Design method of LED SMD (surface mount device) holder moisture-proof structure

Abstract

The invention discloses a design method of an LED SMD (surface mount device) holder moisture-proof structure. The LED SMD holder moisture-proof structure comprises a metal holder, a reflector cup, bonding wires, LED chips, plastic and package adhesive. The reflector cup covers the metal holder; the LED chips are fixed to the metal holder; the package adhesive is used for sealing and protecting the LED chips. The metal holder comprises metal leads embedded in the reflector cup and metal pins exposed from the reflector cup and serving as positive and negative electrodes of the metal holder. The design method is characterized in that area minimization of the metal leads and maximization of bonding of the plastic and the package adhesive are guaranteed on the premise of reserving necessary setting areas for the LED chips and welding areas for the bonding wires. The design of the metal pins of the conventional LED holder is changed, area of the metal leads is reduced to expand the bonding area of the reflector cup and the package adhesive, and further bonding force of the reflector cup and the package adhesive is improved, moisture entering the reflector cup is reduced effectively, moisture proofing is achieved, and accordingly reliability and service life of LED are improved.

Description

technical field [0001] The invention relates to the field of LEDs, and more specifically relates to a design method for a moisture-proof structure of an LED SMD bracket. Background technique [0002] With the development of society, LEDs are becoming more and more common, and people's performance requirements for LEDs are also getting higher and higher. Surface-mounted LED devices for display screens, especially outdoor LED devices, have high requirements on environmental adaptability, and need to have high moisture-proof performance and high and low temperature resistance. However, at present, the LED display still maintains a high failure rate. One of the reasons is that the encapsulation colloid and the cup body are peeled off, so that the gold wire breaks or moisture enters the device to cause failure. Due to the weak bonding between metal and glue, and the area occupied by the metal pins at the bottom of the cup is relatively large, the glue and metal are often the fir...

AI Technical Summary

Problems solved by technology

However, at present, the LED display still maintains a high failure rate. One of the reasons is that the encapsulation colloid and the cup are peeled off, so that the gold wire breaks or moisture enters the device to cause failure.

Due to the weak bonding between metal and glue, and the area occupied by the metal pins at the bottom of the cup is relatively large, the glue and metal are often the first to peel off when absorbing moisture and thermal expansion and contraction, causing the gold wire to break and lead to failure

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