44
Intel
®
Celeron
®
D Processor in the 775-Land LGA Package
Thermal Design Guide
Order #303730
Heatsink Clip Load Metrology
B.5.8
Typical Test Equipment
For the heatsink clip load measurement, use test equipment equivalent to that listed in
.
NOTES:
1. Select load range depending on expected load level. It is best to operate in the high end of the load cell
capability if possible. Check with your load cell vendor for further information.
2. Since the load cells are calibrated in terms of mV/V, a data logger or scanner is required to supply 5 VDC
excitation and read the mV response. An automated model will take the sensitivity calibration of the load cells
and convert the mV output into pounds.
3. With the test equipment listed above, it is possible to automate data recording and control with a 6101-PCI
card (GPIB) added to the scanner, allowing it to be connected to a PC running LabVIEW* or StrainSmart*
software.
4.
IMPORTANT
: In addition to just a zeroing of the force reading at no applied load, it is important to calibrate
the load cells against known loads. Load cells tend to drift. Contact your load cell vendor for calibration tools
and procedure information.
5. When measuring loads under thermal stress (bake for example), load cell thermal capability must be
checked and the test setup must integrate any hardware used along with the load cell. For example, the
Model 13 load cells are temperature compensated up to 71°C as long as the compensation package (spliced
into the load cell's wiring) is also placed in the temperature chamber. The load cells can handle up to 121°C
(operating), but their uncertainty increases according to 0.02% rdg/°F.
Figure 18. Preload Test Configuration
Load Cells (3x)
Preload Fixture (copper
core with milled out pocket)
Table 7. Typical Test Equipment
Item
Description
Part Number
Load cell
Notes: 1, 5
Honeywell*-Sensotec* Model 13 subminiature load cells,
compression only. Select a load range depending on
load level being tested.
www.sensotec.com
AL322BL
Data Logger (or scanner)
Notes: 2, 3, 4
Vishay* Measurements Group Model 6100 scanner with
a 6010A strain card (one card required per channel).
Model 6100