FAQ

(Frequently Asked Questions):

Shipping & Delivery:

After ordering, you should have received an email from us with the tracking number. Sometimes spam filters can prevent emails from reaching your inbox when the sender is new to you. We encourage you to check your junk and spam folders for an email from us and change email settings to allow emails from us. If you have not received your tracking number by 6 pm (PCT) of the order date, send us your email address and the order date at webpage “Contact Us”.

Currently, shipping is available USA, Canada, and Thailand. Free overnight shipping in USA mainland, free delivery of 4~5 days to AK/HI. Free delivery to Canada and Thailand, but the buyer has to pay Duty and taxes. Please send us a short message at our “Contact Us” webpage with your shipping address. We will notify you when shipping is available to your shipping address.

No deliveries can be made to PO Boxes. Residential addresses are acceptable as shipping addresses, without university discount.

We decides the delivery service providers depending on their availability and cost-effectiveness, especially for free overnight delivery. It could be FedEx, UPS, USPS, others.

Warranty: (go to Top)

30 days after receiving the product package based on the delivery tracking records.

The warranty covers labor and parts. We cover the delivery cost when shipping back repaired items to the customer.

Warranty covers only the original buyer.
Warranty does not cover the results from the customers’ misuses, negligence, improper maintenance, and natural disaster, natural worn-out, and cosmetic degradation. .

Please request RMA (Return Material Authorization) number at our webpage, “Contact Us” with your name, your email address, and the Serial Number of the product, and a detailed explanation of the problems and/or reasons. After confirming your purchase, we will send the RMA number to your email address. We (seller) does not accept any return requests without RMA numbers. As stated in the email’s set of instructions, customers must print the RMA number section and place it inside the return-box, and attach the return-shipping label outside the box with transparent tape. For first-time warranty service, we will provide free delivery and send the paid return-shipping label. Please pack the product items (hotplate, power cord, and screws) in the original package box with enough bubble wrap for safe delivery. We will not consider items returned in a damaged state due to insufficient packing.

Excluding the delivery times, it may take 1~2 days, depending the availability of parts.

It passed the warranty period, but I got problems with my Wafer-Hot-Plate. Can I get repair service?

Yes, we will repair at your customer’s expense. Please send your message with a detailed explanation at our web page “Contact Us”.

Technical:

The max temperature is factory-set to 320 C on the controller’s display as a safety precaution. Never attempt a higher temperature. WHP has no responsibility and does not provide warranty service for items damaged or broken by customer misuse or negligence.

I realize that the hotplate is made to be used with silicon wafers. Can I still use wafers made of different materials from silicon wafers?

Check and test your respective dummy wafers at your own risk. We designed the hot plate for use with silicon wafers. We suggest checking thermal expansion differences with silicon wafers and Aluminum (hotplate material).

NOTE: Wafers can be manually loaded onto the hot plate. For easy and safe loading, please use the two screws located about ½” away from the 7” vacuum groove on the hot plate. By default, the screws are positioned on the hotplate for loading 8”-diameter wafers. These screws can be moved and placed according to wafer size. More details on rearranging screws according to wafer size are discussed in the next FAQ.
DIRECTIONS: Position screws according to wafer size. Insert screws halfway. Center the wafer on the hotplate while gently leaning it against the two screws to avoid wafer sliding. After positioning the wafer, turn on the vacuum to secure wafer position. To unload the wafer, turn off the vacuum and gently remove the wafer off the hotplate with a tweezer.

There are vacuum ring patterns etched on the hotplate according to wafer size. By default, the screws are positioned along the vacuum ring pattern for loading 8”-diameter wafers. For smaller wafers, please reinsert them along the ring pattern appropriate to your wafer size. Otherwise, the wafer will not be as secured to the plate surface when the vacuum is turned on.
For holding a smaller diameter wafer, one can block the outer vacuum grooves with setscrews accordingly.

What is the temperature offset between the actual wafer and the displayed temperature?

The temperature sensor is located inside the hot plate’s center. There can be an actual temperature difference between the sensor’s reading and the wafer’s surface temperature, where photo-resist or polymer layers are. We suggest measuring the actual wafer surface temperature with surface thermometer.

The use of either line is to the customer’s discretion. Purchases of the hotplate includes a customized internal vacuum pump that is ready to use upon arrival. The hotplate also has a connection port of OD ¼” for an external vacuum line in a cleanroom.

It is > 5000 hours. Vacuum pump is on only when holding wafer. Since it has brush-less motor, frequent on/off does not make significant impact on its lifetime.