The short answer. Eight of sixteen plants claim FPC or rigid-flex: Kinwong (double-sided and multilayer FPC, high-density flexible, rigid-flex, with a Longchuan FPC plant at full production), Suntak (a Shenzhen FPC plant at 100,000 m²/month — the only published flex capacity in this directory), Champion Asia (FPC and rigid-flex plus SMT and finished-product assembly), Victory Giant (FPC for AI PCs, wearables, AR/VR and for EV control units), Xunjiexing, Haiying, Kaishengshi and Wanyexing.
Why the number is hard to use. Flex capacity in square metres is not comparable across plants, because a 1-layer FPC and a 6-layer rigid-flex use six times the material for the same area — and neither plant publishes its layer mix. One figure, eight claimants, no common unit.
| Plant | What is claimed | Flex capacity | Assembly in-house |
|---|---|---|---|
| Kinwong ¥15.31bn | Double-sided and multilayer FPC, high-density flexible, rigid-flex; Longchuan FPC #2 at full production, alongside rigid and metal-based lines | None | Not stated |
| Suntak ¥7.54bn | 深圳FPC厂 — a dedicated flexible plant among nine factories, with its own monthly figure | 100,000 m²/mo | Yes — 江门一厂 runs EMS |
| Champion Asia ¥2.54bn | FPC and rigid-flex as a product line, with PCBA/SMT and finished-product assembly at a separate Huizhou plant | None | Yes — SMT and box build |
| Victory Giant ¥10.73bn | FPC for AI PCs, wearables and AR/VR; FPC for EV drive, battery, control, ADAS and cockpit electronics | None | Not stated |
| Xunjiexing ¥689m | Flex among five technologies sold from prototype through volume, alongside HDI, high-frequency, heavy copper and metal-backed | None | Not stated |
| Haiying Suining | Rigid-flex alongside HDI, metal-core and double-sided; 293 insured staff, 186 patents | None | Not stated |
| Kaishengshi Suining | FPC and rigid-flex for car-lamp, audio and lamp-bar boards; up to 10 layers; 3 oz heavy copper also claimed | None | Not stated |
| Wanyexing 53 insured staff | Rigid-flex with blind and buried vias, alongside ceramic and copper-core; 5–15 day quote | None | Not stated |
Flexible circuit fabrication changes the process in four places. The base material is a polyimide film with an adhesive or an adhesiveless construction, so dimensional stability across lamination is different and the panel is clamped rather than rigidly located. Vias are usually laser-drilled in polyimide, which behaves nothing like FR4 in a drill. The circuit is protected by a coverlay or a photoimageable coverlayer instead of a solder mask, and the registration of that coverlay to the conductors is where most yield is lost. And stiffeners — FR4, polyimide or stainless — are bonded on the assembly areas, which is a second lamination step with its own tolerance.
Rigid-flex adds a third: the flexible core is laminated into rigid outer layers, and the transition zone has to survive both the press and the bend cycle. A plant that can make a 4-layer rigid board and a 2-layer FPC has not thereby demonstrated rigid-flex; the failure mode lives in the bond between them.
None of the eight plants publishes a flex layer count, a coverlay type, a minimum bend radius, a stiffener spec or an adhesiveless construction option. Those five facts decide whether a flex quote is buildable, and every one of them arrives by email after the NDA rather than from a capability page.
Flexible circuits are rarely shipped bare. They are soldered into a connector, populated with a few components, or bonded into a module — and the handling cost of a thin flex panel dominates the assembly step. That is why the two plants here that combine flex with in-house SMT — Champion Asia (SMT plus finished-product assembly at Xiaojinkou) and Suntak (an EMS plant at Jiangmen) — are structurally different suppliers from the six that make the circuit only.
For a buyer, this decides who owns the yield. If the flex is made in one plant and populated in another, the scrap from handling is contested; if both steps are in one building, one quality system owns the result. Ask which it is before comparing price, because the cheaper circuit is often the more expensive assembly.
One plant publishes a flex number, and it is a big one. Suntak’s Shenzhen FPC plant at 100,000 m²/month is roughly the area of its double-sided plant and 40% of its Zhuhai multilayer plant — so flex is not a sideline there. It is also the only flex capacity figure in sixteen profiles.
“FPC and rigid-flex” can mean two very different factories. A plant that runs single-sided and double-sided FPC for lamp bars (Kaishengshi’s stated speciality) and a plant that runs multilayer rigid-flex for wearables (Kinwong’s Longchuan FPC #2) both use the phrase. Ask for the layer count and the bend requirement.
Capacity in square metres hides the layer mix. 100,000 m²/month of 1-layer FPC and 100,000 m²/month of 6-layer rigid-flex are not the same business, and no plant here publishes the split. Ask for the area by layer count.
Nobody publishes a bend radius or a flex-life figure. If your design flexes in use rather than at assembly, the qualification is dynamic bend testing — and zero of sixteen mention it. That test is yours to specify and theirs to run.
High-layer-count PCB · HDI and any-layer · Quick-turn prototype · IC substrate and SLP · Metal-core, ceramic and heavy copper · all six on capability by process.