........................................................................................................................................................

TOX - Clinching-Technology® e1

TOX®- e Clinching-Technology........................................................................................................................................................

Power point with low resistance
Like conventional clinching, TOX®-eClinching provides
the advantages of very high retaining forces and easy
quality monitoring, alongside excellent electrical conductivity. For this reason, the term TOX®-eClinchingsummarizes know-how, process competence and thetechnical systems required for the production of durable
electrically-conductive connections.
The clinching procedure is ideally suited to theproduction of electronic components. Possible
applications include LED traces, fuses and the contactsof battery cells.
Compared to conventional soldered, welded and screwed connections, TOX®-eClinching provides a better
alternative, as the surfaces do not require pretreatment
and the process does not need any heat input.

II
TOX®-eClinchingcreates excellent, electricallyconductive connections throughmetallic microcontacts.
2

tox-pressotechnik.com

Process Competence........................................................................................................................................................

Creation of conductivity
Areas with the best material bonding

During TOX®-eClinching, a punch presses the sheets
to be joined into a die. The undercut created by theplastic deformation ensures high retention forces in theneck area. An electrical connection is also created withexcellent conductivity.

very high (neck area)
high (base)
good

Joint zone with optimal material bonding
During the clinching process, in addition to the positive
locking and frictional connection, there is also partial
material bonding in the joint zone: The joined sheets
flow into each other in such a way that an optimallyconductive joint is created with the lowest possible
contact resistance due to a large number of micro-contacts.
Enlarged contact surface
The effective contact surface is almost doubled with theclinch forming process. It increases more significantlyin thicker materials. This expanded surface area also
increases the conductivity of the joint.
Numerous microcontacts
assist in the conductive
connection of thematerials.

Flowing coatings
Soft coatings, for example tin coatings on copper, flow
without removal while being thinned to a few μm inthickness. The conductivity is maintained.

Source: TU Dresden

Comparison of contact surfaces
Point nominal diameter

2 mm

2 mm

2 mm

5 mm

5 mm

6 mm

8 mm

Sheet thickness on punch side

0.35 mm0.80 mm0.30 mm0.50 mm

0.60 mm0.35 mm1.15 mm

Sheet thickness on die side

0.50 mm

0.60 mm0.30 mm0.50 mm

0.60 mm0.80 mm1.15 mm

Level reference plane

4.91 mm2

4.91 mm2

4.91 mm2

28.3 mm2

28.3 mm2

38.46 mm2

63.58 mm2

Resulting contact surface

7.67 mm2

7.87 mm2

7.72 mm2

42.55 mm2

44.02 mm253.80 mm2

107.8 mm2

Increase of contact surface

56 %

60 %

57 %

50 %

55 %

39 %

69 %
Source: TU Dresden3Process Competence........................................................................................................................................................

Permanently low contact resistance
TOX®-eClinching is an efficient technology to joinelectrically conductive components safely andpermanently, both mechanically and electrically.
Constant conductivity with high retention forces
As clinch connections safely withstand mechanicalstresses (e. g. torques) and temperature changes in thelong-term, when compared to other joining processes,
the relaxation of the connection is not a significant
factor. The contact resistance will therefore beconstantly low, and the high conductivity will bemaintained. This makes the procedure ideally suited tomeet the high demands of the electrical industry.

A TOX®-eClinch Point remains safely
in the stable range (green point).
Joint relaxation, which is principally unavoidable, is insignificant andpractically not quantifiable.
If the process-specific characteristics are not observed, there is a riskof entering the unstable range (redpoint).

Resistance R

Relaxations in the contact areaRK

unstablestableTensioning
Relaxation
RK = Contact resistance
RM = Material resistance

Joining process
RM
Strength reduction due to relaxation
Contact force FK; mechanical stress σTolerant procedure
To ensure electrical connection, it is important toconsider crucial steps in the design phase. Perfect joint
formation with an ideal remaining bottom thickness andthe resulting high conductivity can only be achieved byusing optimized TOX®-eClinching tools. Even with multi-material clinch joints, the contact resistance does notincrease significantly and the high conductivity is maintained.

K

Contact resistance with tool misalignment
TOX®-eClinching points were measured in tests
with increasing offset, and the contact resistance
was measured. The result: The high conductivity ismaintained even for off-center clinching points.

μΩResistance R

20
1510
500.2

Materials
Punch side:
Die side:4

tox-pressotechnik.com

0.25

0.5mm Offset

Cu ETP R290 sheet thickness 0.8 mm
Cu ETP R290 sheet thickness 0.8 mm

Process Competence........................................................................................................................................................

Flexible installation possiblities
Precision in serial production
With exact placement of the technology in a production
tool, the TOX®-eClinch Points can be precisely
positioned on the piecepart. Process monitoring checks
the joining process to ensure the high quality of theconnections.
Consistent dynamic strength
In comparison to spot welding, the clinching process
does not have the negative properties of the notch
effect. This allows the joint strength to remain constantover various load cycles.
Control dimension X guarantees conductivity
The remaining bottom thickness of a joint affects theelectrical conductivity. As TOX®-eClinching enables
simple quality monitoring for series production, thecontinuous measurement of the control dimension Xensures the consistent conductivity of the connection.

 Frictional connection, positive locking
and material bonding in one process Highly robust connections
 No pretreatment required Joining without heat input
 Very low contact resistance Comprehensive documentation of therelevant process data
The remaining bottom thickness correlates tothe contact resistance
The remaining bottom thickness of a TOX®-eClinch
Point is called control dimension X.
Remaining bottom
thickness = control
dimension X

Compliance with this dimension is important, as
the greater the remaining bottom thickness, thehigher the resistance.
μΩ
250
Resistance R

Flexible with regard to material combinations
Different material combinations – including those thatcannot be soldered or welded – can be joined with theTOX®-eClinching technology. For example, aluminumand copper are a common combination in battery
modules and can be joined without creating an isolatingintermetallic phase. It is also ideally suited to the joiningof sensitive battery cells without heat input.

Advantages

200
150
100
Remaining bottomthickness

50
00.25

0.35

Materials
Punch side:
Die side:

0.450.55mm

Al 1050, sheet thickness 1.2 mm
Cu 5210, sheet thickness 0.4 mm

TOX®- e Clinching joins

Aluminum in copper

Copper in aluminum

Copper in brass

Steel in steel and many others.

5Process Competence........................................................................................................................................................

The perfect TOX®- e Clinch Point for every application
With know-how for maximum conductivity
To ensure electrical conductivity in the long-term,some design principles must be observed in theselection and design of the tools. The basis is the TOX®Clinch-Point shape, which is optimized to achieve thedesired material bonding.

The following point shapes are available asconductivity-optimized versions for TOX®-eClinching:

TOX®- e Round-Joint

TOX®- e SKB

The classic: A round punch presses the materials
to be joined into the round solid die. The result isan aesthetically pleasing round button, which joins
cleanly without any burrs or sharp edges on thesheet metals.

The special die consists of solid and movablesegments. The solid segments center the material
and the punch. The movable elements allow flow
behind the material in the joint.

TOX®- e MICROpoint

TOX®- e TWINpoint

The miniature TOX®-Round-Joint is our answer
to component miniaturization. With a diameterof 2 mm, it is ideal for sheet metal thicknessesof 0.2 – 0.5 mm. As an eClinch joint it is ideal
for joining small
components, as
it ensures propermaterial bonding
along with a small
diameter.

This double joint version provides protection
against rotation and increases the joint strengthcompared to the single joint. Therefore, it is ideal for
eClinching to counteract mechanical relaxation.

6tox-pressotechnik.com

Application examples........................................................................................................................................................
Components as application examples
for TOX®-eClinching
Control box for
li-ion battery
Bus barPlug connection
Fuse box

Auxiliary heater

Bus connection
for building technology
Fuse with U-shaped rail

Fuse box

TOX®-Press
for the joining of fuses
and sheet metal parts.

Power bridgewith capacitor

Plug connection
Pole terminal

TOX®-FinePress
for the joining of electric parts
with a TOX®-MICROpoint.

TOX®-Press Stationfor eClinching offuse components.

7........................................................................................................................................................

TOX® PRESSOTECHNIK GmbH & Co. KG
Riedstrasse 488250 Weingarten / Germany
Find your local contact partner at:
tox-pressotechnik.com
792848 / 81.202103.en Subject to technical modifications.

8

tox-pressotechnik.com