Small package is the future, and the future of the nature of CSP LED

CSP is a package

All along, the industry has misunderstanding on the CSP itself. CSP is the abbreviation of Chip Scale Package, Chinese mean chip level package. It follows the IPC standard of J-STD-012 CSP package definition, refers to the package package size and chip size is not greater than 1.2 times of complete function. As for CSP, it does not represent the low cost, also does not represent the performance of a CSP to the superior, but CSP does not mean what to reform the traditional packaging and so on. CSP is just the definition of a package, similar to SMD. To discuss the CSP cost advantage, must have a combination of CSP package and the benefits of CSP package in specific applications can bring new functions can bring new added value to the end user.

The current mainstream CSPLED structure can be divided into the substrate and the substrate, can also be divided into five surface emitting and side light. The substrate can be regarded as a natural scaffold. Obviously, in order to meet the CSP requirements of the package size, the traditional frame, such as 2835, it can not be used, but does not mean that no CSPLED support, in fact, the cost is much higher than that of CSPLED substrate using SMD. By the size constraints, CSPLED usually cannot use wire bonding chip, such as installing vertical chip or chip, can only use the flip chip or thin film flip chip.

The chip manufacturing cost of itself, and considering the effect of size, price in the short period of the flip chip chip is always greater than the dress. The flip chip high precision chip facing CSPLED welding or arrangement, fluorescent powder glue spraying, membrane pressure, molding or dam in dispensing, coating, cutting LED spectrophotometer, and woven bags, its technical content, process complexity, and equipment requirements is not easier than traditional packaging industry cheap and mature.

Based on the above analysis, conclusions (1) CSP is a packaging device applied in the field of LED, can be regarded as a new form of products different from SMD. (2) CSPLED has not yet formed a recognized mature process route, equipment condition, has not formed the mainstream packaging structure. (3) regardless of the method, the cost may not be less than CSPLED lumens in formal chip and 2835 as the representative of the traditional LED lumens cost in the foreseeable future.

CSP LED is the future mainstream products

So CSPLED can become the future mainstream products? The conclusion is in the affirmative, but must be closely around the characteristics CSPLED to CSPLED performance, user experience and value added, otherwise, in a short period of time, the size of application CSPLED will be affected by the manufacturing cost according to not under the restriction of high.

CSPLED is characterized by small size, high current, high reliability. In order to achieve the small size, high current, high reliability, CSPLEDs should be provided with a ceramic substrate, such as stereo full package five surface emitting CSPLED Shenzhen Avenue Semiconductor Co. Ltd. using ceramic substrate + flip chip manufacturing (as shown in Figure 1) and the ceramic substrate and thin film flip chip manufacturing pure single light emitting CSPLEDs (e.g. as shown in Figure two).

Figure 1: stereo full package five surface emitting CSPLED + ceramic substrate flip chip manufacturing (from Shenzhen Avenue Semiconductor Co. Ltd., yellow fluorescent glue, blue flip chip, red pad, gray represents a ceramic substrate)

Figure two: ceramic substrate and thin film flip chip manufacturing pure single light emitting CSPLEDs (from Shenzhen Avenue Semiconductor Co. Ltd., yellow fluorescent glue, brown for thin film flip chip, white and white walls, red represents pad, gray represents a ceramic substrate)

Compared with ceramic substrate with CSPLED ceramic substrate CSPLED has the following characteristics: (1) compatible with standard SMT, reflow soldering of good quality, high yield, low cost. (2) the anti thermal shock and high current impact ability. (3) fluorescent adhesive fastness, not easy to use because of the super flooding expansion and contraction due to external impact and touch and bring out the blue led to drop. (4) except the back pad, no bare silver layer in the whole structure, compared with the traditional package form, has the better ability of anti - halide resistant and heat-resistant, wet moisture resistant ability.

The three-dimensional full package five surface emitting CSPLED with ceramic substrate and thin film flip chip manufacturing pure single emitting CSPLEDs compared with ceramic substrate + flip chip manufacturing, the former light angle, the light angle is small, high brightness, projection distance; the former because the four corner square with positive light intensity and fluorescent powder rubber coating will lead to uneven spatial color uniformity is poor, the positive side light, no pad dark, no blue yellow core area, spatial color uniformity; the former because of the flip chip substrate still exists, the rubber surface temperature is higher than the latter, which can bear larger driving current the.

Based on the above, with small size, high current and high reliability for the characteristics of the CSPLED is not suitable for floodlighting, is suitable for the light source, and projection distance, light angle, illumination and other requirements of the direction of the center of projection lighting field, such as back light, flash, projector, light lighting (the lights, searchlights, flashlight, work lights, outdoor lights, high roof landscape), small angle lighting etc.. (author: Shenzhen Avenue Semiconductor Co. Ltd. Li Gang)

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