Polycarbonate (PC) and PC/ABS alloys are the default pick for consumer electronics enclosures requiring UL94 V-0, notched Izod impact of 500–800 J/m, and a heat deflection temperature of 130–140°C at 1.82 MPa, with ABS remaining the lower-cost choice for parts that stay below 80–90°C [S3].
The selection question is not "PC or ABS" in the abstract; it is which grade clears the drop, flame, heat, and chemical targets on the bill of materials, and which grade survives the manufacturing process window without warping or losing impact [S3].
Property envelope: PC, PC/ABS, and ABS side by side
Unreinforced polycarbonate sits at the top of the amorphous-thermoplastic impact range, with notched Izod values typically between 500 and 800 J/m, against 150–400 J/m for ABS [S3]. On heat, the gap is equally wide: PC holds a heat deflection temperature of 130–140°C at 1.82 MPa, while ABS falls to 80–95°C under the same load, and PC/ABS blends typically land above 110°C, between the two [S3]. PC is an amorphous, odorless, non-crystalline engineering thermoplastic with high tensile, flexural, and compressive strength, which is why thin-wall molded covers survive drop tests that crack equivalent ABS parts [S1]. For a primer on how these two amorphous resins are defined, see the polycarbonate overview and the broader industrial PC platform context.
PC/ABS alloys merge polycarbonate with acrylonitrile-butadiene-styrene to balance impact, flow, and flame rating, which is why they show up in premium consumer electronics, battery-powered devices, and laptop housings where internal heat builds [S2][S3]. The blend is a true thermoplastic alloy, not a filler system, and the ratio between PC and ABS drives whether you get a flow-friendly molding resin or a tougher, more heat-resistant structural grade [S2].
Where PC wins, where ABS still wins
Specify PC or PC/ABS when the enclosure must pass UL94 V-0 at production wall thickness, survive repeated drops from 1 m and above, and operate near heat sources such as power adapters, fast-charging bricks, and battery compartments [S3]. For cost-driven covers, indoor appliances, and parts that never exceed 80–90°C, FR-ABS (flame-retardant ABS) remains the more economical path because it flows into thin, complex geometries and meets V-0 at lower unit cost [S3].
FR-ABS is the right call for power-adapter rear shells, indoor sensor covers, and remote-control bodies that are never dropped on concrete; PC or PC/ABS is the right call for smartphone bumpers, laptop lids, EV charger housings, and any part that the safety file lists at higher risk of impact or thermal load [S3]. A common mistake is forcing PC into a part that only needs ABS-level impact, which inflates the BOM and tightens the molding window without adding real value.
Decision criteria for an electronics enclosure
Engineers should score at least four criteria before locking the resin: required notched Izod impact, peak continuous service temperature, UL94 rating at production wall thickness, and chemical exposure during assembly, field cleaning, or end-of-life recycling [S3]. For medical and food-adjacent electronics, add biocompatibility and repeated disinfectant exposure (isopropyl alcohol, quaternary ammonium compounds) to the matrix, which often pushes the choice toward filled or coated PC grades rather than neat resin [S3].
A second-order criterion that gets missed is dimensional stability after molding: PC's higher coefficient of thermal expansion and residual stress mean inserts, snap-fits, and threaded bosses need larger draft and tighter radius control than ABS, otherwise warpage shows up at 60–80°C in the field [S3]. For parts that need both metal-like stiffness and PC-class impact, a glass-filled PC or PC/ABS grade trades surface cosmetics for stiffness, and that trade must be priced in early.
Process and secondary operations
PC processes at higher melt temperatures (typically 280–320°C) and tolerates narrower moisture windows than ABS, so drying at 120°C for 4–6 hours is standard before injection molding, and the hopper must stay sealed during any line stoppage [S3]. PC/ABS alloys slide the melt window down by 20–30°C and cut the drying burden, which is one of the practical reasons PC/ABS has displaced neat PC in many high-volume consumer enclosures [S3].
Secondary operations such as chrome plating, pad printing, laser marking, and ultrasonic welding all behave differently on PC versus ABS: ABS is easier to plate and paint, PC holds up better to laser marking without micro-cracking, and PC/ABS gives a workable middle ground for products that need both decorative finishing and impact strength [S3]. UV stabilization is mandatory for any PC or PC/ABS part exposed to sunlight, including outdoor EVSE enclosures and dashboard-mounted electronics; uncoated PC yellows and loses impact within months of UV exposure, while UV-stabilized or coated grades keep transmission and ductility in spec for the service life.
Regulatory and sourcing reality in 2026
Buyers in 2026 still anchor on UL94 V-0 for flame, IEC 60068 for environmental stress, and RoHS/REACH for substance control, and most PC and PC/ABS grades on the market carry the documentation packs these frameworks expect [S3]. For battery-powered devices, additional UN 38.3 and IEC 62133 testing applies to the pack, and the enclosure resin must not propagate flame if a single cell vents, which is the reason V-0 at the actual production wall thickness (not the lab thickness) is non-negotiable.
Pricing through 2026 has stayed volatile: PC resin tracks bisphenol-A feedstocks, while ABS follows butadiene and acrylonitrile, so dual-sourcing PC and ABS grades, or using a PC/ABS alloy, is a reasonable hedge against single-feedstock spikes [S3]. For plant-floor controllers and HMI panels that sit in the same electronics family but in harsher environments, the industrial PC selection for water treatment spec map covers the IP-rated, wider-temperature side of the same resin decision. For projects where enclosure material choice drives downstream bearing and pivot life, the related tapered roller bearing selection for steel mills work shows how material data sheets feed into motion-component sizing.
Common failure modes to design out
Field failures on PC enclosures cluster around stress cracking at inserts exposed to cleaning solvents, brittle fracture at sharp internal corners after a cold drop, and creep around bosses under sustained clamping load; PC/ABS softens the first mode and the last, but still loses to neat PC on the second [S3]. ABS failures cluster around heat sag near heat sources, color shift under UV, and plate delamination when the plating chemistry is pushed, which is why FR-ABS gets retired from outdoor use despite its cost advantage.
The cheapest way to avoid all three failure modes is the same on both resins: draft angles above 1°, generous radii at every internal corner (0.5× wall thickness as a minimum), and a wall-thickness uniformity check on every revision of the molded part, not just the first [S3]. Trackable next signals for buyers are the next two quarters of bisphenol-A spot pricing, the UL94 V-0 dossier refreshes from the major PC and PC/ABS compounders, and any new IEC or UL update that retightens the wall-thickness rules for V-0 at sub-1.5 mm enclosures.
Spec-level background on the components involved: pressure transmitter.