This is the standard laminate used in our
sector of the industry. We carry stocks of all the main variants. The
standard thickness used is 1.6mm, but we also stock 0.8mm, 1.0mm, 1.2mm,
2.0mm, 2.4mm, and 3.2mm. The most common copper thickness is 35 microns
or 1oz square foot but 70 microns 2 oz square Ft is regularly used for
higher current applications.
Its closely related to FR5 which is the old high temperature version, but has now been replaced by
the more common BT Epoxy type.
Not quite so widely used any more are the G10 and G11 Laminates. They
are effectively the old Non flame retardant versions of FR4 and FR5.
The last epoxy laminate worth a mention is the FR3 grade. Its a cross
between FR2 and FR4 as it's constructed from the epoxy resin but using
internal strengthening paper sheets instead of the glass cloth. It had
the advantage of being easier to punch for the traditional punch and
crunch mass production houses.
Listed on the links are two tables of figures from our laminate
specification sheet which include data on, dielectric constant and the
thermal conductivity amongst other things.
As tested in accordance with Mil-s-13949,