High Value Surface
Mounted Resistors
HR Series
Welwyn Components
•
Custom designs / sizes available
•
Resistance range to 50G ohms
•
Terminations available for wire bonding
or soldering
•
Low voltage coefficient of resistance
Electrical Data
Power Rating
The high resistance value of these devices is such that power dissipation is always small. The rating is therefore determined by
voltage considerations only, as shown in the table below.
0503
Resistance range*
Limiting element voltage
Ambient temperature range
TCR
Resistance tolerance
ohms
volts
°C
ppm/°C
%
0 to -2500
10M to 500M:10
>500M : 25, 50
10M to 20G
50
100
-55 to + 155
0 to -2000
0 to -1500
0 to -1000
Measured at 10 volts
100M to 1G:5,10
> 1G to 50G:25, 50
0805
1005
100M to 50G
150
200
1206
Notes
Measured at 10 volts
*Higher values available, consult factory for details
Physical Data
Dimensions (mm) & Weight (g)
Wrap around
Style
0503
0805
1005
1206
†
Planar
C
0.2 ± 0.1
0.3 ± 0.1
0.4 ± 0.15
0.4 ± 0.15
Wt
0.005
0.009
0.015
0.020
A
B
L
A
W
Wrap-around terminations
(3 faces)
T
C
C
T
L
2.0 ± 0.3
2.5 ± 0.3
3.2 ± 0.4
W
1.25 ± 0.2
1.25 ± 0.2
1.6 ± 0.2
T max.
0.5
0.6
0.7
0.7
A
0.3 ± 0.15
0.4 ± 0.2
B
†
0.9min
1.7min
1.25 ± 0.2 0.63 ± 0.15
Not available
Not available
Alternative styles for
surface mounting
resistors
L
W
Planar terminations
This dimension determines the number of conductors which may pass under the surface mounted device.
Construction
The resistor material is screen printed onto a 96% alumina
substrate and covered with a protection comprising of a glaze
followed by an organic coating. This construction gives an
insulated device.
Terminations
Planar (or single-sided) termination is gold and suitable for
wire-bonding; wrap around is suitable for soldering.
Solderability
Wrap-around terminations on HR resistors have good ‘leach’
resistance properties. They will withstand immersion in solder
at 260°C for 30 seconds.
Marking
All relevant information is recorded on the primary package
or reel.
General Note
Welwyn Components reserves the right to make changes in product specification without notice or liability.
All information is subject to Welwyn’s own data and is considered accurate at time of going to print.
A subsidiary of
TT electronics plc
Issue B · 03.02
© 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
20
High Value Surface
Mounted Resistors
HR Series
Welwyn Components
Performance Data
Maximum
Load at rated power: 1000 hours at 70°C
Overload
Shelf life: 12 months at room temperature
Temperature rapid change
Change on Wave Soldering
Voltage proof
Voltage coefficient of resistance (10V - 25V)
∆
R%
∆
R%
∆
R%
∆
R%
∆
R%
volts
%/V
0805
1005
1206
1
0.8
0.2
0.4
0.3
0.05
2
1
2
1
1
0503 : 100
Typical
1
0.2
1
0.3
0.5
0805 to 1206 : 500
Application Notes
Mounting
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 to planar terminations or by reflow soldering of
wrap-around terminations. 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 and wire-
leaded components on the other side. The resistor must be
kept dry during use to avoid leakage. The presence of
moisture will not damage the resistor in any way.
Packaging
Resistor chips are supplied taped and reeled on standard
8mm tape to IEC 286-3.
Quantity per reel 3000 max.
Planar Terminations
Resistor chips are supplied in waffle packs.
Ordering Procedure
Example: HR1206 with solderable wraparound terminations at 10 gigohms and 50% tolerance
on a reel of up to 3000 pieces -
HR1206F
–
10GY
I
Type
Size
Termination
F
G
Solderable wraparound
Gold pad planar
0805, 1206 only
All sizes
Value (use IEC62 code)
Tolerance (use IEC62 code)
J
K
5%
10%
5
Y
25%
50%
Packing
I
Tape
Waffle
0805F, 1206F
G Termination
Up to 3000/reel
Standard
© 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 B · 03.02
21