In lead frame design, one size does not always fit all. Advancements in microelectronics mean there is a growing demand for thinner, smaller and more complex packaging solutions.
Whilst stamping has traditionally been the go-to technology for lead frames – a thin metal frame to which semiconductors are attached during the package assembly process – its high set-up costs, long lead times and lack of flexibility mean it is often uneconomical for scalable volume or micro precision lead frame manufacture.
Photo etching has the flexibility to meet the fast-paced nature of the electronics industry, and the precision required to produce ultra-fine pitch, high pin count lead frames more cost effectively than conventional stamping technology.
Low set-up costs
Photo-etch tooling is digital, so there is no need to cut expensive and difficult to adapt steel moulds. This means that lead frames can be reproduced with zero tool wear, ensuring that the first and one-millionth lead frame is identical.
Prototype to volume – fast
Stamping requires substantial investment in mould fabrication which can take from six to ten months to complete. Lead times using photo-etch tooling is around 90% less than stamped lead frames.
Precision features and accuracy
Photo etching can produce components with a standard minimum feature size of 0.025mm and with accuracy to ±0.025mm – ideal for high lead/pin count, ultra-fine pitch lead frames. Failure rates are minute, and unlike stamping, every lead frame etched is absolutely flat, stress and burr-free.
As photo etching produces component features simultaneously, complex, high-density lead frame designs cost no more to produce than simple ones.
Materials and finishing
Lead frames are typically photo etched in copper or iron-nickel alloys, such as alloy 42, which demonstrate very low thermal expansion.
Precision Micro offers full and selective tin, silver and gold plating to improve wire bond attachment to the semiconductor die.