I've done whatever I want

Chapter 89 Core Process Parameters
What everyone feared inevitably happened.

It's a bit of a curse of Murphy's Law.

Xin Tong's life plan is very clear, and he controls time more strictly than anyone else.

In addition to preparing for the microelectronics major self-examination, Xin Tong also has to prepare for the Six Sigma Green Belt exam. After mastering statistical analysis tools proficiently, Xin Tong is determined to win the next spring exam.

At this time, he began to have a strong interest in Six Sigma DOE exercises.

This is the training part of an intermediate black belt!

His leapfrog training method is very similar to the current training mode of the Olympic mathematics competition classes. The junior high school students have already completed the high school courses.

After understanding, in chip packaging and testing factories, DOE focuses on the parameters of key processes. Obviously, the optimization of process parameters in the bonding process is the core of DOE analysis.

In the days when he was working as a technician in the manufacturing team, Xin Tong adjusted the machine every day and was already very proficient in playing with the ASM bonding machine. Even so, the parameters of the machine were still full of mystery to him like the smile of the Mona Lisa.

According to the process requirements of Mingyueguang Packaging and Testing Factory, the manufacturing team of the engineering department has opened the parameter retrieval authority, allowing small-scale adjustments within the parameter range.

As for where those process parameters came from, the young man knew nothing. Although he knew it, he didn't know why. The young man was obviously not satisfied with this!
After a period of understanding, Xin Tong found that the yield rate of the product is closely related to the process parameters, and the young people are more and more curious about the process parameter settings.

Since he was promoted to a manufacturing engineer, Xin Tong has been freed from the trivial work of adjusting the machine, so that he can spend more time on improving product yield.

When he usually left the workshop, he paid great attention to the parameter settings of the machine. After careful observation, the young man found that the core parameters of the bonding process include bonding temperature, bonding time, bonding pressure and ultrasonic power.

These four core process parameters are like four solid pillars, supporting the magnificent building with high product yield!

The bonding process has high temperature control requirements. Excessively high temperature will not only produce too much oxide and affect the bonding quality, but also reduce the image monitoring accuracy and device reliability due to the influence of thermal stress and strain.

After observation, Xin Tong found that products using lead frames will undergo obvious oxidative discoloration after bonding and baking at high temperature.

The bonding process also has high requirements on bonding time, which refers to the time when the bonding tool applies ultrasonic energy to the wire.

The longer the bonding time, the greater the reaction amount at the contact surface, the larger the diameter of the bonding point, the interface strength increases and the neck strength decreases.

Another important parameter is the bonding pressure. The role of the bonding pressure during bonding is to maintain the contact between the cape and the lead without slipping. At the same time, ultrasonic coupling must be generated on the contact surface between the lead and the pad, but not too large to cause the lead or the bond pad is badly deformed or performed.

The last important parameter is the ultrasound power.Ultrasonic power has a great influence on the bonding quality and appearance, because it plays a leading role in the deformation of the bonding ball.

The ultrasonically vibrated solder ball or wedge rubs along the bond pad metal to form a bond interface.Too little power can lead to narrow, underformed bonds or lifted tails; too much power can lead to broken roots, collapsed bonds, or cracked pads.At the same time, the amplitude of the rivet directly affects the bond deformation.

After figuring out the core process parameters of the bonding process, Xin Tong was eager to give it a try and prepared to conduct a DOE analysis of the bonding process himself to improve his ability to solve problems.

(End of this chapter)