Semiconductor "U" & "M"
Strain Gages Data Sheet
"U" Shaped Gage
Part Number |
Width |
Lead Attachment |
Thickness |
Resistance Ohms @ 78° F |
Gage Factor |
TCGF |
TCR |
|---|---|---|---|---|---|---|---|
| SS-018-011-3000PU | 0.012 | Ball Bond | 0.0004 | 3000±150 | 100±10 | -23% | 42% |
| SS-037-022-500PU | 0.016 | Welded | 0.0004 | 540±50 | 150±10 | -13% | 17% |
| SS-047-025-350PU | 0.016 | Welded | 0.0004 | 325±40 | 100±10 | -10% | 6% |
| SS-047-025-500PU | 0.016 | Welded | 0.0004 | 540±50 | 140±10 | -13% | 16% |
| SS-047-025-1000PU | 0.016 | Welded | 0.0004 | 1000±100 | 160±10 | -20% | 28% |
| SS-060-033-300PU | 0.016 | Welded | 0.0004 | 325±40 | 100±10 | -10% | 6% |
| SS-060-033-500PU | 0.016 | Welded | 0.0004 | 540±50 | 140±10 | -12% | 14% |
| SS-060-033-2000PU | 0.016 | Welded | 0.0004 | 2000±100 | 155±10 | -18% | 24% |
| SS-037-022-10000PU | 0.013 | Welded | 0.0004 | 10000±1000 | 175±10 | -23% | 42% |
| SS-095-060-350PU | 0.016 | Welded | 0.0004 | 350±50 | 120±10 | -9% | 5% |
"M" Gage Schematic
Part Number |
Width |
Lead Attachment |
Thickness |
Resistance Ohms@ 78°F |
Gage Factor |
TCGF |
TCR |
|---|---|---|---|---|---|---|---|
| SS-060-040-2500PM | 0.032 | Welded | 0.004 | 2500±150 | 140±10 | -13% | 17% |
Standard Semiconductor Strain Gages
Piezo-Metrics semiconductor strain gages are made from “P” doped bulk silicon. This is a two terminal resistive device. The silicon is micro machined to shape thus eliminating molecular dislocation or cracks, thereby optimizing performance.
Standard Gage Specifications
| Materials | Czochralski pulled boron doped silicon |
| Leads | .002 dia. Gold x 0.5 in. long. Some gages have .0015 dia. Leads. |
| Contact Pads | Deposited gold with titanium-tungsten adhesion layer |
| Lead Attachments | Wedge-bonded, ball-bonded or parallel gap welded |
| Operating Strain | ±2000 μ inch/inch (3000 μ inch/inch max.) |
| Linearity | Better than ±0.25% to 600 μ inch/inch Better than ±1.5% to 1500 μ inch/inch |
| Max. Operating Temperature | 500°F |
Ordering Guidelines and Examples
A > B > C > D > E > F > G > H |
SS > 080 >0505 > 120 > PB > B > M2 |
|||||
|---|---|---|---|---|---|---|
| A. Model (SS) | SS-080-050-500P U S4 is a Semiconductor Strain gage with a total length of 080 and an active length of 050. The gage has a nominal resistance of 500 at 78 degrees F. The gage is further defined as Dopant P and Configured as a “U”* Gage. S4 specifies a matched set of 4 gages. | B. Total Length | ||||
| C. Active Length |
| |||||
| D. Nominal Resistance at 78° F | ||||||
| E. Dopant | ||||||
| F. U Gage, M Gage, or Leave Blank for Bar Gage* | ||||||
| G. Specifies Single, Matched or Bulk Gages |
Standard Bridge Matching
| Temperature°F Standard Matching |
0°F ±0.6% |
78°F ±0.4% |
278°F ±0.4% |
Percent of Base Resistance |
Standard Packaging
Gages are packed in clear plastic boxes measuring approximately one inch square.
Each clear box lid is labeled with information about the gage.
- Temperature °F is noted along with the corresponding Resistance in Ω
- Gage lot Number is marked as Lt.
- Computer System number used to measure the resistance over temperature
- Gage Position Number identifies the position of the gage on the board in the temperature chamber.
Notes:
- The computer system also measures and records reverse current and TCR ( Thermal Coefficient of Resistance ). This data is used to detect nonperforming gages allowing them to be removed from production.
- Gages are package one gage to a clear box with each box having its own
label. Matched sets will be joined together with clear plastic tape on the
bottom of the boxes.
Matched Gage Information
There are many uses for semiconductor strain gages and to accommodate these applications, Piezo-Metrics offers a number of matching options. SS-060-033-500P-xx
S1 is a single gage, tested and with data.
S2 is a thermally matched set of two gages, tested with data. S4 is a thermally matched set of four gages, tested with data.
We recommend a spare gage be purchased in the event that a gage is damaged during installation. An S3 or S5 at the end of the part number should be designated for this request.
For double bridges requiring eight gages you would specify an S8 at the end of the gage number or S9 for a Spare.
| Ohms | 0°F | 477 |
| 78°F | 517 |
| 278°F | 674 |
Matched Gage Information
There are many uses for semiconductor strain gages and to accommodate these applications, Piezo-Metrics offers a number of matching options. SS-060-033-500P-xx
S1 is a single gage, tested and with data.
S2 is a thermally matched set of two gages, tested with data. S4 is a thermally matched set of four gages, tested with data.
We recommend a spare gage be purchased in the event that a gage is damaged during installation. An S3 or S5 at the end of the part number should be designated for this request.
For double bridges requiring eight gages you would specify an S8 at the end of the gage number or S9 for a Spare.
Standard Matching
Standard Matching is at Three Temperatures and adhere to the following tolerances.
| 0°F | +/- 3 ohms |
| 78°F | +/- 2 ohms |
| 278°F | +/- 2 ohms |
Custom Matching
In general, tighter matching permits better performance especially with respect to bridge temperature compensation. When gages are to be used below 0 F, additional testing is required.
Piezo-Metrics does offer special matching upon request. (Examples Below)
| 500 Ohms matched | 1000 Ohms Matched | ||
|---|---|---|---|
| 0°F | +/- 2 ohms | -65°F | +/- 6 ohms |
| 78°F | +/- 1 ohm | 0°F | +/- 6 ohms |
| 278°F | +/- ohm | 78°F | +/- 4 ohms |
| 278°F | +/- 4 ohms | ||
Since the options for matching and temperature are numerous, please consult with our engineers who will advise if more accurate matching is required for your application 1-805-522-4676.
| Piezo-Metrics: U-Gage | |||
| UNLESS OTHERWISE SPECIFIED Dimensions are in inches tolerances: Angular: mach ±0*30 One place decimal ±0.03 Two place decimal ±0.010 Three place Decimal ± .005 All dia .005 Tir. Radii .005 Max Surface finish | Drawn: 09/09/13 | ||
| PROPRIETARY AND CONFIDENTIAL The information contained in this drawing is the sole property of Piezo-Metrics. Reproduction in part or as a whole without the written permission of Piezo-Metrics is prohibited. | Checked: 09/09/13 |
| Piezo-Metrics: M-Gage | |||
| UNLESS OTHERWISE SPECIFIED Dimensions are in inches tolerances: Angular: mach ±0*30 One place decimal ±0.03 Two place decimal ±0.010 Three place Decimal ± .005 All dia .005 Tir. Radii .005 Max Surface finish | Drawn: 09/09/13 | ||
| PROPRIETARY AND CONFIDENTIAL The information contained in this drawing is the sole property of Piezo-Metrics. Reproduction in part or as a whole without the written permission of Piezo-Metrics is prohibited. | Checked: 09/09/13 |
Below are descriptions and Illustrations of the Gold or Aluminum wire bonds used in the manufacturing of P-doped Silicon semiconductor strain gages and N- doped temperature sensors at Piezo-Metrics.
Types of Bonding
Parallel Gap
Parallel gap bonding is a resistance weld.
This weld uses High current and two Tungsten conductors spaced a short distance apart on the gold pads. Pressing the 0.002 diameter pure gold lead wire to the pads under high current welds the gold wire to the gold pad creating the bond. The leads come off the gage axially and are a minimum length of .050”.
Commonly used on the Straight “Bar”, “U” or “M” shaped gages.
Parallel Gap Bond on a "BAR" Shaped Gage
| Piezo-Metrics: Parallel Gap Bonding | |||
| UNLESS OTHERWISE SPECIFIED Dimensions are in inches tolerances: Angular: mach ±0*30 One place decimal ±0.03 Two place decimal ±0.010 Three place Decimal ± .005 All dia .005 Tir. Radii .005 Max Surface finish | Drawn:9/19/14 | ||
| PROPRIETARY AND CONFIDENTIAL The information contained in this drawing is the sole property of Piezo-Metrics. Reproduction in part or as a whole without the written permission of Piezo-Metrics is prohibited. | Checked:9/19/14 |
Ball Bonding
The ball bond is an elevated temperature ultrasonic bond.
Gold wire ( 0.0020 or 0.0015 diameter) is grabbed by a ceramic capillary, a tail of Gold wire is formed at the first cut off and forms a ball. This ball is vibrated as it presses onto the Gold or Aluminum pad fusing it to the pad as shown. Both gold wires are initially perpendicular to the gage then are bent 90 within .100”. Wires are minimum length of .050”. This bond is used when pad space is limited (small and miniature gages).
Commonly used on the Straight “Bar”, or “U” shaped gages.
Ball Bond on a "BAR" Shaped Gage
| Piezo-Metrics: Ball Bonding | |||
| UNLESS OTHERWISE SPECIFIED Dimensions are in inches tolerances: Angular: mach ±0*30 One place decimal ±0.03 Two place decimal ±0.010 Three place Decimal ± .005 All dia .005 Tir. Radii .005 Max Surface finish | Drawn:9/19/14 | ||
| PROPRIETARY AND CONFIDENTIAL The information contained in this drawing is the sole property of Piezo-Metrics. Reproduction in part or as a whole without the written permission of Piezo-Metrics is prohibited. | Checked:9/19/14 |
Wedge Bond
An ultrasonic bond fusing the gage lead wire onto the pad with pressure and vibration.
Although this weld can be used with Gold or Aluminum pads and with Gold or Aluminum lead wires, Piezo-Metrics currently stocks only one gage, the 0.047-025-1000PU with 0.0030 diameter pure Aluminum leads that are a minimum of .050” long wedge bonded onto aluminum pads. This gage is operational up to 1000 degrees F.
Commonly used on the “U” shaped gages.
Wedge Bond on a "U" Shaped Gage
| Piezo-Metrics: Wedge Bonding | |||
| UNLESS OTHERWISE SPECIFIED Dimensions are in inches tolerances: Angular: mach ±0*30 One place decimal ±0.03 Two place decimal ±0.010 Three place Decimal ± .005 All dia .005 Tir. Radii .005 Max Surface finish | Drawn:9/19/14 | ||
| PROPRIETARY AND CONFIDENTIAL The information contained in this drawing is the sole property of Piezo-Metrics. Reproduction in part or as a whole without the written permission of Piezo-Metrics is prohibited. | Checked:9/19/14 |
