The IPC-4552A performance specification sets requirements for Electroless Nickel/Immersion Gold (ENIG) deposit thicknesses for applications including soldering, wire bonding and as a contact finish. The IPC-4552A is intended for use by chemical suppliers, printed board manufacturers, electronics manufacturing services (EMS) and original equipment manufacturers (OEM). The IPC-4552A standard may be used to specify acceptance criteria to meet performance requirements in addition to those found in the IPC-6010-FAM Printed Board Performance Specifications. The ENIG deposit specified by using this document will meet the highest coating durability rating as specified in the J-STD-003 printed board solderability specification.

The IPC-4552A specification is based on three critical factors:

• 1. The ENIG plating process is in control producing a normal distribution for nickel and gold deposit thickness.
• 2. That the tool used to measure the deposit and therefore control the process is accurate and reproducible for the thickness range specified.
• 3. That the ENIG plating process results in uniform deposit characteristics.

If any of these three critical factors are not met, then the deposit produced will not meet the performance criteria defined