Deep considerations on LED package technology

This paper focus our attention on the deep considerations for LED package technology. The research includes the following content: (i) the influence of binding force between the chip and substrate, the leakage rate of silver paste conductive adhesive, the failure rate of light emission based on different glue quantities from different companies are studied carefully; (ii) a variety of abnormalities appeared in the process of die bond are demonstrated, and some failure reasons of lighting extracting are analyzed, and the correct processing method for dealing of these abnormalities are suggested; (iii) the influence of the size, abrasiveness, the tear force, and the power of porcelain mouth on package product performance and the quality are discussed; (iv) the influence of phosphor particle size, the amount of anti-settling powder, the viscosity of the fluorescent glue, and the baking conditions on white LED color coordinates and color concentration are analyzed. For same batch of the same chip packaging technology with same device setting parameters, there are still existing a certain bias in lighting output power, color coordinates and color concentration etc. It is found that many key factors are coming from the less consideration for package materials. The uneven distribution of mixing or dispensing phosphors is also a key factor to influence the package quality of SMD and COB light source.