Dose: 80 - 2400 mJ/cm2, adjustable in single digits

Wafer Size: up to Ø450mm (with frame)

Curing Area: 580mm x 580mm

Substrate thickness: max 5mm, larger thicknesses possible

Minimum substrate diameter: Ø6" standard, smaller substrates also possible

Throughput: up to 120 units per hour (UPH)

Width: 709mm

Depth: 732mm

Height (with cover open): 763mm

Height (with cover closed): 194mm

Weight: 33kg

Number of LEDs: 96

Peak Wavelength: 365nm +/- 3nm / 385nm & 405nm optional

Radiant flux per LED: 800mW

Homogeneity of dose: +/- 10%

Nitrogen pressure: 3 bar

Nitrogen connector: outer diameter Ø 6mm

Main Power: 100-240 VAC, 50/60 Hz

Certification: CE Certified, IEC 204-1 safety standards

The U-450 UV-LED curing system is a very efficient solution for exposing UV tape. Usually, this step takes place after the separation of the wafer to reduce the adhesion force when picking the die. The use of this curing device ranges from creating development samples in R&D departments, start-ups, or universities to series production in large companies for a throughput of up to 120 wafers per hour. This device can be used to cure commercially available UV tapes of the leading manufacturers with an average wavelength of 365 nm, 385 nm, or 405 nm exclusively in the UVA range.

By using LEDs instead of traditional technologies, numerous advantages are gained including a longer lifetime, lower maintenance costs, no warm-up time, and no ozone gas or dangerous mercury gas generation. In contrast to common mercury vapor lamp systems, this device does not require a long warm-up time and is ready for use immediately upon being turned on. With the U-450 and its 96 high powered LEDs, an adjustable dose between 80 and 2400 mJ/cm² per working cycle can be achieved. Higher doses can be achieved by exposing the substrate a second time immediately after the first pass. 

Very short set-up times, low operating costs, small footprint, and the high quality end results have made the U-series from Powatec a product that has been in great demand internationally in cleanroom applications for 15 years. 

Process Overview

Open the cover and manually place the mounted wafer and frame onto the glass curing area with the wafer side facing up, this will allow the adhesive tape to be fully exposed by the UV-LED array. The UV dosage required by your specific tape can be easily set using the display by first selecting the operation mode associated with your wafer's diameter, then selecting the program with the required dosage. Once the cover is closed the device begins the curing process automatically, after which the mounted wafer can be manually removed for further processing (e.g., die picking). 

Nitrogen Purge Option

The U-450 can be equipped with a nitrogen purge option located above the LED array, which will improve the chemical reaction of the process by reducing the concentration of oxygen in UV exposure area. A nitrogen purge is a common application in the industry when curing UV tape, especially when operating with mercury gas lamp systems to neutralize ozone. Although the LEDs used in the U-450 do not emit ozone during the curing process, the nitrogen purge option is still recommended especially when working with small dies (5mm x 5mm or smaller) to ensure a higher quality result. The reason is that in the area of contact between the UV tape and the wafer (along the border of the wafer/dicing lanes), the adhesion layer of the UV tape tends to be less reactive when exposed to air (oxygen) and adhesive residuals can remain on the die. These adhesive residuals on small dies or very sensitive wafers can result in an unsuccessful picking operation.

Calibration Option

The UV Integrator is a calibration tool used to measure the intensity of the LEDs over time. This tool provides a relative comparison of intensity over time to ensure the correction of the conveyor speed setting table, so it is worth noting this measurement method does not allow absolute measurements. During the exposure process, the intensity is integrated and displayed in radiant flux of mJ/cm².