Case Study: Reel-to-Reel Selective Gold Plating on Stamped Terminals

Case Snapshot

A European connector manufacturer needed a reel-to-reel stamped terminal with a selective gold finish for an automotive electronics program. The part ran at high volume, required stable contact resistance over the vehicle lifetime, and had to pass the customer's salt-spray and plating-thickness audits on every lot. ISTAMPING took the program from DFM to production with an in-house progressive die and a managed reel-to-reel selective plating line.

Parameter	Value
Part	Stamped terminal, selective gold plated
Material	C5191 phosphor bronze, 0.30 mm strip
Die	In-house progressive die, 16 stations
Press	Aida 60T, 300 SPM
Plating	Reel-to-reel selective gold, 2-8 µm
Quality	IATF 16949:2016, CMM + in-line vision

Why the Customer Came to ISTAMPING

The program had two prior supplier attempts. The first delivered parts on time but plating thickness wandered outside the print across the reel, and the customer's incoming audit flagged it. The second supplier held the gold thickness but could not hold flatness after selective plating, which broke the customer's SMT placement window. Both failures trace back to the same root: stamping and plating were treated as two handoffs instead of one process.

ISTAMPING runs stamping and reel-to-reel plating under one roof with one quality system. The strip never leaves the process chain between the press and the plating bath, so registration, tension and flatness are controlled by the line, not by handling. That single-chain architecture is what the customer was looking for.

The Engineering Approach

The DFM review started from the print, not from the die. The terminal's critical features were the contact beam spring rate, the selective plating window and the flatness spec after plating. Our tool room designed a 16-station progressive die with in-die coining on the contact beam to stabilize springback, and a piloting system that holds strip registration to ±0.005 mm. The die was built, tried out and qualified on our own Aida 60T press before the first production lot.

Plating ran on the reel-to-reel selective line with a gold thickness target of 2-8 µm on the contact zone only, which keeps precious-metal cost down while meeting the contact-resistance requirement. Thickness is verified with X-ray fluorescence on every reel, and salt-spray testing follows ASTM B117 on a sampling basis per lot. Because the strip stays flat through the line, the post-plating flatness check holds inside the customer's placement window.

Production Results

Metric	Result
Press speed	300 SPM, multi-up tooling
Positioning tolerance	±0.005 mm (piloted die)
Gold thickness	2-8 µm selective, XRF verified per reel
Salt spray	Pass ASTM B117 sample per lot
Quality system	IATF 16949:2016, SPC on critical dimensions
Lead time	Sample parts 3 weeks after DFM approval

First-article inspection covered all dimensions on the print, and the customer's PPAP submission was approved without a single open item on the plating audit. Production has since run in multi-million-piece batches with in-line vision catching any dimensional drift before it becomes a lot-level issue.

Why This Case Matters for Your Program

If your part combines high-volume stamping with a critical finish, the supplier selection is really a process-chain decision. Ask the same questions we had to answer for this customer: Is the die built and proven in-house? Does plating run in the same chain as stamping? Is thickness verified per reel, not per batch? Is the quality system automotive-grade? Those four answers decide whether your program ships on time with a stable finish or spends a year re-qualifying suppliers.

Send us the drawing and your annual volume. We will run the same DFM review for your part and give you a tooling price with the piece-cost curve at three volumes, so the decision is visible before you sign.