What do these 5 packaging companies do to CSP LED?

Talk about a long time in the CSP, the industry continues to grow up in the dispute, and today, the king does not want to repeat what the future of CSP will be replaced in the future, what is the trend of what. Because recently in thinking about CSP, found a very interesting thing, that is, CSP changed, become chinese.

As everyone knows, CSP came out, then replace the original LED package remarks shocked four, which also became a major industry forum topic of debate, although still did not discuss what results, but there are still people some impressive speech.

Now it seems that a lot of people guess the beginning, but did not guess the outcome. Know that CSP will have a part of the market, but also know that it will start from the backlight, but we certainly did not expect the original CSP to the hands of Chinese enterprises, so many changes have happened.

Encapsulation from CSP process

After such a long development, I think we are no longer in a strange state of CSP. At present, there are many ways to realize the white light technology of CSP, and the best way to realize the Wafer is that it is not a kind of technology. This is because of this process to achieve the CSP, fluorescent glue can only cover the surface of the LED chip, blue light will leak through the four weeks from the sapphire, affecting the uniformity of color space distribution.

Because of this, there are companies to consider the removal of sapphire, the use of thin-film chip process, so that although the reduction of blue light leakage, but the cost is too high, still can not become mainstream. This also leads to the mainstream technology market is still the use of cutting chip technology.

It is because the cutting technology mainstream, the traditional packaging enterprises have the opportunity, because there are similar to the fluorescent powder coating, testing, taping and other processes.

Since it comes to the package, then the current market CSP has the following three main packaging structure:

A. is made of silica gel fluorescent powder, the five side of the light, high light efficiency, but the top and the surrounding color temperature consistency control is poor.

B. uses the surrounding titanium dioxide protection to cover the fluorescent film, only the top of a light-emitting surface, light consistency and directivity is very good, but the loss of the surrounding light output, light effect will be low.

C. uses the full coverage of the fluorescent film, plus a transparent silica gel fixed molding, but also five out of the light, high light efficiency, light quality is slightly worse.

In addition to the packaging process itself, CSP and these packaging issues

First of all, over reliance on flip chip technology, such as chip cost, light efficiency, reliability, and chip resistance to ESD breakdown;

Secondly, the phosphor coating technology and its high precision, which directly affect the color temperature Bin rate and color space distribution;

Third, CSP packaging devices because of small size, the higher the accuracy of the SMT patch requirements;

Fourth, the reflow process will affect the hole rate of the solder joint, which will affect the heat dissipation and reliability of the product;

Fifth, the difference of thermal expansion coefficient between LED chip and substrate is easy to produce stress, which will directly affect the reliability of the chip;

Therefore, it is the key factor to ensure the reliability of the CSP package to ensure the reliability of the device when it is used in the application.

Under difficult circumstances, packaging enterprises do?

Although there are many problems with CSP, but as the leading enterprises in LED packaging, are accelerating the development of the product, they spent a lot of thought on the CSP, the following is an online Jun asked some companies.

Ruifeng

In the past, only one side of the light CSP light side will be considered, not from the structural design of the direction of this type of light guide and extract. For improving the structure of single side light emitting CSP products, the white wall adhesive is processed into a structure with an opening inclined angle.

This structure can be the original in the white walls, phosphor particles, chip and colloid repeated reflection and refraction, is eventually absorbed into the horizontal direction of the heat excitation fluorescent glue part of photons through the white wall side guide wall inclined smooth, thus significantly enhance the light efficiency.

In addition to this, but also to mention the Ruifeng FEMC products, because the core of CSP or FC, and his own strengths and FC EMC combine together to open a new model of packaging enterprises. This development Elec-Tech as Dr. Mo Qingwei said, CSP is not a great scourges, it does not lock, instead it is a LED industry innovation, but also a challenge, but also new opportunities!

FEMC structure diagram

Lehman

The CSP device used by Lehman's process for preparation of fluorescent glue laminated is prepared, with no external device sealing structure, and by improving the configuration of the fluorescent glue, the thickness of phosphor layer and the top side of the regulation of CSP, can improve the consistency of optical devices, improve the CSP device in the spot terminal application problems the.

Preparation of CSP devices

Flash energy-saving lighting

CSP's traditional five surface light CSP (figure a) and single side out of the CSP (Figure b), has been successfully produced and stable supply, into 2017, will extend the established structure of the transfer of technology continues to introduce new routes.

Compared with the SMD light source, the five surface CSP light source has obvious advantages in brightness and reliability, but because of its unique structure, it has the disadvantage of the uniformity of light and color