Abstract
Next generation of smart systems in different application
areas such as automotive, medical and consumer
electronics will have various electronic, optical and
mechanical functions integrated in polymer packages. We
have studied the in-mould integration of electronic and
optoelectronic modules with injection moulding and
film-overmoulding technologies. A test set was made to
find out adhesion strength between various overmoulding
thermoplastic materials and thermoplastic films that
could be used as substrates for flexible printed
circuits. By overmoulding we mean here that the film is
set as an insert into injection moulding mould and
thermoplastic polymer is cast on the film in injection
moulding process. Both overmoulding and polymer materials
were mainly transparent. It was found out that generally
adhesion between the substrate and overmoulded plastic
was poor, but some good material pairs could still be
found. Situation is especially difficult with materials
which can withstand high temperatures. These materials
can be bound together only by special means. Adhesion was
tested by ISO 8510-1 standard in addition to visual
inspection. It was noticed that another problem beside
poor adhesion was warping. Some of the tested
overmoulding material pairs are not suitable for
overmoulding, because of their remarkable high difference
in coefficient of linear thermal expansion, which leads
to distinct warping effect of the foil and overmoulded
plastic package. Deformation takes place also after
demoulding when plastics are cooling to room temperature.
PET, PEN, and PC -type foils were tested as flexible
printed circuit substrates. The overmoulding materials
were PC, COC, PMMA and PS. Investigated high temperature
resistant foil materials were PI and LCP and
corresponding overmoulding materials LCP and LCP/PPS
blend. A test structure was also made, in which bare die
and SMT electronic components were assembled to foil with
different interconnection methods before overmoulding
process. Characterization of overmoulded components was
carried out by visual inspection and by functional
testing. It was found out that with correct injection
moulding process parameters, all components survived the
challenging conditions of the injection moulding process.
Original language | English |
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Title of host publication | IMAPS Nordic Annual Conference Denmark 2008 |
Publisher | IMAPS Nordic |
Pages | 207-212 |
Publication status | Published - 2008 |
MoE publication type | B3 Non-refereed article in conference proceedings |
Event | IMAPS Nordic Annual Conference 2008 - Helsingör, Denmark Duration: 14 Sep 2008 → 16 Sep 2008 |
Conference
Conference | IMAPS Nordic Annual Conference 2008 |
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Country | Denmark |
City | Helsingör |
Period | 14/09/08 → 16/09/08 |
Keywords
- overmoulding
- adhesion
- in-mould integration