1. Add adhesive and remove surface moisture
2. Anti corrosion coating
3. Stabilization of the corrosion-resistant layer
4. Exposure
5. Development of corrosion inhibitors
6. Curing of corrosion inhibitor
7. Inspection
The coating of the chip is achieved through the spin coating method on a rotating chuck. At low rotation, the resist is rotated and then leveled at a speed of, for example, 2000 to 6000 rpm. According to the subsequent process, the thickness of the resist layer can reach up to 2 microns. The thickness depends on the rotational speed and viscosity of the resist.
In order to obtain a uniform layer, the resist contains water and a solvent that softens it. For stability reasons, the wafer is subsequently annealed (post/soft baked) at approximately 100 degree C. Water and solvent partially evaporate, and some moisture must be retained for subsequent exposure.
Wafer coating is a unique process that facilitates the automatic application of chip bonding adhesives at the wafer level, followed by the B-stage to form a chip bonding film. FUNSONIC's spray coating technology is suitable for wafer coating, which can achieve process speed, thickness control, and material uniformity. After the hot or UVB stage and wafer cutting, chip connections are achieved through heating and pressure to produce consistent adhesive lines and small, controlled corners. The adhesive coating on the backside of the wafer is an ideal choice for chip mounting applications where corner control is crucial.
Coated semiconductor wafers, especially silicon wafers, are suitable for use in the semiconductor industry, particularly for manufacturing high-density integrated electronic components such as microprocessors or storage chips. For modern microelectronics, strict requirements for global and local planarity, edge geometry, thickness distribution, reference local planarity on one side (known as nanotopology), and defect free starting materials (so-called substrates) are necessary.
