Contact pin

Abstract

To provide a contact pin capable of surely and stably obtaining a conduction with a ball-like solder of a semiconductor device.SOLUTION: A contact pin includes: a first main body part and a second main body part that are formed by an elastic piece extended to a first direction, is faced each other in a second direction that is orthogonal to the first direction, and includes a plane symmetrical shape in regard to a surface containing the first direction, and a base part that is continued to an end part on a lower side as the other of the first direction of the first and second main bodies, and supports the first and second main body parts. A gap between the first main body part and the second main body part becomes narrow toward an upper side from the bas part side and is reached to a narrowest part. In a widest part provided from the narrowest part to an end part on the upper side has a shape of which the gap is expanded. The gap of the second direction of the first main body part and the second main body part is provided in a shape where it is bent in a direction so as to be narrow toward the upper side from the widest part while having a border of the widest part.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a contact pin used when conducting a continuity test or measuring characteristics of a semiconductor device. [Background technology]

[0002] Conventionally, one of the contact devices used when performing electrical measurements on semiconductor devices is a contact socket for semiconductor devices (hereinafter, also simply referred to as a "contact socket"). In a contact socket, contact pins are brought into contact with solder exposed from the package of the accommodated semiconductor device, thereby achieving electrical continuity between an external measuring device and the semiconductor device.

[0003] In such a contact socket, Patent Document 1 discloses a contact pin that prevents the electric component from floating up, ensures contact stability, and allows the contact portion to be easily shaped.

[0004] Furthermore, Patent Documents 2 and 3 disclose contact terminals that can prevent the contact terminals from coming off from between the movable contact portions in the electrode portion of the semiconductor device and prevent damage to the electrode portion of the semiconductor device even if the electrode surface of a BGA-type packaged semiconductor device placed on the socket body of an IC socket warps in one direction during testing or if the electrode surface rises and falls up and down. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2004-199921 A [Patent Document 2] JP 2017-152265 A [Patent Document 3] JP 2020-061378 A Summary of the Invention [Problem to be solved by the invention]

[0006] In a contact socket for a semiconductor device having a BGA type package, in order to ensure electrical contact with a ball-shaped solder, it is preferable to clamp the ball-shaped solder with contact pins. In this case, it is also necessary to obtain a wiping effect in which the contact pins rub the surface of the solder appropriately, breaking the oxide film on the solder surface and increasing conductivity. In particular, in an aging test, stable contact over a long period of time under severe environmental conditions is required.

[0007] An object of the present invention is to provide a contact socket and a contact pin for a semiconductor device, which are capable of obtaining reliable and stable electrical connection with the ball-shaped solder of the semiconductor device. [Means for solving the problem]

[0008] In order to solve the above problems, one aspect of the present invention is a contact socket for a semiconductor device comprising: a contact pin having first and second body portions, both of which are made of elastic pieces extending in a first direction, facing each other in a second direction perpendicular to the first direction, and having a plane-symmetrical shape with respect to a plane including the first direction; a base portion connected to the lower end portion of the first and second body portions, which is the other side of the first direction, and supporting the first and second body portions; a fixed portion that accommodates the base; and a slide portion that is movable in the first direction and has an accommodation portion that accommodates a portion of each of the first and second body portions.

[0009] In this contact socket for a semiconductor device, the first body portion has a first contact portion at its upper end in one of the first directions for contacting an electrode protruding downward from the semiconductor device, and the second body portion has a second contact portion at its upper end for contacting the electrode of the semiconductor device, and each of the first contact portion and the second contact portion has a contact protrusion protruding in the second direction. The accommodating portion has a first accommodating portion that accommodates a portion of the first main body portion, a second accommodating portion that accommodates a portion of the second main body portion, and an intervening portion that is located between the first accommodating portion and the second accommodating portion in the second direction and is capable of contacting the inner surfaces of each of the first main body portion and the second main body portion.

[0010] The contact pin has a shape in which the distance between the first body portion and the second body portion narrows from the base side toward the upper side until it reaches the narrowest portion, and then the distance widens from the narrowest portion to the widest portion before reaching the upper end.

[0011] The sliding portion moves in the first direction so as to be positionable at a first position where the intervening portion elastically deforms to separate the first body portion and the second body portion by contacting an inner surface between the narrowest portion and the widest portion, thereby widening the separation distance in the second direction between the first contact portion and the second contact portion to be greater than the width of the electrode in the second direction; a second position which is a position further away from the fixed portion than the first position, where the intervening portion is positioned between the narrowest portion and the widest portion, and where the elastic recovery force of the first body portion and the second body portion brings the contact protrusion into contact with the electrode; and a third position which is a position further away from the fixed portion than the second position, where the outer surface of the first body portion contacts the inner surface of the first accommodating portion and the outer surface of the second body portion contacts the inner surface of the second accommodating portion, thereby generating a force that brings the contact protrusion of the first contact portion and the contact protrusion of the second contact portion closer together than at the second position.

[0012] According to this configuration, when the slide portion is disposed in the first position, the first contact portion and the second contact portion of the contact pin are opened. When the slide portion is disposed in the second position, the contact protrusion of the contact pin comes into contact with the electrode of the semiconductor device. When the slide portion is disposed in the third position, the contact protrusion of the contact pin fits into the electrode of the semiconductor device. In this contact socket for a semiconductor device, the first body portion and the second body portion of the contact pin are plane-symmetrical, so that the contact protrusion of the contact pin fits evenly into both sides of the electrode of the semiconductor device.

[0013] In the contact socket for a semiconductor device, the first and second body portions and the first and second housing portions may be formed so that a force is generated in a direction that moves the contact position of the contact protrusion with the electrode downward when the slide portion moves from the second position to the third position, whereby the contact protrusion of the contact pin bites into the electrode of the semiconductor device from top to bottom, breaking an oxide film or the like on the surface of the electrode and ensuring electrical continuity.

[0014] In the contact socket for a semiconductor device, the ridges formed by the upper tips of the contact protrusions may be configured to extend to the tips of the contact protrusions while inclining downward at a first angle within a predetermined range with respect to the second direction, when viewed in a third direction perpendicular to the first and second directions, so that the tips of the contact protrusions of the contact pins are inclined downward, and the electrodes of the semiconductor device are bitten by the contact protrusions from above downward.

[0015] In the above-mentioned contact socket for a semiconductor device, each of the contact protrusions of the first body portion and the contact protrusions of the second body portion may have a pair of protrusions, and the pair of protrusions may be arranged side by side in a third direction perpendicular to the first direction and the second direction. In this way, the pair of protrusions provided on each of the first body portion and the second body portion of the contact pin engages the electrode of the semiconductor device at a total of four points, two points on the left and two points on the right as viewed in the first direction.

[0016] In the contact socket for a semiconductor device, the contact protrusion may be formed by pressing an elastic piece, and the pair of protrusions may be comprised of corners of the elastic piece. This allows the contact protrusions of the contact pin to be formed by pressing the elastic piece, making manufacturing easier than forming the contact protrusions by cutting.

[0017] In the first position of the contact socket for a semiconductor device, each of the first body portion and the second body portion may be bent in a direction such that the distance in the second direction between the first body portion and the second body portion narrows from the widest portion toward the upper side, with the widest portion as a boundary. This causes each of the first body portion and the second body portion of the contact pin to have a shape that narrows inward from the widest portion upward, making it easier for the first body portion and the second body portion to bite into the electrode from top to bottom even when they clamp in the second direction.

[0018] In the contact socket for a semiconductor device, the narrowest portion may be located closer to the base than an intermediate position between the upper end and a fulcrum that supports the first and second body portions at the base, whereby the position of the narrowest portion where the intermediate portion abuts acts as a force point and the position of the contact protrusion acts as a point of action, and the amount of movement of the contact protrusion is greater than the amount of movement of the narrowest portion.

[0019] In the contact socket for a semiconductor device, each of the first body portion and the second body portion may have a reinforcing portion having a locally high elastic modulus in the vicinity of the joint with the base portion, whereby the mechanical strength of the first body portion and the second body portion is increased by the reinforcing portion.

[0020] In the above-mentioned contact socket for a semiconductor device, the electrode may be provided in a partial spherical shape, and in the second position, the contact protrusion may be configured to contact a part of the electrode above a great circle of the partial spherical shape as viewed in the first direction, whereby the contact protrusion of the contact pin contacts a surface of the semiconductor device above the great circle of the partial spherical shape of the electrode, and the contact protrusion is securely engaged with the electrode.

[0021] Another aspect of the present invention is a contact pin for use in a contact socket for a semiconductor device, comprising: a first body portion and a second body portion, both of which are made of elastic pieces extending in a first direction, facing each other in a second direction perpendicular to the first direction, and having a plane-symmetrical shape with respect to a plane including the first direction; and a base connected to a lower end portion of the first body portion and the second body portion, which is the other of the first direction, and supporting the first body portion and the second body portion, wherein the first body portion has a first contact portion at an upper end portion, which is one of the first directions, for contacting an electrode protruding downward from the semiconductor device, and the second body portion has a second contact portion at an upper end portion for contacting an electrode of the semiconductor device, each of the first contact portion and the second contact portion having a contact protrusion protruding in the second direction, and the first body portion and the second body portion have a shape such that the distance between the first body portion and the second body portion narrows from the base side toward the upper side, until it reaches a narrowest portion, and then the distance widens from the narrowest portion to a widest portion provided before reaching the upper end portion.

[0022] With this configuration, the first and second body portions of the contact pin are plane-symmetrical and have an approximately X-shaped configuration together, so that the first and second contact portions sandwich the electrode of the semiconductor device so as to evenly embrace the electrode from both sides, and the contact protrusion bites into the electrode due to a force directed from the top to the bottom of the electrode. Effect of the Invention

[0023] According to the present invention, it is possible to provide a contact socket and a contact pin for a semiconductor device, which are capable of obtaining reliable and stable electrical connection with the ball-shaped solder of the semiconductor device. [Brief description of the drawings]

[0024] [Figure 1] 1 is a schematic perspective view illustrating a contact socket for a semiconductor device according to an embodiment of the present invention; [Diagram 2] 1 is a schematic side view illustrating a contact socket for a semiconductor device according to an embodiment of the present invention; [Diagram 3]1 is a schematic cross-sectional view illustrating a contact socket for a semiconductor device according to an embodiment of the present invention. [Figure 4] 2 is a partially enlarged cross-sectional view illustrating a contact socket for a semiconductor device according to the embodiment; [Diagram 5] FIG. 2 is a perspective view illustrating a contact pin. [Figure 6] FIG. 2 is a front view illustrating a contact pin. [Figure 7] FIG. 2 is a side view illustrating a contact pin. [Figure 8A] 4 is an enlarged perspective view illustrating a contact portion of a contact pin; FIG. [Figure 8B] 4 is an enlarged front view illustrating a contact portion of a contact pin; FIG. [Figure 9A] 5A to 5C are cross-sectional views illustrating a contact operation by the contact socket according to the embodiment. [Figure 9B] 5A to 5C are cross-sectional views illustrating a contact operation by the contact socket according to the embodiment. [Figure 9C] 5A to 5C are cross-sectional views illustrating a contact operation by the contact socket according to the embodiment. [Figure 10A] 11 is a perspective view illustrating a contact state between a contact portion of a contact pin and a solder ball; FIG. [Figure 10B] 11 is a front view illustrating a contact state between a contact portion of a contact pin and a solder ball; FIG. [Figure 10C] 11 is a plan view illustrating a contact state between a contact portion of a contact pin and a solder ball; FIG. [Figure 11] 11 is a front view showing a specific example of a contact portion of a contact pin. FIG. [Figure 12] 11 is a side view showing a specific example of a contact portion of a contact pin. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the same members are designated by the same reference numerals, and the description of members that have already been described will be omitted as appropriate.

[0026] (Contact Socket) FIG. 1 is a schematic perspective view illustrating a contact socket for a semiconductor device according to the present embodiment. FIG. 2 is a schematic side view illustrating the contact socket for a semiconductor device according to the present embodiment. FIG. 3 is a schematic cross-sectional view illustrating a contact socket for a semiconductor device according to this embodiment. FIG. 4 is a partially enlarged cross-sectional view illustrating the contact socket for a semiconductor device according to this embodiment. The contact socket 1 according to this embodiment is a socket for achieving electrical continuity with the electrodes of the semiconductor device 100 when the characteristics of the semiconductor device 100 are measured.

[0027] The measurement target of the contact socket 1 is a semiconductor device 100 consisting of a BGA (Ball Grid Array). The contact socket 1 is provided with a plurality of contact pins 10 for making conductive contact with solder balls B, which are a plurality of electrodes of the semiconductor device 100 consisting of a BGA. In addition to the contact pins 10, the contact socket 1 is provided with a fixed portion 20 that houses the contact pins 10, and a sliding portion 30 that allows the contact pins 10 to move.

[0028] The contact pin 10 has a first body portion 11 and a second body portion 12, each of which is made of an elastic piece extending in one direction, and a base portion 13 that supports the first body portion 11 and the second body portion 12. In this embodiment, the extension direction of the contact pin 10 is defined as a first direction D1, one of the directions perpendicular to the first direction D1 is defined as a second direction D2, and a direction perpendicular to the first direction D1 and the second direction D2 is defined as a third direction D3. The first direction D1 is also referred to as the up-down direction, and the second direction D2 is also referred to as the left-right direction.

[0029] The first body portion 11 and the second body portion 12 face each other in the second direction D2 and have plane-symmetric shapes with respect to a plane including the first direction D1. The base portion 13 is connected to the lower end portions of the first body portion 11 and the second body portion 12, which is the other side in the first direction D1, and supports the lower end sides of the first body portion 11 and the second body portion 12.

[0030] The contact pins 10 are provided corresponding to the multiple solder balls B of the semiconductor device 100 consisting of a BGA. The lower end side of the contact pins 10 is embedded in the base substrate 50, and a first body portion 11 and a second body portion 12 extend upward, which is one side of the first direction D1. The semiconductor device 100 is placed with the solder balls B on the lower side, and a conductive contact is made between the tip portions of the contact pins 10 facing upward so as to face the solder balls B and the solder balls B.

[0031] The fixing portion 20 is disposed on the upper side of the base substrate 50, and supports the base 13 of the contact pin 10 by embedding the base 13. The base 13 supported by the fixing portion 20 serves as a fulcrum for the movement of the first body portion 11 and the second body portion 12 of the contact pin 10.

[0032] The slide portion 30 is disposed above the fixed portion 20, between the base portion 13 and the tip portion of the contact pin 10, and is provided so as to be slidable in the first direction D1. The slide portion 30 has an accommodating portion 31 that accommodates a part of each of the first body portion 11 and the second body portion 12 of the contact pin 10.

[0033] The accommodating portion 31 has a first accommodating portion 311 that accommodates a portion of the first main body portion 11, a second accommodating portion 312 that accommodates a portion of the second main body portion 12, and an intervening portion 313 that is located between the first accommodating portion 311 and the second accommodating portion 312 in the second direction D2 and is capable of contacting the inner surfaces of each of the first main body portion 11 and the second main body portion 12.

[0034] The contact pin 10 penetrates the housing portion 31 of the sliding portion 30 in the first direction D1, and exposes the tip portions of the first body portion 11 and the second body portion 12 to the upper side of the sliding portion 30.

[0035] The vertical movement of the slide portion 30 changes the contact position of the interposition portion 313 with the first body portion 11 and the second body portion 12, and changes the distance in the second direction D2 between the first body portion 11 and the second body portion 12. This change in distance switches between sandwiching the solder ball B between the first body portion 11 and the second body portion 12 and releasing the sandwiching.

[0036] The contact pins 10 are electrically connected to an external device through the base substrate 50. When measuring the semiconductor device 100, the contact socket 1 brings the solder balls B of the semiconductor device 100 into contact with the contact pins 10, thereby electrically connecting the semiconductor device 100 to an external device (measuring device), thereby inputting and outputting signals. Testing of the semiconductor device 100 using the contact socket 1 is performed in various environments. For example, in a burn-in test, a characteristic test and a reliability test are performed for a long time in a high-temperature environment. An important element of the contact socket 1 is that it is possible to maintain a reliable state of electrically conductive contact between the solder balls B and the contact pins 10 for a long time, even in such a harsh environment.

[0037] (Contact pin) FIG. 5 is a perspective view illustrating a contact pin. FIG. 6 is a front view illustrating the contact pin. FIG. 7 is a side view illustrating a contact pin. The first body portion 11 of the contact pin 10 has, at its upper end portion, which is one side in the first direction D1, a first contact portion 111 for contacting a solder ball B (see FIG. 2) that is an electrode protruding downward from the semiconductor device 100 (see FIG. 2). The second body portion 12 of the contact pin 10 has, at its upper end portion, a second contact portion 121 for contacting the solder ball B. Each of the first contact portion 111 and the second contact portion 121 has a contact protrusion 113 that protrudes in the second direction D2.

[0038] Moreover, the contact pin 10 has a shape in which the distance between the first body portion 11 and the second body portion 12 narrows from the base portion 13 side toward the upper side to the narrowest portion 10a, and then the distance widens from the narrowest portion 10a to the widest portion 10b provided before the upper end portion. That is, the contact pin 10 is provided in a substantially X-shaped shape that is line-symmetric (bilaterally symmetric) between the first body portion 11 and the second body portion 12 when viewed from the front (third direction D3).

[0039] As shown in Fig. 4, the interposition portion 313 of the sliding portion 30 moves up and down between the narrowest portion 10a and the widest portion 10b between the first body portion 11 and the second body portion 12 of the contact pin 10. When the interposition portion 313 is located at the narrowest portion 10a, a force is applied from the interposition portion 313 to the first body portion 11 and the second body portion 12 in a direction to widen the gap between them, and the gap between the first body portion 11 and the second body portion 12 is widened. On the other hand, when the interposition portion 313 is located at the widest portion 10b, a force is not applied from the interposition portion 313 to the first body portion 11 and the second body portion 12 in a direction to widen the gap between them, and the gap between the first body portion 11 and the second body portion 12 does not widen.

[0040] The relationship between the amount of vertical movement of the slide portion 30 and the amount of change in the spacing between the first body portion 11 and the second body portion 12 is set by the width of the intervening portion 313 and the inclination angle (inclination angle with respect to the first direction D1) of the first body portion 11 and the second body portion 12 between the narrowest portion 10a and the widest portion 10b.

[0041] The first body portion 11 and the second body portion 12 of the contact pin 10 are arranged in a substantially X-shape that is line-symmetrical when viewed from the front (third direction D3), so that the first body portion 11 and the second body portion 12 both move symmetrically from left to right by the vertical movement of the interposition portion 313 of the slide portion 30. As a result, the gap between the first body portion 11 and the second body portion 12 is evenly changed around the center between them.

[0042] Since the first body portion 11 and the second body portion 12 of the contact pin 10 are elastic pieces, when the interposed portion 313 is located at the widest portion 10b and is not in contact with the inner surfaces of the first body portion 11 and the second body portion 12, the outer surface of the first body portion 11 abuts against the inner surface of the first housing portion 311, and the outer surface of the second body portion 12 abuts against the inner surface of the second housing portion 312. This restricts the expansion of the gap between the first body portion 11 and the second body portion 12.

[0043] As shown in Fig. 6, the first body portion 11 and the second body portion 12 are preferably provided in a shape in which the upper sides of the widest portion 10b are bent in a direction in which they approach each other. That is, the first body portion 11 and the second body portion 12 are preferably provided in a shape in which the width of the first body portion 11 and the second body portion 12 in the second direction D2 between the first body portion 11 and the second body portion 12 narrows from the widest portion 10b upward, with the widest portion 10b as a boundary. As a result, the first body portion 11 and the second body portion 12 above the widest portion 10b are each shaped to be narrowed inward. This shape makes it easier for the first body portion 11 and the second body portion 12 to bite the solder ball B (see Fig. 2) from top to bottom when they pinch each other in the left-right direction.

[0044] Each of the first body portion 11 and the second body portion 12 may have a reinforcement portion 15 having a locally high elastic modulus near the joint with the base portion 13. Examples of the reinforcement portion 15 include an uneven structure or a rib structure provided on the surface of each of the first body portion 11 and the second body portion 12. The first body portion 11 and the second body portion 12 are elastically deformed by the vertical movement of the slide portion 30, and the stress of this elastic deformation tends to concentrate near the joint with the base portion 13. For this reason, by providing the reinforcement portion 15, the mechanical strength of the first body portion 11 and the second body portion 12 can be increased.

[0045] The material of the contact pin may have a suitable electrical conductivity, and specific examples include copper-based materials such as copper and copper alloys, aluminum-based materials such as aluminum and aluminum alloys, and iron-based materials such as iron and steel. Since the contact protrusion 113 of the contact pin is formed by pressing as described below, the contact pin preferably has excellent press workability (plastic deformability). Furthermore, since the gripping force of the contact protrusion 113 for the solder ball B includes the elastic recovery force of the first body portion 11 and the second body portion 12, the contact pin preferably has a suitable spring property. From the viewpoint of meeting these requirements, beryllium copper is an example of a suitable material of the contact pin.

[0046] (Contact part of contact pin) FIG. 8A is an enlarged perspective view illustrating a contact portion of a contact pin. FIG. 8B is an enlarged front view illustrating the contact portion of the contact pin. The first body portion 11 has, at its upper end, a first contact portion 111 for contacting a solder ball B (see FIG. 2) of the semiconductor device 100, and the second body portion 12 has, at its upper end, a second contact portion 121 for contacting the solder ball B. In addition, each of the first contact portion 111 and the second contact portion 121 has a contact protrusion 113 protruding in the left-right direction.

[0047] For example, each of the contact protrusions 113 of the first body portion 11 and the contact protrusions 113 of the second body portion 12 has a pair of protrusions 113a, and the pair of protrusions 113a is configured to be aligned in the third direction D3. As a result, the pair of protrusions 113a provided on each of the contact protrusions 113 of the first body portion 11 and the contact protrusions 113 of the second body portion 12 bite into the solder balls B of the semiconductor device 100 at a total of four points, two points on the left and two points on the right as viewed in the first direction D1.

[0048] The first body portion 11 and the second body portion 12 are elastic pieces, and the contact protrusions 113 are formed by pressing the elastic pieces. The pair of protrusions 113a are formed by bending corners of the rectangular elastic pieces diagonally inward and downward by pressing. As a result, the contact protrusions 113 of the contact pin 10 are formed by pressing the elastic pieces, which makes manufacturing easier than forming them by cutting.

[0049] 8B, when viewed in the third direction D3, the ridge lines L formed by the upper tips of the contact protrusions 113 are configured to extend to the tips of the contact protrusions 113 while inclining downward at a first angle θ within a predetermined range with respect to the second direction D2. As a result, the tips of the contact protrusions 113 of the contact pins 10 are inclined downward, and the contact protrusions 113 bite into the solder balls B of the semiconductor device 100 from top to bottom. At this time, a biting force is applied from each of the four protrusions 113a downward from the contact points of the protrusions 113a toward the center of the solder ball B, and the floating of the semiconductor device 100 can be effectively suppressed.

[0050] The contact protrusions 113 may have a surface layer made of another material on the material (base material) constituting the first body portion 11 and the second body portion 12. For example, if a surface layer made of a material harder than the base material, such as rhodium, a rhodium alloy, or diamond-like carbon, is provided, the contact pressure of the contact protrusions 113 biting into the solder balls B can be increased. This allows the oxide film on the solder balls B to be appropriately destroyed, and the metal contact between the contact protrusions 113 and the solder balls B to be more stable, thereby reducing the contact resistance.

[0051] A preferred example of the surface layer is a laminated structure having, from the substrate side of the contact protrusion 113, an underlayer such as nickel, a layer made of gold or a gold alloy (gold-based material layer), and a layer made of rhodium or a rhodium alloy (rhodium-based material layer). The underlayer and gold-based material layer are intended to enhance the adhesion of the rhodium-based material layer to a substrate made of beryllium copper or the like, and the thickness of the underlayer is, for example, about several μm, and the thickness of the gold-based material layer is, for example, 0.1 μm or less. The rhodium-based material layer can enhance the mechanical strength as a layer by having a certain degree of thickness, but if it is excessively thick, cracks due to internal stress are likely to occur. Therefore, although it depends on the composition, it may be preferable that the rhodium-based material layer be about 1 μm to 10 μm. Note that the rhodium-based material layer has less interaction with the solder than the gold-based material layer, so even if the contact pressure with the solder ball B increases due to the high hardness of the rhodium-based material layer, the rhodium-based material layer is less likely to adhere to the solder ball B.

[0052] As another example of the surface layer, the outermost surface of the surface layer may be made of a gold-based material layer from the viewpoint of reducing the contact resistance between the contact protrusion 113 and the solder ball B. In this case, it may be preferable that a layer made of silver or a silver alloy (silver-based material layer) is located between the gold-based material layer located at the outermost surface and the underlayer.

[0053] The gold-based material layer is soft, so the contact area with the solder ball B is easily increased, which has the advantage of lowering the contact resistance, but for cost reasons and other reasons, it is not practical to form a thick film. For this reason, if there are minute protrusions on the surface due to, for example, processing variations in the contact protrusions 113, the contact pressure with the solder ball B becomes locally high in the gold-based material layer on the contact protrusions 113, and adhesion tends to occur between the gold-based material layer and the solder ball B in the areas with high contact pressure. This tendency is easily evident in burn-in tests, in which the contact time between the gold-based material layer and the solder ball B becomes long.

[0054] Therefore, by arranging a silver-based material layer, which is as soft as the gold-based material layer and has excellent conductivity, on the underlayer side of the gold-based material layer, even if there are minute protrusions on the surface of the contact protrusions 113, the silver-based material layer can be appropriately deformed to mitigate the effect of the minute protrusions and prevent a local increase in the contact pressure between the gold-based material layer and the solder balls B. From the viewpoint of appropriately fulfilling the function of mitigating such a contact state of the silver-based material layer, it may be preferable in some cases for the thickness of the silver-based material layer to be about 1 μm to 10 μm.

[0055] (Contact operation) 9A to 9C are cross-sectional views illustrating a contact operation by the contact socket according to the present embodiment. FIG. 9A shows the sliding portion 30 in a state where it has been slid to a first position, FIG. 9B shows the sliding portion 30 in a state where it has been slid to a second position, and FIG. 9B shows the sliding portion 30 in a state where it has been slid to a third position.

[0056] As shown in FIG. 9A, in the first position, the intervening portion 313 of the sliding portion 30 contacts the inner surfaces of the first body portion 11 and the second body portion 12 between the narrowest portion 10a and the widest portion 10b. The contact of the intervening portion 313 with the first body portion 11 and the second body portion 12 causes the first body portion 11 and the second body portion 12 to elastically deform in a direction separating them from each other. Due to this elastic deformation, the separation distance in the second direction D2 between the first contact portion 111 and the second contact portion 121 becomes wider than the width of the solder ball B in the second direction D2, and the first contact portion 111 and the second contact portion 121 do not contact the solder ball B. The first position is a position that allows the semiconductor device 100 to be attached to and detached from the contact socket 1 (see FIG. 2).

[0057] As shown in FIG. 9B, in the second position, the sliding portion 30 is located farther away from the fixed portion 20 (see FIG. 3) than in the first position. Between the narrowest portion 10a and the widest portion 10b, the intervening portion 313 of the sliding portion 30 is located closer to the widest portion 10b than in the first position. As a result, the elastic recovery force between the first body portion 11 and the second body portion 12 makes the gap between the first body portion 11 and the second body portion 12 in the second direction D2 narrower than in the first position. As a result, the first contact portion 111 of the first body portion 11 and the second contact portion 121 of the second body portion 12 sandwich the solder ball B so as to evenly embrace it from the left and right directions, and the contact protrusion 113 makes contact with the solder ball B.

[0058] As shown in Fig. 9C, in the third position, the sliding portion 30 is located further away from the fixed portion 20 (see Fig. 3) than in the second position. In the third position, the interposed portion 313 is not in contact with the first body portion 11 and the second body portion 12, the outer surface of the first body portion 11 is in contact with the inner surface of the first accommodation portion 311, and the outer surface of the second body portion 12 is in contact with the inner surface of the second accommodation portion 312. As a result, a force is applied to the contact protrusions 113 of the first contact portion 111 and the contact protrusions 113 of the second contact portion 121 to bring them closer to the solder ball B than in the second position, and the contact protrusions 113 are evenly engaged with the solder ball B from both the left and right sides.

[0059] To release the contact between the contact protrusion 113 and the solder ball B, the slide portion 30 is moved in the opposite manner to the above from the third position shown in Fig. 9C to the second position shown in Fig. 9B and further to the first position shown in Fig. 9A. This causes the first body portion 11 and the second body portion 12 to open evenly on the left and right, and the contact protrusion 113 moves away from the solder ball B.

[0060] Here, it is preferable that a tapered portion 313a is provided on the lower end side of the interposition portion 313. The tapered portion 313a is provided on the surface facing the first body portion 11 and the second body portion 12. The taper angle of the tapered portion 313a (angle with respect to the first direction D1) is slightly larger than the inclination angle of the inner surface of each of the first body portion 11 and the second body portion 12. As a result, in the operation (release operation) in which the sliding portion 30 moves from the third position to the second position and further to the first position, the contact between the interposition portion 313 and the first body portion 11 and the second body portion 12 is made nearly parallel to each other due to the tapered portion 313a, and the interposition portion 313 can be moved smoothly.

[0061] In addition, the narrowest part 10a of the contact pin 10 is preferably provided on the base 13 side from the intermediate position between the fulcrum that supports the first body part 11 and the second body part 12 at the base 13 and the upper end part. In other words, the position of the narrowest part 10a of the contact pin 10 is preferably provided below the intermediate position between the base 13 and the upper end part. As a result, the position of the narrowest part 10a of the contact pin 10 where the interposed part 313 abuts is the force point, and the position of the contact protrusion 113 is the action point, and the position of the force point is located on the fulcrum side from the intermediate point between the fulcrum and the action point, so that the movement amount of the contact protrusion 113 can be made larger than the movement amount of the narrowest part 10a. In other words, the tip of the first body part 11 and the second body part 12 can be opened and closed widely with a small movement amount of the slide part 30.

[0062] In this embodiment, the first body portion 11 and the second body portion 12 can be moved uniformly in the left and right directions by moving the slide portion 30 in the up and down direction. This makes it possible to narrow the left and right movable range of the movable members such as the contact pins 10 and the slide portion 30, compared to the case where the slide portion 30 is moved in the left and right direction or the first body portion 11 and the second body portion 12 are operated non-uniformly in the left and right direction. This makes it possible to narrow the arrangement interval between the contact pins 10 adjacent to each other in the left and right direction, and also makes it possible to accommodate solder balls B with a narrow pitch. In addition, it is possible to suppress the contact socket 1 from becoming large in the left and right direction.

[0063] With this type of operation, when the contact protrusion 113 of the contact pin 10 comes into contact with the solder ball B, contact begins when the slide portion 30 is in the second position, and as the slide portion 30 moves from the second position to the third position, the first body portion 11 and the second body portion 12 are pressed from both the left and right sides by the inner surfaces of the first accommodating portion 311 and the second accommodating portion 312 of the slide portion 30, causing the contact protrusion 113 to bite into the solder ball B.

[0064] The contact protrusions 113 bite into the solder balls B evenly from both the left and right sides. When the sliding portion 30 moves from the second position to the third position, a force is generated in a direction that moves the contact position of the contact protrusions 113 with the solder balls B downward, so that the contact protrusions 113 bite into the solder balls B from above to below, breaking the oxide film on the surface of the solder balls B and ensuring electrical continuity.

[0065] (contact with solder balls) FIG. 10A is a perspective view illustrating a contact state between a contact portion of a contact pin and a solder ball. FIG. 10B is a front view illustrating a contact state between the contact portion of the contact pin and the solder ball. FIG. 10C is a plan view illustrating a contact state between the contact portion of the contact pin and the solder ball. For ease of explanation, in Figures 10A to 10C, solder ball B is represented as a sphere, but the solder ball B as an electrode provided on semiconductor device 100 has a partial spherical shape (spherical cutout shape) with the lower portion exposed from semiconductor device 100 when a specified position above great circle S is cut out by a plane.

[0066] 10A to 10C show the positional relationship between the contact protrusion 113 and the solder ball B when the sliding portion 30 is in the second position. When the solder ball B is sandwiched from both sides by the first contact portion 111 and the second contact portion 121, the contact protrusion 113 of the first contact portion 111 and the contact protrusion 113 of the second contact portion 121 each come into contact with the solder ball B. At this time, the contact protrusion 113 comes into contact with an upper side of the partial spherical great circle S of the solder ball B when viewed in the first direction D1. As a result, the contact protrusion 113 of the contact pin 10 comes into contact with a surface of the solder ball B that is upper than the partial spherical great circle S, and the contact protrusion 113 is securely bitten into the solder ball B.

[0067] Furthermore, when the slide portion 30 is in the third position, a clamping force is applied to the first body portion 11 and the second body portion 12 more than when the slide portion 30 is in the second position, so that the contact protrusions 113 come into contact with the solder balls B with an even stronger clamping force from the contact position. At this time, the clamping force of the first body portion 11 and the second body portion 12 acts as a force that moves the left and right contact protrusions 113 diagonally downward and inward from the contact position. As a result, the contact protrusions 113 come into contact with the solder balls B and then clamp down on the surface while clamping down on the solder balls, reliably breaking the oxide film on the surface of the solder balls B and allowing electrical continuity with low resistance. This contact by clamping the contact protrusions 113 maintains reliable electrical continuity even under conditions such as aging tests and burn-in tests.

[0068] (Example of contact part of contact pin) FIG. 11 is a front view showing a specific example of a contact portion of a contact pin. FIG. 12 is a side view showing a specific example of a contact portion of a contact pin. The contact pin 10 is formed by pressing an elastic member. The contact pin 10 is provided in a line-symmetric (bilaterally symmetric) X-shape with the first body portion 11 and the second body portion 12 facing each other on their inner sides by pressing. The contact protrusions 113 are formed by pressing the rectangular corners of the tip portions of the first body portion 11 and the second body portion 12, which are bent diagonally inward, to form protrusions 113a whose corners are pointed downward and inward.

[0069] In this manner, since the contact protrusions 113 can be formed by pressing together with the formation of the first body portion 11 and the second body portion 12, the manufacture of the contact pins 10 is easier than forming them by cutting.

[0070] As described above, according to the embodiment, it is possible to provide the contact socket 1 and the contact pin 10 that can obtain reliable and stable electrical connection with the solder balls B of the semiconductor device 100.

[0071] Although the present embodiment and its specific examples have been described above, the present invention is not limited to these examples. For example, those in which a person skilled in the art appropriately adds or removes components from or modifies the design of the above-described embodiment or its specific examples, or those in which the features of the embodiments are appropriately combined, are also included within the scope of the present invention as long as they include the gist of the present invention. [Explanation of symbols]

[0072] 1...Contact socket 10…Contact pin 10a…Narrowest part 10b…Wideth part 11...First body part 12...Second body part 13...Base 15...Reinforcement part 20…Fixed part 30…Slide section 31…Storage section 50…Base board 100...Semiconductor device 111...First contact part 113…Contact protrusion 113a...Protrusion 121…Second contact part 311…First storage section 312…Second storage section 313...intervening part 313a...Tapered section B: Solder ball L...Ridge line S: Great circle θ…first angle

Claims

1. A contact pin for use in a contact socket for a semiconductor device, a first body portion and a second body portion, each of which is made of an elastic piece extending in a first direction, facing each other in a second direction perpendicular to the first direction, and having a plane-symmetric shape with respect to a plane including the first direction; a base portion connected to the other lower end of the first body portion and the second body portion in the first direction and supporting the first body portion and the second body portion; Equipped with the first body portion has a first contact portion at an end portion on an upper side in the first direction for contacting an electrode protruding downward from the semiconductor device; the second body portion has a second contact portion at the upper end portion for contacting the electrode of the semiconductor device; each of the first contact portion and the second contact portion has a contact protrusion protruding in the second direction; a contact pin having a shape in which the first body portion and the second body portion have a space between them that narrows from the base side toward the upper side and reaches a narrowest portion, and the space between them widens from the narrowest portion to a widest portion provided before reaching the upper end, and the contact pin is formed in a shape that bends in a direction in which the space between the first body portion and the second body portion in the second direction narrows from the widest portion toward the upper side, with the widest portion as a boundary.

2. 2. The contact pin as described in claim 1, wherein, when viewed in a third direction perpendicular to the first direction and the second direction, the ridge lines formed by the upper tip of the contact protrusion each extend to the tip of the contact protrusion, inclined downward at a first angle within a predetermined range relative to the second direction.

3. Each of the contact protrusions of the first body portion and the contact protrusions of the second body portion has a pair of protrusions, The contact pin according to claim 1 , wherein the pair of protrusions are aligned in a third direction perpendicular to the first direction and the second direction.

4. the contact protrusion is formed by pressing the elastic piece, The contact pin according to claim 3 , wherein the pair of protrusions are formed from corners of the elastic piece.

5. The contact pin according to claim 1 , wherein the narrowest portion is provided closer to the base than an intermediate position between a fulcrum that supports the first body portion and the second body portion at the base and the upper end portion.

6. The contact pin according to claim 1 , wherein each of the first body portion and the second body portion has a reinforced portion having a locally high elastic modulus in the vicinity of a connection portion with the base portion.

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