98
Dynamic Series Connectors
Dynamic Series Connectors
Dynamic Series Connectors Dynamic Series Connectors
346
Dynamic Series Connectors
Guideline for selecting plating ( )
Whether to use gold or tin plating varies depending on
the voltage, current, environment (vibration, temperature,
gas, etc.), number of contact positions, and other
variables. Gold plating is recommended for general
industrial machinery, but in reality cost considerations are
also a factor. To help in this selection, these guidelines
have been put together for the Dynamic Series as a
reference in the selection process.
Table 1 shows us that gold should always be used for
applications under 3 volts and 1 ampere. When the voltage is
over 30 and amperage is over 1, tin plating can be used. The
most difficult area to make a selection is in the undetermined
zone. In this zone either gold or tin plating can be used, but
the environment causes extensive variation. In a clean
environment tin plating is acceptable. However, use gold
plating if the environment is bad, such as in high heat or
humidity, the presence of gas is possible, vibration is extreme,
mating and demating are excessive, or other factors.
Selecting based on the number of contact positions is often
forgotten. The higher the contact pressure the more possible
it is to use tin plating or no plating, regardless of the voltage
or current mentioned in section 1. However, if they are too
high, mating and demating become impossible so the
connector function is lost. To get around this, we can drive
the voltage and current down into a workable zone, but then
we run into the problem of oxidation. Then, to prevent
oxidation, we use tin (approximately 2.94 N optimum contact
pressure) or gold (approximately 1.18 N) plating. But, the
contact pressure increases proportionally as we increase the
number of contact positions, causing mating and demating
to become difficult. Generally speaking, given a 39.2 N limit
for mating/demating by hand, it becomes difficult without
using leverage, such as a lever or jack screw.
The Dynamic D-3000 series has a maximum of 20 contact
positions. That means the contact pressure with tin plating is
3.92 N, and with gold plating is 2.45 N and 1.47 N (high
pressure types and standard types are available for some
applications).
For instance, given 3.92 N for tin plating, we can calculate
insertion and extraction forces of 58.8 N and 49.0 N, which is
difficult because it exceeds the range for barehanded work.
Once we understand this, we see that as contact positions
increase we must use gold plating regardless of the voltage
and current conditions mentioned in section 1.
Table 2 shows the applicable maximum number of contact
positions as a reference.
Although the environment was discussed in section 1 about
voltage and current, it is summarized again here.
Use gold plating in a bad environment, particularly for high
vibration or heat, the presence of gas or other bad conditions.
Gold is a noble metal. This means that gold does not react
easily with other materials, which means that its surface does
not oxidize or tarnish when exposed to air. Of all metals, only
gold has this property. Other metals, noble metals except
gold, such as platinum or rhodium for example, do not produce
absolutely no oxide film. This is a very important property for
contacts. In consideration of this, there is no better material
than gold plating if the environment is bad.
Also, if vibration is an issue, there is the risk of fretting
corrosion (micro-abrasion). Always use gold plating. If possible,
high-contact pressure connectors are recommended.
2) Selection based on number of contact positions (selection based on contact pressure)
1) Selection based on voltage and current
3) Environment (vibration, humidity, gas, etc.)
Voltage
Current
Gold-plated
Below 3 V
Below 1 A
( 1 ) Gold plating Standard contact pressure:
(2) Gold plating High contact pressure:
(3) Tin plating High contact pressure:
1.47N
2.45N
3.92N
Applicable maximum number of contact positions
20
20
12
Contact pressure
Undetermined zone
3 to 30 V
1 to 10 A
Tin-plated
30 to 100 V
Over 10 A
No plating (reference)
Over 100 V
Over 0.1 A
(Table - 1)
(Table - 2) Note: Insertion force and extraction force are not the same as contact pressure.
These guidelines apply to the D-3000 series only. Please
note that they may not be suitable for other products.
4
Wire to Board Connectors
347
Dynamic Series Connectors
Guideline for selecting plating ( )
Contact between dissimilar metals
Combining tin and gold tends to create a lot of ionization, producing
electrolytes from condensation so corrosion is likely to occur. This
combination is not recommended because it could produce worse
results than a combination of just tin.
The above information has been summarized in "Plating selection
at a glance" for your convenience.
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Being consistent within an application
We recommend that, as much as possible, the same type of plating
be used within an application. This is to prevent connections being
made between dissimilar metals, gold and tin as mentioned above,
during assembly and maintenance. And for the same reason, we
recommend using the same plating in factories or workplaces
where assembly or harness production is done.
4) Other considerations
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Standard pressure
High pressure
Standard pressure
High pressure
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Standard specifications
Vibration
Bad environment
Extensive mating/unmating
Many contact positions
Standard specifications
Vibration
Bad environment
Extensive mating/unmating
Many contact positions
Standard specifications
Vibration
Bad environment
Extensive mating/unmating
Many contact positions
The above table is basically for industrial machinery, and was made with a wide margin. This table is not applicable for every
situation as there are many combinations depending on the application. It is intended to be used as a guideline only.
0.38Tin-plated
Plating selection at a glance
Application
Voltage/current
Below 3 V
Below 1 A
3 to 30 V
1 to 10 A
Over 30 V
Over 1 A
0.76
Gold-plated
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These guidelines apply to the D-3000 series only. Please
note that they may not be suitable for other products.