Laminate

The laminates used in the electrical industry belong to the group of the fiber-reinforced composites and consist of a reinforcing fabric (e-glass) and a polymer matrix (resin bed). For rigid base materials, e-glass is used almost exclusively. This is also described as the carrier material. By using different resin systems, the characteristics of the base material can be altered.

Content

Rigid laminates
Flexible laminates and cover films
HF-laminates (e.g. Teflon)

Rigid laminates

Rigid laminates

Epoxy

HTG Epoxy

Polyimide

IMS

IPC 4101 denomination

GFN

GFG

GIJ

 -

TG glass transition temp. [°C]

135

180

220

100/170

CTE "Z" [ppm / °C]

180

150

55

 -

CTE "X&Y" [ppm / °C]

14 - 18

14 - 18

12 - 15

 -

Water absorption [%]

0.10

0.10

0.32

0.10

Relative permittivity [1 MHz]

4.4 - 4.8

4.1 - 4.3

4.2 - 4.5

5.5

Flammability [UL]

94 V-0

94 V-0

94 V-0

94 V-0

Dielectric strength [Volts / mil]

1000

1000

1200

1200


FR4 epoxy-laminates TG 135
FR4 is still the standard base material for the production of printed circuit oards. The TG is between 110 and 140 °C.
HTG-epoxy-laminates TG 180
Laminates on the basis of epoxy resin are used with resins like triazine resin to increase the TG. HTG-epoxy-laminates are offered with TG values from 145 to 180.
Polyimid-laminates TG 220
High performance laminates for assignments with a high tenacity or high operating temperatures. This laminate is mainly used in military aviation. The disadvantages are the slightly brittle resin, a higher absorption of water and the lower adhesive strength of the copper foil.
IMS (insulated metallic substrat)
The copper layer is laminated on a carrier plate, using an insulation layer (similar to a pre-preg). This material is particularly suitable for components which require a high heat conduction (e.g. power relays and power LEDs).
Currently, we only produce one-sided, not plated through boards (including solder resits on the component side) made of this material. As a solder surface, we preferably offer ChSn or ChNiAu. Upon agreement, we also offer hot air leveling.

Flexible laminates and cover films

Polyester foils (low cost electronic) or polyimide films (trade name Kapton) are used as a flexible carrier material. We exclusively use polyimide films, as they offer a much higher solder bath resistance and therefore can be used for almostall electronic applications.
We use two different groups of flexiblae laminates:
Laminates with acrylic coating (LF)
To laminate the copper onto the flexible carrier (plating), the manufacturer uses a 25 µm thick acrylic adhesive. This material does not meet the UL 94-V0 requirements. Furthermore, the acrylic adhesive has a high z-axis expansion, which may lead to cracked sleeves under thermal stress.
Glueless laminates (AP)
To laminate the copper onto the flexible carrier, the manufacturer uses anchor polyimides. These do not have disrupting adhesive layers. However, the advantages of glueless laminates can only be used if no cover film is applied within the through connections (windowing).
Cover films (LF, FR)
Cover films consist of an acrylic adhesive layer and a polyimide film. The adhesive of the FR cover film contains a flame retardant to meet the UL 94-V0 requirements. FR cover films are to be used in combination with glueless laminates (AP).

Flexible materials

Acrylic adhesive

Polyimide films

Polyimide pre-preg

Water absorption in %

4

1.33

0.7

CTE "Z" [ppm / °C]

425

48

55

TG glass transition temp. [°C]

40

390

210


Additional information and data sheets can be obtained from the manufacturer DuPont.

HF-laminates

RT/Duroid 5870, RT/Duroid 5880
Very low dimensional stabilty in X-Y and Z. The material is very sensitive towards pressure and tensile stress. Production of multilayers is difficult.
Ultralam 2000 (discontinued by the producer as of August 1st of 2014)
Good dimensional stability in X-Y but very high z-axis expansion. Mechanically durable material. Suitable for the production of multilayers.
RT/Duroid 6002
Very good dimensional stability in X-Y and Z. Suitable for the production of multilayers due to the low z-axis expansion.
RT/Duroid 6006
Good dimensional stability in X-Y but a relatively high z-axis expansion. Suitable for the production of multilayers. Material is very sensitive.
RT/Duroid 6010 LM
Good dimensional stability in X-Y and Z, suitable for the production of multilayers. Material is very sensitive.
RO 3003, RO 3006, RO 3010
Very good dimensional stability in X-Y and Z. The material has good mechanical characteristics and is suitable for the production of multilayers, as well as hybrid circuits (material mix with FR4).
RO 4003 C, RO 4350 B
Very good dimensional stability in X-Y but relatively high z-axis expansion. Material is suitable for the production of multilayers, as well as hybrid circuits (material mix with FR4).Soldermasks can be applied.

Additional information and data sheets can be obtained from the manufacturer  Rogers Corporation or from the trader Mauritz.