1. Field of the Invention
The present invention relates to a testing probe, and more particularly to a testing probe capable of enhancing test reliability using a conductive silicon section through which a stable test current flows.
2. Description of the Prior Art
Chips are integrated circuits that perform a variety of functions using logic elements fabricated on a thin small piece of semiconducting material. Such functions are activated by electrical signals transmitted from a printed circuit board (PCB) through buses.
In general, a lot of chips are mounted in a variety of electronic products, and play an important role in determining the performance of each electronic product.
Further, the PCB is constructed so that a conductor, copper, is coated to form circuit wiring on a thin board made of an insulator, such as epoxy resin or bakelite resin. The PCB has electric/electronic elements such as integrated circuits, resistors, and switches soldered on the circuit wiring.
Microchips refer to chips in which the electronic circuit of the PCB is integrated at high density. In order to check whether or not such a chip is normal before the chip is mounted on and assembled with any electronic product, the chip must be tested using test equipment.
In this testing method, the chip is mounted on a testing socket. In order to test the chip in the testing socket without damaging it, a testing probe is mounted and used.
The testing socket is generally mounted on a testing PCB, and the microchip to be tested is placed on the testing socket. Then, the test is performed. The testing socket is mounted with a plurality of testing probes.
As illustrated in
When a microchip is tested using this construction, the microchip is placed on a testing socket, and is pressed downward using a pressing unit installed on the testing socket. Thereby, the microchip comes into contact with the probe projection of the upper plunger.
As illustrated in
Thus, the current of the testing PCB flows to separately provided test equipment (not shown) through the testing probe. In this process, it is possible to test normal operation of the semiconductor chip.
Reliability tests using the testing probe are dependent upon a smooth flow of the current flowing through the testing probe. Although the coil spring 30 is compressed, the coil spring 30 comes into contact with the inner wall of the barrel 20 only within a specific area A, and thus the current flowing to the lower plunger through the coil spring 30 is attributed to an unstable response characteristic of the test current in the testing process.
Accordingly, embodiments of the present invention are directed towards providing a testing probe capable of enhancing test reliability by modifying a structure so as to allow stable test current to flow.
According to an aspect of the present invention, there is provided a testing probe, which includes: a barrel, opposite ends of which are open; an upper plunger, at an upper end of which a probe projection is formed so as to be in contact with a connection terminal of a semiconductor chip, and a lower portion of which is held in an upper portion of the barrel; and a lower plunger, an upper portion of which is held in a lower portion of the barrel. The barrel receives a conductive silicon section having conductivity due to metal powder contained in a silicon cylinder, and the conductive silicon section electrically connects the upper plunger and the lower plunger, and elastically supports downward pressure transmitted to the upper plunger during testing each semi-conductor chip.
Here, the barrel may include a coil spring installed therein so as to elastically support the upper plunger.
Further, the coil spring may have an inner diameter larger than an outer diameter of the conductive silicon section by a range from 0.02 mm to 0.2 mm.
According to another aspect of the present invention, there is provided a testing probe for testing semiconductor chips. The testing probe includes: an upper plunger, at an upper end of which a probe projection is formed so as to be in contact with a connection terminal of a semiconductor chip; a barrel, having open opposite ends and holding a lower portion of the upper plunger 10 in an upper portion thereof; a lower plunger, an upper portion of which is held in a lower portion of the barrel; a coil spring elastically supporting the upper plunger held in the barrel; and a conductive silicon section held in the coil spring and having conductivity due to metal powder contained in a silicon cylinder. When coming into contact with the semi-conductor chip, the upper plunger is primarily and elastically supported by the coil spring and is secondarily and elastically supported by the conductive silicon section.
According to embodiments of the present invention, the conductive silicon section, in which metal powder is contained to impart conductivity, can be held in the barrel, and elastically support the upper plunger during testing, and stable test current can flow along the conductive silicon section, so that the testing probe can enhance test reliability.
Reference will now be made in greater detail to a testing probe according to exemplary embodiments of the present invention with reference to the accompanying drawings.
As illustrated in
First, in the embodiment illustrated in
The conductive silicon section 50 is formed of silicon having elasticity and metal powder having conductivity in a cylindrical shape, and thus has elasticity and conductivity.
Accordingly, in the process of testing semiconductor chips, vertical force transmitted through the probe projection 12 is elastically supported by the conductive silicon section 50, and test current applied to the probe projection 12 is conducted to the lower plunger 40 through the conductive silicon section 50.
Next, the testing probe according to another exemplary embodiment of the present invention will be described.
The embodiment illustrated in
The coil spring 30 is mounted in the barrel 20 so as to elastically support the upper plunger 10. A difference (d2 minus d1) between an inner diameter d1 of the coil spring 30 and an outer diameter d2 of the conductive silicon section 50 may be limited to a range from 0.02 mm to 0.2 mm.
In general, the coil spring used for the testing probe is manufactured using a wire having a diameter between 0.02 mm and 0.20 mm. At this time, the coil spring has an inner diameter between 0.2 mm and 2.0 mm according to a target to be tested.
The conductive silicon section 50 is deformed in a radial outward direction during compression, and thus may come into contact with an inner diameter region of the coil spring 30. As such, the conductive silicon section 50 must be spaced apart from the coil spring 30 by a predetermined interval within the aforementioned dimensional range, so that the conductive silicon section 50 and the coil spring 30 can normally and elastically support the upper plunger 10.
Next, the testing probe according to another exemplary embodiment of the present invention will be described.
*The embodiment illustrated in
Thus, in the normal state, the conductive silicon section 50 is spaced apart from the upper plunger 10 by a predetermined distance L without contact with the bottom of the upper plunger 10.
In the process of testing the semiconductor chip, the upper plunger 10 is supported by the coil spring 30 in the initial stage. Then, after the upper plunger 30 is shifted by the predetermined distance L, the conductive silicon section 50 elastically supports the upper plunger 10 while coming into contact with the bottom of the upper plunger 10. Of course, the coil spring 30 elastically support the upper plunger 10 as well.
As illustrated in
Although a testing probe in which a conductive silicon section is accommodated in a barrel according to exemplary embodiments of the invention have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
The present invention is applicable to a testing probe, and more particularly to a testing probe capable of enhancing test reliability using a conductive silicon section through which a stable test current flows.
Number | Date | Country | Kind |
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10-2009-0060509 | Jul 2009 | KR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/KR09/04206 | 7/29/2009 | WO | 00 | 1/3/2012 |