{"id":2292,"date":"2026-07-04T10:30:57","date_gmt":"2026-07-04T02:30:57","guid":{"rendered":"https:\/\/metalstampingparts.ltd\/?page_id=2292"},"modified":"2026-07-04T10:30:57","modified_gmt":"2026-07-04T02:30:57","slug":"lead-frame-coplanarity-burr-rfq-guide","status":"publish","type":"page","link":"https:\/\/metalstampingparts.ltd\/lead-frame-coplanarity-burr-rfq-guide\/","title":{"rendered":"Lead Frame Coplanarity and Burr RFQ Guide"},"content":{"rendered":"

Short answer:<\/strong> Lead frame RFQs should define coplanarity, lead sweep, burr direction, plating, carrier strip support, cleanliness, and tray or reel handling before price is compared. The drawing should separate solderable areas, contact areas, cut edges, and cosmetic limits, then state the inspection fixture, sample quantity, and whether measurements are taken before or after plating and packing.<\/p>\n

A lead frame can be dimensionally close and still create assembly trouble if the leads are swept, the seating plane is unclear, or burrs point toward a solder or bonding surface. The RFQ should treat the lead frame as an assembly input, not only a flat stamped outline.<\/p>\n

Use this page with the lead frame stamping guide<\/a>, reel-to-reel stamping guide<\/a>, coplanarity guide<\/a>, and terminal plating thickness inspection guide<\/a>.<\/p>\n

Lead frame details to define before quoting<\/h2>\n\n\n\n\n\n\n\n\n
Detail<\/th>\nWhy it matters<\/th>\nRFQ evidence<\/th>\n<\/tr>\n<\/thead>\n
Coplanarity plane<\/td>\nDifferent datums can make the same part pass or fail.<\/td>\nSeating plane, fixture support, probe points, and measurement condition.<\/td>\n<\/tr>\n
Lead sweep<\/td>\nThin leads can move during forming, plating, packing, or handling.<\/td>\nLead width, pitch, tip location, allowed sweep, and sample stage.<\/td>\n<\/tr>\n
Burr direction<\/td>\nBurrs can affect soldering, bonding, insertion, or plating coverage.<\/td>\nFunctional edge map, maximum burr, and accepted cut-edge exposure.<\/td>\n<\/tr>\n
Handling format<\/td>\nCarrier strip, trays, reels, and loose packing change deformation risk.<\/td>\nCarrier design, pocket support, stack height, and no-touch surfaces.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Define the functional surfaces first<\/h2>\n

Lead frames often have several surfaces with different functions: solder tails, bond pads, contact fingers, alignment holes, carrier bridges, dam bars, and trim edges. If those zones are not identified, the supplier may optimize the wrong feature. A burr that is harmless on a carrier bridge may be unacceptable on a solder tail or bond area.<\/p>\n

The drawing should show which dimensions are checked in strip, after trim, after form, after plating, and after packing. If plating is applied after stamping, ask whether buildup changes coplanarity or lead spacing. If pre-plated strip is used, ask how exposed cut edges and forming strain are controlled.<\/p>\n

Separate prototype evidence from production evidence<\/h2>\n

Prototype lead frames may be laser cut, wire cut, or stamped with simpler tooling. That can prove geometry, but it may not prove final strip feed, burr direction, plating coverage, or tray handling. For production, the quote should explain how pilot samples will be measured and what changes when the tool runs at normal speed.<\/p>\n

If the lead frame goes into soldering, bonding, insert molding, or automated assembly, define the receiving evidence early. A good first article package may include dimensional data, photos of edge condition, plating thickness, coplanarity readings, cleanliness notes, and packed sample photos. For solderable areas, connect the plan to the solderability test guide<\/a>; for residue-sensitive surfaces, use the cleanliness control guide<\/a>.<\/p>\n

RFQ details to include<\/h2>\n