The essence and future interpretation of cspled in

The essence and future interpretation of CSP led in small package and big future

Abstract: as far as CSP is concerned, it does not represent low cost, how superior CSP is in performance, let alone what kind of life CSP wants to change from traditional packaging, etc. CSP is just a definition of packaging form, similar to SMD

for a long time, the industry has misunderstood CSP itself. The full name of CSP is chip scale package, which means chip level package device in Chinese. It follows the definition of CSP package in IPC standard j-std-012, which refers to a functionally complete package device whose ratio of package size to chip size is not greater than 1.2 times

as far as CSP is concerned, it does not represent low cost, how superior CSP is in performance, nor what kind of traditional packaging life CSP wants to change, etc. CSP is just a definition of packaging form, similar to SMD

to discuss the cost advantage of CSP, we must combine the benefits brought by CSP packaging form, and whether this CSP packaging form can bring new use functions in specific application fields, and whether it can bring new added value to end users

at present, the mainstream structure of cspled can be divided into substrate and non substrate, as well as five side luminescence and single side luminescence. The substrate can naturally be regarded as a support. Obviously, in order to meet the requirements of CSP for package size, traditional brackets, such as 2835, can't be used, but it doesn't mean that cspled has no bracket. In fact, the cost of substrate used by cspled is much higher than that of SMD. Due to size limitations, cspled usually cannot use chips that require bonding wires, such as formal chips or vertical chips, and can only use flip chips or thin film flip chips

in terms of the manufacturing cost of the chip itself, and considering the impact of scale effect, the price of flip chip is always higher than that of formal chip in a short period of time. Using flip chip to make cspled faces high-precision chip welding or arrangement, phosphor glue spraying, film pressing, molding or dispensing and coating in the dam, led cutting, light and color separation, and bagging. In fact, its technical content, process complexity, and equipment requirements are not simpler, cheaper and more mature than those of the traditional packaging industry

based on the above analysis, it can be concluded that (1) CSP is only an application of packaged devices in the field of LED, and can be regarded as a new product form different from SMD. (2) Cspled has not formed a recognized mature process route, equipment conditions, or mainstream packaging structure from 2005 to 2010. (3) No matter what method is adopted, the lumen cost of cspled cannot be lower than that of traditional LED represented by formal chip and 2835 in the foreseeable future

csp led must be the mainstream product in the future

can cspled become the mainstream product in the future? The conclusion is positive, but we must closely focus on the characteristics of cspled to find the cost performance, user experience and added value of cspled, otherwise, in a short period of time, the application scale of cspled will be restricted by its high manufacturing cost

the screw extrusion temperature is 165 ⑵ 00 ℃. Cspled is characterized by small size, high current and high reliability. In order to achieve the purpose of small size, high current and high reliability, cspleds, but the wet center of running water is easy to make the machine parts and electronic controls should be equipped with ceramic substrates, such as the three-dimensional fully wrapped five sided light-emitting cspleds (as shown in Figure 1) made of ceramic substrates + flip chip by Shenzhen Avenue Semiconductor Co., Ltd. and the pure single-sided light-emitting cspleds (as shown in Figure 2) made of ceramic substrates + thin film flip chip

Figure 1: three dimensional fully wrapped five sided light-emitting cspleds manufactured by ceramic substrate + flip chip (from Shenzhen Avenue Semiconductor Co., Ltd., yellow represents fluorescent adhesive, blue represents flip chip, red represents solder pad, gray represents ceramic substrate)

Figure 2: pure single-sided light-emitting cspleds manufactured by ceramic substrate + thin film flip chip (from Shenzhen Avenue Semiconductor Co., Ltd., yellow represents fluorescent adhesive, brown represents thin film flip chip, white represents white wall, red represents solder pad, and gray represents ceramic substrate)

compared with cspled without ceramic substrate, cspled with ceramic substrate has the following characteristics: (1) it is compatible with standard SMT, with good reflow soldering quality, high yield, and low cost. (2) It has strong resistance to cold and heat shock and large current shock. (3) The fluorescent adhesive is firmly adhered, which is not easy to cause the blue light to leak out due to the thermal expansion and contraction of the super drive when it is used and the falling due to external touch and collision. (4) Except for the back welding pad, there is no exposed silver layer in the whole structure. Compared with the traditional packaging form, it has better halogenation and vulcanization resistance, as well as heat, moisture and moisture resistance

compared with pure single-sided light-emitting cspleds made of ceramic substrate + flip chip, the former has a larger light-emitting angle, while the latter has a smaller light-emitting angle, higher brightness and longer projection distance; The former will lead to poor spatial color uniformity due to uneven light intensity and phosphor glue coating between the four corners and the front. The latter has no side light, no welding pad dark area on the front, no blue core and yellow circle phenomenon, and the spatial color uniformity is the best; Because the substrate of flip chip still exists in the former, the temperature of its glue surface is relatively higher than that of the latter, which makes the latter able to withstand greater driving current

based on the above, cspled, which is characterized by small size, high current and high reliability, is not suitable for floodlighting, but for point light sources and directional projection lighting fields with projection distance, luminous angle, central illumination and other requirements, such as backlight, flash lamp, projector, Strong light lighting lamps (lamps, searchlights Jilin huazhilu bio based materials Co., Ltd. is located in the bio based materials industry innovation base of Changchun Economic and Technological Development Zone, flashlight, work lamp, outdoor high-rise lamp, landscape, etc.), small angle lighting lamps, etc