Industry
Electronics
Connector housings, PCB enclosures, and switch components in dielectric, flame-rated, and ESD-safe materials, molded to the tight pitch tolerances a mating part demands.
What is different about this sector
An electronics housing is rarely judged on looks. It has to hold a pin pitch that a connector on the other end of the assembly line was also molded to, survive a reflow oven or a wave solder bath without warping, and in a lot of designs it has to self-extinguish rather than burn. Those are material and tolerance questions before they are anything else.
Parts also tend to be small and thin-walled, which changes the tooling: more cavities to hit a unit cost, tighter cooling to hold cycle time, and gate placement chosen for fill balance across a wall that may be under a millimetre.
Standards that come up
| Standard | What it covers |
|---|---|
| UL94 | Flammability classification for plastics, from V-0 (self-extinguishes within 10 seconds, no flaming drips) down through V-1, V-2, and HB (a slower horizontal burn rate, the weakest rating that still qualifies for many enclosures). |
| IEC 60695-2-11 | The glow-wire test, GWFI and GWIT, applied to housings near a potential ignition source such as a connector or a switch contact. |
| ANSI/ESD S20.20 | The electrostatic discharge control program standard. Static-dissipative materials fall in the 105 to 1011 ohm-per-square surface resistivity range; below that a material is conductive, above it, insulative. |
| RoHS (2011/65/EU, amended 2015/863) | Restricts lead, mercury, cadmium, hexavalent chromium, and several brominated flame retardants and phthalates in the resin and any metal inserts. |
| REACH SVHC | The EU's substances-of-very-high-concern list, updated roughly twice a year. A resin compliant last year is not automatically compliant on this year's list. |
Materials commonly specified
| Material | Typical electronics use |
|---|---|
| PBT and PBT-GF | Connector housings and terminal blocks. Good dielectric strength and dimensional stability through soldering heat, the default for anything that mates with a pin. |
| PC and PC-ABS, flame-retardant grades | Enclosures and covers where UL94 V-0 is specified. Standard, non-FR grades of the same resins will not carry the rating, so the grade has to be named on the drawing, not just the polymer family. |
| ABS | Non-flame-rated enclosures, bezels, and cosmetic housings for equipment that sits away from ignition sources. |
| POM (acetal) | Switch and latch mechanisms, battery contacts, and other low-friction moving parts inside an enclosure. |
| TPE and TPU | Cable strain reliefs, grommets, and gaskets, often two-shot molded onto a rigid PC or PBT shell. |
LCP and PPS are common in surface-mount connectors that go through a reflow oven, because both hold dimension at 260 °C better than PBT does. Neither is on our own press fleet today; a program that needs them is quoted with a partner tool named at quotation, not molded in-house.
Process choices that matter for a connector or enclosure
- Insert molding places a stamped brass or phosphor bronze terminal in the tool and overmolds it in one shot, holding pin position to the housing without a secondary assembly step. The tradeoffs against inserting a terminal into a molded housing afterwards are covered on our overmolding versus insert molding guide.
- Thin-wall sections below 1 mm need a fast-fill, high-injection-pressure setup and a resin with the flow to match; specify the wall thickness early so the material and gate design are chosen together.
- Hot runner tooling removes the cold sprue and runner marks from a cosmetic enclosure surface and cuts material waste, worth it once volume clears the extra tool cost.
- Multi-cavity tools bring unit cost down on high-volume connector housings, at the cost of tighter cavity-to-cavity dimensional matching, which is where CMM sampling across cavities earns its keep.
Typical applications
- Connector housings and shells, board-to-board and board-to-wire
- PCB enclosures, chassis, and mounting brackets
- Switch, button, and relay housings
- Cable strain reliefs, grommets, and cord bushings
- Sensor housings for panel-mount and inline instrumentation
- Battery pack components and EV electronics enclosures, where the automotive and electronics material lists overlap
What we do not do in-house: PCB assembly and SMT placement, and EMI or RFI shielding, whether by conductive coating or metal can. Those stay with your electronics contract manufacturer or a specialist finisher; we mold and, where asked, ship parts on to them.
Also serving
Other industries
Automotive
Components for automotive programs, from prototype through production volumes.
Robotics
Structural and enclosure parts for robotics programs, where volumes sit between prototype and full production.
Industrial equipment
Wear parts, housings, and replacement components, often in engineering grades and modest volumes.
Questions
Frequently asked
What electronics buyers ask before nominating a molder. Each answer comes from the sections above.
Ask an engineerWhich materials are typical for electronics housings and connectors?
PBT and PBT-GF for connector bodies, chosen for dielectric strength and dimensional stability through soldering heat; flame-retardant PC and PC-ABS graded to UL94 V-0 for enclosures; POM for switch and latch mechanisms where low friction matters; and TPE or TPU for cable strain reliefs, grommets, and gaskets. LCP and PPS, common in surface-mount connectors, are not on our own press fleet and would be sourced through a partner tool.
Can Trumould mold flame-rated or ESD-safe parts?
Flame-retardant grades of PC and PBT rated to UL94 V-0 run on our own presses when the resin is specified and its certificate supplied. ESD-safe compounds, carbon-loaded or antistat grades in the 105 to 1011 ohm-per-square range under ANSI/ESD S20.20, are sourced per program rather than stocked as standard, so lead in early with the target resistivity.
Does Trumould insert-mold metal terminals into connector housings?
Yes, stamped brass or phosphor bronze terminals and pins are placed in the tool and overmolded in one shot. The tradeoffs against a two-piece assembled housing are covered on our overmolding versus insert molding guide, and tolerance on pin pitch and mating features holds to ±0.05 mm on critical features, CMM-verified.
Let’s get started on your part
Send your CAD files and target volumes. We come back with a price, a lead time, and any design notes that would reduce either.