M02016

M/A-COM Technology Solutions Inc. (MACOM) and its affiliates reserve the right to make changes to the product(s) or information contained herein without notice.

Visit www.macom.com for additional data sheets and product information.

For further information and support please visit:

http://www.macom.com/support

16

CMOS Transimpedance Amplifier with AGC

for Fiber Optic Networks up to 1.25 Gbps

Rev V4

4.4.1

Assembly

The M02016 is designed to work with a wirebond inductance of 1 nH ±0.25 nH. Many existing TO-Can

configurations will not allow wirebond lengths that short, since the PIN diode submount and the TIA die are more

than 1 mm away in the vertical direction, due to the need to have the PIN diode in the correct focal plane. This can

be remedied by raising up the TIA die with a conductive metal shim. This will effectively reduce the bond wire

length. Refer to Figure 4-3 for details.

MACOM recommends ball bonding with a 1 mil (25.4 µm) gold wire. For performance reasons the PINA pad is

smaller than the others and also has less via material connected to it. It therefore requires more care in setting of

the bonding parameters. For the same reason PINA has no ESD protection.

In addition, please refer to the MACOM Product Bulletin on Recommended Assembly Procedures (document

number 0201x-PBD-002-A). Care must be taken when selecting chip capacitors, since they must have good low

ESR characteristics up to 1.0 GHz. It is also important that the termination materials of the capacitor be compatible

with the attach method used.

For example, Tin/Lead (Pb/Sn) solder finish capacitors are incompatible with silver-filled epoxies. Palladium/Silver

(Pd/Ag) terminations are compatible with silver filled epoxies. Solder can be used only if the substrate thick-film

inks are compatible with Pb/Sn solders.

4.4.2

Recommended Assembly Procedures

For ESD protection the following steps are recommended for TO-Can assembly:

a. Ensure good humidity control in the environment (to help minimize ESD).

b. Consider using additional ionization of the air (also helps minimize ESD).

c. It is best to ensure that the body of the TO-can header or the ground lead of the header is grounded

grounded. When this is done and the procedure below is followed, the photodiode will help reduce the

impact to PINA of any positive charge on the wire bonder when bonding to PINA, which is the very last

bond placed. (Because the PD is already bonded to PINK and PINK has an internal ESD diode between

d. The most reliable protection to prevent ESD damage on the die is to assure that the wirebonder (including

the spool, clamp, etc.) is properly grounded.

1. Wire bond the ground pad(s) of the die first.

2. Then wire bond the VCC pad to the TO-Can lead.

3. Then wire bond any other pads going to the TO-Can leads (such as DOUT, DOUT and possibly MON)

4. Next wire bond any capacitors inside the TO-Can.

5. Inside the TO-can, wire bond PINK.

6. The final step is to wire bond PINA.