Processing technology for E color difference management and control of COB Mini/Micro LED printed circuit board

Abstract

The invention discloses a processing technology for COB Mini / Micro LED printed circuit board delta E color difference management and control, and belongs to the technical field of printed circuit boards.The processing technology comprises the steps of: board thickness consistency, namely controlling the thickness tolerance of a finished board through the adjustment of raw materials and press fit parameters; bonding pad consistency, namely, controlling the copper surface range of a substrate through coating uniformity and browning copper reduction; ink color consistency, namely only reserving die bonding pads on a COB circuit surface, embedding all conductive wires, using blind holes to realize penetrating connection; and coating consistency, namely determining coating thickness consistencyby using push-pull force of lamp bead bonding. The appearance color difference of the printed circuit board is controlled from four aspects, namely, board thickness consistency, bonding pad consistency, ink color consistency and coating consistency; the consistency of the same plane light source is realized, the visual color difference is not perceived, the quality yield is greatly improved, andmeanwhile, the color difference of the surface of the PCB can be less than or equal to 0.5 / NBS, i.e., the color difference of the board surface of the circuit board is controlled.

Description

technical field [0001] The invention relates to the technical field of printed circuit boards, in particular to a processing technology for controlling ΔE color difference of COB Mini / Micro LED printed circuit boards. Background technique [0002] Mini LED packaging mainly includes two solutions: COB (Chip on Board) technology and IMD (Integrated Mounted Devices) integrated packaging technology. COB technology is to directly package the LED chip on the module substrate, and then carry out overall molding for each large unit. The IMD technology (N in 1) integrates two, four or six sets of RGB lamp beads into a small unit. [0003] The difficulties of Mini / Micro COB packaging technology are mainly reflected in two aspects: optical consistency and printed circuit board chromatic aberration consistency. In addition to the problem of chromatic aberration consistency of printed circuit boards, board thickness consistency is also one of the technical problems leading to the gap b...

AI Technical Summary

Problems solved by technology

In addition to the problem of chromatic aberration consistency of printed circuit boards, board thickness consistency is also one of the technical problems leading to the gap between modules. If the gap between modules or units is too large, the display effect and overall aesthetics will be affected.

At the same time, due to local differences in plate thickness, the thickness of the sealant will be inconsistent, resulting in differences in the brightness of the light source

In addition, due to the local differences in the surface treatment process and the deviation of the pad size, even if the consistency of the chip is guaranteed, it will also lead to large differences in light output and reflections.

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