Electronic Injection Moulding: Precision Components for Electronics
Electronic injection moulding: connectors, housings, switches, and PCB components. FR materials, EMI shielding, precision tolerances for electronic devices. UL94 V-0 rated, ±0.02mm tolerance.
Electronic Injection Moulding: Precision Components for Electronics
Electronic injection moulding produces connectors, housings, switches, insulators, and PCB components with precision tolerances of ±0.02mm. Flame-retardant materials rated to UL94 V-0 ensure safety compliance for electronic devices.
At FIRMFG, our electronic moulding service covers the full range of electronic components — from USB Type-C connectors with 0.4mm pin pitch to power supply housings with integrated EMI shielding. We use high-performance engineering materials including LCP, PBT, PPS, and FR-ABS that withstand SMT reflow soldering at 260°C.
This guide covers component types, material selection, EMI/RFI shielding methods, precision requirements, insert moulding, and UL certification. Or, skip ahead and request a quote for an immediate price and lead time.
Electronic Moulding Quick Specifications
Key specifications for precision electronic injection moulding.
| Specification | Value |
|---|---|
| Tolerance | ±0.02 mm |
| Wall Thickness | 0.5 – 2.0 mm |
| Flame Retardant Rating | UL94 V-0 |
| CTI (Comparative Tracking Index) | ≥ 175 V |
| Pin Pitch Accuracy | ±0.03 mm |
| Materials | FR-ABS / LCP / PBT / PC / PPS |
Electronic Components We Mould
From micro connectors to power supply housings, we produce the full range of electronic plastic components.
Connectors & Terminals
USB, HDMI, board-to-board, wire-to-board, and FFC connectors. Precision pin pockets with ±0.02mm tolerance for reliable mating and signal integrity.
Example: USB Type-C connectors with 0.4mm pin pitch
Housings & Bases
Enclosures, shields, and base plates for electronic modules. Flame-retardant materials, EMI shielding integration, and SMT-compatible flatness.
Example: Power supply housings in FR-ABS V-0
Switches & Buttons
Tactile switches, rocker buttons, and push-button actuators. Precise snap-fit mechanisms, tactile feedback, and durable cycle life testing.
Example: Tactile switches rated for 100,000 cycles
Insulators
Standoffs, bushings, and insulating barriers. High dielectric strength materials (CTI ≥ 175V) for electrical isolation in compact assemblies.
Example: PCB standoffs in PBT with CTI 250V
Cable Management
Clips, ties, strain reliefs, and cable guides. Flexible yet durable materials that withstand repeated assembly and thermal cycling.
Example: Strain relief boots for USB cables
Sensors
Sensor housings, mounts, and optical windows. Material selection for specific sensor types — IR-transparent, UV-blocking, or chemically inert.
Example: PIR sensor housings with IR-transparent window
Electronic Material Selection
Flame-retardant engineering plastics with UL94 ratings for electronic applications. Material selection based on temperature, precision, and electrical requirements.
| Material | UL Rating | Properties | Best For |
|---|---|---|---|
| Flame-Retardant ABS | UL94 V-0 | Good impact resistance, paintable, cost-effective, 110°C heat deflection | General electronic housings, enclosures |
| LCP (Liquid Crystal Polymer) | UL94 V-0 | High temp to 280°C, exceptional dimensional stability, thin-wall capable, low shrink | Precision connectors, SMT components |
| PBT (Polybutylene Terephthalate) | UL94 V-0 | Excellent electrical insulation, low moisture absorption, good chemical resistance | Connectors, switches, insulators |
| PC (Polycarbonate) | UL94 V-0/V-1 | Transparent, high impact strength, 135°C heat deflection, good dimensional stability | Transparent housings, optical covers |
| PPS (Polyphenylene Sulfide) | UL94 V-0 | High temp to 240°C, chemical resistant, inherently flame retardant, high CTI | High-temp connectors, automotive electronics |
| PA (Nylon 6/66) | UL94 V-2 | High strength, wear resistant, good fatigue resistance, can be glass-filled | Structural electronic components, cable ties |
All flame-retardant materials carry UL Yellow Cards. We provide material certification and compliance documentation for every production batch.
EMI/RFI Shielding Solutions
Integrated EMI shielding for electronic housings. Four methods with shielding effectiveness from 30 to 80 dB.
Conductive Coating
Nickel, copper, or silver-based conductive paint is sprayed onto the inner surface of the housing. Shielding effectiveness of 40–60 dB across 30 MHz to 1 GHz. Ideal for complex geometries.
Metal Insert Shielding
Pre-formed copper or steel shielding cages are inserted into the mold and overmolded with plastic. Provides 60–80 dB attenuation and mechanical protection for sensitive components.
Shielding Mesh Overmolding
Conductive metal mesh is overmolded into the housing wall, creating an integral Faraday cage. Combines structural integrity with EMI shielding in a single molded part.
Conductive Compounding
Thermoplastic resin is compounded with conductive fillers (carbon fiber, stainless steel fiber, or nickel-coated graphite) to achieve inherent shielding of 30–50 dB without secondary operations.
| Shielding Method | Effectiveness | Frequency Range | Cost Impact |
|---|---|---|---|
| Conductive Coating | 40 – 60 dB | 30 MHz – 1 GHz | Low (secondary operation) |
| Metal Insert Shielding | 60 – 80 dB | 30 MHz – 10 GHz | Medium (insert tooling) |
| Shielding Mesh Overmolding | 50 – 70 dB | 100 MHz – 5 GHz | Medium (mesh material) |
| Conductive Compounding | 30 – 50 dB | 30 MHz – 1 GHz | Low (material cost only) |
Precision Requirements for Electronic Moulding
Electronic components demand the tightest tolerances in injection moulding. Here is how we achieve them.
Micro Connector Tolerance
Connector pin pockets and mating features held to ±0.02mm tolerance. Critical for reliable signal transmission in high-density connectors with 0.4mm pin pitch.
Pin Pitch Precision
Pin pitch accuracy of ±0.03mm ensures proper alignment with PCB pads during SMT assembly. Cumulative pitch error across multi-pin connectors is controlled through cavity-by-cavity measurement.
Flatness Control
Housing flatness of 0.05mm or better ensures proper seating on PCBs and consistent gasket compression for EMI shielding. Achieved through optimized gate placement and cooling.
Coplanarity
SMT-compatible coplanarity of 0.10mm or less prevents solder defects during reflow assembly. Mold design, material selection, and post-mold annealing control warpage.
SMT Compatibility
Parts withstand reflow soldering at 260°C (Pb-free) without deformation. LCP and PPS materials maintain dimensional stability through multiple reflow cycles.
Dimensional Stability
Long-term dimensional stability under thermal cycling and humidity. Low moisture absorption materials (LCP, PPS, PBT) prevent post-mold dimensional drift in service.
Insert Moulding for Electronic Components
Metal contacts, terminals, and shielding inserts molded directly into plastic electronic components.
Insert moulding is critical for electronic components that require metal-to-plastic integration. Metal contacts and terminals are placed in the mold cavity before injection, then encapsulated in plastic to create a single, integrated component. This eliminates assembly steps, improves reliability, and enables automated production of connectors, sensors, and shielded housings.
Metal Contacts
Brass and phosphor bronze contacts overmolded for connectors and terminals
EMI Shields
Copper and steel shielding cages overmolded into housing walls
Threaded Inserts
Brass threaded inserts for PCB mounting and assembly fasteners
Learn More About Insert Injection Moulding
Detailed guide on insert moulding technology, metal insert types, and applications.
UL94 Flame Retardant Ratings
Understanding UL94 ratings for electronic component safety. All materials carry UL Yellow Card certification.
| UL94 Rating | Test Criteria | Applications |
|---|---|---|
| V-0 | Afterflame ≤ 10s, no flaming drips | Connectors, housings, PCB components — highest safety level |
| V-1 | Afterflame ≤ 30s, no flaming drips | General electronic housings, internal components |
| V-2 | Afterflame ≤ 30s, flaming drips allowed | Cable ties, clips, non-critical housings |
| HB | Slow burning on horizontal specimen | Non-critical internal parts, low-risk applications |
| 5VA | No afterflame, no hole in plaque | High-safety enclosures, fire-resistant housings |
| 5VB | No afterflame, hole in plaque allowed | Fire-resistant housings, appliance enclosures |
The UL Yellow Card is an official document from Underwriters Laboratories that certifies a material's flame rating, minimum wall thickness, and color. We provide UL Yellow Card references for all flame-retardant materials used in your project.
Electronic Moulding FAQ
Answers to the most common questions about electronic injection moulding at FIRMFG.
QWhat flame retardant rating do your electronic components meet?
We mould components to UL94 V-0 as standard for electronic applications, using flame-retardant materials such as FR-ABS, LCP, PBT, PPS, and PC. V-0 is the highest vertical burn rating, meaning afterflame time is ≤10 seconds with no flaming drips. For applications requiring even higher fire resistance, we offer UL94 5VA-rated materials. We also provide V-1, V-2, and HB rated materials for non-critical components where cost optimization is important.
QWhat is the minimum pin pitch you can mould?
We achieve pin pitch accuracy down to 0.4mm with ±0.03mm tolerance using LCP (liquid crystal polymer) material, which offers exceptional dimensional stability and thin-wall capability. For 0.5mm pitch connectors, we use PBT or LCP with multi-cavity molds. The minimum pitch depends on material flow characteristics, pin pocket geometry, and mold precision. We use EDM (electrical discharge machining) for pin pocket fabrication to achieve the required precision.
QWhat is the maximum heat resistance of your electronic moulding materials?
LCP (liquid crystal polymer) withstands continuous operating temperatures up to 280°C and short-term excursions to 320°C, making it ideal for SMT-compatible connectors that must survive Pb-free reflow soldering at 260°C. PPS (polyphenylene sulfide) operates up to 240°C with inherent flame retardancy. FR-ABS is rated to 110°C for general housings. PC (polycarbonate) handles 135°C. Material selection depends on your operating temperature, reflow requirements, and mechanical loads.
QHow do you provide EMI shielding for electronic housings?
We offer four EMI shielding methods: (1) conductive coating — nickel/copper/silver paint sprayed on the housing interior (40–60 dB); (2) metal insert shielding — pre-formed copper or steel cages overmolded into the housing (60–80 dB); (3) shielding mesh overmolding — conductive mesh integrated into the housing wall; (4) conductive compounding — plastic resin mixed with conductive fillers (30–50 dB). The best method depends on your shielding effectiveness requirement, frequency range, and budget.
QDo you provide UL certification for electronic moulding materials?
Yes. All flame-retardant materials we use carry UL Yellow Cards certifying their UL94 ratings. We provide UL Yellow Card references, material certificates, and compliance documentation for each production batch. The UL Yellow Card is a published document from Underwriters Laboratories that lists the material, color, minimum wall thickness, and flame rating. We can also assist with UL component recognition for your finished parts if your application requires it.
QWhat tolerance can you achieve for electronic injection moulding?
We achieve ±0.02mm tolerance for precision features such as connector pin pockets, mating interfaces, and critical dimensions. For general electronic housings, ±0.05mm is standard. Tolerance depends on part geometry, material shrinkage characteristics, mold temperature control, and production volume. We use CMM (coordinate measuring machine) inspection on every batch, with SPC (statistical process control) monitoring for high-volume production. For critical dimensions, we can adjust the mold after first article inspection to achieve tighter tolerances.
Applications of Electronic Moulding
Precision moulded components for consumer electronics, industrial controls, and telecommunications.
USB/Type-C Connectors
Precision connectors with 0.4mm pitch
Power Supply Housings
FR housings for power electronics
Sensor Housings
Sensor mounts and optical windows
Relays
Coil bobbins and relay housings
Switches
Tactile, rocker, and push switches
PCB Connectors
Board-to-board and wire-to-board
Related Injection Moulding Services
Explore our other injection moulding capabilities.
Injection Moulding Service
Complete injection moulding services from prototyping to full production. Aluminum and steel tooling options for all volumes.
Learn MoreInsert Injection Moulding
Metal insert moulding for threaded contacts, terminals, and EMI shields embedded in plastic electronic components.
Learn MorePrecision Injection Moulding
Ultra-precision moulding with ±0.02mm tolerance for micro connectors, optical components, and critical-dimension parts.
Learn MoreStart Your Electronic Moulding Project
Upload your CAD files and get a free electronic injection moulding quote within 24 hours. UL94 V-0 materials, EMI shielding, ±0.02mm precision. SMT-compatible components for electronic devices.