04 – PCB base materials and their properties

04.1 Base material types classified according to their use

Name	Design	Use	Contour
FR2	Paper-base laminate, phenolic resin Cu single- and double-sided, 18, 35, 70 µm	Single- and double-sided PCBs, non-plated through PCBs	Routing / scoring, can be punched at room temperature
CEM1	Core: Paper, epoxy resin Exterior: Glass fibre epoxy resin, Cu single- and double-sided, 18, 35, 70 µm	Single- and double-sided PCBs, double-sided, non-plated through PCBs	Routing / scoring
CEM3	Core: Paper, epoxy resin Exterior: Glass fibre epoxy resin, Cu single- and double-sided, 18, 35, 70 μm	Single- and double-sided PCBs, double-sided, non-plated through PCBs	Routing / scoring, can be punched at room temperature
FR4	Glass fibre, epoxy resin Cu single- and double-sided, 18, 35, 70, 105 µm (others on request)	Single- and double-sided PCBs, double-sided, non-plated through PCBs, multilayer	Routing / scoring
FR4 High Tg (FR5)	Glass fibre, epoxy resin Cu single- and double-sided, 18, 35, 70, 105 µm (others on request)	Single- and double-sided PCBs, double-sided, non-plated through PCBs, multilayer	Routing / scoring
Teflon	Teflon, glass fibre Cu single- and double-sided, 18, 35, 70 µm (others on request)	Single- and double-sided PCBs, double-sided, plated through PCBs, multilayer, high-frequency PCBs >1 GHz	Routing / scoring
Polyimid	Cu single- and double-sided, 18, 35 µm	Single- and double-sided PCBs, double-sided, plated through PCBs, multilayer, rigid-flex PCBs, high temperature PCBs	Routing / laser cutting, can be punched at room temperature

Standard thicknesses of rigid material:
0,5 mm / 0,8 mm / 1,0 mm / 1,2 mm / 1,6 mm / 2,0 mm / 2,4 mm / 3,2 mm / other thicknesses on request.

Polyimide can also be used as a rigid base material when reinforced with glass fibre, thickness 1,6 mm, other thicknesses on request.

04.2 Base materials and their technical properties

Property	Unit	Pre- treatment	FR2	CEM1	CEM3	FR4	FR4 High Tg	Teflon	Poly- imide
Glass transition temperature Tg	°C	–	30	60/90	125	135	150/170/210	160	> 250
Adherence of CU foil	N/mm	–	2,0	1,7	1,4	2,0	> 1,4	> 1,4	1,2
Bending strength lengthwise 0,8 to 3,2 mm	N/mm	–	160	400	480	600	600	600	110
Bending strength crosswise	N/mm	–	140	320	330	450	490	490	100
Dielectric constant at 1MHz	–	*D 24/23	4,1	4,2	5,0	4,2–4,8	4,5–5,4	2,5–2,8	3,8
Electric strength	kV	*D 48/50	15	40	–	40	–	–	90
Surface resistance	Ohm	*C 96/35/90	10⁹	10¹¹	10¹¹	10¹¹	10¹¹	10¹¹	10¹¹
Volume resistivity	Ohm/cm	*C 96/35/90	10¹⁰	10¹³	–	10¹²	–	–	10¹⁴
Solder-bath resistance	S	–	15–20	30	–	120	–	–	–
Combustibility UL 94	–	–	V1	V0	V0	V0	V0	V0	V0
Creepage formation DIN IEC 112	CTI	–	250	–	–	175–200	–	–	160–175
Water- absorbation	%	*E 24/50	0,75	–	–	–	–	–	2,5
Temperature limit	°C	–	105	–	–	–	–	–	–
Thermal expansion	Ppm/°K	*E 0/100	270–330	300	190	170	100–200	100–200	–

*C – Pre-treatment in humid air | *D – Pre-treatment in distilled water | *E – Storage in drying chamber