The present invention relates to an electric contact to be electrically connected to an electric component such as a semiconductor device (hereinafter referred to as “IC package”), and a socket for electric component having the electric contact disposed therein.
A contact pin disposed in an IC socket serving as the socket for electric component has been conventionally known as the electric contact of type as described above. The IC socket is configured to be disposed on a wiring board for accommodating the IC package to be inspected. Terminals of the IC package and electrodes of the wiring board are electrically connected to each other via the contact pins so that the test such as a continuity test is conducted.
A contact pin conventionally known as described above is formed by bending the member having plate-like end portions, and an intermediate portion with both plate-like and wave-shaped sections into an integrated structure of a contact part to be brought into contact with the wiring board, a contact part to be brought into contact with the IC package, and a spring part for urging those contact parts in a mutually separating directions (see, for example, Patent Literature 1).
In the above-described Patent Literature 1, as a result of contracting the contact pin against the urging force of the spring part, the contact pin is contracted to the level in excess of the limit of the elastic deformation of the spring part. The resultant plastic deformation of the spring part may cause the risk of failure in restoration to the original state.
It is an object of the present invention to provide an electric contact (contact pin) with durability improved by preventing the plastic deformation of the spring part and a socket (IC socket) for electric component.
In order to solve the above-described problem, the invention according to claim 1 provides an electric contact to be disposed between a first electric component and a second electric component to establish electric connection therebetween, which includes a first contact part to be in contact with the first electric component, a second contact part to be in contact with the second electric component, and a cylindrical spring part formed from a conductive material with a plate-like section and a wavy section. It is configured to make a section between the first contact part and the second contact part extendable/contractible via the spring part. The spring part has a wave-like shape by continuously forming wave-shaped parts alternately on one and the other sides of an axis as a center for connecting the first contact part and the second contact part, and is formed into a cylindrical shape while having a projection of the wave-shaped part on one side confronting a recess between the projections of the wave-shaped parts on the other side. The projection of the wave-shaped part on the one side enters into the recess between the wave-shaped parts on the other side to bring the projection on the one side into abutment on the projection adjacent to the recess of the wave-shaped part on the other side upon contraction of the spring part to stop a contracting motion, and establish a conduction state between the projections abutted on each other.
In the invention according to claim 2 in addition to the invention according to claim 1, a protrusion is provided on the projection in a direction orthogonal to the axis, and configured to enter into the recess.
The invention according to claim 3 provides a socket for electric component including a socket body which is to be disposed on a first electric component, and includes a storage part to accommodate a second electric component, and the electric contact according to claim 1 or 2, which is disposed in the socket body, and to be in contact with a terminal of the first electric component, and a terminal of the second electric component.
The invention according to claim 1 is configured to allow the projection of the wave-shaped part on the one side to enter into the recess between the wave-shaped parts on the other side. Upon contraction of the spring part, the projection on the one side abuts on the projection adjacent to the recess of the wave-shaped part on the other side, which stops the contraction movement, and establishes the conduction state between the projections abutted on each other. This makes it possible to prevent the plastic deformation of the spring part without exceeding the limit of the elastic deformation. As a result, durability of the electric contact may be improved.
The invention according to claim 2 is configured to have the projection provided with the protrusion formed in the direction orthogonal to the axis. As the protrusion is structured to enter into the recess, the protrusion securely enters into the recess, making it possible to prevent the elastic deformation in excess of the limit.
The invention according to claim 3 includes the electric contact according to claim 1 or 2. This makes it possible to provide the socket for electric component, which prevents the plastic deformation of the spring part of the electric contact without exceeding the limit of the elastic deformation.
Embodiments of the present invention will be described.
An IC socket 10 as a “socket for electric component” according to the embodiment is configured to be disposed on a wiring board 1 as a “first electric component” as shown in
The IC package 2 (see
As
As
As
The contact pins 60 are inserted into through holes (not shown) which vertically penetrate through the upper holding member 31, the center holding member 32, the lower holding member 33, and the floating plate 40 while being vertically extendable/contractible. In the embodiment, the contact pins 60 are arranged in a matrix with respect to the contact module 30 as described above. However,
As
The contact pin 60 is formed from a conductive material 60A as shown in
The lower plate-like part 60B as shown in
The upper plate-like part 60B as shown in
The wavy part 60C as shown in
In reference to the developed state as shown in
In reference further to
A protrusion 95 extending in the direction orthogonal to the axis L is formed on a tip portion of the projection 93 of each of the wave-shaped parts 92 at the farthest location from the axis L. The protrusion 95 is configured to enter into the confronting recess 94 as shown in
The another plate-like part 60D is curved or bent cylindrically along the axis L to provide the intermediate part 96 which is not in the form of the spring at substantially the intermediate position of the spring part 91 as shown in
The thus formed contact pin 60 is configured to have the first contact part 71, the second contact part 81, the intermediate part 96, and two divided spring parts 91.
The thus formed contact pin 60 is configured to have the small-diameter first tip end portion 72 of the first contact part 71 inserted into the through hole of the lower holding member 33 of the contact module 30, and extended downward of the lower holding member 33. The small-diameter second tip end portion 82 of the second contact part 81 is inserted into the through hole of the floating plate 40. The intermediate part 96 of the spring part 91 at substantially an intermediate position is inserted into the through hole of the center holding member 32 of the contact module 30. In this way, the contact pin 60 may be held by the contact module 30.
Functions of the IC socket 10 provided with the contact pins 60 each constituted by the above-described single member will be described.
The IC socket 10 is used in the state where the contact pins 60 are fitted with the contact module 30 of the socket body 20 to allow extension of the first tip end portion 72 of the first contact part 71 downward of the lower holding member 33, and insertion of the second tip end portion 82 of the second contact part 81 into the floating plate 40 as well as insertion of the intermediate part 96 into the center holding member 32.
The IC socket 10 is positioned and fixed to the wiring board 1 so that the first tip end portion 72 of the first contact part 71 is brought into contact with the electrode of the wiring board 1. At this time, the first tip end portion 72 is pushed upward by the wiring board 1 as well as the entire contact pins 60. As a result, the second contact part 81 is also pushed upward.
The IC package 2 is then seated on the floating plate 40 to bring the solder ball into contact with the second tip end portion 82 of the second contact part 81. In the above-described state, the operation member is operated to press the IC package 2 downward using the cover members. The floating plate 40 is lowered together with the IC package 2 against the upward urging force so that the solder ball presses the second tip end portion 82 while being pushed downward against the urging force of the spring part 91.
As the protrusion 95 is configured to enter into the recess 94, when the force is applied in the direction for contracting the spring part 91 along the axis L against the urging force, the protrusion 95 is brought into abutment on side walls 93a of the respective projections 93 at both sides of the recess 94 into which the protrusion 95 has entered by a predetermined contracting amount. The thus applied stopper force prevents further contraction of the spring part 91. As a result, the spring part 91 no longer contracts in excess of the prescribed amount. This makes it possible to prevent failure of plastic deformation of the spring part 91 to the level over the elastically deformable range.
The first contact part 71 and the spring part 91 are integrally linked, and the second contact part 81 and the spring part 91 are integrally linked. As the spring part 91 is compressed, the respective wave-shaped parts 92 of the spring part 91 come into contact with each other. This establishes electric coupling in a short distance from the first contact part 71 to the second contact part 81 compared with the case where electricity flows along the spring part 91 in the developed state as shown in
As the spring part 91 is compressed, the abutment state of the protrusion 95 of the spring part 91 on the respective side walls 93a of the projections 93 at both sides of the recess 94 into which the protrusion 95 has entered is held for establishing the electric coupling from the first contact part 71 to the second contact part 81 in the short distance. Further in the state where the electrode of the wiring board 1 is in electric connection to the solder ball of the IC package 2 under the appropriate contact pressure with the spring part 91 which urges the first contact part 71 and the second contact part 81 in the mutually separating direction, the continuity test to the IC package 2, for example, the burn-in testing is conducted.
This embodiment is obtained by modifying the contact pin 60 according to the above-described first embodiment into a contact pin 160 constituted by two members as shown in
As
The first member 170 is formed from a first member conductive material 170A as shown in
The plate-like part 170B as shown in
The wavy part 170C as shown in
In reference to the developed state as shown in
In reference further to
A protrusion 179 extending in the direction orthogonal to the axis L is formed on a tip portion of the projection 177 of each of the wave-shaped parts 176 at the farthest location from the axis L as shown in
The another plate-like part 170D is curved or bent cylindrically along the axis L to provide the intermediate part 174 which is not in the form of the spring at substantially the intermediate position of the spring part 175 as shown in
The thus formed first member 170 includes the first contact part 171, an intermediate part 174, and two divided spring parts 175.
The second member 180 as a member formed into a rod-like shape along the axis L has a hollow rod-like structure. The second member may be formed to have a solid rod-like structure. The second member 180 is formed from a second member conductive material 180A as shown in
The second member conductive material 180A as shown in
The lock part 183 is formed to have a diameter larger than that of the spring part 175 of the first member 170, on which an end portion of the spring part 175 is brought into abutment.
The insertion portion 185 is configured to have a size and a shape so as to have its diameter smaller than that of the lock part 183 of the second contact part 181, to be inserted to the inside of the spring part 175 of the first member 170, and to be slidably inserted to the inside of the inserted portion 173 of the first contact part 171 of the first member 170. The insertion portion 185 is configured to have a length so as to be inserted to the inside of the inserted portion 173 of the first contact part 171 in the state where no force is applied to the spring part 175 into which the insertion portion has entered in the contracting direction, and configured so as not to have the tip end of the insertion portion 185 reaching a boundary between the inserted portion 173 and the first tip end portion 172 when the stopper force is applied to the spring part 175 under contraction in the contracting direction with the protrusion 179.
A protrusion 186 is formed on a surface of a wall of the insertion portion 185 around the lock part 183 of the second contact part 181 while extending by a predetermined amount. In this case, semi-spherical protrusions 186 are disposed at two opposite points, respectively on the wall surface at the same positions in the direction of the axis L of the insertion portion 185. This makes it possible to hold the spring part 175 in abutment on the lock part 183 so as not to be detached therefrom.
The thus formed second member 180 includes the second contact part 181 and the insertion portion 185.
The contact pin 160 is formed by inserting the insertion portion 185 of the second member 180 into the inserted portion 173 of the spring part 175 and the first contact part 171 of the first member 170, and bringing the end portion of the spring part 175 into abutment on the lock part 183 for holding the spring part 175 with the protrusions 186.
The thus formed contact pin 160 is configured to have the small-diameter first tip end portion 172 of the first contact part 171 of the first member 170 inserted into the through hole of the lower holding member 33 of the contact module 30, and extended downward of the lower holding member 33 (corresponding to the first tip end portion 72 as shown in
Functions of the IC socket 10 provided with the contact pins 160 each constituted by the first member 170 and the second member 180 as described above will be described.
The IC socket 10 is used in the state where the contact pins 160 are fitted with the contact module 30 of the socket body 20 to allow extension of the first tip end portion 172 of the first contact part 171 of the first member 170 downward of the lower holding member 33, and insertion of the second tip end portion 182 of the second contact part 181 of the second member 180 into the floating plate 40 as well as insertion of the intermediate part 174 of the first member 170 into the center holding member 32.
The IC socket 10 is positioned and fixed to the wiring board 1 so that the first tip end portion 172 of the first contact part 171 is brought into contact with the electrode of the wiring board 1. At this time, the first tip end portion 172 is pushed upward by the wiring board 1 as well as the entire first member 170. As a result, the second member 180 is also pressed upward via the lock part 183 of the second contact part 181 of the second member 180, on which the end portion of the spring part 175 has abutted.
The IC package 2 is then seated on the floating plate 40 to bring the solder ball into contact with the second tip end portion 182 of the second contact part 181. In the above-described state, the operation member is operated to press the IC package 2 downward using the cover members. The floating plate 40 is lowered together with the IC package 2 against the upward urging force so that the solder ball presses the second tip end portion 182 while having the second member 180 being pushed downward against the urging force of the spring part 175.
As the protrusion 179 is configured to enter into the recess 178, when the force is applied in the direction for contracting the spring part 175 along the axis L against the urging force, the protrusion 179 is brought into abutment on side walls 177a of the respective projections 177 at both sides of the recess 178 into which the protrusion 179 has entered by a predetermined contracting amount. The thus applied stopper force prevents further contraction of the spring part 175. As a result, the spring part 175 no longer contracts in excess of the prescribed amount. This makes it possible to prevent failure of plastic deformation of the spring part 175 to the level over the elastically deformable range.
At this time, the insertion portion 185 of the second member 180 is slidably inserted to the inside of the inserted portion 173 of the first contact part 171 of the first member 170 so that the electrode of the wiring board 1 and the solder ball of the IC package 2 are electrically coupled in the short distance via the second contact part 181 and the insertion portion 185 of the second member 180, and the inserted portion 173 and the first contact part 171 of the first member 170. This makes it possible to establish electric connection of those components with the low resistance value.
The spring part 175 integrated with the first contact part 171 has its upper end portion abutted on the second contact part 181. As the spring part 175 is compressed to bring the respective wave-shaped parts 176 of the spring part 175 into abutment on each other, the electric coupling is established from the first contact part 171 to the second contact part 181 in the shorter distance compared with the case where electricity flows along the spring part 175 in the developed state as shown in
Compression of the spring part 175 allows electric coupling between the first contact part 171 and the second contact part 181 in the short distance through slidable insertion of the insertion portion 185 of the second member 180 to the inside of the inserted portion 173 of the first member 170, and electric coupling from the first contact part 171 to the second contact part 181 in the short distance while holding the abutment state of the protrusion 179 of the spring part 175 on the side walls 177a of the projections 177 at both sides of the recess 178 into which the protrusion 179 has entered. Further in the state where the electrode of the wiring board 1 is electrically connected to the solder ball of the IC package 2 under the appropriate contact pressure with the spring part 175 which urges the first contact part 171 of the first member 170 and the second contact part 181 of the second member 180 in the mutually separating direction, the continuity test to the IC package 2, for example, the burn-in testing is conducted.
The contact pins 60, 160 of the above-described embodiments are configured to allow the projections 93, 177 of the wave-shaped parts 92, 176 on one side to enter into the recesses 94, 178 between the wave-shaped parts 92, 176 on the other side so that the projections 93, 177 on one side are brought into abutment on the projections 93, 177 adjacent to the recesses 94, 178 of the wave-shaped parts 92, 176 on the other side, respectively upon contraction of the spring parts 91, 175 for stopping the contraction movement, and further establishing the conduction state between the projections 93, 177 abutted on each other. It is therefore possible to prevent the plastic deformation of the spring parts 91, 175 in excess of the limit of the elastic deformation. As a result, durability of the contact pins 60, 160 may be improved.
The contact pins 60, 160 of the above-described embodiments are configured to have the protrusions 95, 179 formed on the tip portions of the projections 93, 177, respectively in the direction orthogonal to the axis L. As the protrusions 95, 179 are structured to enter into the recesses 94, 178, the protrusions 95, 179 securely enter into the recesses 94, 178, making it possible to prevent the spring parts 91, 175 from exceeding the limit of the elastic deformation.
The IC sockets 10 according to the above-described embodiments include the above-described contact pins 60, 160, respectively. It is possible to provide the IC socket 10 which prevents the spring parts 91, 175 of the contact pins 60, 160 from plastically deforming in excess of the limit of the elastic deformation.
The first contact pin 60 according to the first embodiment as described above is constituted by the single member. The contact pin 160 according to the second embodiment as described above is constituted by the two members, that is, the first member 170 and the second member 180. Therefore, the number of components used for producing the contact pin 160 may be made smaller than the number of those used for producing the generally employed contact pin constituted by multiple members.
The contact pin 160 according to the second embodiment as described above is configured to allow insertion of the insertion portion 185 of the second member 180 to the inside of the spring part 175 of the first member 170 so as to electrically connect the first member 170 and the second member 180. This makes it possible to reduce an electricity passage distance from the wiring board 1 in contact with the first contact part 171 to the IC package 2 in contact with the second contact part 181 so as to be shorter than the distance of the case where electricity passes through the entire spring part from the first member to reach the second member. As a result, the resistance value of the contact pin 160 may be reduced. The second member 180 serving as the core material may provide the contact pin 160 with higher strength.
The contact pin 160 according to the second embodiment as described above is configured to bring the insertion portion 185 inserted to the inside of the spring part 175 into contact with the first contact part 171. This makes it possible to reduce the electricity passage distance to be shorter than the case where the insertion portion 185 is in contact only with the spring part 175. As a result, the resistance value of the contact pin 160 may be further reduced.
As the IC socket 10 according to the second embodiment as described above includes the above-described contact pin 160, the IC socket 10 allows the number of components used for producing the contact pin 160 to be smaller than the conventional case. As the IC socket 10 includes the above-described contact pin 160, the electricity passage distance from the wiring board 1 in contact with the first contact part 171 to the IC package 2 in contact with second contact part 181 may be made shorter than the conventional case. This makes it possible to provide the IC socket 10 with the reduced resistance value of the contact pin 160.
The “electric contact” according to the present invention is not limited to the contact pins 60, 160 each with the structure according to the corresponding embodiment as described above, but may be applied to the other structure. In the embodiment as described above, the “socket for electric component” according to the present invention has been applied to the IC socket 10 provided with the cover members and the operation member, which is not limited to the one as described above. The socket for electric component may be applied to the IC socket with no cover or the like, and any other device except the IC socket.
Number | Date | Country | Kind |
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2016-254011 | Dec 2016 | JP | national |
This application is a U.S. National Stage Application which claims the benefit under 35 U.S.C. § 371 of PCT International Patent Application No. PCT/JP2017/046159, filed, Dec. 22, 2017, which claims the foreign priority benefit under 35 U.S.C. § 119 of Japanese Patent Application No. 2016-254011, filed Dec. 27, 2016, the contents of which are incorporated herein by reference.
Filing Document | Filing Date | Country | Kind |
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PCT/JP2017/046159 | 12/22/2017 | WO | 00 |