Plan Optik AG offers re-usable carriers for thin wafer handling which can be used for mechanical release of the device wafers.
There is an ongoing wafer thickness reduction in the semiconductor industry since years. The market is demanding for smaller devices, cost reduction and increased number of functions. Therefore smaller package sizes need to be generated. Mainly consumer applications are driving this progression but the demand for smaller package sizes is also associated with technical advantages. This could be a better electrical performance and an improved thermal management. Thin wafers also enable 3D packaging of sensors such as CMOS image sensors and others.
Producing thin wafers in high quantities puts high requirements on handling and processing tools.
Due to their low thickness, semiconductor wafers are vulnerable to stress and breakage. Warping of the wafers during handling and processing causes a high yield loss or even makes it impossible to handle the wafers any more. This means, a Thin wafer handling technology with a high grade of flexibility on wafer and substrate sizes is needed.
One of the most common techniques is the temporary bonding of the thick device wafers to a rigid carrier of high accuracy by using a polymer based adhesive. After handling and processing the device wafer in standard semiconductor process tools the release (de-bonding) is done by various techniques: These typically are chemicals which dissolve the adhesive, heat which decreases the viscosity of the adhesives or by laser which reduces the adhesive force.
A pretty smart approach is mechanical release since it requires no costly tools and processes and the active areas of the devices wafers are not getting in contact with chemicals or heat. The wafers are bonded to a carrier in two different zones. The outer zone in the perimeter (edge zone) with a high adhesion and the inner zone (center of wafer) with low adhesion. This results in a low force needed for separation of wafer and carrier.
Plan Optik is producing such carriers used for mechanical release in processes such as Zone Bond ©, Edge Zone Release © and Edge Zone Debond © by Brewer Science respectively EVG. Since a variety of glass materials with different coefficient of thermal expansion can be used as carrier wafers, there are cte adapted carriers for all standard semiconductor device wafer materials such as Si, GaAs, InP or even SiC. Additionally due to it’s tranparency for visible light it enables an easy and save monitoring of the temporary bonding process.
Carriers for mechanical release are available at a ttv as low as 1µm (depending on diameter and thickness) and from many cte adapted materials. These carriers can be re-used up to 50 times.
In order to guarantee the highest quality, Plan Optik employs a quality management system certified as per IATF 16949, ISO 14001 and ISO 9001.
Please ask for a customized solution fitting to your process and product requirements here.