HCOB and GOB-level LED displays differ significantly in terms of process, materials, optics, contrast, and precision. HCOB performs better in thermal stability, flatness, thickness control, contrast, and precision, while GOB, although simpler in process, suffers from uncontrollable thickness and low contrast. A detailed comparison is as follows:
Process Differences
HCOB: Employs a high-temperature molding process, using high-precision molds to mold the colloid at 90°C, curing it for 5-10 minutes. This process allows for precise control of thermal stability, precision, flatness, and thickness, and effectively addresses the issue of adhesive cracking caused by LED heat.
GOB: Employs a room-temperature dispensing process, using fixtures to automatically mix and flatten ordinary epoxy resin colloid at room temperature, similar to the potting process used in outdoor products. This process relies on intermolecular coagulation for curing, which can lead to shrinkage and a higher likelihood of requiring secondary processing.
Material Differences
HCOB: Uses a high-temperature molded polymer synthetic colloid with added coagulants and UV stabilizers, solving the yellowing problem of ordinary epoxy resin. Material performance is improved through melanin adjustment and a frosted mold design.
GOB: Uses a common epoxy resin solution, with relatively basic material performance, prone to yellowing, and unable to achieve a frosted finish through material design.
Optical Image Differences
HCOB: Through precision mold control of thickness, the colloid edge thickness exceeds the LED height by only 0.2mm, resulting in almost no secondary light refraction. This significantly reduces edge refraction issues (such as bright lines at the viewing angle) when splicing large sizes.
GOB: Differences in the flatness of the self-leveling colloid result in a thicker finished product. This leads to noticeable edge refraction issues when splicing large sizes, affecting image uniformity.
Contrast Differences
HCOB: The mold design results in a frosted surface after molding (similar to a matte black lamp), increasing screen contrast by 40% and enhancing image depth.
GOB: The finished surface is mirror-like, making it impossible to achieve a matte or frosted effect. Contrast is lower, and image detail is weaker.
Precision Differences:
HCOB: High-precision molding technology allows for overall molding precision control within 0.2mm, and it is already widely used in mainstream 1.2, 1.5, and 1.8mm pitch products.
GOB: Room temperature molding relies on molecular coagulation, achieving a best precision of only 0.5mm. It also suffers from shrinkage issues, requiring secondary processing for some products to meet precision requirements.
Summary: HCOB, through high-temperature molding, high-polymer synthetic colloids, and precision mold design, outperforms GOB in thermal stability, flatness, thickness control, contrast, and precision, making it particularly suitable for scenarios with high image quality requirements. GOB has a simpler process and lower cost, but suffers from uncontrollable thickness and low contrast, and is mostly used in applications with lower precision requirements.
