Reasons and solutions for heating of LED flexible light strips

The rapid development of the LED lighting industry has virtually changed people's lifestyles, but there are still some technical issues that need to be further improved during the development process. We are an LED manufacturer, mainly producing LED flexible light strips, LED line lights, LED panel lights, LED floodlights and other lighting products usually use 3528 light strips and 5050 light strips. Today, LEDER Lighting will bring you to understand the heating problems and solutions of LED flexible light strips in the LED lighting industry.

   1. Circuit design issues:

At present, the most commonly used specifications of LED flexible light strips are 12V and 24V. The 12V is a 3-series multi-channel parallel structure, and the 24V is a 6-series multi-channel parallel structure. Since the LED flexible light strip is to be connected and used, each light How long the tape can be connected has a lot to do with the width of the line and the thickness of the copper foil during design. Because the current intensity per unit area is related to the cross-sectional area of the line, if this is not taken into account when wiring, then when the connection length exceeds the current that the line can withstand, the light strip will be damaged due to overcurrent. Heat generation, while damaging the circuit board, also reduces the service life of the led.
       
  2. Production process issues:

  Since the LED flexible light bar is a series-parallel structure, when a short circuit occurs in a certain group of circuits, it will cause the voltage of other LEDs in the same group to rise, the brightness of the LED will increase, and the corresponding heat will also increase. rise. The most obvious is that in the 5050 light strip, when there is a short circuit in any chip circuit of the 5050 light strip, the current of the short-circuited light bead will double, that is, 20mA will become 40mA, and the brightness of the light bead will increase. It will become very bright, but at the same time, the heat will increase sharply, and in severe cases, the circuit board will be burned within a few minutes. However, because this problem is relatively obscure, it is generally not paid attention to, because the short circuit does not affect the normal light emission of the light strip. Visual inspection, if you only do electrical testing, often ignore this problem, which is why many LED flexible light bar manufacturers always encounter customer complaints that the product is hot but can't find the reason.

 

Solution:

1. Circuit design: Make the wiring as wide as possible for the circuit, and the distance between the circuits is 0.5mm. It is better to fill up the rest of the space. The thickness of the copper foil should be thickened as far as possible without violating the customer's requirements for the total thickness of the circuit board. The general thickness is 1~1.5.

2. Production process:

A. When printing solder paste, try not to allow tin connection between pads to avoid soldering short circuit caused by poor printing;

B. Avoid short circuit when patching;

C. Check the patch position before reflow;

          D. After reflow, do a visual inspection first to ensure that there is no short circuit in the light strip, and then do an electrical test recheck. During the recheck, pay attention to whether the LED is abnormally bright or abnormally dark after it is lit.