Electronics manufacturer Tyco Amp Den Bosch has changed the material it uses
for moulding PCMCIA (PC card) header from liquid crystal polymer (LCP) to
Stanyl® polyamide 4,6 (PA46), gaining overall cost savings, better mechanical
properties, and very low warpage. Stanyl grade 46HF 5040, a high-flow
formulation, easily meets the flow properties of LCP, allowing ready moulding
of the tiny features in the header while enhancing much needed mechanical
properties.
PC cards are often used in portable and laptop computers to provide plug-in
expansion, network connectivity, telecommunications modems, and a host of
add-on functions developed over many years. Very low warpage, dimensional
stability and high strength are critical to the application, as the slim cards
are produced to very high dimensional tolerances and feature locating keys
under 1 mm thick.
The header must securely hold 68 pins with a pitch of 0,6mm. a little more
than half a millimetre apart and stand up to often rough card insertion
practices of portable computer owners. In addition, the heat resistance of
Stanyl fits within the production processes of the laptop mainboard, which
requires lead free soldering of surface-mount electronic components.
The header design adds complexity in that it incorporates card slots extending
several centimetres out from the header itself. Such a design saves assembly
labour but adds moulding challenges, made even more challenging by the
minuscule dimensions of the moulded features. Model variations include
single-card and dual-card headers.
“We worked with Tyco particularly to reduce rejects due to warpage,” said
Patrick Duis, application development manager, connectors, DSM Engineering
Plastics. “Stanyl High Flow enables consistent production of the highly
detailed part, and we were able to help Tyco achieve lower per-part cost.”
Stanyl High Flow grade 46HF 5040 is one of the Stanyl family of heat-resistant
polyamide moulding compounds, produced and marketed exclusively by DSM and
available worldwide. Stanyl is used in demanding applications in the
automotive and electrical and electronics industries, as well as many other
applications. Stanyl is offered in a wide variety of grades including
high-flow, abrasion-resistant, and unfilled (non-reinforced), as well as
grades containing glass fibres, minerals, lubricants, impact modifiers, or
flame retardants.
Higher crystallinity and a faster rate of crystallization give Stanyl a
technical edge over such engineering plastics as PA6, PA66, polyesters, and
other high heat-resistant resins such as semi-aromatic polyamides (PPAs), PPS
and LCPs. Compared to these, Stanyl grades show better heat resistance,
mechanical properties at elevated temperatures, wear and friction behaviour
and, with faster cycle time and increased flowability, improved processing
economics. A dedicated staff of DSM specialists provides technical support in
design, moulding, and material selection of Stanyl.
