Probe bonding method having improved control of bonding material
View Patent ↗In assembly of probe arrays for electrical test, a problem can arise where a bonding agent undesirably wicks between probes. According to embodiments of the invention, this wicking problem is alleviated by disposing an anti-wicking agent on a surface of the probe assembly such that wicking of the bonding agent along the probes toward the probe tips is hindered. The anti-wicking agent can be a solid powder, a liquid, or a gel. Once probe assembly fabrication is complete, the anti-wicking agent is removed. In preferred embodiments, a template plate is employed to hold the probe tips in proper position during fabrication. In this manner, undesirable bending of probes caused by introduction or removal of the anti-wicking agent can be reduced or eliminated.
1. A probe assembly comprising:
a bonding cavity;
a plurality of probes disposed in said bonding cavity;
a bonding agent disposed in and cured in said bonding cavity; and
an anti-wicking agent disposed on a surface of said bonding cavity prior to curing.
2. The probe assembly of claim 1 comprising said anti-wicking agent removed from said bonding cavity after said bonding agent has cured.
3. The probe assembly of claim 1 further comprising a guide plate assembly having a first guide plate separated from a second guide plate by a spacer, said guide plate assembly defining said bonding cavity.
4. The probe assembly of claim 3 wherein said guide plate assembly comprises holes in said first and second guide plates.
5. The probe assembly of claim 4 wherein said plurality of probes are disposed in said holes.
6. The probe assembly of claim 5 comprising gaps of about 5 μm to about 40 μm between said plurality of probes and said guide plates.
7. The probe assembly of claim 5 comprising a lateral probe spacing that is less than about 150 μm.
8. The probe assembly of claim 4 wherein said first guide plate comprises a corresponding first hole pattern, said second guide plate comprises a corresponding second hole pattern and said first hole pattern is aligned with second hole pattern.
9. The probe assembly of claim 4 wherein said probes comprise probe tip sections that face the same way relative to said guide plate assembly.
10. The probe assembly of claim 1 wherein said bonding agent comprises a material selected from the group consisting of epoxy, thermally set material, molten plastic, and injection molding material.
11. The probe assembly of claim 1 further comprising:
a probe tip template; and
a tip section of said probes, said tip section engaged with said probe tip template prior to disposing said anti-wicking agent.
12. The probe assembly of claim 11 wherein said probe tip template comprises a material selected from the group consisting of polyimide, ceramic, and metal.
13. The probe assembly of claim 1 wherein said anti-wicking agent comprises a powder.
14. The probe assembly of claim 13 wherein said bonding agent does not substantially wick into said solid powder.
15. The probe assembly of claim 13 wherein said anti-wicking agent comprises a fine powder having a particle size of about 3 μm.
16. The probe assembly of claim 1 wherein said anti-wicking agent comprises talc.
17. The probe assembly of claim 1 wherein said anti-wicking agent comprises starch flour.
18. The probe assembly of claim 1 wherein said anti-wicking agent is compacted.
19. The probe assembly of claim 1 wherein said anti-wicking agent comprises a gel.
20. The probe assembly of claim 19 wherein said gel comprises a silicone based gel.
21. The probe assembly of claim 19 wherein said gel and said bonding agent are substantially.
22. The probe assembly of claim 1 wherein said anti-wicking agent comprises a liquid.
23. The probe assembly of claim 22 wherein said liquid comprises a compatible masking fluid.
24. The probe assembly of claim 22 wherein said liquid and said bonding agent are substantially.