Burn-in socket with improved terminals

A burn-in socket includes an insulative seat with a plurality of terminal-retained passageways, a sliding member defining a plurality of terminal-receiving passageways, a driven frame and a plurality of terminal retained in terminal-retained passageways of the seat and received in the terminal-receiving passageways of the sliding member. Each of the terminal-receiving passageways defines two opposite inner sides. Each terminal includes a base portion, a board-connecting portion and a pair of clamping arm consisting of a movable arm and a static arm, the pair of clamping arms defining clamping end at tips thereof. The pair of clamping arms are located elastically against corresponding inner sides, the static arm defines a lower curved portion with a projecting end and an upper linear portion, the projecting end of the lower curved portion of the static arm elastically presses against the movable arm permanently.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a burn-in socket for testing an IC package, and particularly to a burn-in socket having improved terminals to simply and improve an insulative seat of the burn-in socket.

2. Description of Related Art

Burn-in socket is an indispensable equipment for ensuring the proper normal function of an integrated circuits (IC) package before it is delivered. Conventional burn-in sockets typically include a base with a plurality of terminals, a driven frame mounted upon the base and movable in a top-to-bottom direction, and a sliding board assembled on the base and driven by the frame to slide in a longitudinal direction. The terminal usually has a pair of clamping arms including a movable arm and a static arm, the movement of the sliding board can bring the clamping arms to open.

The base defines terminal-receiving passageways to accommodate the pairs of clamping arms. Generally each of the terminal-receiving passageways includes two holes to receive clamping arms respectively since the clamping arms are long, thereby avoiding swaying of the two clamping arms. On the other hand, each terminal-receiving passageway is weaker in base's strength.

Hence, an improved socket is required to overcome the above-mentioned disadvantages of the related art.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a burn-in socket with improved terminals.

To achieve the aforementioned object, a burn-in socket comprises an insulative seat with a plurality of terminal-retained passageways, a sliding member receiving in insulative housing and defining a plurality of terminal-receiving passageways, a driven frame located on the sliding member and driving the sliding member moving relative to the insulative seat and a plurality of terminal retained in terminal-retained passageways of the insulative seat and received in the terminal-receiving passageways of the sliding member. Each of the terminal-receiving passageways defines two opposite inner sides. Each terminal comprises a base portion retained in the insulative seat, a board connecting portion and a pair of clamping arm consisting of a movable arm and a static arm, the pair of clamping arms defining clamping ends at tips thereof. The pair of clamping arms are located elastically against corresponding inner sides, the static arm defines a lower curved portion with a projecting tip and an upper linear portion, the projecting tip of the lower curved portion of the static arm elastically presses against the movable arm permanently.

DETAILED DESCRIPTION OF THE INVENTION

Referring toFIGS. 1 and 2, a burn-in socket100in accordance with the preferred embodiment of the present invention is used to electrically connect an IC package (not shown) and comprises an insulative seat1, a plurality of terminals2in the seat, a sliding member3, a pair of pressing members4, a driven frame5and a protecting board7.

The insulative seat1has a rectangular configuration, and defines a receiving cavity10among four sidewalls11connecting with each other in turn and a plurality of terminal-retained passageways12in a center of the bottom of the receiving cavity10and four receiving holes13on four corners thereof for receiving coil springs50to support the driven frame5. Please notes, the terminals2are received in the terminal-retained passageways12and fitly retained in the insulating seat1. Each passageway12is retained with only one terminal2.

The sliding member3is assembled in the insulative seat1, and defines an array of terminal-receiving passageways30for receiving the terminals2, the terminal receiving passageways30are aligned with the corresponding terminal-retained passageways12in the seat one by one. The sliding member3is provided with a biasing post32at one corner thereof for positioning a coil spring33. The sliding member3has a plurality of locking legs31protruding from two sides of two longitudinal ends thereof, each locking portion31has an arch surface. The sliding member3is limited in receiving cavity10of the seat by the locking legs31in a vertical direction. The biasing post32with the spring33extends horizontally in a diagonal line, so that the sliding member3moves horizontally in a diagonal line by the driven frame5and returns back by restoring forces of the springs33. As shown inFIG. 3, the array of the terminal-receiving passageways30of the sliding member3is arranged in a plurality of rows and columns. Each row of the passageways30is linear which are aligned with each other. In columns, two adjacent passageways30for example are offset from each other. A rib300projects upright between every two adjacent passageways in each row of the passageways. The rib300is oriented in the column direction is construed in a crescent-moon shape with two higher ends and a lower centre so as to nicely receive a corresponding soldering ball of the IC package. When the sliding member3is assembled in the receiving cavity of the seat1, the plurality of the terminals2are ready to be inserted into the seat1and the sliding member3moves in a lower to upper direction.

Referring toFIG. 4throughFIG. 6, each terminal2stamped from a metal strip, includes a main body20retained in the terminal-retained passageways12of the seat, a pair of clamping arms upwardly extending from the main body20and a soldering portion23downwardly extending from the main body20to connect with a printed circuit board. The pair of clamping arms includes a movable arm21with deflectable elasticity and a static arm42with deflectable elasticity, both of them defines clamping ends212,222at tips thereof to clamp one soldering ball of the IC package. The movable arm21is construed with a lower linear portion210and an upper curved portion211, the upper curved portion curves toward the static arm with a projecting tip213pressing against the static arm22. The static arm22is construed with a lower curved portion and an upper liner portion221, the lower curved portion curved toward the movable arm with a projecting tip223. The projecting tip223presses against the lower linear portion210of the movable arm21.

FIG. 5toFIG. 6show an assembly process of one terminal3into the seat1and the sliding member3after the sliding member3is retained in the seat1. Each terminal-retained passageway12of the seat1has opposite inner sides or dividing wall121,122. The two clamping arms of the terminal2are firstly inserted into a same terminal-retained passageway12. Please notes, the terminal-retained passageway12has no rib and partition wall therein, thereby the clamping arms21,22upwardly moving successfully. When the terminal2moves up to a certain extent, the upper linear portion221of the static arm22and the lower linear portion210of the movably arm21is located against the inner sides121,122, and the projecting tip213of the upper curved portion211of the movable arm21presses against the upper linear portion221of the static arm22. According to the lever principle of the movable arm21, the clamping end212move far away from the clamping end222, so that there is a largest gap between the two clamping ends which is ready for insertion of the terminal to the terminal-receiving passageway30of the sliding member3. The two clamping arms are inserted into two adjacent terminal-receiving passageways30of the sliding member3, the rib300is located between the movable arm21and the static arm22. As best shown inFIG. 6, the inner sides121,122are disposed against the lower linear portion210and the lower curved portion220and the lower curved portion is against the lower linear portion at least. Moreover, the lower end of the upper linear portion is against the inner side122. Therefore, an inter-engagement of the movable arm21and static arm22in a long cantilever form is established to avoid swaying of the two clamping arms. The upper curved portion211is free from the upper linear portion221. That means, each terminal-receiving passageway30is in a form two spaced holes with partitioning wall35therein.

Referring toFIGS. 1 and 2, the driven frame5is assembled to the seat1on the sliding member3which can be driven downwards to push the pair of pressing members50shift outwards and returns back by the springs50. A positioning frame8is further provided between the driven frame5and the sliding member3to receive the IC package. A protecting board7is attached at a bottom of the seat with terminal passageways70.

Referring toFIGS. 7 and 8, the movable arm21and the static arm22is located at an original portion and a small distance may be existed therebetween. When the driven frame5is depressed to bring the sliding move in the diagonal direction, the movable arm21is forced by partitioning wall35of the sliding member3to move from the original position to an open position in which the gap between the clamping arm becomes larger, while the static arm41of the terminal4remains at its original state. The larger gap is ready for accommodate the solder ball of the IC package. When the driven frame5is released as shown inFIGS. 9 and 10, the burn-in socket is fitly retained in the receiving cavity10to establish an electrical connection between the IC package and the test socket.

However, the disclosure is illustrative only, changes may be made in detail, especially in matter of shape, size, and arrangement of parts within the principles of the invention.