Dose: 145 - 1520 mJ/cm2

Wafer Size: up to Ø300mm (without frame) / up to Ø400mm (with frame)

Frame: up to Ø400mm DTF 2-12 and DTF 2-12-1

Substrate thickness: max 5mm, larger thicknesses possible

Minimum substrate diameter: Ø8" standard, smaller substrates also possible

Throughput: up to 200 UPH

Width: 994mm

Depth: 515mm

Height: 173mm

Weight: 25 kg

Conveyor speed: 4.7 mm/s - 42.5 mm/s

Number of LED: 72 (9 strips of each 8 LED)

Peak Wavelength: 365nm +/- 3nm

Radiant flux per LED: 750mW

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-300 UV-LED exposer is a very efficient solution for exposing UV film. 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 200 wafers per hour. This device can be used to expose commercially available UV films of the leading manufacturers, with an average wavelength of 365nm exclusively in the UVA range.

By using LEDs instead of traditional means, there are numerous advantages that are gained including 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. Also, with the use of our potentiometer, the conveyor speed and thus the exposure time can be precisely adjusted according to the specification of the UV film. With the U-300 and its 72 high powered LEDs, an adjustable dose between 145 and 1520 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

Manually place the mounted wafer and frame onto the conveyor with the wafer side facing up, this will allow the adhesive tape to be fully exposed by the UV-LED array. The UV light dose required for your specific tape can be easily adjusted on the potentiometer by setting it to the corresponding conveyor speed; lower conveyor speeds result in higher doses and vice versa. Once the substrate has fully traversed the LED array, it can then be manually removed for further processing (e.g., die picking). A pre-installed limit switch detects when the frame or substrate is near the end of the conveyor and automatically turn it off. The blue glass shield offers enough protection against UV light for one to safely operate the U-300 with the cover open. Nevertheless, if specific customer safety requirements dictate the cover must be closed during UV cycling, this device is equipped with a cover switch that can be activated to only operate when the cover is closed, and to switch off the LEDs if the cover is opened. 

Nitrogen Option

The U-300 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-300 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.

The nitrogen purge option comes integrated into a specialized UV protection shield and additional components in the U-300 housing ensure an even distribution of nitrogen over the surface area of the LED array.

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. The disc-shaped measuring device is optimized for the application of the U-300 by placing it on the conveyor like a wafer. During the exposure process, the intensity is integrated and displayed in radiant flux of mJ/cm².