. Be careful not to exert too much force on the sample. Clamping introduces stress on the package/wafer that can result in cracking or warping during the thinning process.
Image Added |
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* _Proper contact angle in this image is exagerated for illustrative purposes. |
Typical Sample Mounting Technique Examples | Image Modified | Image Modified | Image Modified |
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Wax Mount to Glass Slide and Mechanically Clamped | Mechanical Clamping for Decapsulation Image from http://www.ultratecusa.com
| Wax Mounting Direct to Sample Holder Image from http://www.ultratecusa.com |
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Selected Area Polish of Wafer Backside Process ExampleSet Processing ParametersThe parameters needed for backside polishing are directly observable and will not require cross sectioning of a sample as is required with decapuslation. The tool can only polish a rectangular area with radiused corners, no other geometry is possible. - Tool rotational speed (2000 rpm recommended starting point)
- Minimum: 1600 rpm
- Maximum: 2400 rpm
- Table speed (3.5 mm/sec recommended starting point)
- Geometry
- Start Point (μm)
- Xstart = - (Length of Area to polish in X axis-Tool Diameter) / 2
- Ystart = (Length of Area to polish in Y axis-Tool Diameter) / 2
- End Point (μm)
- Xend = (Length of Area to polish in X axis-Tool Diameter) / 2
- Yend = - (Length of Area to polish in Y axis-Tool Diameter) / 2
- Depth of polish in Z axis (μm)
- Processing times
- As a general rule, the more area to be thinned and polished the longer each step of the process will take, increase processing time accordingly.
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Area to be Polished * Length x Width (mm2) | Tool Diameter (mm) | Suggested Polishing Force ( grams) | Processing factor (seconds/mm2) |
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up to 4 | 0.4 | 5 | 300 | 4 to 9 | 0.7 | 15 | 100 | 9 to 36 | 1.0 | 30 | 25 | 36 to 81 | 2.0 | 100 | 12 | 81 to 225 | 3.0 | 300 | 4.0 | 225 to 625 | 5.0 | 500 | 1.5 | 625 and up | 8.0 | 900 | 0.5 | - Corner radius need not be taken into consideration for calculating area to be polished.
- To estimate processing time in seconds, based on the tool diameter selected, select
the appropriate processing factor and multiply by processing area. Values are typically between 5 and 15 minutes.
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Instructions | Graphics |
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Step 1 - Set the processing timer - Navigate to Keypad Screen
- Press Image Modified, enter appropriate time in seconds then press Image Modified.
| Image Modified | Step 2 - Set the table rastering speed (3.5 mm/s recommended) - Navigate to Keypad Screen
- Click Image Modified, enter desired table speed into the field, then click Image Modified.
| Image Modified | Step 3 - Select polishing pattern - Navigate to Table Travel Pattern Select screen
- Click on the radio button below the desired pattern.
(ASAP-1 or ASAP-1 X recommended)
| Image Modified | Step 4 - Set polishing force - Navigate to Keypad Screen
- Press Image Modified, enter appropriate force in grams, then press Image Modified.
| Image Modified | Step 5 - Set tool diameter - Navigate to Load/Save Recipes screen and press Image Modified button.
- Click radio button next to selected tool diameter
| Image Modified | Step 6 - Verify above settings are active - Navigate to the Load/Save Recipes Screen
- In the left column review:
- Time setting
- Speed setting
- Selected pattern
- Force setting
- In the right column review:
| Image Modified |
Processing - Four StepsThis process recipe should be considered a guide, the procedure can be modified to meet your specific needs. The following procedure should yield a thinned surface with no scratches in a cavity the size of your choosing.
| Tool Type | Application | Coolant/Slurry | Process Time (minutes) |
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Stage 1 | Fine Diamond | Silicon Thinning | Extender Fluid | 10 per 50 μm | Stage 2 | XYLEM | Pre-polish | Blue diamond paste and extender fluid | 10 | Stage 3 | XYLEM | Intermediate polish | Yellow diamond paste and extender fluid | 10 | Stage 4 | XYBOVE | Final polish | Colloidal Silica | 5 | * Process times are flexible and you may need to run the polishing steps longer to achieve your desired results. |
Processing Stage 1 - Silicon Thinning Expand |
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Instructions | Graphics |
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Step 1 - Mount the selected diameter Fine Diamond tool into the spindle. - Make sure to align the flat on the tool shank with the set screw
when inserting the tool into the spindle. Image Modified
| Image Modified | Step 2 - Mount the sample to be thinned. - Wafer piece mounted backside up onto a glass slide using
Crystal Bond 555-HMP and then mechanically clamped to the sample holder shown.
| Image Modified | Step 3 - Apply one to two drops of Extender Fluid to the area to be polished. | Image Modified | Step 4 - Gently lower the head into operating position.Image Modified- Be careful, damageto the tool will occur, and you may be
held responsible for damages, if you release the locking mechanism and allow the polishing head to drop onto the force sensor.
| Image Modified | | Image Modified | |
Image Modified | | Image Modified Image Modified | | Image Modified Image Modified | | Image Modified | Step 10 - Start the spindle (2000 RPM recommended)- From the Keypad screen, click Image Modified, enter desired rotational speed into
the field, then click Image Modified. The spindle will begin rotating at the set speed.
| Image Modified | | Image Modified Image Modified Image Modified | Step 12 - Continuing to thin the sample - Since our extender fluid will become saturated with ground material,
if you need to thin your sample by more than 50 μm, you should do so in multiple steps. - From the Keypad screen click Image Modified, enter 20 into field,
then click Image Modified. The head should lift 20 μm off the sample and force should read ~0. - Use your hand to gently lift the head to the top of travel. Engage the
locking handle by rotating the handle clockwise until tight. Make sure the head is locked before removing the support of your hand. - Wipe up the used extender fluid using a clean wipe and isopropyl
alcohol. - Apply another drop or two of fresh extender fluid.
- Gently lower the head into operating position.
Image Modified - Be careful, if you release the locking mechanism and allow the
polishing head to drop onto the force sensor, damage to the tool will occur.
- Return to Step 10 above and continue. Repeat steps 10 through 12 until
the desired thinning has been achieved.
| Rasing the head Image Modified
Lowering the head Image Modified
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Processing Stage 2 - Pre-polishInstructions | Graphics |
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Step 1 - Raise the head to allow access to the sample and tool. | Image Modified | Step 2 - Thoroughly clean your sample and realign for pre-polish - After the thinning process it is necessary to thoroughly clean your
sample to remove large particles that would cause scratches that can't be removed during the pre-polish step. - If the sample was removed for cleaning, you must realign and clamp your
sample, see these instructions.
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| Step 3 - Mount the selected diameter Xylem tool into the spindle. - Make sure to mount the tool reserved for the blue diamond paste, it will
be marked with blue paint on the mounting flat. - Make sure to align the flat on the tool shank with the set screw
when inserting the tool into the spindle.
| Image Modified | Step 4 - Apply a small amount of Blue Diamond paste to the thinned area. | Image Modified
| Step 5 - Apply one to two drops of Extender Fluid to the thinned area and spread blue diamond paste. | Image Modified | Step 6 - Gently lower the head into operating position. Image Modified- Be careful, if you release the locking mechanism and allow the
polishing head to drop onto the force sensor, damage to the tool will occur.
| Image Modified | | Image Modified Image Modified Image Modified | Step 8 - Move to the center of the selected area - Navigate to the Set Scan Start/Endpoints screen
- Press Image Modified. The head will move to the defined XY origin.
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| | Image Modified | Step 10 - Start the spindle (2000 RPM recommended) - From the Keypad screen, click Image Modified, enter desired rotational speed into
the field, then click Image Modified. The spindle will begin rotating at the set speed.
| Image Modified | | Image Modified Image Modified Image Modified |
Instructions | Graphics |
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Step 1 - Raise the head to allow access to the sample and tool. | Image Modified | Step 2 - Thoroughly clean your sample and realign for intermediate polish - After the blue compound it is necessary to thoroughly clean your
sample to remove large particles that would cause scratches that can't be removed during the intermediate polish step. - If the sample was removed for cleaning, you must realign and clamp your
sample, see these instructions.
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| Step 3 - Mount the selected diameter Xylem tool into the spindle. - Make sure to mount the tool reserved for the yellow diamond paste, it will
be marked with yellow paint on the mounting flat. - Make sure to align the flat on the tool shank with the set screw
when inserting the tool into the spindle.
| Image Modified | Step 4 - Apply a small amount of Yellow Diamond paste to the thinned area. | Image Modified | Step 5 - Apply one to two drops of Extender Fluid to the thinned area and spread yellow diamond paste. | Image Modified | Step 6 - Gently lower the head into operating position. Image Modified- Be careful, if you release the locking mechanism and allow the
polishing head to drop onto the force sensor, damage to the tool will occur.
| Image Modified | | Image Modified Image Modified Image Modified | Step 8 - Move to the center of the selected area - Navigate to the Set Scan Start/Endpoints screen
- Press Image Modified. The head will move to the defined XY origin.
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| | Image Modified | Step 10 - Start the spindle (2000 RPM recommended) - From the Keypad screen, click Image Modified, enter desired rotational speed into
the field, then click Image Modified. The spindle will begin rotating at the set speed.
| Image Modified | | Image Modified Image Modified Image Modified |
Processing Stage 4 - Final polishInstructions | Graphics |
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Step 1 - Raise the head to allow access to the sample and tool. | Image Modified | Step 2 - Thoroughly clean your sample and realign for intermediate polish - After the blue compound it is necessary to thoroughly clean your
sample to remove large particles that would cause scratches that can't be removed during the intermediate polish step. - If the sample was removed for cleaning, you must realign and clamp your
sample, see these instructions.
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| Step 3 - Mount the selected diameter Xbove tool into the spindle. - Make sure to mount the tool reserved for the yellow diamond paste, it will
be marked with yellow paint on the mounting flat. - Make sure to align the flat on the tool shank with the set screw
when inserting the tool into the spindle.
| Image Modified | Step 4 - Apply one to two drops of Extender Fluid to the thinned area and spread yellow diamond paste. | Image Modified | Step 5 - Gently lower the head into operating position. Image Modified- Be careful, if you release the locking mechanism and allow the
polishing head to drop onto the force sensor, damage to the tool will occur.
| Image Modified | | Image Modified Image Modified Image Modified | Step 7 - Move to the center of the selected area - Navigate to the Set Scan Start/Endpoints screen
- Press Image Modified. The head will move to the defined XY origin.
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| | Image Modified | Step 9 - Start the spindle (2000 RPM recommended) - From the Keypad screen, click Image Modified, enter desired rotational speed into
the field, then click Image Modified. The spindle will begin rotating at the set speed.
| Image Modified | | Image Modified Image Modified Image Modified |
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