e13.09.24 Glas-PCB-pl - Laser Zentrum Hannover eV

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18 Νοε 2013 (πριν από 3 χρόνια και 4 μήνες)

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Press Release


Laser Zentrum Hannover e.V.

Page

1

of

3

Press
Release:
Electronic Circuit Board Based on Th
in Glass


Electronic Circuit Board Based on Thin
Glass: Improved Functionality for Aerospace
Technology


Hannover,
September

24th
,
2013

Polymers are often used as an electrically isolating base material
for circuit boards. However, miniaturization and extreme stress

are pushing the limits of printed circuit boards (PCB) made of
epoxy
-
resin, glass
-
fiber fabrics (FR4) and polyamides.
H
igh
temperatures
often
cause
deformation or decomposition of
the
plastic materials
.


Due to the thermal expansion characteristics
of the

materials used, there is subsequently a risk of cracks or
breakage in the dielectrical layer. This can, for example, lead to
pad cratering, i.e. the formation of craters on the surface of the
PCB.

For high temperature applications
above 250 °C, thin glass

could be a suitable substitute for the conventional polymers used
as a basis material for the circuit boards, since glass has a high
chemical stability and a low thermal expansion coefficient of
7,2

*

10
-
6

K
-
1
.

The field of a
erospace technology

has
intere
sting
application
s

for these new, thin glass circuit boards.

T
ogether with project partners
, t
he

Las
er

Zentrum Hannover e.
V. (LZH)

is
developing

production processes for multi
layer
circuit boards based on thin glass with 145 µm thicknesses.

The
trend to m
iniaturization and higher processing speeds in the
PCB industry is a special challenge for manufacturing. In the
“Glass PCB Project”, scientists in the Glass Group of the
Production and Systems Department are working on developing
Press Release


Laser Zentrum Hannover e.V.

Page

2

of

3

Press
Release:
Electronic Circuit Board Based on Th
in Glass


two different laser proce
sses for processing these special
materials:
First,

a laser
is used
to structure the metal layers.
According to the PCB layout,
a laser is used to make
conducting
tracks

by

remov
ing

excess metal from a thin glass base.

The
advantages of laser ablation are
especially apparent in the
extremely fine structural resolution of the metal
,

without
causing
damag
e to

the sensitive material.

Secondly
, a lase
r is used to form holes or vias to

connect the
different circuit board layers, or the conventional components.
T
he LZH is
currently
working on finding suitable laser
parameters to drill through the materials without causing
thermal damage. Also, the vias should be of high quality
,

and be
reproducible at high speeds.
Optimal results aim at generating
parallel vias th
rough the glass

layers.

The process time, which is
dependent on the material thickness and the circuit board layout,
is presently 2 s for drilling a microvia with
a
0.2 mm diameter
through
a 170 µm thick material
, with a tendency towards
shorter times.

Als
o, comparative investigation
s

carried out by project partner
TU Berlin (main area of research


Technologies for
Micropherics
) show that new material systems based on thin
glass
must

use the laser for drilling vias, since conventional,
mechanical drilling
causes unwanted microcracks, and

the
service life of the drills is 40 times shorter.

Altogether, three scientific institutes and four
industrial
companies are involved in the joint project. The LZH develops
the laser processes for structuring the circuit b
oard layouts and
for drilling the vias, and the industrial partners such as Schott
Press Release


Laser Zentrum Hannover e.V.

Page

3

of

3

Press
Release:
Electronic Circuit Board Based on Th
in Glass


AG provide thin glass materials. The circuit board manufacturer
Hotoprin
t

GmbH & Co. K
G

offer
s

both production processes for
the thin glass circuit boards and
electroplating
. KCS Europe
GmbH is in charge of coating technologies (sputtering) of the
conducting metal layers on the thin glass. Furthermore, CCI
Eurolam GmbH is involved as a specialist for materials for
circuit board manufacturing.
Process

h
andling of the thin glas
s
sheets
for

mul
tilayer boards is being
researched

by the Institute
of Transport

and Automation Technology (ITA) of the
University of Hannover.

The project “Glas
s
PCB


Development

of a Multilayer Circuit
Board Based on Thin Glass” will be funded by the
Ce
ntral
Innovation Program SME

(ZIM) of the
Federal Ministry of
Economics and Technology

(BMWi) until the middle of 2014.

Contact:


Laser Zentrum Hannover e.V.

Dipl.
-
Biol. Lena Bennefeld

Hollerithallee 8

D
-
30419 Hannover
,
Germany

Tel.: +49 511 2788
-
238

Fax:
+49 511 2788
-
100

E
-
Mail:
l.bennefeld
@lzh.de

http://www.lzh.de


The Laser Zentrum Hannover e.V. (LZH) carries out research and development in the field of laser technology and is
supported by the Ministry of Economic Affairs, Labour and Transport of the St
ate of Lower Saxony (Niedersächsisches
Ministerium für Wirtschaft, Arbeit und Verkehr).

You can find the LZH press releases with
a WORD
-
download and when possible illustrations

at www.lzh.de

under
"
publications/press releases
"



Illustration caption:
Laser

stru
cturi
ng
of metal coated thin glass