Long lead times for these capacitors have created a problem for many of the manufacturers that use this type of electronic component in their product. Lead times for certain capacitors are now as long as 32 weeks. This is a result of problems in getting the raw materials needed to the capacitor manufacturers.
Here are a few suggestions on what can be done to help find a solution to the long lead times. In some cases it may be possible to substitute the capacitor required with a different dielectric that may be available for example using polypropylene in place of polyester. Another is to look for parts with a better tolerance such as 5% in place of 10%. In some case it may be possible to use axial style capacitors and then bend the leads to make them work in place of the radial style.
Selecting the right capacitor for your application is a decision that includes price and delivery. Certain materials that were considered common choices for the dielectric are now either obsolete or made in a very limited supply. Polycarbonate and polystyrene are two such materials. The limited availability has resulted in most cases with higher prices. The dissipation factor (DF), low equivalent series resistance (ESR) and maximum operating temperature are just some of the factors that should be considered when determining which dielectric will work best in your application.
Film capacitors are commonly used for filtering blocking and bypassing applications. The most popular styles are precision, pulse and high energy and interference suppression capacitors. Some of the leading manufacturers of this style capacitor are AVX, Epcos, Kemet, Illinois Capacitor, and Wima. If you would like more information on this style of capacitor please contact us.