Surface Mounted
Resistors
Welwyn Components
CR Series
Application Notes
Operating Temperature Range
Packaging
Wrap-around Termination
Chip resistors are supplied taped and reeled on standard
8mm tape to IEC 286-3.
The chips themselves can operate at a maximum temperature
of 155°C (see performance claims above). For soldered chips,
the joint temperature should not exceed 110°C. This
condition is met when the stated power levels at 70°C are
used.
Quantity per reel; 3000 max.
Mounting
Planar Terminations
Resistor chips are supplied in waffle packs.
This chip resistor is ideally suited for handling by automatic
methods due to its rectangular shape and the small
dimensional tolerances. Electrical connection to a ceramic
substrate or to a printed circuit board can be made by wire
bonding (eg suffix ‘G’ in CR0805G) or by reflow soldering of
wrap-around terminations (eg suffix ‘F’ in CR0805F).
The ‘F’ terminations provide good leach properties and ensure
reliable contact. Due to the robust construction the resistor
chip can be immersed in the solder bath for 30 seconds at
260°C. This enables the resistor to be mounted on one side
of a printed circuit board and other wire-leaded components
on the other side.
Ordering Procedure
Specify type reference, value and tolerance as shown in this example of CR0805 10M 0.1%:
Type
CR0805
10M
B
Resistance value
(IEC62 code)
Tolerance
(IEC62 code)
B
C
D
F
0.1%
0.25%
0.5%
1%
G
J
2%
5%
© Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com
Issue F · 10.05
19
TTELEC [ TT Electronics ]
