Is buying JEDEC trays like buying a Model T Ford – you can have any color you want as long as it’s black?
JEDEC Trays are molded from a variety of plastic materials, and we all know that plastics come in almost every color imaginable. Why is it that most JEDEC trays are black? The short answer is: CARBON.
JEDEC trays are used to transport, process, and store many types of components, many of which are sensitive to ESD, electrostatic discharge – getting zapped by static electricity. One of the best ways to make the trays ESD-safe is to mix some form of carbon with the plastic. Carbon is black and, when mixed with plastic, it makes the plastic black. So, the easiest way to make ESD-safe JEDEC trays results in black trays. Trying to change a black, carbon-loaded plastic into some other color requires adding pigment. The pigment has special properties to make it disperse well and those properties are not ideal for trays so you don’t want to add too much.
But what if you really don’t want black trays? What if you want different colors for different uses? Maybe you want to use a bright colored tray for parts that failed a test or use different colors to indicate which processes have been completed. Do you have options?
The good news is that there are options. There are a few colors that can be produced in carbon-loaded, ESD-safe plastics. An example is NoStat® C60 whose standard color is blue. The colors available for carbon-loaded plastics are not vibrant, decorator colors but they are definitely not black. For low-temp, non-bakeable trays there are additional options that use alternatives to carbon-loading to get ESD protection. Without the carbon, bright, lush colors are possible. Currently these non-carbon, ESD-safe options are not available for high-temp, bakeable trays.
There are costs for custom colors that may seem high if tray quantities are going to be low. The startup cost to mix a special batch of material, test it, and set up to mold trays is about the same for 10 or 100 trays as it is for 100,000. Standard color trays are more likely to be in stock and cost less. For these reasons, standard colors are used for most low volume applications.