The positive and negative poles of 5050 SMD lamp beads
5050 chip lamp beads usually have four electrodes, two of which are positive electrodes and the other two are negative electrodes. So how to judge the positive and negative electrodes of SMD LEDs? The following is a common method to determine the positive and negative poles of 5050 SMD lamp beads: Determining the positive and negative poles of 5050 lamp beads
Observe the appearance: The positive and negative poles of the 5050 SMD lamp beads can usually be judged by their appearance characteristics. Under normal circumstances, the 5050 SMD lamp bead LED is square. One of the four right angles has a missing corner, which is the place of the small circle. The other corners have no missing corners. The end with the missing corner is the negative electrode.
5050 patch missing corner
For a digital multimeter, select the diode setting, and touch the red and black test leads to both ends of the LED. When the LED is glowing, the red test lead is in contact with the positive electrode, and the other end is the negative electrode. *If you can see it, take it out and take a look. have
Use a voltmeter to measure, select the maximum range of the voltmeter, use wires to connect the switch in series to the two poles of the power supply, quickly open and close the switch. If the pointer of the meter is found to deflect forward, it means that the positive connection of the voltmeter is the positive pole. On the contrary, it is the negative pole
The above is the judgment of the positive and negative poles of 5050 SMD lamp beads. How do you judge it? How to judge 5050 light-emitting diodes? Let’s work together and learn together
5050SMD ,5050chip LED
There are many welding methods for LED lamp beads on the chip, and the following is one of the commonly used methods for reference. First, use an electric soldering iron to heat some soldering tin on the positive and negative electrode pads of the lamp bead (the soldering tin must not be too much, otherwise, the positive and negative electrode pads will be connected once heated with a hot-air gun), then use a hot-air gun to heat the positive and negative electrode pads at the same time, after the tin melts, use tweezers to place the positive and negative electrodes of the lamp bead on the corresponding pad.
LED is the light emitting diode, which is a semiconductor solid light emitting device that converts electric energy into light energy. Its core is the PN junction. In addition to the forward conduction, reverse cut-off and breakdown characteristics of the general PN junction, it also has the light emitting characteristics under certain conditions. Its structure mainly includes the following parts: lead, bracket, encapsulation glue, bonding wire, LED chip, solid crystal glue and phosphor. The discoloration failure of LED lamp bead is closely related to its material, structure, packaging process and service conditions. The following will analyze the causes of its discoloration through specific cases.
LED lamp beads are also called light emitting diodes. It has a wide range of applications. Its luminous colors include red light, emerald green light, yellow green light, yellow light, purple light, blue light, white light and orange light. The above is monochromatic light. It can also be made into two or three colors.
The gold wire used to package LED lamp beads contains more than 99.99% gold. It is produced by drawing gold from this material. In addition to 99.99% gold, this gold also contains less than 1% other trace elements. One of the core components of LED lamp bead packaging is gold wire, which is the bridge connecting the luminous chip and the welding point, and plays a decisive role in the service life of LED lamp bead. So how to identify the purity of gold thread?