Solar LED street lamp bead death cause analysis in the countryside

一个。 Basic information: 1. Bad sample: high-power white light products. 2. Feedback the bad sample quantity: 114 PCS. B。 Normal test VF and IR 88 PCS, can light up normally. Take its

basic information: 1. Bad sample: high power white light products. 2. Feedback bad sample number: 114. b。 Content: abnormal feedback abnormal samples for testing, a total of 114 samples of the bad situation is as follows: 1. Normal test VF and IR 88, can light up normally. Take 5 ml of normal product and 1 ml of normal product, remove the lens, in 350 ma aging under the normal temperature of 48 hours. No bad light phenomenon, all parameters are normal. 2. 26 PCSC open circuit trouble light. Cause analysis/investigation results: 1. Open circuit failure lamp reason analysis: random 6 PSC failure lamp samples disassembly analysis, found that existed in the 4 PSC gold wire C point break, leading to the failure lamp; Other 2 c disconnect at point d, which leads to the lights. Attachment: wire in wire processing arc each location are defined as follows: figure 1: the definition of figure 1 point a bonding wire: chip electrode and golden connection; B: golden and gold wire connection point is the ball neck. The scope of point C: arc welding wire; Point D: support the joint of the solder joint and gold thread; Point E: stents the solder joint and the joint of the anode; 2. From the death of the breakpoint lamp, disconnect the general reason: 2. 1. Used for breaking point C: 2. 1. 1. The gold itself tensile force is insufficient; Needless to say, the tensile test can detect whether to gold wire tensile values specified in the specifications. Gold wire itself insufficient tensile force is related to processing surface smoothness, such as the 'seal'; When there is no damage to the edge, it can withstand strong pulling force. If the edge is damaged, can use a force to pull it down. The reason is the same. 2. 1. 2, porcelain mouth pollution, wear lead to damaged gold wire break, artificial repair wire arc lead to gold wire scratch; The situation is similar to 2. 1. 1. Below is a schematic diagram of figure 2. Figure 2: damage gold wire diagram 2. 1. 3, external force is too large/glue internal stress tensile wire; For the fracture of gold wire by external force is too large, three of the following should be a detailed analysis. 2. This part is mainly due to the porcelain mouth caused by quality problems, service life is over. The service life of the ceramic nozzle can't fixed to determine the actual joint lead yield, but by combining joint effect to determine the lead. When insufficient output requirements, if the wire bonding effect is not qualified, In combination with microscopy at high magnification) And should be replaced immediately. In addition, the manual rework, folding and improper thread repair can also lead to gold wire scratch. The picture above shows the gold thread of scratches. 2. 2. D point disconnect: 2. 2. 1. Wire parameters optimization mismatch: power and pressure, etc. Wire parameter adjustment of main stress check: the adhesion strength of the point a, b from the golden ball to the smooth transition of gold wire d point from the gold thread to gradual transition of solder bar as shown in figure 4. Wire, however, improper optimization and match the parameters, such as too much power and pressure, will lead to peace and too thin electrode and the tensile strength is insufficient. As shown in the figure below: figure 3: the second electrode