular manner.

FIG. 23 shows various embodiments of the conductive particles 611. The conductive particles 611 may have various shapes, such as a grid shape (see FIG. 23 (a)), a triangle shape (see FIG. 23 (b)), a star shape (see FIG. 23 (c)), a tripod shape (see FIG. 23 (d)), an S shape (see FIG. 23 (e)), and a double S shape (see FIG. 23 (f)).

In the case of such a shape, when the conductive particle 611 is combined with another conductive particle 611, since the conductive particle 611 is entangled with the other conductive particle 611, not only the contact area is wide, but also the conductive particle 611 can be prevented from separating from the conductive part. In addition, due to the internal space, the conductive particle 611 itself can be deformed in an elastic manner or the bonding strength with the silicone rubber can be improved, and thus the conductive part can be easily deformed as a whole, the electrical connection ability can be improved, and the conductive particle 611 can be prevented from separating from the conductive part.

In addition, the conductive particles with an S shape (see FIG. 23(e)) and the conductive particles with a double S shape (FIG. 23(f)) have increased elasticity due to the shape of the conductive particles themselves and have excellent bonding strength between the conductive particles, and thus the conductive part can be easily deformed as a whole, the electrical connection ability can be improved, and the conductive particles can be prevented from separating from the conductive part.

In the above embodiments, the main body of the conductive particles has a stripe shape, a grid shape, a triangle shape or a star shape, but is not limited thereto. For example, the main body may have any one of an H shape, an X shape, an O shape, a C shape, an S shape, an N shape, a V shape, a W shape, a Z shape and a + shape, or a shape in which a plurality of each shape is continuously connected. In this case, the protruding portion may also have a corresponding shape while being narrower in width than the main body portion.

Although one or more embodiments have been described with reference to the drawings, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the following claims.

100: Connector

110: Conductive part

111: Conductive particles

120: Insulation part/insulation body

140:Testing equipment

141:Pad

150: Device to be tested

151: Terminal/hemispherical terminal/ball terminal

Claims (21)

A conductive particle is used for a test connector. The test connector is arranged between a device to be tested and a test equipment to electrically connect the terminal of the device to be tested and the pad of the test equipment to each other. A plurality of the conductive particles are distributed in an elastic insulating material and contact each other when the device to be tested is in contact, thereby forming a conductive path for transmitting electrical signals. The conductive particle comprises: a body portion, comprising a conductive material; The main body has a flat lower surface disposed on the bottom and has a width that decreases from the lower surface toward the upper part; and a protruding portion, comprising a conductive material, the protruding portion protrudes downward from the lower surface of the main body, is integrally connected to the main body, and has a width narrower than the width of the lower surface of the main body, wherein the main body has a curved portion that becomes rounded from the bottom to the upper end of the main body. The conductive particles as described in claim 1, wherein the upper end of the body portion has a flat surface parallel to the bottom of the body portion. The conductive particle as described in claim 1, wherein the upper end of the main body portion has a convex curved shape, and thus the main body portion as a whole has a hemispherical shape. The conductive particles as described in claim 1, wherein the main body portion has any one of a strip shape, a grid shape, a triangle shape, a star shape, an S shape, and a double S shape. The conductive particle as described in claim 1, wherein the body portion has any one of an H shape, an X shape, an O shape, a C shape, an S shape, an N shape, a V shape, a W shape, a Z shape and a + shape or has a shape in which a plurality of each shape are continuously connected. The conductive particle as described in claim 1, wherein the main body portion is configured by stacking different materials into multiple layers. Conductive particles as described in claim 6, wherein the different materials include any one of ferromagnetic metal materials, highly elastic metal materials and highly conductive metal materials. The conductive particles as described in claim 1, wherein the plurality of protrusions are separated from each other. The conductive particles as described in claim 1, wherein the plurality of protrusions are spaced at equal intervals relative to the center of the bottom of the main body. Conductive particles as described in claim 1, wherein the remaining outer surfaces of the body portion except the bottom are coated with a high conductivity layer. Conductive particles as described in claim 1 or 9, wherein the bottom of the protruding portion is coated with a high conductivity layer. The conductive particles as described in claim 1, wherein a concave portion is formed inwardly between the main body portion and the protruding portion. A test connector is provided between a plurality of terminals of a device to be tested and a plurality of pads of a test device to electrically connect the plurality of terminals to the plurality of pads, the test connector comprising: a conductive portion, in which a plurality of conductive particles are distributed in a thickness direction in an elastic insulating material at a plurality of positions corresponding to the plurality of terminals of the device to be tested; and an insulating portion, which insulates the conductive portion and supports the conductive portion, wherein the plurality of conductive particles Each includes: a body portion, comprising a conductive material, the body portion having a flat lower surface on the bottom and having a width that decreases from the lower surface toward the upper part; and a protruding portion, comprising a conductive material, the protruding portion protruding downward from the lower surface of the body portion, integrally connected to the body portion and having a width narrower than the width of the lower surface of the body portion, wherein the body portion has a curved portion that becomes rounded from the bottom to the upper end of the body portion. A method for manufacturing conductive particles, wherein the conductive particles are used for a test connector, wherein the test connector is disposed between a device to be tested and a test equipment to electrically connect the terminal of the device to be tested and the pad of the test equipment to each other, and a plurality of the conductive particles are distributed in an elastic insulating material and contact each other when the device to be tested is in contact, thereby forming a conductive path for transmitting electrical signals, the method comprising: (a) preparing a conductive particle; (a) forming a substrate; (b) forming a molding layer on the substrate; (c) forming a groove for particle formation by removing at least a portion of the molding layer; (d) forming a first coating layer inside the groove for particle formation; and (e) forming a second coating layer in a protruding manner, the second coating layer being integrally connected to the first coating layer around the groove for particle formation and having a width that decreases in an upward direction. The method as described in claim 14 further includes (f) removing the molding layer after operation (e). A method as claimed in claim 14, wherein operation (a) includes forming a conductive coating on the substrate. The method as described in claim 16 further includes (g) removing the conductive coating formed on the substrate after operation (f). The method described in claim 14 further includes (c-1) forming a third coating layer by coating a highly conductive material to a thickness less than the thickness of the molding layer between operations (c) and (d). The method described in claim 14 further includes (e-1) coating a highly conductive metal on the second coating layer after operation (e). The method of claim 14, wherein operation (d) includes forming the first coating layer by coating with different metal materials and stacking the different metal materials into multiple layers. The method of claim 14, wherein operation (e) includes forming the second coating layer by coating with different metal materials and stacking the different metal materials into multiple layers.

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