Zero force base
Zero force base , zero force recording or engl. Zero Insertion Force ( ZIF ) is a term for a socket for wired electronic components, in which no compressive or tensile forces are required to insert or remove the component. In a normal IC socket, the contact pins of the component are clamped by the resilient contacts of the socket. Accordingly, a force must be applied when inserting the component in order to press the pins into the contacts. In order to remove the component again, an even higher force is usually necessary. In the case of complex ICs, such as processors with several hundred contacts, a very high force is required for this (approx. 0.5 to 1.6 N per pin ), which increases the risk of the component, socket or circuit board being inserted or removed to damage the component.
With the zero-force socket, the contact springs are opened mechanically before the IC is inserted, so that the contact pins can be inserted into the socket without any effort. When closing, the contact springs are pressed against the pins and thus ensure electrical contact and mechanical hold at the same time.
Since zero force sockets are more expensive than normal IC sockets, they are particularly used for expensive ICs such as microprocessors and for ICs that have to be changed frequently. In the case of PCs , ZIF sockets have completely replaced the older so-called low insertion force sockets (LIF) since the mid-1990s.
Simpler, inexpensive designs that are only suitable for a few insertion cycles are preferably used on the motherboards. For test and programming devices there are correspondingly more robust, but also more expensive versions that are designed for tens of thousands of contacting cycles.
Test socket
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The zero force sockets for components in DIP housings are also known under the well-known brand name Textool sockets from 3M . The general term test or programming socket is more neutral . Such bases are also made by various other manufacturers.
Programming socket are mainly used in test and programming devices (for example for microprocessors such as the AVR family or PIC family used), as normal IC socket designed would wear out there due to the high stress too fast and also the connections of the components would have to be first directed , since the connections are slightly outwards ex works. There are versions that can contact housing sizes from DIP48 down to DIP8, so adapters for different housing types are not necessary.
There are also zero force sockets for SMD housings such as SO designs . These are mostly used for test and programming adapters.
literature
- Weifeng Liu, Michael Pecht: IC Component Sockets . John Wiley & Sons, 2004, ISBN 978-0-471-46050-3 .
