Probe card preparation

Y. Kwon(Yonsei Univ.)

for EQENG, Notice, & Yonsei

Contents• PIN layout & pad definition from

CERN• Probe pin layout plan• Schematics for probe card circuit• Transparent chuck under considera-

tion

PAD layoutTotal 103 pads to make contact

PAD sizeWe want dual pin contact for each pad.

Needle layout

Invisible

Chip

Specification

1. 103 x 2 = 206 pins.

3. 8 LEDs to check probe card position by eye.4. Contact status check at every 10 ms.

5. Contact status report by ethernet.

0. Dual pins for each pad Pin A for external connection (power/ground/IO), Pin B to check pin contact with the pad

2. 14 + 3 relays as switches when we decouple pin A and pin B

Algorithm to check contact

1. Disconnect power/input using relay.2. Send 1.8(V) logic pulse to each digital input pad via

pin A and read pin B.

If no pair read back, raise chuck via .If any pair reads back, 3. Start careful adjustment ’. 4. Send 1.8(V) sequential logic pulse to other digital input

pad via pin A and read pin B.

5. Raise ’ up until all input pad pairs read back.6. Send 1.8(V) sequential logic pulse to digital input pads

via pin A and read pin B. (We will skip step 6 if we worry damage by electrical shock).

7. Raise ’ up until all input pad pairs read back.8. FPGA pull down for power pin B, FPGA pull up for ground pin B. 9. Disconnect FPGA output for pin A.10. Connect power.11. Check FPGA pin status12. Raise ’ up until all pin B status is OK.13. Disconnect pin B for analog input.

Use LED to display current status properly.

FPGA flexibility enables variation of algorithm.

Pin A

Pin B

Input

Pin A Pin B

Output

Pin B’s

Power

Pin B’s

Ground

Transparent chuck?

Chucks in preparation

Optimum number of vacuum holes to be decided.

Summary• Probe pin layout investigated.• Probe card schematics ready.• Transparent chuck in preparation.