Design guide elastomeric Inter-Connectors

To achieve reliable connections with Shin-Etsu Inter-Connectors, certain rules are to be followed regarding the design of the Inter-Connector, it's application and it's usage. For elastomeric Inter-Connector, proper holder constructions and certain compression have to be considered carefully in combination with guidance to align the substrates.

Compression and resistance characteristics:
To achieve a stable resistance with elastomeric Inter-Connectors, a certain compression has to be applied to the Inter-Connector to create a chain connection between conductive particles inside the Inter-Connector and provide proper contact pressure towards the substrates. For the wire types of elastomeric Inter-Connectors, the compression provides the required contact pressure from the wires to the substrates.

Alignment, pitch and skew:
Overall tolerances of the assembly construction dominate the choice of the type of Inter-Connector and it's pitch and height. A general rule is to have 4 to 5 carbon conductive lines per substrate contact to provide stable resistances over the contacts. For metal based Inter-Connectors, the required resistance and current density have to be considered to fix the most suitable type of Inter-Connector and its dimensions in combination with the design of contact patterning on the substrates.
Besides the alignment tolerances of the assembly, the skew of the Inter-Connector has to be considered to specify the Inter-Connector and assembly. Skew is defined as the angle offset of the perpendicular direction of the conductive layers of an Inter-Connector.

Inter-Connector and holder construction:
Due to applied Z-axis compression, elastomeric Inter-Connectors will expand in the X-axis and Y-axis. The volume of the compressed Inter-Connector is same as the volume of the uncompressed Inter-Connector. Only sponge silicone rubber sections of the Inter-Connectors can absorb some volume reduction. To guarantee stable compression and avoiding collapses, proper holders are recommended in combination with special design rules for the Inter-Connector itself.

Typical holder design
     
 Holder design - side view
 Hh ≥ 0.6•HCN
 Holder design - top view
 Wh = WCN + 0.2~0.3
 Inter-Connector - basic outline
 

Compression forces and Young's modulus:

Applicable forces to compress the elastomeric Inter-Connectors can be achieved by using Young's models.

Load = (A•Z + B•(W - Z))•L•C/100

Young's modulus
(general silicone rubber)
 

Load: required compression force (N)
Z: conductive core of the Inter-Connectors (mm)
W: width of the Inter-Connector (mm)
L: length of the Inter-Connector (mm)
C: compression rate (%)
A: Young's modulus of the conductive core (N/mm2)
B: Young's modulus of the support material (N/mm2)

Young's modulus (parameter A and B)
  Unit  
 Carbon core 0.25P  N/mm2  9.5
 Carbon core 0.18P  N/mm2  8.0
 Carbon core 0.10P  N/mm2  7.5
 Carbon core 0.05P  N/mm2  7.3
 SS-type support material (SS-20)  N/mm2  1.3
 SG-type support material (SPO-951)  N/mm2  1.3
 SP-type support material  N/mm2  1.3

Note:

Shin-Etsu Inter-Connector has been registered in the European Community, TM No. 000299016, and in the United States of America, TM No. 2078941.
Every item or numerical value indicated herein is measured by Shin-Etsu and out of guarantee.
Compression curves are for reference only. Actual resistances and compression forces are up to the design of substrates and holder constructions.
More information can be found in the design guides.
The quality of the assembled Inter-Connector is out of guarantee.
Please make sure to review the purpose and conditions of use and practice your own tests.
Industrial ownership like patent doesn't guarantee the usage of the Inter-Connector.