has a uniform thickness in the width direction and the length direction of the probe pin 100.

In addition, the probe pin 100 includes a support portion 140 provided outside the elastic portion 130 along the length direction of the probe pin 100 so as to guide the elastic portion 130 to be compressed and extended in the length direction of the probe pin 100 and prevent the elastic portion 130 from being buckled when compressed.

As the first plunger 110 is vertically moved downward inside the support portion 140, an additional contact point is formed between the first plunger 110 and the support portion 140.

The second plunger 120 moves vertically upward inside the support portion 140 and performs a wiping operation at a second contact point. During an overdrive process in which the probe pin 100 tests the chip, the support portion 140 of the probe pin 100 maintains a vertical state, and the second plunger 120 performs the wiping operation on the chip as it is tilted while maintaining a contact pressure with the chip.

The pitch between the probe pins 100 installed in the guide plates GP1 and GP2 of the vertical probe card 10 is in the rage of 50 μm to 150 μm. The lateral width of the probe pin 100 is in the range of 40 μm to 200 μm, and the thickness of the probe pin 100 is in the range of 40 μm to 200 μm.

The probe pin 100 of the vertical probe card according to the exemplary embodiment of the present disclosure is provided by stacking a plurality of metal layers in the thickness direction of the probe pin 100. The plurality of metal layers include a first metal layer 160 and a second metal layer 180. The first metal layer 160 may be made of a metal having relatively high wear resistance compared to the second metal layer 180, preferably a metal selected from rhodium (Rh), platinum (Pt), iridium (Ir), palladium (Pd), nickel (Ni), manganese (Mn), tungsten (W), phosphorus (P), or an alloy thereof, or a palladium-cobalt (PdCo) alloy or a palladium-nickel (PdNi) alloy, or a nickel-phosphorus (NiP) alloy, a nickel-manganese (NiMn) alloy, a nickel-cobalt (NiCo) alloy, or a nickel-tungsten (NiW) alloy. The second metal layer 180 may be made of a metal having relatively high electrical conductivity compared to the first metal layer 160, preferably a metal selected from copper (Cu), silver (Ag), gold (Au), or an alloy thereof.

The first metal layer 160 is disposed on each of the upper and lower sides in the thickness direction of the probe pin 100, and the second metal layer 180 is disposed between the first metal layers 160. For example, the probe pin 100 is provided by sequentially stacking the first metal layer 160, the second metal layer 180, and the first metal layer 160, and the number of stacked layers is at least three.

The probe pin 100 of the vertical probe card according to the exemplary embodiment of the present disclosure includes: the first plunger 110 located at a first end side of the probe pin 100 and having an end serving as a first contact point; the second plunger 120 located at a second end side of the probe pin 100 and having an end serving as a second contact point; the elastic portion 130 elastically displacing the first plunger 110 and the second plunger 120 in the length direction of the probe pin 100; and the support portion 140 guiding the elastic portion 130 to be compressed and extended in the length direction of the probe pin 100 and provided outside the elastic portion 130 along the length direction of the probe pin 100 so as to prevent the elastic portion 130 from being bent or curved in the horizontal direction when compressed.

The probe pin 100 is inserted into a guide hole of the upper guide plate GP1 and a guide hole of the lower guide plate GP2.

The first contact point of the first plunger 110 is connected to the connection pad CP of the space transformer ST, and the second plunger 120 is connected to a connection pad of a test object. Here, the test object may be a semiconductor chip.

The clastic portion 130 includes: a first elastic portion 131 connected to the first plunger 110; a second elastic portion 135 connected to the second plunger 120; and an intermediate fixing portion 137 connected to the first elastic portion 131 and the second elastic portion 135 between the first elastic portion 131 and the second elastic portion 135 and provided integrally with the support portion 140. The elastic portion 130 has a uniform cross-sectional shape in the thickness direction of the probe pin 100. In addition, the elastic portion 130 has a uniform thickness throughout. Each of the first and second elastic portions 131 and 135 is formed by repeatedly bending a plate having an actual width t in an “S” shape, and the actual width t of the plate is uniform throughout. The ratio of the actual width t of the plate to the thickness of the plate is in the range of 1:5 to 1:30.

Before the probe pin 100 tests the semiconductor chip, the first plunger 110 is in a state in contact with the connection pad CP so that the first elastic portion 131 is compressively deformed in the length direction of the probe pin 100, and the second plunger 120 is in a state not in contact with the chip. Whereas, when the probe pin 100 tests the chip, the second plunger 120 is brought into contact with the chip so that the second elastic portion 135 is compressively deformed.

The first plunger 110 has a first end serving as a free end and a second end connected to the first elastic portion 131 so that the first plunger 110 is elastically movable vertically by contact pressure. The second plunger 120 has a first end serving as a free end and a second end connected to the second elastic portion 135 so that the second plunger 120 is elastically movable vertically by contact pressure.

The first elastic portion 131 has a first end connected to the first plunger 110 and a second end connected to the intermediate fixing portion 137. The second elastic portion 135 has a first end connected to the second plunger 120 and a second end connected to the intermediate fixing portion 137.

The support portion 140 includes a first support portion 141 provided at a left side of the elastic portion 130 and a second support portion 145 provided at a right side of the elastic portion 130.

A locking portion 149 is provided on an outer wall of the support portion 140 so that the support portion 140 is caught and fixed to the upper guide plate GP1. The locking portion 149 includes an upper locking portion 149a caught on an upper surface of the upper guide plate GP1 and a lower locking portion 149b caught on a lower surface of the upper guide plate GP1.

The intermediate fixing portion 137 is formed to extend in the width direction of the probe pin 100, and connects the first support portion 141 and the second support portion 145 to each other.

The first elastic portion 131 is provided above the intermediate fixing portion 137, and the second elastic portion 135 is provided below the intermediate fixing portion 137.

The first elastic portion 131 and the second elastic portion 135 are compressed or extended with respect to the intermediate fixing portion 137. The intermediate fixing portion 137 is fixed to the first and second support portions 141 and 145 and functions to limit the movement of the first and second elastic portions 131 and 135 when the first and second elastic portions 131 and 135 are compressively deformed.

The intermediate fixing portion 137 separates a region in which the first elastic portion 131 is provided and a region in which the second elastic portion 135 is provided. Therefore, foreign substances introduced into an upper opening 143a are blocked from flowing toward the second elastic portion 135, and foreign substances introduced into a lower opening 143b are also blocked from flowing toward the first elastic portion 131. With this, the movement of the foreign substances introduced into the support portion 140 is limited, thereby preventing the operation of the first and second elastic portions 131 and 135 from being disturbed by the foreign substances.

The first support portion 141 and the second support portion 145 are formed along the length direction of the probe pin 100. The first support portion 141 and the second support portion 145 are integrally connected to the intermediate fixing portion 137 extending along the width direction of the probe pin 100. In addition, the first and second elastic portions 131 and 135 are integrally connected to each other through the intermediate fixing portion 137, so that the probe pin 100 is constructed as a single body.

Each of the first and second elastic portions 131 and 135 is formed by alternately connecting a plurality of straight portions 130a and a plurality of curved portions 130b. Each of the straight portions 130a connects the curved portions 130b adjacent in the left and right directions, and each of the curved portions 130b connects the straight portions 130a adjacent in the upper and lower directions. The curved portions 130b have an arc shape.

The straight portions 130a are disposed at a central portion of each of the first and second clastic portions 131 and 135, and the curved portions 130b are disposed at outer peripheral portions of each of the first and second elastic portions 131 and 135. The straight portions 130a are provided parallel to the width direction so that the curved portions 130b can be more easily deformed by contact pressure.

The first and second elastic portions 131 and 135 are connected to the intermediate fixing portion 137 at the curved portions 130b of the first and second elastic portions 131 and 135. With this, the first and second elastic portions 131 and 135 maintain elasticity with respect to the intermediate fixing portion 137.

While the first elastic portion 131 requires an amount of compression sufficient to allow respective first plungers 110 of the plurality of probe pins 100 to make stable contact with respective connection pads CP of the space transformer ST, the second elastic portion 135 requires an amount of compression sufficient to allow respective second plungers 120 of the plurality of probe pins 100 to make stable contact with respective chips. Therefore, the first elastic portion 131 and the second elastic portion 135 have different spring coefficients from each other. For example, the first elastic portion 131 and the second elastic portion 135 are provided to have different lengths from each other. Also, the length of the second elastic portion 135 may be longer than that of the first elastic portion 131.

A flat portion 130c is provided at each of upper and lower portions of each of the curved portions 130b. The flat portion 130c has a flat surface shape. The flat portions 130c adjacent in the upper and lower directions are brought into surface contact with each other when the first and second elastic portions 131 and 135 are deformed. During test, as the first and second elastic portions 131 and 135 are compressed, the flat portions 130c adjacent in the upper and lower directions are brought into surface contact with each other. With this, electrical signal transmission can be quickly and stably performed through the curved portions 130b provided at the outer peripheral portions of the first and second clastic portions 131 and 135.

Each of the curved portions 130b is connected to two straight portions 130a. The two straight portions 130a are located within a range that does not exceed the distance between opposite sides of each of the curved portions 130b. One straight line portion 130a is connected to a first side of each of the curved portions 130b bent downward from the upper portion thereof, and the other straight portion 130a is connected to a second side of each of the curved portions 130b bent upwardly from the lower portion thereof. Thus, the distance between the two straight portions 130a connected to one curved portion 130b does not exceed the distance between opposite sides of the one curved portion 130b. With this, it is possible to provide more curved portions 130b and straight portions 130a within the same length range of the elastic portion 130, so that the first and second clastic portions 131 and 135 can have sufficient elasticity. As a result, it is possible to shorten the length of the elastic portion 130.

Meanwhile, the distance between the curved portions 130b adjacent in the upper and lower directions is shorter than that between the straight portions 130a adjacent in the upper and lower directions. With this, when the first and second elastic portions 131 and 135 are compressed, the curved portions 130b adjacent in the upper and lower directions are brought into contact with each other first to form a current path through the curved portions 130b, and then when an additional overdrive is applied, the first and second elastic portions 131 and 135 are further deformed through the straight portions 130a adjacent in the upper and lower directions.

Opposite ends of the first support portion 141 and opposite ends of the second support portion 145 are close to each other but spaced apart from each other to form openings. The openings include the upper opening 143a allowing the first plunger 110 to pass therethrough in the vertical direction and the lower opening 143b allowing the second plunger 120 to pass therethrough in the vertical direction. The upper opening 143a and the lower opening 143b function to prevent the first and second plungers 110 and 120 from excessively protruding from the support portion 140 by a restoring force of the first and second elastic portions 131 and 135.

The first support portion 141 includes a first door portion 144a extending toward the upper opening 143a, and the second support portion 145 includes a second door portion 144b extending toward the upper opening 143a. The first door portion 144a and the second door portion 144b face each other and are spaced apart from each other by a gap that defines the upper opening 143a. The width of the upper opening 143a is configured to be smaller than the lateral length of the straight portions 130a of the first elastic portion 131.

The first plunger 110 is connected to a straight portion 130a of the first elastic portion 131 and has a rod shape extending in the length direction of the probe pin 100. The first plunger 110 vertically passes through the upper opening 143a formed by the first support portion 141 and the second support portion 145. In addition, since the lateral length of the straight portions 130a of the first elastic portion 131 is larger than the width of the upper opening 143a, the straight portions 130a of the first elastic portion 131 do not pass through the upper opening 143a. With this, an upward stroke of the first plunger 110 is limited.

The end of the first support portion 141 and the end of the second support portion 145 are close to each other but spaced apart from each other to form the upper opening 143a allowing the first plunger 110 to pass therethrough in the vertical direction. When the first plunger 110 is vertically moved downward inside the support portion 140, the width of the upper opening 143a is reduced to cause the first and second support portions 141 and 145 to be brought into contact with each other to form an additional contact point.

The first support portion 141 includes a first extension portion 145a extending toward the inside of the support portion 140, and the second support portion 145 includes a second extension portion 145b extending toward the inside of the support portion 140.

The first extension portion 145a is connected to the first door portion 144a. The first extension portion 145a has a first end connected to the first door portion 144a and a second end extending toward the inside of the support portion 140 and serving as a free end.

The second extension portion 145b is connected to the second door portion 144b. The second extension portion 145b has a first end connected to the second door portion 144b and a second end extending toward the inside of the support portion 140 and serving as a free end.

The first plunger 110 includes a first protruding piece 110a extending toward the first extension portion 145a and a second protruding piece 110b extending toward the second extension portion 145b. When the first plunger 110 is moved downward by a pressing force, the first protruding piece 110a and the second protruding piece 110b are brought into contact with the first and second extension portions 145a and 145b, respectively.

As the first plunger 110 is moved downward, the first protrusion piece 110a and the second protrusion piece 110b are brought into contact with the first extension portion 145a and the second extension portion 145b, respectively, to form additional contact points.

The first extension portion 145a and the second extension portion 145b are formed to be inclined. Thus, when the first plunger 110 is vertically moved downward, the first protrusion piece 110a and the second protrusion piece 110b press the first extension portion 145a and the second extension portion 145b, respectively, so that the gap between the first door portion 144a and the second door portion 144b is reduced. In other words, as the first plunger 110 is vertically moved downward, the first door portion 144a and the second door portion 144b are deformed to approach each other, thereby reducing the width of the upper opening 143a. As such, when the first plunger 110 is moved downward inside the support portion 140, the first and second support portions 141 and 145 and the first plunger 110 are brought into contact with each other as the width of the upper opening 143a is reduced, thereby forming additional contact points.

As the first plunger 110 is moved downward, the first and second protruding pieces 110a and 110b and the first and second extension portions 145a and 145b are primarily brought into contact with each other to form additional contact points, and as the first plunger 110 is further moved downward, the first and second door portions 144a and 144b and the first plunger 110 are secondarily brought into contact with each other to form additional contact points. Due to the vertical downward movement of the first plunger 100, an additional current path is formed between the first plunger 110 and the support portion 140. This additional current path is formed directly from the support portion 140 to the first plunger 110 without passing through the elastic portion 130. Due to the formation of the additional current path, a more stable electrical connection is possible.

The width of the upper opening 143a is reduced in proportion to the downward movement distance of the first plunger 110. In addition, when a downward pressure is applied to the first plunger 110 even after the contact of the first and second door portions 144a and 144b with the first plunger 110, a frictional force between the first and second door portions 144a and 144b and the first plunger 110 is further increased. The increased frictional force prevents excessive downward movement of the first plunger 110. With this, it is possible to prevent excessive compression deformation of the elastic portion 130 (more specifically, the first elastic portion 131).

The second plunger 120 is connected to the second elastic portion 135 at an upper portion thereof, with an end passing through the lower opening 143b.

The second plunger 120 includes a connecting portion 129 connected to the elastic portion 130, a protruding tip 125 providing a second contact point, and an inner body 121 provided between the connecting portion 129 and the protruding tip 125 and not separated to the outside of the support portion 140.

A first end of the connecting portion 129 is connected to the elastic portion 130, more specifically, the second elastic portion 135, and a second end of the connecting portion 129 is connected to the inner body 121.

The second plunger 120 repeatedly performs upward and downward movement operations. At this time, the second plunger 120 and the support portion 140 located laterally thereof are brought into sliding contact with each other. The inner body 121 is configured in a hemispherical shape when viewed in a plan view to minimize a sliding friction force between the second plunger 120 and the support portion 140. The inner body 121 has minimal frictional resistance with respect to the support portion 140 due to the hemispherical shape thereof.

The inner body 121 is a portion located inside the support portion 140. The lateral length of a lower surface of the inner body 121 is configured to be larger than the width of the lower opening 143b to prevent the inner body 121 from being separated from the support portion 140.

A stepped portion 127 is provided at the protruding tip 125 of the second plunger 120. The stepped portion 127 is formed such that the width of the second plunger 120 increases from the second contact point toward the lower opening 143b at a portion of the second plunger 120 protruding from the support portion 140.

During a wiping operation of the second plunger 120, shavings are generated from an oxide layer 8. The shavings are electrodeposited and agglomerated together, and these shavings are caught on the stepped portion 127 and induced to fall naturally and are prevented from continuously growing. In addition, the stepped portion 127 functions to prevent the shavings from moving to the inside of the support portion 140.

As the second plunger 120 is vertically moved upward inside the support portion 140, the second contact point thereof performs a wiping operation. The second elastic portion 135 of the elastic portion 130 is connected to the second plunger 120 at a position eccentric to the axial line of the second plunger 120 so that the second plunger 120 performs the wiping operation at the second contact point when the second plunger 120 is moved upward.

The connecting portion 129 is inclined with an inclination angle and is connected to the second elastic portion 135 and a spherical surface of the inner body 121. A first end of the connecting portion 129 is connected to the spherical surface of the inner body 121 at a position on or close to the axial line of the second plunger 120, and a second end of the connecting portion 129 is connected to the second elastic portion 135 at a position farther from the axial line than the first end. Preferably, the first end of the connecting portion 129 is connected to the inner body 121 at a position on the axial line of the inner body 121, and the second end of the connecting portion 129 is connected to the second elastic portion 135 at a position corresponding to a curved portion 130b of the second elastic portion 135.

When the second plunger 120 is moved upward, the inner body 121 receives a deflected repulsive force by the connecting portion 129 inclinedly connected to the second elastic portion 135 on an upper surface of the inner body 121. With this configuration, when the second plunger 120 is vertically moved upward by a pressing force, the inner body 121 receives an eccentric resistance force. The eccentric resistance force acts on an upper side of the inner body 121 to generate a rotational moment in the inner body 121. As a result, as illustrated in FIG. 8c, the protruding tip 125 of the second plunger 120 performs the wiping operation on the test object as it is tilted while maintaining an appropriate contact pressure with the test object.

As the protruding tip 125 of the second plunger 120 is tilted while maintaining the appropriate contact pressure, cracks are generated in the oxide layer 8, and a conductive material layer of the electrode pad WP is exposed through the cracks and is brought into contact with the protruding tip 125. As a result, an electrical connection is made. In addition, by the wiping operation, it is possible to minimize damage to the electrode pad WP and to extend the useable life of the probe pin 100 by not causing an excessive amount of shavings of the oxide layer 8.

The wiping degree against the electrode pad WP of the test object at the second contact point is controllable by the size of the gap between the lower opening 143b and the protruding tip 125. The gap between the lower opening 143b and the protruding tip 125 is a factor that determines an allowable tilting angle. The larger the gap between the lower opening 143b and the protruding tip 125, the larger the tilting angle of the second contact point of the protruding tip 125 is, and on the other hand, the smaller the gap between the lower opening 143b and the protruding tip 125, the smaller the tilting angle of the second contact point of the protruding tip 125 is.

In the related art, an oxide layer 8 on an electrode pad WP of a test object is removed as a probe pin 7 is buckled, i.e., bent or curved, by pressure applied to the opposite ends thereof and a contact point thereof performs a sliding operation. The oxide layer 8 may be easily removed by excessive pressure that causes the probe pin 7 to be curved in the width direction. However, there is a contradictory problem in that damage to the electrode pad WP is also increased. In particular, as the electrode pad WP is becoming smaller in response to the trend toward a narrower pitch, damage to the electrode pad WP by the probe pin 7 due to excessive contact pressure is becoming more frequent.

On the contrary, in the case of the probe pin 100 according to the exemplary embodiment of the present disclosure, when receiving a contact pressure, the second plunger 120 performs the wiping operation as the second elastic portion 135 is compressively deformed from a spring structure in which the plate is repeatedly bent in advance. Thus, it is possible prevent excessive pressure from being applied to the electrode pad WP, thereby minimizing damage to the electrode pad WP.

As described above, there is a difference in basic operating principle of the wiping operation between the probe pin 100 according to the exemplary embodiment of the present disclosure and the probe pin 7 according to the related art. In the case of the related art, the probe pin 7 itself performs the wiping operation as it is elastically deformed. Whereas, in the case of the present disclosure, the second plunger 120 performs the wiping operation as it is tilted while the support portion 140 maintains a vertical state.

Unlike the conventional wiping operation (conventional vertical probe card) of removing the oxide layer 8 by applying excessive contact pressure to the oxide layer 8 or the conventional wiping operation (conventional cantilever probe card) of removing the oxide layer 8 by scrubbing the oxide layer 8, the second plunger 120 according to the exemplary embodiment of the present disclosure removes the oxide layer 8 as it is tilted while maintaining an appropriate contact pressure at the second contact point, thereby minimizing damage to the electrode pad WP.

The first and second plungers 110 and 120, the elastic portion 130, and the support portion 140 are simultaneously manufactured using a plating process to form a single body. The probe pin 100 is configured such that plates are integrally connected to each other to constitute the first and second plungers 110 and 120, the elastic portion 130, and the support portion 140.

The plates constituting the probe pin 100 have a width. Here, the width means a distance between a first surface of the plates and a second surface thereof facing the first surface. The plates constituting the probe pin 100 have a minimum width corresponding to the smallest width and a maximum width corresponding to the largest width. The actual width t of the plates may be an average value of the widths of all the plates, or a median value of the widths of all the plates, or an average value or a median value of the widths of the plates corresponding to at least a part of the configurations constituting the probe pin 100, or an average value or a median value of the width of at least one of the plates corresponding to the elastic portion 130 and the support portion 140, or a value of the width obtained when the plates are continuous with the same width by equal to or larger than 5 μm.

Since the actual width t of the plates is configured to be smaller than the overall thickness H of the plates, a structure in which thin plates stand up in the thickness direction is formed.

The probe pin 100 is provided as a single body, and includes: the support portion 140 formed in the form of a plate extending in the length direction; the intermediate fixing portion 137 provided inside the support portion 140 and formed in the form of a plate extending in the width direction while crossing the support portion 140; the first elastic portion 131 formed in the form of a bent plate at the upper side of the intermediate fixing portion 137; the second elastic portion 135 formed in the form of a bent plate at the lower side of the intermediate fixing portion 137; the first plunger 110 formed in the form of a plate at an upper end of the first elastic portion 131; and the second plunger 120 formed in the form of a plate at a lower end of the second elastic portion 135. As described above, the probe pin 100 is provided as a single body in which the plates are integrally connected to each other.

The plates constituting the first and second plungers 110 and 120, the elastic portion 130, and the support portion 140 may be different from each other in the actual width t, but may have the same thickness.

The probe pin 100 according to the exemplary embodiment of the present disclosure is formed such that the actual width t of the plates is small while the overall thickness H of the plates is large. In other words, the overall thickness H is configured to be large compared to the actual width t of the plates. Preferably, the actual width t of the plates constituting the probe pin 100 is in the range of 5 μm to 15 μm, the overall thickness H of the plates is in the range of 40 μm to 200 μm, and the actual width t and the overall thickness H of the plates have a ratio in the range of 1:5 to 1:30. For example, the actual width t of the plates may be substantially 5 μm, and the overall thickness H of the plates may be 50 μm, so that the actual width t and the overall thickness H of the plates may have a ratio of 1:10.

According to the method of manufacturing the probe pin 100 according to the exemplary embodiment of the present disclosure, which will be described later, it is possible to make the actual width t of the plates constituting the elastic portion 130 equal to or less than 10 μm, more preferably 5 μm. Since it becomes possible to form the elastic portion 130 by bending the plates having an actual width t of 5 μm, it is possible to reduce the overall width W of the probe pin 100. As a result, it is possible to cope with a narrower pitch. In addition, since the overall thickness H is configured in the range of 40 μm to 200 μm, it is possible to shorten the length of the elastic portion 130 while preventing damage to the elastic portion 130. Also, it is possible for the elastic portion 130 to have an appropriate contact pressure by the configuration of the plate even when the length thereof is shortened. Furthermore, as it becomes possible to increase the overall thickness H compared to the actual width t of the plates constituting the elastic portion 130, the resistance to moments acting in the front and rear directions of the elastic portion 130 is increased, resulting in improved contact stability.

As it becomes possible to shorten the length of the elastic portion 130, the overall thickness H and the overall length L of the probe pin 100 have a ratio in the range of 1:3 to 1:9. Preferably, the overall length L of the probe pin 100 is in the range of 300 μm to 3 mm, and more preferably 450 μm to 600 μm. By shortening the overall length L of the probe pin 100 in this way, it is possible to effectively cope with high-frequency characteristics. Also, the elastic recovery time of the elastic portion 130 can be shortened, thereby shortening the test time.

The overall thickness H and the overall width W of the probe pin 100 have a ratio in the range of 1:1 to 1:5. Preferably, the overall thickness H of the probe pin 100 is in the range of 40 μm to 200 mm, and the overall width W of the probe pin 100 is in the range of 40 μm to 200 μm. By shortening the overall width W of the probe pin 100 in this way, it is possible to implement a narrower pitch.

Meanwhile, the overall thickness H and the overall width W of the probe pin 100 may be configured to be substantially the same. Thus, it is not necessary to join a plurality of separately manufactured probe pins 100 in the thickness direction so that the overall thickness H and the overall width W become substantially the same. In addition, as it becomes possible to make the overall thickness H and the overall width W of the probe pin 100 substantially the same, the resistance to moments acting in the front and rear directions of the probe pin 100 is increased, resulting in improved contact stability. Furthermore, with the configuration in which the overall thickness H of the probe pin 100 is equal to or larger than 70 μm and the ratio of the overall thickness H to the overall width W thereof is in the range of 1:1 to 1:5, overall durability and deformation stability of the probe pin 100 can be improved and thereby contact stability with the electrode pad WP can be improved. In addition, as the overall thickness H of the probe pin 100 is configured to be equal to or larger than 70 μm, it is possible to improve current carrying capacity.

When the probe pin 100 is manufactured using a photoresist mold, the overall thickness H is inevitably smaller than the overall width W. For example, in the case of the probe pin 100 thus manufactured, the overall thickness H may be less than 40 μm and the overall thickness H and the overall width W may have a ratio in the range of 1:2 to 1:10. Thus, the resistance to moments that deform the probe pin 100 in the front and rear directions by contact pressure is weak. In order to prevent problems occurring due to excessive deformation of the clastic portion 130 on front and rear surfaces of the probe pin 100, it should be considered to additionally form a housing on the front and rear surfaces of the probe pin 100. However, according to the exemplary embodiment of the present disclosure, an additional housing is not necessary.

The method of manufacturing the probe pin 100 of the vertical probe card according to the exemplary embodiment of the present disclosure will be described with reference to FIGS. 9a to 9d.

FIG. 9a is a plan view illustrating a mold M in which an inner space IH is formed. FIG. 9b is a sectional view taken along line A-A′ of FIG. 9a. The mold M may be made of an anodic aluminum oxide film, a photoresist, a silicon wafer, or a material similar thereto. However, a more preferred material for the mold M is an anodic aluminum oxide film. Therefore, the probe pin 100 according to the exemplary embodiment of the present disclosure has an effect exhibited by the use of the mold M made of the anodic aluminum oxide film as well as an effect exhibited by the structural advantages. Hereinafter, the mold M made of the anodic aluminum oxide film will be described as a preferred embodiment of the mold M.

The anodic aluminum oxide film means a film formed by anodizing a metal as a base material, and pores mean holes formed in the process of forming the anodic aluminum oxide film by anodizing the metal. For example, when the metal as the base material is aluminum (Al) or an aluminum alloy, the anodization of the base material forms the anodic aluminum oxide film consisting of anodized aluminum (Al₂O₃) on a surface of the base material. However, the metal is not limited thereto, and includes Ta, Nb, Ti, Zr, Hf, Zn, W, Sb, or an alloy thereof. The resulting anodic aluminum oxide film includes a barrier layer in which no pores are formed therein vertically, and a porous layer in which the pores are formed therein. After removing the base material on which the anodic aluminum oxide film having the barrier layer and the porous layer is formed, only the anodic aluminum oxide film consisting of anodized aluminum (Al₂O₃) remains. The anodic aluminum oxide film may have a structure in which the barrier layer formed during the anodization is removed to expose the top and bottom of the pores, or a structure in which the barrier layer formed during the anodization remains to close one of the top and bottom of the pores.

The anodic aluminum oxide film has a coefficient of thermal expansion of 2 to 3 ppm/° C. With this, the anodic aluminum oxide film is less likely to undergo thermal deformation due to temperature when exposed to a high temperature environment. Thus, even when the probe pin 100 is manufactured in a high-temperature environment, a precise probe pin 100 can be manufactured without thermal deformation.

Since the probe pin 100 according to the exemplary embodiment of the present disclosure is manufactured using the mold M made of the anodic aluminum oxide film instead of a photoresist mold, there is an effect of realizing shape precision and a fine shape, which were limited in realization with the photoresist mold. In addition, when the conventional photoresist mold is used, a probe pin with a thickness of 40 μm can be manufactured, but when the mold M made of the anodic aluminum oxide film is used, the probe pin 100 with a thickness in the range of 40 μm to 200 μm can be manufactured.

A seed layer SL is provided on a lower surface of the mold M. The seed layer SL may be provided on the lower surface of the mold M before the inner space IH is formed in the mold M. Meanwhile, a support substrate (not illustrated) is formed under the mold M to improve handling of the mold M. In this case, the seed layer SL may be formed on an upper surface of the support substrate, and then the mold M having the inner space IH may be coupled to the support substrate. The seed layer SL may be made of copper (Cu), and may be formed by a deposition method.

The inner space IH may be formed by wet-etching the mold M made of the anodic aluminum oxide film. To this end, a photoresist may be provided on the upper surface of the mold M and patterned, and then the anodic aluminum oxide film in a patterned and open area may react with an etching solution to form the inner space IH.

Thereafter, an electroplating process is performed in the inner space IH of the mold M to form the probe pin 100. FIG. 9c is a plan view illustrating the electroplating process performed in the inner space IH. FIG. 9d is a sectional view taken along line A-A′ of FIG. 9c.

During the electroplating process, a plurality of metal layers are stacked in the thickness direction of the probe pin 100 by growing the metal layers in the thickness direction of the mold M, so the metal layers have a uniform cross-sectional shape in the thickness direction of the probe pin 100. The plurality of metal layers include a first metal layer 160 and a second metal layer 180. The first metal layer 160 may be made of a metal having relatively high wear resistance compared to the second metal layer 180, preferably a metal selected from rhodium (Rh), platinum (Pt), iridium (Ir), palladium (Pd), nickel (Ni), manganese (Mn), tungsten (W), phosphorus (P), or an alloy thereof, or a palladium-cobalt (PdCo) alloy or a palladium-nickel (PdNi) alloy, or a nickel-phosphorus (NiP) alloy, a nickel-manganese (NiMn) alloy, a nickel-cobalt (NiCo) alloy, or a nickel-tungsten (NiW) alloy. The second metal layer 180 may be made of a metal having relatively high electrical conductivity compared to the first metal layer 160, preferably a metal selected from copper (Cu), silver (Ag), gold (Au), or an alloy thereof.

The first metal layer 160 is provided on each of a lower surface and an upper surface of the probe pin 100 in the thickness direction, and the second metal layer 180 is provided between the first metal layers 160. For example, the probe pin 100 is provided by sequentially stacking the first metal layer 160, the second metal layer 180, and the first metal layer 160, and the number of stacked layers is at least three.

After the plating process is completed, the temperature is raised to a high temperature and pressure is applied to pressurize the metal layers on which the plating process is completed so that the first metal layer 160 and the second metal layer 180 are made more dense. When a photoresist is used as a mold, the process of raising the temperature to a high temperature and applying pressure cannot be performed because the photoresist exists around the metal layers after the plating process is completed. On the contrary, according to the exemplary embodiment of the present disclosure, since the mold M made of the anodic aluminum oxide film is provided around the metal layers on which the plating process is completed, even when the temperature is raised to a high temperature, it is possible to densify the first metal layer 160 and the second metal layer 180 with minimized deformation because of the low coefficient of thermal expansion of the anodic aluminum oxide film. Thus, it is possible to obtain the first metal layer 160 and the second metal layer 180 with a higher density compared to the technique using the photoresist as the mold.