1. LED chip
For the quality of a lamp bead, the chip of the lamp bead is the key element, followed by the strength of the packaging manufacturer. At the current domestic packaging level, the slightly stronger manufacturers have almost the same level of packaging. The key element is the LED chip. Let me share with you the relevant knowledge of LED chips.
1. At present, high-power LED chips mainly have 24mil, 38mil, 45mil and other specifications. Generally speaking, the larger the chip size, the better the electrical effect, the higher the stability, and the higher the brightness (luminous flux) can be done. The higher the end of the application, the more expensive the corresponding price.
2. Generally 45mil square piece 1w can achieve 110 ~ 120LM, and can achieve 3w (160 ~ 180LM); 38mil square piece can achieve 90 ~ 100lm, mainly 80 ~ 90LM, many people choose 38mil for indoor lighting , But high-end customers still choose 45mil; 24mil, can achieve 70 ~ 80LM, but in fact to achieve 60LM is more suitable, the lumen is too high, easy to die, burn out.
3. The type of chip: square piece, round piece, bead hair_piece, loose crystal.
Square piece: Positive specification square piece refers to the one selected by the manufacturer: brightness, voltage, antistatic ability, color difference are in the same standard range!
Nine points from different locations on the wafer are taken for parameter testing:
1). Mainly test the voltage, wavelength, brightness, and the wafers that can meet the standard parameters of the normal shipment before proceeding to the next operation. If the nine-point test does not meet the relevant requirements, put it aside Also deal with.
2) After the wafer is cut into chips, the visual inspection (VI / VC) of 100, the operator should use a microscope with a magnification of 30 times for visual inspection.
3). Then use a fully automatic sorting machine to automatically select, test and classify the chips based on different voltage, wavelength and brightness prediction parameters.
4) Afterwards, check (VC) and label the LED chip. The chip area should be in the center of the blue film. There are more than 5000 chips on the blue film, but it must be ensured that the number of chips on each blue film is not less than 1000. The chip type, batch number, quantity and photoelectric measurement statistics are recorded on the label , Attached to the back of waxed paper. The chip on the blue film will have the same visual inspection test as the sub-visual inspection standard to ensure that the chip is neatly arranged and qualified. In this way, LED chips (collectively referred to as square pieces on the market) are now made.
Large wafer means that it has not been selected: the difference in brightness is large, the voltage fluctuation is large, the antistatic ability is inconsistent, and the running wavelength (large color difference)
The wafers that do not meet the relevant requirements are processed separately. These wafers cannot be directly used for LED square wafers, so they are not subject to any sorting and are sold directly to customers, that is, the current LED circle on the market. sheet.
Pearl hair_piece: Commonly known as hair_piece, he has all the bad things of the big round film, the big one is all colors, not just simply running the wavelength (large color difference)!
There are some chips on the blue film that do not meet the normal shipping requirements, so they naturally become edge pieces or wool_pieces
Scattered crystals: In the process of making LED chips, sort out some chips with defects or worn electrodes, these are the scattered crystals behind
Chip type selection order:
Regular square film> Large round film> Bead wool film> Loose crystal
Second, the selection of LED lamps
Because a lamp uses more LED lamp beads, the cost of the lamp beads greatly affects the price of the finished lamp. Some users choose lamps made of lamp beads of poor quality in order to be cheap, which affects the use. Life, after one and a half years of use, the light dimmed, the lamp beads burned out, and finally had to swallow the bitter fruit, which is not worth the gains!
At present, the low-priced lamp beads on the market generally choose 24mil square pieces, large round pieces, hair_pieces, and even loose crystals.
1. Large round chip lamp beads are widely used in the market. Large round chips are much cheaper than square chips. Such better chips can also achieve 90 ~ 100LM, but because such light beads are not carefully selected like square chips. Of course, there are more problems, such as dead lights, burnout, large light attenuation, and poor color difference consistency.
2.24mil, can achieve 70 ~ 80LM, but in fact it is more suitable to achieve 60LM, the lumen is too high, it is easy to die, burn out, and the light attenuation is large. The lumen of the lamp beads made by the square piece is not high enough to meet the actual requirements.
3. The hair piece and loose crystal are bad, so I won't say much about it. The faults that appeared in the past are all included.
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