Power electronics & energy storage
Copper from 0.5 to 20 oz, aluminium IMS cores, 400–800 V DC creepage planning and Class 3 documentation with a microsection per lot, all inside one Shenzhen plant. Engineering review and quotation inside 24 hours.
Where power boards fail
In inverters, converters and battery racks a board failure is a safety event, not a warranty claim. These are the three places a power design goes wrong before it ever reaches the field.
A 100 A-class bus is not a trace-width sum. Copper weight, the via array that carries the current between layers and the area available to dump heat into the enclosure are one decision. Under-specify the copper and the board still passes electrical test, then fails on temperature.
Above 400 V DC the build is set by creepage and clearance, the CTI grade of the laminate and the geometry of the isolation barrier, not by the schematic. Gaps drawn only on the surface layers, with the barrier broken on an inner plane, are a routine cause of a failed dielectric withstand test.
On a metal-core build the dielectric between the copper and the aluminium base carries the whole thermal and voltage load. Its grade, the copper weight on top of it and the coating scheme have to be chosen together, or the assembly delaminates across the thermal cycles the converter will actually see.
Requirement to process
Heavy copper, metal cores and high-voltage isolation are quoted as routine work here, not as engineering exceptions. The table below is the range we hold in-house; anything outside it is answered at engineering review.
| Requirement | How we build it |
|---|---|
| Copper weight | 0.5 – 20 oz in-house. Power stages are specified at 4 – 20 oz; heavy copper starts at 3 oz = 105 µm and reaches 20 oz = 700 µm. |
| Metal-core and IMS | Aluminium-backed insulated metal substrate for LED drivers, gate-drive stages and any assembly that has to move heat straight into a heatsink. |
| Laminate | High-Tg FR-4 at Tg ≥ 170 °C as the floor for lead-free reflow and continuous thermal load; high-CTI grades (Material Group I (CTI ≥ 600)) for the isolation barrier. |
| Board thickness | 0.4 – 3.2 mm, with the thicker end used where a barrier has to be held through the board rather than across the surface. |
| Maximum board size | 600 × 1200 mm, which covers most inverter, converter and rack-control formats without splitting the panel. |
| Creepage and clearance | Partitioned routing and gap design to the limits in your safety file, held consistently across inner layers. We do not publish fixed millimetre values: the numbers come from the standard your product is certified to. |
| Impedance | ±10% as standard and ±5% on premium builds, both verified by a TDR coupon at the board edge rather than by a calculation. |
| Fine features | 2.5 mil line and space at the HDI grade, 6 mil (0.15 mm) as the cost-optimal production grade, 0.2 mm minimum mechanical drill, 0.15 mm minimum annular ring. |
Environment protection
Every assembly is cleaned ultrasonically and with DI water before coating, and the coating is applied selectively to IPC-CC-830B so connectors, test points, terminal blocks and press-fit holes stay solderable and serviceable.
Inspection chain
The chain is the same for a 100-piece first production run and a 20,000-piece annual programme. Judgement criteria are named on every gate, so a buyer can audit the record against the standard rather than against our word.
Bare boards and components inspected on receipt: dimensions, test coupon, date code, quantity, solderability.
Koh Young paste inspection on volume, area, height and alignment; out-of-tolerance prints trigger a wipe and reprint.
Omron VT-RNS and SAKI BF-18D on 100% of boards, on every SMT line: missing parts, polarity, offset, tombstoning, joint quality.
Nordson DAGE XD7600NT on hidden joints, a minimum of 5 pieces per lot, judged to J-STD-001 for voiding and bridging.
Takaya APT-1500F with four heads, fixture-free, so a first article is electrically verified without waiting for a bed-of-nails.
Agilent i3070 with up to 3,072 test points: opens, shorts, passive values, diode orientation, IC continuity, per-board pass or fail on file.
A fixture built for the product simulates the real load: power-up, signal integrity, firmware programming, system-level behaviour.
Final visual inspection to IPC-A-610 Class 2 or Class 3 as ordered, with an inspector stamp, serial number where required, and photographs.
Outgoing check on packaging, labelling, quantity and documents, sampled to AQL ANSI/ASQ Z1.4 (general inspection level II, single sampling, normal severity, AQL 0.65 for major defects) before the carton is sealed.
Per-board serialisation, photograph archive and material certificates shipped with the lot; monthly quality review with 8D/CAPA.
Compliance on both sides
Two different lists get confused in this industry. The first row is what the plant holds. The second row is the standards our build class and documentation package are written against so that your certification body sees a consistent file, the listings themselves belong to your product.
Quality system certified to ISO 9001:2015 and audited annually by SGS. High-voltage builds are held to IPC-6012 Class 3 documentation: per-lot microsection, thermal stress, ionic cleanliness at or below 1.56 µg/cm² NaCl equivalent, and material lot traceability.
Recognised printed wiring board manufacturing, held with UL for the fabrication process, so your end product can carry a UL component recognition.
Compliant lead-free lines. Declarations of conformity come from the laminate and component suppliers, and a per-board material declaration report ships with the lot.
Per-lot microsection and thermal stress results, ionic cleanliness at or below 1.56 µg/cm² NaCl equivalent, and material lot traceability held against the board serial number.
Full scanned certificate package released on request.
Application case
The project type we see most in this industry: a push-pull or SEPIC-class topology board with a bulk-capacitor bank, a heatsink footprint and a metal-core sister board on the same order.
Quotation in 24 hours
Tell us the voltage class, the continuous current on the main paths and the safety standard the product is certified to. First production of 100–500 pieces and series of 2,000–20,000 a year run on the same lines.
Send your Gerber, BOM or a plain description. An engineer, not a sales script, reviews it and replies within one working day. NDA on request.
