SMD LED PCB board design

SMD LED is a new type of surface mount semiconductor light-emitting device, which has the advantages of small volume, large scattering angle, good uniformity of illumination, high reliability, etc. The color of the light includes various colors including white light, so it is widely used in Various electronic products. PCB boards are one of the main materials for making SMD LEDs. The development of each new SMD LED product begins with the design of PCB board drawings. The design of the PCB front and back graphics and SMD LED assembly drawings and finished drawings should be given, and the designed PCB board drawings should be given. For the professional production of LED PCB board manufacturers, the design of its quality directly affects the quality of the product and the implementation of the manufacturing process. Therefore, designing a flawless SMD LED PCB is not an easy task and must take into account many factors that affect the design. To this end, this article will discuss the design of the SMD LED PCB board from the following aspects.

First, the chip type LED PCB board structure selection

The types of SMD LED PCBs are based on the structure: a via-type structure, a trench-type structure, etc.; according to the number of wafers used for a single chip-type LED: single crystal type, double crystal type, and three crystal type. The difference between the via-type structure PCB board and the trench-type structure PCB board is that the former needs to cut two directions when cutting, and the single finished electrode is semi-arc type; the latter only needs to cut one direction when cutting. The choice of the design of the PCB and the chip-mounted LED using several wafers is based on the requirements of market users. When the user does not make special requirements, the PCB board is generally designed to be slotted. The PCB substrate is a BT board.

Second, the choice of the direction of the slotted hole

If you choose to design the PCB board with a slotted hole structure, you must consider which direction to select the slotted hole. In general, the grooving hole is designed along the width of the PCB, because this can minimize the deformation of the PCB after compression molding.

Third, PCB board size selection

The choice of the dimensions of each new SMD LED PCB must be considered: 1 requires the number of products to be designed on each PCB. 2 Whether the degree of deformation of the PCB after compression molding is within an acceptable range.

When the process is not affected, the number of products on each PCB board is designed as much as possible, which is beneficial to reduce the cost of a single product. Moreover, since the colloid shrinks after compression molding, the PCB board is prone to deformation. Therefore, the PCB board must be designed in consideration of the number of each type of chip LED, but the number of groups can be designed. This can meet the requirements of the number of SMD LEDs on a single PCB board, and does not make the PCB shape of the colloid shrinkage after the compression molding is too large. A large PCB shape will cause the PCB to be cut and cut, and the colloid and the PCB are easily peeled off.

PCB board thickness selection is based on the overall thickness requirements of the SMD LEDs used by the user. The thickness of the PCB board should not be too thick. If it is too thick, it will not be able to bond the wires after solid crystal. The thickness of the PCB board should not be too thin. Too thin will cause the PCB to become too large due to shrinkage of the colloid after molding.