Updated July 2026.
Wireless charger projects often lose time before the first prototype. A buyer selects a reference board, an industrial designer builds an enclosure around it, and only then does the team discover that the coil position, adapter, heat path or certification plan does not fit. A better roadmap starts with the product requirements and treats the transmitter, mechanics and compliance path as one system.
Stage 1: write a measurable product brief
Define the exact product type: magnetic pad, stand, folding multi-device charger, vehicle mount, embedded surface or transmitter subsystem. List the target phone models, expected charging profile, package contents, markets, annual volume and intended launch date.
For multi-device products, specify simultaneous load. “Phone 25W + watch + earbuds” is a different input and thermal problem from “up to 25W when the phone zone is used alone.” Clear wording here prevents a misleading specification later.
Stage 2: freeze the mechanical stack
Share a drawing that identifies the coil center, charging-surface thickness, materials, camera clearance, magnet geometry and available PCB volume. Decorative materials matter: fabric, leather, glass, paint, adhesives and air gaps all contribute to distance and heat transfer.
If the charger folds or rotates, define hinge-life and cable-routing requirements early. The electrical design should be tested in the representative mechanical assembly, not only on an open bench.
Stage 3: select the electrical architecture
The supplier should propose a controller, power stage, coil and ferrite arrangement that fits the device and input requirements. Review USB-C PD profiles, standby behaviour, firmware-update method, protection strategy and any host communication.
A certified subsystem may reduce risk for some projects. A custom board may be necessary for shape, connector, cost or interface reasons. Ask which elements may be changed without reopening validation and which are controlled parts.
Stage 4: build an engineering prototype
The first prototype is for learning, not photography. Test charging start, alignment, sustained power, temperature, foreign-object response, acoustic noise, standby power and abnormal conditions. Use the target phones, cases, cable and adapter.
Record conditions with every result. A power number without phone model, battery state, temperature and test duration is difficult to reproduce and not useful for a design decision.
Stage 5: design verification and pre-compliance
After the architecture is stable, run a documented verification matrix. Include dimensional inspection, device compatibility, thermal cycling where appropriate, cable and connector stress, drop or hinge testing, and pre-compliance EMC checks for the intended markets.
Resolve failures before cosmetic tooling is locked. Moving a coil, adding shielding or changing an adapter after tooling can affect both appearance and certification.
Stage 6: certification and market-access work
Agree who owns the WPC submission, authorized-lab coordination, samples, documentation and retest cost. A product can only be marketed as Qi Certified after its exact record is issued. Verify the final Qi ID in the WPC database.
Plan market-specific safety, EMC and environmental documentation separately. The required set depends on product configuration and destination, so it should be written into the purchase specification rather than assumed from a generic factory certificate.
Stage 7: pilot run and production control
A pilot run checks whether the approved design can be built repeatedly. Review assembly fixtures, coil and magnet location, soldering, adhesives, firmware version, end-of-line tests and traceability. Define golden samples and acceptance limits for power, temperature and charging position.
Critical components should not be substituted without engineering review. A lower-cost coil, ferrite sheet or MOSFET can change loss and temperature even when the product still powers on.
What to send CowinLink
For a useful first review, provide the target devices, mechanical drawing or available space, surface materials, input source, expected power, host interface if any, target markets, certification objective and forecast volume. CowinLink can then recommend a finished-product ODM path or a custom TX/RX development path.
Use the project inquiry form and attach enough information to identify the difficult constraint. That usually produces a better technical answer than a request for “best price on a 25W board.”
Primary references: WPC Qi overview and WPC certified product database.
