Issue link: https://iconnect007.uberflip.com/i/1547450
62 SMT007 MAGAZINE I NOVEMBER 2026 No, not in a properly run process. The tip tempera- ture is set by the housing resin, not by anything on the board. ABS forms at roughly 200–230°C, polycar- bonate at 260–300°C, PA66 at around 280–320°C, with glass-filled grades running about 20°C hotter. 10 The tool touches the stud, the contact is brief, and the board sees warm plastic rather than hot steel. The thermal risk to the laminate and to nearby solder joints becomes real only when the process goes wrong: a tip parked against the board, a missing stud that lets the tool bottom out on laminate, an operator improvising. The keep-out ring is also your thermal insurance, and displacement verification catches the missing-stud case before the tool does. Board thickness is the designer's other lever. The common 1.6 mm build spreads load well and is the default assumption in most staking geometry. Thinner boards, 1.0 mm and below, flex more under the same force, so the support and placement rules tighten accordingly. Flag board thickness to the mechanical team early; boss and standoff geometry are designed around it, and a late change from 1.6 mm to 1.2 mm quietly invalidates someone's stackup. One more material note that saves grief: If the housing is glass-filled (30% glass-filled nylon is everywhere in automotive), the stud will not form a clean dome. The fibers do not melt. The usual answers are a hollow stud with a flared profile, or a different retention method entirely. That decision changes the hole size and the keep-out, which is exactly why it needs to happen before layout freeze. Co-design the Joint, or Redesign the Board Everything in both parts rolls up into one habit: Put the PCB and the enclosure in the same room before either is finalized. The stackup makes the case on its own (Figure 5). The boss standoff height has to clear the tallest bottom-side component. Standoffs commonly run from 3 to 25 mm and are sized from the board's bottom-side profile. The stud has to stand proud of the board by 1.5 to 2 times its diameter to supply the head's volume. Hole positions on the board have to match boss positions in the tool within the clearance you specified. Each number crosses the ECAD/MCAD boundary, and each is trivial in co-design and miserable in ECO. Sometimes the right answer is not to stake at all. Heat staking is permanent; removing a board means drilling off the heads, and it goes back together once, at best, with a screw. If the board needs field service, use screws and inserts. If the housing is a thermoset, staking is off the table; you cannot re-melt a material that cured. If the layout genuinely cannot afford the Figure 5: The stackup that crosses the ECAD/MCAD boundary. Standoff height clears the tallest bottom-side component; the stud stands proud of the board by 1.5–2 × D to supply the head's volume. Left stake shown formed, right stake shown before forming.