KR20070073233A - Test socket for bga package - Google Patents

Abstract

A test socket for a BGA(Ball Grid Array) package is provided to minimize the damage of an external connection ball, have a low-inductance structure corresponding to a high frequency, and have self alignment for having the low pollution of the external connection ball and improving fine pitch correspondence and contact alignment. A test socket is formed in a position corresponding to an external connection ball(110) arranged on one surface of a BGA package(100). The text socket includes a probe pin(30) electrically connected with a pitch expansion board(50). The probe pin(30) includes a coil spring(31) and a conductive rubber(35). The coil spring(31) has an inner diameter which is narrower than a diameter of the external connection ball(110). A filament is wound by a certain number to form the coil spring(31). The wiring of one side of the coil spring(31) is contacted with the external connection ball(110), and the wiring of the other side of the coil spring(31) is contacted with a pitch expansion board(50). The conductive rubber(35) surrounds the coil spring(31).

Description

Test Socket for BA Package {Test Socket for BA Package}

1 is a cross-sectional view showing an example of a test socket for a BGA package according to the prior art,

2 is a cross-sectional view showing another example of a test socket for a BGA package according to the prior art;

3 is a cross-sectional view showing another example of a test socket for a BGA package according to the prior art;

4 is a cross-sectional view showing a test socket for a BGA package according to an embodiment of the present invention;

5 is a cross-sectional plan view of the probe pins in the test socket for the BGA package of FIG. 4, and

6A and 6B are operational state diagrams for the test socket for the BGA package of FIG.

Explanation of symbols on the main parts of the drawings

10; Test socket 20; Probe Pin Support Body

21; Probe pin mounting holes 30; Probe pin

31; Coil spring 31a; Top winding

31b; Lowest winding 35; Conductive rubber

50; Pitch expansion substrate 55; Board Pad

100; BGA package 110; External connection ball

The present invention relates to a test socket for a semiconductor chip package, and more particularly, to a test socket for a BGA package that performs electrical connection with a tester by physical contacting a BGA package having an external connection surface on one surface thereof. .

Semiconductor devices manufactured through a package assembly process are tested to ensure operational reliability. As the semiconductor device test, electrical property tests for checking the normal operation or disconnection of the semiconductor device, and burn-in tests for checking the lifetime and defect occurrence of the semiconductor device under severe operating conditions are well known. The test is usually carried out with a semiconductor device mounted in a test socket. The semiconductor device and the test apparatus are electrically connected through the test socket.

The test socket has a different structure depending on the type of semiconductor device, but in the case of the BGA package, the pogo pin type, the coil spring type, and the insulating property depend on the type of the probe pin provided in the test socket which is in physical contact with the external connection ball. Polymeric methods are typical. This article introduces the problem of test sockets for BGA packages.

1 to 3 are cross-sectional views showing test sockets for a BGA package according to the prior art.

The test socket 310 of the pogo pin method as shown in FIG. 1 is externally connected due to the force applied at the time of contact because the portion of the probe pin 330 that contacts the external connection ball 110 of the BGA package 100 is a pointed window. The ball 110 may be damaged, and thus voids may be generated in the external connection ball 110 or at a joint thereof when the product is mounted.

The test socket 410 of the coil spring pin method as shown in FIG. 2 is damaged to the external connection ball 110 when the probe pin 430 composed of the coil spring contacts the external connection ball 110 of the BGA package 100. This small but high inductance makes it difficult to test high frequency products.

The insulating polymer pin type test socket 510 as shown in FIG. 3 is capable of dealing with high frequency products without damaging the external connection ball 110, but the BGA package 100 due to the probe pin 530 made of insulating polymer. Surface contamination is easily generated in the external connection ball 110 of the external contact ball 110 has a problem that the contact force is weak due to the lack of elasticity with respect to the product having a ball coplanarity of 3mil or more.

Accordingly, an object of the present invention is to provide a test socket having a low inductance structure for minimizing damage to an externally connected ball, a low inductance structure for high frequency response, less contamination of the externally connected ball, and a self-aligning function for fine pitch response and improved contact alignment. It's there.

In order to achieve the above object, the present invention provides a test socket for a BGA package, which is formed at a position corresponding to an external connection ball arranged on one surface of the BGA package, and includes a probe pin electrically connected to a pitch expansion substrate. The probe pin has an inner diameter smaller than the diameter of the external connection ball, and a coil spring is formed by winding a predetermined number of times, and one coil is in contact with the external connection ball, and the other winding is in contact with a pitch expansion substrate. A test socket for a BGA package including a conductive rubber surrounding the coil spring is provided.

In the test socket for a BGA package according to the present invention, the conductive rubber may be a structure for embedding the coil spring. And, it is preferable that the coil spring is formed by projecting a predetermined portion of the upper and lower ends from the conductive rubber. In particular, it is preferable that the uppermost winding and the lowest winding protrude from the conductive rubber.

Hereinafter, an embodiment of a test socket for a BGA package according to the present invention will be described with reference to the accompanying drawings.

Example

4 is a cross-sectional view illustrating a test socket for a BGA package according to an embodiment of the present invention, and FIG. 5 is a plan cross-sectional view of the probe pin in the test socket for the BGA package of FIG. 4.

4 and 5, the test socket 10 for the BGA package of the present embodiment has a probe pin 30 made of a coil spring 31 and a conductive rubber 35. The probe pin 30 has a structure in which the conductive rubber 35 surrounds the coil spring 31. A plurality of probe pins 30 are provided in the test socket 10, and each probe pin 30 is installed at a position corresponding to the external connection ball 110 of the BGA package 100. The probe pin 30 is accommodated in the probe pin support body 20 in which the probe pin installation holes 21 are formed.

In more detail, the probe pin support body 20 has a probe pin installation hole 21 in which the probe pin 30 is received at a position corresponding to the external connection ball 110 of the BGA package 100. The probe pin installation hole 21 penetrates through the probe pin support body 20, and the lower end portion has a diameter larger than that of the upper portion to form a jaw. A portion of the upper end of the probe pin 30 is accommodated in the upper portion of the probe pin installation hole 21, and a portion of the lower end of the probe pin 30 is accommodated in the lower portion thereof.

The coil spring 31 constituting the probe pin 30 is a wire wound in a spiral shape, and is formed to be separated from each other by a predetermined distance between neighboring windings to provide an elastic force. As described above, the probe pin 30 is coupled to the conductive rubber 35 so as to surround the coil spring 31. Here, the conductive rubber 35 may have a structure for embedding the coil spring 31, or a structure surrounding the outer or inner side of the coil spring 31. The conductive rubber 35 has elastic force by itself so that it does not significantly interfere with the contraction of the coil spring 31.

The probe pin 30 is accommodated in the probe pin mounting hole 21. The lower end portion of the coil spring 31 has an outer diameter larger than the upper diameter of the probe pin attachment hole 21. Accordingly, the lower end of the coil spring 31 is caught by the jaw of the probe pin support body 20, thereby preventing the probe pin 30 from being separated. Probe pin 30 has a predetermined length protrudes from the probe pin support body 20 in the upper portion and the lower portion.

In the coil spring 31, the uppermost winding 31a and the lowermost winding 31b protrude a predetermined length from the conductive rubber 35. The uppermost winding 31a of the coil spring 31 not covered with the conductive rubber 35 is formed to have an inner diameter smaller than the diameter of the external connection ball 110 of the BGA package 100. Accordingly, the uppermost winding 31a of the coil spring 31 and the external connection ball 110 are smoothly contacted.

In the contact between the external connection ball 110 and the coil spring 31, line contact is made. In the contact process, the contact area with the external connection ball 110 is large, and the force applied to the external connection ball 110 is dispersed. Force is distributed in the physical contact process to increase the life of the socket, minimizing damage to the external connection ball (110). In addition, since the contact surface is increased compared to the pogo pin method, it is possible to secure a low impedance.

Preferably, the inner diameter of the coil spring 31 is set close to the diameter of the outer connection ball 110. Self alignment may be performed in the process of contact between the external connection ball 110 and the coil spring 31 to optimize the alignment of the external connection ball 110 and the probe pin 30 due to a package alignment error. In addition, since it has a self-aligning function for improving contact alignment, it is possible to cope with fine pitch. Unlike the conductive polymer method, less pollution occurs and elasticity shortage does not occur with temperature.

The conductive rubber 35 constituting the probe pin 30 provides an electrical diameter path when the external connection ball 110 of the BGA package 100 and the substrate pad 55 of the pitch expansion substrate 50 come into contact with each other. Allow current to flow in the shortest distance. Accordingly, the inductance of the probe pin 30 is minimized.

On the other hand, the uppermost winding (31a) and the lowest winding (31b) of the coil spring 31 is exposed from the conductive rubber 35, the foreign matter is not easily laminated. In addition, the lowest winding 31b of the coil spring 31 is exposed from the conductive rubber 35 so as to be in good contact with the substrate pad 55 of the pitch expansion substrate 50.

6A and 6B are operational state diagrams for the test socket for the BGA package of FIG.

6A and 6B illustrate a process in which the test socket 10 for the BGA package of the present embodiment is automatically aligned when an alignment error between the external connection ball 110 and the coil spring 31 occurs. In general, the external connection ball 110 and the probe pin 30 are in contact with each other by pressing in a state where the alignment of the external connection ball 110 and the probe pin 30 of the BGA package 100 is completed.

However, as shown in FIG. 6A, when the external connection ball 110 and the coil spring 31 are not aligned correctly and an error occurs, the diameter of the coil spring 31 approaches the diameter of the external connection ball 110. Since it is formed in the size to the position alignment is automatically made while moving in the direction of the arrow as in Figure 6b during the pressing process. As the coil spring 31 is contracted, the external connection ball 110 and the substrate pad 55 of the pitch expansion substrate 50 are electrically connected to each other. Of course, the electrical path between the external connection ball 110 and the substrate pad 55 is the shortest distance by the conductive rubber 35. As a result, the input and output of the signal is accurately performed during the test.

Meanwhile, the test socket for the BGA package according to the present invention is not limited to the above-described embodiment and may be variously modified within a range not departing from the technical spirit of the present invention. This will be readily apparent to those skilled in the art.

According to the test socket for the BGA package according to the present invention as described above, the damage of the external connection ball in contact with the probe pin is minimized, the life of the probe pin is increased, the response to the fine pitch and poor contact alignment is improved. In addition, since the inductance is lowered due to the conductive rubber, it is advantageous to cope with high frequency products.

Claims (4)

A test socket for a BGA package formed at a position corresponding to an external connection ball arranged on one side of a BGA package, the test socket including a probe pin electrically connected to a pitch extension substrate. The probe pin has an inner diameter smaller than the diameter of the external connection ball, and a coil wire is formed by winding a predetermined number of times, and one coil is in contact with the external connection ball, and the other winding is in contact with the pitch expansion substrate; A test socket for a BGA package comprising a conductive rubber surrounding the coil spring. According to claim 1, The conductive rubber is a test socket for a BGA package, characterized in that the structure of embedding the coil spring. According to claim 1, The coil spring is a test socket for the BGA package, characterized in that a portion of the top and bottom exposed from the conductive rubber. The method of claim 3, wherein And the coil spring has a top winding and a bottom winding exposed from the conductive rubber.

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