Surface-mount Fuses
Fundamentals
Overview
TE Circuit Protection offers the widest selection of surface-mount
fuses available for addressing a broad range of overcurrent
protection applications. Helping to prevent costly damage and
promote
a safe environment for electronic and electrical
equipment, our single-use chip fuses provide performance stability
to support applications with current ratings from .5A up to 20A.
TE Circuit Protection also offers the telecom FT600 fuse for
telecommunications applications. This telecom fuse helps comply
with North American overcurrent protection requirements,
including Telcordia, GR-1089, TIA-968-A (formerly FCC Part 68),
and UL60950 3rd edition.
Multi-layer Design for Chip Fuses
The multi-layer design has the benefit of exposing more f
use
element surface area to the glass-ceramic absorption
m
ate
rial.
When the fuse elements open, there is more mate
rial for the
vaporizing fuse metals to absorb into, resulting in a v
ery e
ffi
cie
nt
and effective quenching of the fuse arc.
Figure 1
Multiple Fuse
Elements
Substrate Single Fuse Glass
Material Element Coating
Figure 1 compared the multi-layer design of our S
F
F fuses with
standard glass coated designs. The g
lass
coate
d designs
rely on
the coating on only one side of the
fuse element
t
o abso
rb the
vaporizing fuse material when it op
ens. Th
erefo
re
, t
here is mu
ch
less absorption material available t
o a
b
sor
b the
fu
se
metals
. T
h
e
result can be prolonged arcing and
pos
sible coatin
g bre
ach
.
Multi-layer Design
Single-layer Glass Coated Design
Fault Zones
Figure 2 shows how the absorpti
on characteristic
s of
the
two
designs differ. The multi-layer design indicates a clea
n s
ep
ara
tion
with the fuse element evenly diffusin
g into the surro
unding
ceramic substrate. In the glass coated desi
gn, the element
diffusion takes place in a small portio
n of
the dev
ice an
d is only
absorbed by the glass material dire
ct
ly
ab
ove the
area of failure.
11
Multi-layer Design
Single-layer Glass Coated Design
Wire-In-Air Design for 2410
SFV
Fuses
The 2410(6125) is a Wire-In-Air SMD F
use which is very suitable
for secondary level over current protection applications.
Figure 3
Glass fiber enforced
epoxy body
Figure 3 compared our straight wire element design 2410SFV
fuses with normal corrugating wire design fuse. The straight wire
element in air performs consistent fusing and cutting
characteristics together with excellent inrush current
withstanding capability.
Straight wire element
Copper terminal
plated with Ni and Tin
Introduced PCB assembly technology into 2410SFV fuses design
and manufacture, we achieved on lead free completely and no
end cap falling off risk comparing with traditional ceramic body
with end cap fuse.
Ceramic body
Corrugate wire element
End cap plated with Tin
75