TWI411785B - Coaxial probe for wafer probe card and spider using the coaxial probe - Google Patents

Abstract

This invention relates to a coaxial probe for a wafer probe card, which includes: a tungsten(W) or tungsten alloy probe body having a first end portion and a second end portion, wherein the first end portion is angled with respect to the probe body and has a tip; one or more insulating layers deposited on a region of the probe body, wherein the region do not cover the tip of the first end portion and the second end portion; and a metal conductive layer deposited on at least one portion of the insulating layer.

Description

Coaxial probe for wafer probe card and test head using the same

The present invention relates to a coaxial probe for a wafer probe card and a probe using the coaxial probe, and more particularly to a coaxial probe for a wafer probe card capable of effectively providing noise shielding and using the same Test head for coaxial probes.

Wafer testing technology has been continuously used along with semiconductor process technology, so that the bare crystal can be tested for quality before packaging, and the cost of defective packaging is avoided. In recent years, the semiconductor process technology has advanced by leaps and bounds. At present, the channel length of the transistor has evolved from 0.15 micrometers to 0.13 micrometers to the latest 90 nanometer process. The IC is getting smaller and smaller, the function is getting stronger, and the number of pins is increasing. The more you come. Therefore, the number of probes of the probe card and the probe density are continuously increased to cope with the current testing requirements. However, when testing, the coupling between the capacitor and the inductor is prone to noise, which causes instability of the test and even causes a short circuit. Therefore, there is a need for a wafer test probe that provides noise shielding.

In view of the above problems, an embodiment of the present invention provides a coaxial probe for a wafer probe card, comprising: a tungsten or tungsten alloy probe body having a first end and a second end, wherein the The first end portion is inclined relative to the probe body and has a tip end; one or more insulating layers are deposited on a region of the probe body, wherein the region does not cover the tip end of the first end portion and the a second end portion; and a metal conductive layer deposited on at least a portion of the insulating layer.

Another embodiment of the present invention can provide a test head using a coaxial probe mounted on a wafer test printed circuit board, the test head comprising: a spacer disposed on the printed circuit board; a portion disposed on the spacer; a coaxial probe; a thermosetting conductive polymer disposed on the ring portion and fixing the coaxial probe on the ring portion; and a ground portion respectively coupled to the thermosetting conductive polymer And the printed circuit board connection. The coaxial probe includes: a tungsten or tungsten alloy probe body having a first end and a second end, wherein the first end is inclined relative to the probe body and has a tip; a plurality of insulating layers deposited on a region of the probe body, wherein the region does not cover the tip end of the first end portion and the second end portion; and a metal conductive layer deposited on at least a portion of the insulating layer . The second end of the probe body of the coaxial probe is coupled and secured to the printed circuit board. The thermoset conductive polymer coats at least a portion of the metal conductive layer of the coaxial probe.

Other embodiments and advantages of the present invention will become more apparent from the detailed description of the accompanying drawings.

1A shows a schematic cross-sectional view of a coaxial probe 1 in accordance with an embodiment of the present invention. As shown in FIG. 1A, the coaxial probe 1 comprises: a tungsten or tungsten alloy probe body 3; one or more insulating layers 5 deposited on a region of the probe body 3; and a metal conductive layer 7 deposited on at least a portion of One or more layers of insulating layer 5. The probe body 3 has a first end 3a and a second end 3b, wherein the first end 3a is inclined with respect to the probe body 3 and has a tip 31. It may be noted that the region in which the one or more insulating layers 5 are deposited does not cover the tip end 31 and the second end portion 3b of the first end portion 3a of the probe body 3. The metal conductive layer 7 can be deposited to completely or partially cover the insulating layer 5 deposited on this region, that is, the metal conductive layer 7 can be deposited on at least a portion of the insulating layer 5. The one or more insulating layers 5 may, for example, comprise a ceramic material and serve to insulate between the probes. The metal conductive layer 7 can be used as a shielding layer to isolate noise interference. The insulating layer 5 having a thickness of nanometer or micron and the metal conductive layer 7 can be separately deposited by, for example, the following deposition methods: chemical vapor deposition (CVD), physical vapor deposition (PVD, Physical vapor deposition), evaporation, sputtering, or ion plating. The above deposition methods are well known to those skilled in the art of coating, and the principles and processing procedures thereof will not be described herein. For example, in an embodiment of the invention, the insulating layer 5 may have a thickness of about 1 nm to about 100 μm, and the conductive layer 7 may have a thickness of about 1 nm to about 100 μm.

FIG. 1B shows a partial enlarged view of the coaxial probe 1 of FIG. 1A. As shown in FIG. 1B, FIG. 1B shows a partially enlarged portion of the area A of FIG. 1A. It can be clearly seen from FIG. 1B that none or more of the insulating layer 5 and the metal conductive layer 7 do not cover the second end portion 3b of the tungsten or tungsten alloy probe body 3.

2 shows a perspective view of a test head 10 in accordance with an embodiment of the present invention. 3 shows a schematic partial cross-sectional view of the test head 10 of FIG. 2 mounted on a wafer test printed circuit board 21 of a wafer probe card in accordance with an embodiment of the present invention. As shown in FIG. 2 and FIG. 3, the test head 10 includes a spacer 11 disposed on the wafer test printed circuit board 21, and a ring portion 13 disposed on the spacer 11; the coaxial probe 1 of FIG. 1A; thermosetting The conductive polymer 15 is disposed on the ring portion 13 and fixes the coaxial probe 1 to the ring portion 13; and the ground portion 17 is connected to the thermosetting conductive polymer 15 and the printed circuit board 21, respectively. The second end portion 3b of the probe body 3 of the coaxial probe 1 is connected and fixed to the signal soldering point 23 of the printed circuit board 21 by solder 19 to transmit the signal measured by the coaxial probe 1 to the printing. The circuit board 21, and as shown in FIGS. 1B and 3, the solder 19 is not in contact with the one or more insulating layers 5 and the metal conductive layer 7, but is only in contact with the probe body 3. The ground portion 17 may be, for example, a cylindrical or sheet-like electrical conductor, and is connected and fixed to the first grounding point 24 of the printed circuit board 21 by the solder 20. The thermosetting conductive polymer 15 covers at least a portion of the metal conductive layer 7 of the coaxial probe 1. The metal conductive layer 7 of the coaxial probe 1 is connected to the second ground point 25 of the printed circuit board 21 so that the noise can be transmitted through the metal conductive layer 7 of the coaxial probe 1 and the second ground point 25 of the printed circuit board 21. . In addition, by the arrangement of the thermosetting conductive polymer 15, the grounding portion 17, and the first grounding point 24 of the printed circuit board 21, the noise can be further transmitted through the thermosetting conductive polymer 15, the ground portion 17, and the printed circuit board 21. The first grounding point 24 is derived to enhance the ability to derive noise, thereby effectively reducing the external noise interference or the interference between the probes when the probe transmits the signal, thereby increasing the stability of the wafer test. . Although, in FIG. 3, the metal conductive layer 7 and the ground portion 17 are respectively connected to the second grounding point 25 of the printed circuit board 21 and the first grounding point 24, in another embodiment of the present invention, the metal conductive layer 7 and the grounding portion 17 can be connected to the same grounding point. The thermosetting conductive polymer 15 may be, for example, a thermosetting conductive paste or a thermosetting conductive resin. Further, the spacer 11 is provided on the printed circuit board 21, and its fixing property can be enhanced by the reinforcing plate 27 of the printed circuit board 21.

While the invention has been described herein with reference to the preferred embodiments of the embodiments of the invention Modifications, variations, and equivalents are still within the scope of the appended claims.

1. . . Coaxial probe

3. . . Probe body

3a. . . First end

3b. . . Second end

5. . . Insulation

7. . . Metal conductive layer

10. . . Test head

11. . . Gasket

13. . . Ring

15. . . Thermosetting conductive polymer

17. . . Grounding

19. . . Solder

20. . . Solder

21‧‧‧Printed circuit board

23‧‧‧Signal solder joints

24‧‧‧First grounding point

25‧‧‧second grounding point

27‧‧‧ reinforcing plate

31‧‧‧ tip

In the accompanying drawings, the same elements are denoted by the same reference numerals.

1A shows a schematic cross-sectional view of a coaxial probe in accordance with an embodiment of the present invention;

Figure 1B shows a partial enlarged view of the coaxial probe of Figure 1A;

2 shows a perspective view of a test head in accordance with an embodiment of the present invention; and

3 is a schematic partial cross-sectional view showing the test head of FIG. 2 mounted on a wafer test card of a wafer probe card in accordance with an embodiment of the present invention.

1. . . Coaxial probe

10. . . Test head

11. . . Gasket

13. . . Ring

15. . . Thermosetting conductive polymer

17. . . Grounding

19. . . Solder

Claims (7)

A coaxial probe for a wafer probe card, comprising: a tungsten or tungsten alloy probe body having a first end and a second end, wherein the first end is inclined relative to the probe body And having a tip; one or more insulating layers deposited on a region of the probe body, wherein the region does not cover the tip end of the first end and the second end, and the one or more insulating layers comprise The ceramic has a thickness of 1 nm to 100 μm; and a metal conductive layer is deposited on at least a portion of the insulating layer and has a thickness of 1 nm to 100 μm. The coaxial probe of the wafer probe card according to claim 1, wherein the one or more insulating layers are deposited by chemical vapor deposition, physical vapor deposition, evaporation, sputtering, or ion plating. . The coaxial probe of the wafer probe card of claim 1, wherein the metal conductive layer is deposited by chemical vapor deposition, physical vapor deposition, evaporation, sputtering, or ion plating. A test head using a coaxial probe mounted on a wafer test printed circuit board, the test head comprising: a spacer disposed on the printed circuit board through a reinforcing plate; a ring portion disposed at the a coaxial probe comprising: a tungsten or tungsten alloy probe body having a first end and a second end, wherein the first end is inclined relative to the probe body and has a tip; one or more insulating layers deposited on a region of the probe body, wherein the region does not cover the tip end of the first end and the second end, and the one or more insulating layers comprise ceramic and Having a thickness of 1 nm to 100 μm; and a metal conductive layer deposited on at least a portion of the insulating layer and having a thickness of 1 nm to 100 μm; a thermosetting conductive polymer disposed on the ring portion and fixing the coaxial probe to the ring portion, wherein the thermosetting conductive polymer covers at least a portion of the metal conductive layer of the coaxial probe; and a ground portion Connected to the thermosetting conductive polymer and the printed circuit board, respectively, wherein the second end of the probe body of the coaxial probe is connected and fixed to the printed circuit board. The test head using the coaxial probe according to claim 4, wherein the thermosetting conductive polymer is a thermosetting conductive adhesive or a thermosetting conductive resin. A test head using a coaxial probe according to claim 4, wherein the one or more insulating layers are deposited by chemical vapor deposition, physical vapor deposition, evaporation, sputtering, or ion plating. The test head using the coaxial probe according to claim 4, wherein the metal conductive layer is deposited by chemical vapor deposition, physical vapor deposition, evaporation, sputtering, or ion plating.