26 March 2014
Wafer Mounting for Dicing
Equipment: Model 300, 3100 and 3150 Wafer Film Frame Tape Applicators
|Application:||Wafer mounting for dicing|
|Equipment:||Models 300, 3100 & 3150 Wafer Film Frame Tape Applicators|
|Process:||Frame-mounted adhesive tape is used to hold wafers for dicing. After dicing, the wafer is washed and the die are picked from the tape. The wafer is washed and the die are picked from the tape. The wafer needs to adhere to the tape well enough to make it through the dicing and cleaning process, but the die need to be easily removable.
Tape is unwound from a roll and mounted to the wafer and frame at a consistent temperature and pressure. The frame has orientation notches that must be correctly positioned relative to the flat or orientation notch on the wafer. The circuit side of the wafer must not make contact with the chuck in some cases, because of fragile structures in the circuit. Air must not be trapped as the tape is applied to the wafer. The tension in the tape should be equal in all directions around the mounted wafer. Unequal tension can cause a shift during dicing.
Dicing tape comes in rolls of various lengths on three- inch cores. Some tapes have a liner that must be separated from the adhesive before mounting. Static that is generated in unwinding should be eliminated before the tape comes in contact with the devices to be diced are static sensitive.
|Machine Discussion:||The mounting system needs a chuck to hold the wafer and the frame in the proper orientation. Alignment marks for the wafer and locating pins for the frame are commonly used. The wafer is usually held by vacuum. Magnets, vacuum or clamps can hold the frame. In the case of a non-contact requirement the wafer chuck is hollowed out except for a narrow strip around the perimeter of the wafer. There should be some provision to support the center of the wafer during tape application. The wafer chuck should be heated to between 40 and 65 degrees centigrade and should not vary from the set point by more than five degrees.
Tape is pulled from the roll and held in close proximity to the wafer. The tape should be held in a way that prevents wrinkles and evenly tensions the tape in all directions. A static eliminator should be mounted in the tape to fit the film frame with consistent pressure. The pressure should be adjustable. Regardless of the mechanism, it must not entrap air.
A cutter is needed to trim the tape to fit the film frame. The excess tape can be rolled up or separated from the roll and discarded. A device should be available to peel the liner from the adhesive and discard it into a container or roll it up on a core.
|Machine Features:||The Model 300, Model 3100 and Model 3150 Wafer/Film Frame Tape Applicators offer the following features:
The standard platen has alignment marks machined for wafer sizes appropriate for that model. Vacuum holds the wafer in position. Heater in the platen support heat it up to 75 degrees centigrade. A digital temperature controller controls the temperature.
A non-contact platen option is available. This feature holds the wafer sizes appropriate for that model. Vacuum holds the wafer in position. Heaters in the platen support heat it up to 75 degrees centigrade. A digital temperature controller controls the temperature.
A non-contact platen option is available. This feature holds the wafer in position by vacuum around its perimeter. A pressure backup supports the wafer during tape application. The Model 3100 handles wafers up to 6 inches in diameter, the Model 3150 handles wafers up to 8 inches in diameter and the Model 300 handles wafers up to 12 inches in diameter.
Pins locate the film frame. Magnets hold it in place. All film frames can be accommodated.
A tensioner frame holds the tape just above the wafer. The operator moves the captive roller across the wafer, which excludes air as it rolls. An adjustable, spring-loaded platen support provides optimum contact pressure during tape application.
An optional static eliminator, which is mounted in the tape path, is available to prevent static electricity from building up in the tape.
The trimming system features a carbide wheel for long cutter life. The cutoff blade automatically retracts when not in use.
|Required Equipment:||The following equipment from Semiconductor Equipment Corporation is required to perform this application:|
|The following equipment from Semiconductor Equipment Corporation is optional to perform this application:|
Phone: (805) 529-2293 x 21
Fax: (805) 529-2193