The present invention relates to a socket for electrical parts for detachably accommodating and holding an electrical part such as a semiconductor device (called as xe2x80x9cIC packagexe2x80x9d hereinafter) and also relates to a method of assembling such socket for electrical parts.
As a conventional xe2x80x9csocket for electrical partsxe2x80x9d of this kind, there has been provided an IC socket for detachably accommodating and holding an IC package as xe2x80x9celectrical partxe2x80x9d.
The IC package includes, for example, a BGA (Ball Grid Array) type of IC package in which solder balls as a number of terminals are provided to the lower surface of the package body so as to protrude downward in a grid (lattice) arrangement having vertical (Y) and horizontal (X) rows.
The IC socket is provided with a socket body, a number of contact pins disposed to the socket body so as to contact the terminals of the IC package, respectively. Furthermore, a movable member for contacting or separating the contact pins to or from the solder balls of the IC package, through elastic deformation of the contact pins, is also arranged to be vertically movable.
Furthermore, the socket body is provided with lever members to be rotatable (pivotal) about pivotal shafts so as to vertically move the movable member, and an operation member for rotating the lever members is also provided for the socket body to be vertically movable.
When this operation member is vertically moved, the lever members are rotated (pivoted), and according to this rotating motion, the movable member is vertically moved, thus contacting or separating contact portions of the contact pins to or from the solder balls of the IC package.
However, in such conventional IC package as mentioned above, a base end portion of the lever member is secured to the socket body to be rotatable through a rotation shaft and an E ring is also provided for preventing the lever member from coming off from the socket body, so that the number of elements or parts is increased and the assembling working is hence increased, thus being inconvenient and disadvantageous.
Furthermore, in order to prevent the front end portion of the lever member from falling sideways, the front end portion of the lever member is coupled to the operation member to be rotatable through a support shaft, so that, in this meaning, the number of elements or parts is increased and the assembling working is hence increased, thus being inconvenient.
An object of the present invention is to substantially eliminate defects or drawbacks encountered in the prior art mentioned above and to provide a socket for electrical parts and a method of assembling the same, by which the number of elements or parts to be utilized can be effectively reduced as well as reduction of the assembling workings.
This and other objects can be achieved according to the present invention by providing, in one aspect, a socket for electrical parts in which a number of contact pins contacting a number of terminals of an electrical part is arranged to a socket body in which the electrical parts is accommodated, an operation member is provided for the socket body to be vertically movable in an installed state, and when the operation member is vertically moved, a movable member is moved through lever members to thereby displace the contact pins to be electrically contacted to or separated from the terminals of the electrical part,
wherein the socket body is formed with boss portions to which base end portions of the lever members are secured to be rotatable and the socket body is formed with guide wall sections so as to guide side portions of the base end portions of the lever members to thereby prevent the lever members from coming off from the boss portions.
In a preferred embodiment of the above aspect, the operation member is formed with guide grooves into which front end portions of the lever members are inserted so as to prevent the lever members from falling sideways.
The socket body is formed of synthetic resin, the boss portions are integrally formed with the socket body and the lever members are formed of metal material. The base end portions of the lever members are formed with holes into which the boss portions are fitted. The terminals of the electrical part are solder balls. The socket is an IC socket and the electrical part is an IC package.
In a modified aspect, there is provided a socket for electrical parts comprising:
a socket body to which an electrical part having a number of terminals is accommodated;
a number of contact pins arranged to the socket body so as to accord with the arrangement of the terminals of the electrical part;
an operation member disposed to the socket body to be vertically movable in an installed state;
lever members provided for the socket body to be rotatable in association with the vertical movement of the operation member; and
a movable member disposed to the socket body to be movable in accordance with the movement of the operation member through the lever members to thereby displace the contact pins so as to contact or separate the contact pins to or from the terminals of the electrical part,
the socket body being formed with boss portions, the lever members being formed with base end portions which are fitted to the boss portions to be rotatable, and the socket body being formed with guide wall sections so as to guide side portions of the base end portions of the lever members to thereby prevent the lever members from coming off from the boss portions.
In another aspect, there is also provided a method of assembling a socket for electrical parts in which a number of contact pins contacting a number of terminals of an electrical part is arranged to a socket body which accommodates the electrical part and which is provided with an operation member and a movable member which is operatively connected to the operation member through lever members,
wherein the lever members are fitted to the boss portions of the socket body to be rotatable, when the lever members are rotated while being guided along guide wall sections of the socket body and the operation member is disposed to the socket body to be vertically movable.
The operation member is formed with guide grooves into which front end portions of the lever members are inserted so as to prevent the lever members from falling down sideways.
According to the present invention of the characters mentioned above, the base end portions of the lever members are fitted to the boss portions of the socket body to be rotatable and the guide wall sections are formed to the socket body so as to guide the side portions of the base end portions of the lever members to prevent the lever member from coming-off from the boss portions. Accordingly, it is not necessary to specifically locate any member for preventing the coming off of the lever members, thus reducing the number of parts or elements to be assembled and improving the assembling working of the lever members and others. Furthermore, the formation of the guide grooves eliminates the location of any member such as a support shaft for supporting the lever members.
Moreover, the socket body is formed of synthetic resin and the lever members are formed of metal material. Accordingly, the boss portions can be easily molded integrally with the socket body and the lever members can ensure the good rigidity thereof.
The nature and further characteristic features of the present invention will be made more clear from the following descriptions made with reference to the accompanying drawings.