LED flip chip technology PK package-free technology who is better?

LED packaging companies in the era of meager profit urgently need new packaging technology to break the dilemma of increasing revenue and not increasing profits. Regardless of whether it is for domestic manufacturers or foreign manufacturers, the main challenge in the future increase of LED packaging market share is still from technology. Therefore, regardless of the mainland crystal science, Taiwan's new century-based flip-chip technology, or the csp technology led by Philips in the LED industry has received much attention in the industry.

Recently, Nichia Chemical Co., Ltd. Akutaghachi also said that the investment scale of the LED industry has increased by 30% to 40% annually, but the price of end products has maintained a downward trend of 20-30%. This reverse trend has led to investment by LED operators. The profit margin is expanding, and related manufacturers must continually explore a lower-cost process solution. At this stage, flip chip packaging can greatly streamline the LED process and reduce the production cost. Therefore, the ELEDS flip chip technology of Nichia is still planned this year. In October, it entered the mass production stage, and the production capacity is about tens of millions. Nichia believes that the technology is expected to become a mainstream product within 3 to 5 years. The application field can span automotive, lighting and backlight products, and seize the lead in advance. machine.

The ancestry of past and present

Flip-Chip, also known as "dip crystal package" or "dip crystal package", is a type of chip packaging technology. This packaging technology mainly differs from the past method of chip packaging. In the past, the chip was placed on a substrate, and the bonding technology was used to connect the chip to the connection point on the substrate. The flip chip packaging technology is to add a bump to the chip connection point, and then flip the chip over to connect the bump directly to the substrate.

The technology originated in the 1960s and is now relatively mature in foreign countries and Taiwan, but the progress in the mainland market is relatively slow, and only a few companies are involved. In addition to the low packaging yield, the main reason is that the cost of this set of processes is relatively high, and the mainstream packaging market, which is dominated by small and medium-sized packaging companies, is still difficult to accept.

The concept of CSP was originally proposed by chip companies. If it is the basic meaning, it needs to remove the substrate part, but considering the existing packaging technology to consider, the removal of the substrate part is temporarily inoperable. Therefore, most of the current light source companies will produce more CSP devices. Available in a flip-chip package. With this package, the more common flip-chip devices can improve the light efficiency by 10%-15%, while meeting the requirements of chip-scale packaging. Therefore, existing CSP packages exist based on flip chip technology.

Among the many existing package formats, only flip-chip technology can make the CSP package easier to implement. Traditional dressing and vertical structures encounter many difficulties when implementing CSP packaging, and the timely emergence of flip-chip technology can solve this problem. Because if a formal or vertical structure is used, it must be ensured to have an opening on it. Such a package will expose the electrode, which will cause many challenges in coating the phosphor during white packaging. If the flip-chip structure is used, the electrodes are all underneath, and no lead wires are needed. Therefore, a whole piece of phosphor powder and fluorescent glue can be coated to be once in place, thereby greatly reducing the difficulty of the CSP packaging process.

Advantages highlight the price behind the sadness

It is known that the flip-chip LED light source eliminates the need to hit the gold line, and the probability of dead light is reduced by 90%, thus ensuring the stability of the product. The positive-loading chip package form is mainly electrically connected through a gold wire, and the impact of a large current is extremely easy to burn the gold wire. The flip-chip package used to connect the chip and the ceramic substrate accounts for about 60% of the chip area. Compared with the gold wire, its electrical contact surface is expanded by more than 1000 times, and the current density can be increased by 10,000 times. The chip thrust will increase to more than 2000g, so the reliability of the entire packaged device will be higher.

For the positive package chip packaging method, most of the current industry uses silver glue to solidify the crystal, because the chip and the substrate are mainly inorganic components, and the silver paste is an organic component. The organic component and the inorganic component are greatly different in thermal expansion coefficient, and in the case of alternating hot and cold, the chip is easily peeled off from the substrate.

Industry experts expect that flip chip technology does not need to be wired and packaged, the cost has plummeted, but the price is too high, and it is currently limited to the application of high current. It is expected that it will penetrate into the market of 1 to 3 watts in 2015. It is beneficial to open up new markets.

The CSP device, because it is based on flip-chip technology, also has no gold wire, no bracket, so the various "free package", "no package" vocabulary came into being. The concept of "free packaging" is actually a more commercially motivated promotion by some Taiwanese manufacturers to promote its CSP white light chip. The reality is that these chip companies can indeed provide white light chips, but enterprises on the application side cannot use it directly. From the chip to the final source of the CSP device, it still has to go through the packaging process. In general, some basic processes in the traditional packaging process, CSP devices are also required. According to the current packaging requirements of the LED industry, it is necessary to dissipate heat and dissipate the light, while taking into account the mechanical protection and the reasonable combination of electrical, and CSP devices are also indispensable for these requirements.

However, most of the current CSP devices are chip companies, but there are few packaging companies. Like this type of CSP device, many packaging factories are still unable to produce it for a while, and usually the chip company will directly make the chip into a light source product and supply it to the application manufacturer for use. To some extent, the current CSP devices do not seem to have much to do with the general packaging plant in terms of process flow. The reason is mainly because there are technical barriers in CSP packaging, and many packaging companies lack some technical conditions in this regard, so usually the whole process is often arranged by the chip factory. Therefore, there are also many people in the industry who say that with the general increase in CSP devices in the future, traditional packaging companies are likely to move toward the end of the industry.

Therefore, no matter from the flip-chip or CSP, in terms of the current industry situation, this is just an industry speculation, and the package forms are various. CSP packaging or flip chip technology has become the mainstream packaging mode of the future industry. It remains to be seen. Inspection.