Two major reasons for the heating of LED light strips

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Two major reasons for the heating of LED light strips [Copy link]

1. Circuit design problem The most commonly used specifications of LED light strips are 12V and 24V. The 12V is a 3-string multi-way parallel structure, and the 24V is a 6-string multi-way parallel structure. Since LED light strips are to be connected for use, the specific length of each light strip that can be connected is closely related to the width of the line and the thickness of the copper foil during design. Because the current intensity that can be borne per unit area is related to the cross-sectional area of the line, if this is not taken into account during wiring, then when the connection length exceeds the current that the line can withstand, the light strip will heat up due to overcurrent, damaging the circuit board while also reducing the service life of the LED.

2. Production process problem Since LED light strips are in a series-parallel structure, when a short circuit occurs in a group of circuits, it will cause the voltage of other LEDs in the same group to increase, the brightness of the LED will increase, and the corresponding heat will also increase. The most obvious is in the 5050 light strip. When any chip circuit of the 5050 light strip has a short circuit, the current of the short-circuited lamp bead will double, that is, 20mA becomes 40mA. The brightness of the lamp bead will become very bright, but the heat will also increase dramatically at the same time. In serious cases, the circuit board will be burned within a few minutes. However, this problem is relatively obscure and generally not paid much attention to, because the short circuit does not affect the normal light emission of the light strip. If the employee responsible for testing only pays attention to whether the LED is emitting light, but does not check the abnormal brightness, or does not do an appearance inspection, but only does an electrical test, this problem will often be ignored. This is why many LED light strip manufacturers always encounter customer complaints that the product is heating up but they can't find the reason. Solution: 1. Circuit design: Make the wiring of the circuit as wide as possible. 0.5mm spacing between the lines is enough, and the rest of the space is best filled up. The thickness of the copper foil should be increased as much as possible without violating the customer's requirements for the total thickness of the circuit board. The general thickness is 1~1.5 OZ; 2. Production process: A. When printing solder paste, try not to allow tin connection between the pads to avoid welding short circuits caused by poor printing; B. Avoid short circuits when mounting chips; C. Check the chip position before reflow; D. After reflow, perform an appearance inspection to ensure that the light strip has no short circuit and then perform an electrical test review. During the review, pay attention to whether the LED is abnormally bright or dark after it is lit.

hk6108

The production of assembly line operation is amazing. The boards can only be inspected visually after they are made. It will take forever to inspect them all, and spot checks may leave some fish slipping through the net...

qwqwqw2088

If the drive power design is not done well, the so-called circuit design and production process in the solution cannot be solved.