LED Module Light-Shielding Layout for Precise Emission Positioning

The patent applies preliminary action by pre-forming recesses in the PCB at the intended light-emitting element positions before the reflow mounting process. These recesses are created with precise positioning using photolithography and etching techniques. During reflow, the light-emitting elements settle into these pre-prepared recesses, which constrains their final positions and prevents deviation. This preliminary structural preparation ensures that even during the thermal reflow process, the elements maintain accurate positioning, thereby resolving the contradiction between mass production efficiency and positioning precision.

The patent applies local quality by creating localized recesses only at specific positions on the PCB where light-emitting elements need to be mounted, rather than modifying the entire PCB surface. Each recess is precisely formed at the intended element position using photolithography masks that define only the necessary areas. This localized modification maintains the overall simplicity of the PCB structure while providing precise positional control exactly where needed, thus resolving the contradiction between manufacturing simplicity and position control.

The patent applies universality by using the photolithography and etching processes to serve multiple functions: they are used to form the circuit traces on the PCB and simultaneously to create the positioning recesses for the light-emitting elements. The same photolithography mask that defines the circuit pattern also defines the recess locations and shapes. This multi-functional use of the existing photolithography-etching workflow eliminates the need for separate recess-forming processes, thereby improving position precision without significantly increasing overall manufacturing complexity.