Spin Coater Model KW-4A, Two Stage Spinning, 110 /60 Hz Operation

Spin Coater Model KW-4A, Two Stage Spinning, 110 /60 Hz Operation
Spin Coater Model KW-4A, Two Stage Spinning, 110 /60 Hz Operation
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Spin Coater Model KW-4A, Two Stage Spinning, 110 /60 Hz Operation CE Certified


  • 2-Stage Spinning 
  • Stage 1: 500-2,500 rpm, 2-18 Seconds
  • Stage 2: 1,000-8,000 rpm, 3-60 Seconds
  • Vacuum: 2.1 CFM
  • Speed Stability: <1%


  • 115 VAC, 60 Hz, 1 Amp

SPI Supplies is pleased to offer the Model KW-4A spin coater. It is economically price, compact and easy to use. The unit is optimized to produce precise and uniform depositions of thin films and coatings. Its rugged, vibration-free and portable design makes it a versatile tool for any high quality research facility.

Two stage spin process
This approach allows dispensing at low speeds and homogenizing the coating at high speed. The KW-4A spin coater can be used to deposit metal oxide thin films, polymer coatings, and organic thin films on a wide variety of substrates as well as the novel SPI Supplies Silicon Nitride Membrane Windows which are now available in a spin-coatable form, Multi-Frame Arrays. The higher the spin speed, the thinner the final spun coating will be. 

Other potentially useful information:
The largest substrate, theoretically, would be a 9" (229 mm) diagonal measurement. Normally, the largest standard size chuck for the KW-4A is 6" (152 mm). Above that size, we have normally offered semi-custom or custom spin coaters. Some space must be allowed between the wall of the bowl and the substrate to avoid splashback, this being the reason for the maximum size being less than the maximum bowl diameter. A second reason has to do with the size of the motor and the need for a larger motor for wafer sizes greater than 6". However if one is working with a thinner-than-normal wafer, for example, one of the ultra thin wafers, then it can be possible to stretch the unit to its limits and coat an 8" wafer. However, one would need a specially fabricated 8" chuck. Note however that we do not want to be in the position of guaranteeing that an 8" wafer could be coated in all instances. If you do not want to carry the burden of this risk yourself, then please do not order this unit for 8" wafers.

What comes "standard" with the KW-4A spin coater:
The basic unit comes with a 7" (178 mm) coating well and a lid to fit the coating well. The disperser, chucks, optional wells and lids, and purge cabinets are purchased separately.

Compact size:
The Model KW-4A has a depth of 10" (25.4 cm), width of 8.5" (21.5 cm) and height of 8.5" (21.5 cm). Weight: 15 lbs (6.8 kg). This small "footprint" makes it the ideal solution where bench space is in short supply. Shipping dimensions: 17" (43.2 cm) x 14" (35.6 cm) x 11" (27.9 cm); shipping weight: 20 lbs (9.1 kg). 

Recommended accessories:
Besides the obvious pump, and we would recommend one that is made by Gast Manufacturing, Inc. one will have to select one or more vacuum "chucks" to hold their substrates, and also, they will have to select a liquid dispenser. It is therefore important to order the chuck that seems best for your type of work. We generally recommend the next smaller size chuck that is just smaller in size than your largest substrate. It is imperative that there be no exposed chuck surface, otherwise the coating liquid will be sucked away into the vacuum system, which of course is quite undesirable. If you are working with samples of various sizes, it might be beneficial to have more than one size chuck. A user of the KW-4A Spin Coater may also need the optional dispenser (See bottom of the page listing). The approximate range of viscosity at temperature of 25°C of the fluids to be used with the Model KW-4A dispenser is 0.600 cP (Benzene) to 10,000 (Honey).

A few comments about the recommended pump:
We recommend a particular pump manufacturing by Gast Manufacturing, Inc. mainly because it has been found to be highly reliable for this particular application and it is also quite reasonably priced. One can of course pay much more for a pump but in terms of its function and performance, none will perform better than our recommended pump. 


Purge cabinets:
Three special purge cabinets are available for purchase. Some spin coating protocols call for the spin coating to be done under an inert atmosphere such as dry nitrogen and the use of a purge cabinet allows one to operate in this kind of a protected environment. The smallest cabinet, SPI #12191-AB, will accommodate the KW-4A spin coater but some times there are other items that must be placed in the protected environment and therefore some customers have a need for a larger cabinet There are other optional accessory items that might be needed as described on the Model KW-4A Optional Accessory Listing. 

2-Stage Spinning 
Stage 1: 500-2,500 rpm, 2-18 Seconds
Stage 2: 1,000-8,000 rpm, 3-60 Seconds

115 VAC, 60 Hz, 1 Amp
220 VAC, 50 Hz, 1 Amp