Marking is a technique used for placing identification and traceability onto an integrated circuit package through the use of distinguishing marks. This will give the product the name of device, the company’s logo, a date code, and more in order to not only verify who has produced the equipment but also whether it is reliable or not. Marks are placed on the integrated circuit package during Test, while others are established during Assembly.
Marking contains two processes that are commonly used. These are ink marking and laser marking. Ink marking is usually done using pad printing for products. The process involves the transfer of an ink pattern from a flat block with an engraved pattern filled with ink, called a plate, to the package. This is done using a silicone rubber stamp pad, which is used to repel the ink. This makes the transfer more efficient as well as clean. Silicone rubber is also elastic and resilient, so it is possible to print on uneven surfaces as well as flat ones.
Pad printing is a very simple way of marking. First, the stamp pad is passed over the ink’s surface. Next, the ink from the surface adheres to the pad. Then, the pad is placed over the surface which it is to mark before being applied to it. Finally, the ink sticks to the surface and leaves the pad. It is a very fast and simple process.
Laser marking, the second type of marking used on semiconductors, is thusly named because it requires a laser beam to engrave the surface markings. Lasers come in a wide variety and can be used for different purposes as well, but there are three specific lasers used for the semiconductor industry. These are the CO2 laser, the diode laser, and the YAG laser. These can be used for surface processing, welding, cutting, and other purposes as well.
There are some very common marking failure attributes that may occur during laser marking. They include the following: