Automobile parts

With the rapid development of AI vehicles, autonomous driving is moving from concept to large-scale deployment. The cornerstone of achieving higher-level autonomous driving is "multi-sensor fusion" — the collaborative operation of multiple perception hardware components such as cameras, millimeter-wave radar, and LiDAR.

Although these sensors operate on different principles, their plastic housings and structural components share one extremely stringent common requirement: "They must never interfere with signals, and they must be absolutely precise." For the injection molding and mold industry, this is not only a contest of precision, but also a comprehensive test of material application, molding processes, and mold design.

Challenge 1: Micron-Level Dimensional Accuracy and "Alignment"

Multi-sensor fusion requires the data from each sensor to perfectly align in space, which places extremely high precision demands on the mounting bases.

Optical Coaxiality: If the lens barrel or bracket of an automotive camera undergoes even the slightest deformation or eccentricity, it will cause image distortion and effectively "blind" the AI algorithm.

Radar Pointing Accuracy: If the mounting surface of a millimeter-wave radar or LiDAR housing lacks sufficient flatness, it will cause a deviation in the radar wave emission angle — an error that can be magnified to several meters at a distance of tens of meters.

Challenge for Molds: This requires the mold itself to have extremely high machining precision and to maintain high repeatability during mass production injection molding. The mold must feature excellent cooling design (such as uniform water line layout and targeted water well cooling for deep cavities) to keep molding shrinkage and warpage strictly controlled at the micron level.

Challenge 2: Molding Control of Special Materials

To protect the sensors and allow signals to pass through smoothly, the plastic parts can no longer use ordinary ABS or PP; instead, special engineering plastics are required.

Low Dielectric Constant Materials: Millimeter-wave radar covers typically use materials such as PBT, PPO/PPE, or PPS, which must ensure microwave transmittance and must not absorb or reflect signals.

High Fill and Weather Resistance: Exterior sensors must withstand high-low temperature shocks and harsh environmental corrosion, so glass fiber is often added to the materials to enhance rigidity.

Challenge for Molds: High-fill materials have poor flowability, special shrinkage rates, and cause significant wear on mold steel. Mold design must optimize gate positions to prevent localized shrinkage unevenness caused by glass fiber orientation; at the same time, mold surfaces require special treatment to accommodate highly corrosive materials.

Challenge 3: Near-Absolute Zero Surface Defects

Sensor housings (especially LiDAR windows and camera front covers) must not only be molded but also be "transparent."

No Weld Lines: Any weld lines, gas marks, or sink marks will cause light refraction or radar wave attenuation, and the part will be directly judged as scrap.

Absolute Purity: No impurities or black spots are allowed, otherwise they will interfere with AI visual recognition.

Challenge for Molds: This places extremely high demands on the mold's venting design (which must be absolutely smooth with no trapped gas or burning), temperature control (mold temperature must be extremely uniform), and the surface polishing process for high-gloss/transparent molds.

Challenge 4: Sealing and Three-Proofing of Complex Structures

Sensors exposed to harsh exterior environments must achieve IP67 or even IP69K waterproof and dustproof ratings.

Overmolding and Inserts: For sealing purposes, metal terminals are typically insert-molded into the plastic, or a soft material is overmolded onto the hard plastic housing to serve as a sealing ring.

Sealing Precision: Even a trace of flash at the interface between the hard and soft materials will cause water leakage.

Challenge for Molds: This requires the mold to achieve the utmost precision in insert positioning and sealing surface fit, preventing the soft material from being flushed away or overflowing during high-pressure injection.