Case Study: Reducing Re-Spins for a Compact Consumer Gadget Through DFM-Driven Prototyping
When a fast-moving consumer brand approached PCB Power to address repeated re-spins on a pocket-sized gadget, the focus quickly narrowed to one critical factor: manufacturability. While the brief appeared straightforward, the reality involved tight clearances, a dense component layout, and plastics that allowed virtually no margin for assembly variation
By focusing on DFM -first approach from the start, we reduced production problems, achieved consistent build quality, and helped the product launch on time—without changing the original PCB design..
Project Snapshot
Product: Battery-powered companion device for daily carry
Constraints: Small enclosure, high I/O density, strict target
Primary issues: Inconsistent solder joints, intermittent field failures, and late changes forcing new boards
Goal: Fewer re-spins and a predictable ramp to pilot build
The Initial Problem
Early samples looked acceptable on the bench but struggled in real assembly and testing. Typical symptoms included:
Tombstoning on passive components
Voiding under the power stage
Intermittent BGA behaviour that appeared only after thermal cycling
Our DFM-Driven Approach
Instead of simply running another quick board, the team paused for a short, intensive DFM sprint around assembly behaviour and process windows.
DFM corrections and build rules
Critical geometries and solderability features were reviewed.The outcome was a clear set of build rules covering copper balance near hot components, the use of copper thieving where planes created uneven heating, and target fillet conditions for components that were most sensitive to stress. The intent was not to re-design the PCB, but to define the manufacturing limits within which it could be built consistently.
Stencil and paste optimisation
The stencil became a primary lever. Apertures were grouped by component class and adjusted to match real wetting behaviour. Over large pads, window-pane patterns were introduced to reduce voiding on high-current regions. For fine-pitch devices, controlled reductions helped prevent excess paste without compromising coverage.
Thermal Profile
Reflow profiles were matched to the actual mix of parts. Preheat, soak, peak temperature spread, and cooling rates were tuned to reduce tombstoning and avoid mechanical stress. Profiles were locked only after multiple runs showed stable joints and repeatable X-ray readings.
Validation based on coupons
Instead of going directly to another full re-spin, the team employed coupon panels that looked like the most critical soldering features. These coupons made it easy to quickly check out modifications to stencils, profiles, and the impacts of copper balancing. Adjustments could be made in 48 hours without having to build a complete board.
Test and inspection access
DFM also focused on how quickly each build could be verified. Compact access features and boundary-scan strategies were formalised so that every lot could be checked at speed, using a defined combination of AOI, X-ray sampling, and functional checks. The emphasis was on creating a repeatable inspection model that fit within the existing outline.
All changes were driven and validated on PCB Power’s own line, then packaged into a manufacturing-focused build.
Results You Can Measure
The DFM-first approach produced outcomes that were both tangible and repeatable:
Re-spins cut: Reduced from three rounds on earlier, similar projects to a single controlled update on this programme
Time to pilot: Brought forward by two weeks by proving risks on coupons instead of repeatedly rebuilding complete boards
Why Work With PCB Power
Manufacturability is not treated as an afterthought. It is treated as a dedicated discipline alongside product intent. PCB Power’s team understands how theoretical requirements translate into line behaviour, and we use that understanding to close loops quickly and keep schedules intact.
How We Like To Start
Share the product intent, constraints, and latest manufacturing data. PCB Power runs a focused DFM screen and proposes a small, prioritised list of changes aimed at maximum impact with minimum disruption. Those changes are proven on coupons and pilot builds before rollout.
