Processing Sapphire with Lasers

Solutions

The range of applications for high-intensity LEDs has begun to expand. In addition to cell phones, they are used in liquid-crystal TV backlights, car headlights, and lighting. Mid- to long-term growth in the market is expected. When processing the sapphire used in high-intensity LEDs, separation using a diamond scriber and breaking has been the standard. However, as the market has grown, there has been strong demand for improved throughput and yield ratios. Laser processing has rapidly become more prevalent, and it is becoming the standard for processing sapphire for use in high-intensity LEDs.
This page describes sapphire processing using DISCO's laser saw.

Problems with Diamond Scribers

The following problems have been pointed out with regard to the conventional process of separation using diamond scribers and breaking:

Variable processing quality
The yield ratio is not stable because the process is dependent on the operator's skill.
Operating costs
It is necessary for the operator to always stay close to the equipment, which results in higher labor costs.
Number of machines
Since throughput cannot be increased, a lot of machines are required.

Advantages of Processing Sapphire with Lasers

In terms of processing methods with lasers, there are ablation processing and a method that uses stealth dicing.
In comparison to the conventional processing method, using a laser saw to process sapphire maintains the same light intensity while having various advantages, such as improved throughput and yield ratios and reduced operating costs.

Figure 1. Sapphire Scribing Using Ablation Process (Fully Automated Process)
* The water-soluble protection film HogoMax coating function is optional.

Figure 2. Sapphire Processing Using Stealth Dicing

Improved Throughput
High feed speed, several times that of a diamond scriber, results in significantly improved throughput.
Improved Yield Ratio
Simply by entering the processing parameters, it is possible to maintain consistent processing quality without relying on the operator's skill.
Reduction in Operator's Duties
With a fully automated machine, full automation is possible just by entering the device data and setting a cassette onto the machine. It is possible to cut down on the time spent exchanging wafers and significantly reduce the operator labor and man-hours required with a diamond scriber.

Advantages of Processing Sapphire by Stealth Dicing

For high value-added devices requiring high light intensity, processing with stealth dicing, with which almost no reduction in intensity occurs, is ideal. Since separation is performed using internal processing, it is possible to narrow the street and to expect an increase in the number of possible die. And even if the substrate is thick, die separation which reduces the decrease in intensity is possible.

The respective advantages and disadvantages of processing sapphire using a diamond scriber or laser saw are as shown in the table below.