To protect your investment, prevent probing errors and avoid device damage, be sure to carefully follow the four-step cleaning process described here for the off-line cleaning of your Pyramid Probe card core. Failure to follow these steps could result in damage to your probe card.
The required materials you’ll need to complete the core cleaning process include:
- Brush supplied from Cascade Microtech that is labeled as such
- Solvent: Isopropyl alcohol (2-propanal) CMOS grade, 99.5% and Methanol CMOS grade
- Equipment
- CDA (clean, dry air) or N2 (nitrogen) nozzle regulated to 40 psi maximum (2.75 bars or 275 kPa)
- Low-power, stereo-zoom microscope
- Ring lighting works best
- 10x to 50x zoom range
- Clean-room gloves
- CDA (clean, dry air) or N2 (nitrogen) nozzle regulated to 40 psi maximum (2.75 bars or 275 kPa)
- Wearing gloves is recommended when handling Pyramid Probe cards
- Avoid touching the probe card face or probe tips with the metal ferrule or handle of the brush
- Never clean the sides (wings) of the core. Only clean the probe card face
- Use a maximum of 40 psi (275 kPa) air-nozzle pressure on Pyramid Probe card cores
- Before any type of cleaning, always inspect the Pyramid Probe core placed on a flat surface, wafer-side up, under the microscope
Step 1: Inspecting the Probe Card Core
Inspect the core under the microscope for any damage and/or loose particles. If loose particles are found, hold an acceptable air nozzle vertical to the probe card face, three inches (75 mm) from the core. Activate the air stream before approaching the core with the air nozzle, as the nozzle will tend to move forward even at low pressure. Continue to Step 2: Preparing the Cleaning Brush. If no loose particles are found, go directly to Step 2: Preparing the Cleaning Brush.
Step 2: Preparing the Cleaning Brush
Complete the following steps to ensure that the brush is clean and you are not adding particles to the membrane or causing damage:
- Aiming the air nozzle away from the microscope and work area, blow out any debris in the brush head
- Use a squeeze bottle of IPA or methanol to wet the brush, and then blow out the brush head again
Step 3: Cleaning With Brush
Complete the following steps to moisten or loosen any particles or residue on the probe card face. Then remove the particles or residue with strokes of the cleaning brush.
- Use a squeeze bottle of IPA or methanol to re-wet the brush
- Hold the brush vertical to the probe face
- Starting from either the left or right side of the probe face, use a circular motion to clean across the probe face and back again. Use enough force to feel the probe tips. If the brush tip begins to dry, apply more IPA or methanol. Do not allow the brush to dry out
- Clean the brush again, according to the steps described in Step 2: Preparing the Cleaning Brush
- Re-wet the brush and use smooth brushstrokes to wipe the probe card face from edge to edge. DO NOT use a back and forth motion
- Repeat from top to bottom to remove particles from entire probe face.
Step 4: Blow Away Particles and Solvent
Complete the following steps to blow the remaining IPA or methanol containing particles/residue away from the probe card face.
- Hold an acceptable air nozzle vertical to the probe face, three inches (75 mm) from the core. Activate the air stream before approaching the core with the air nozzle, as the nozzle will tend to move forward even at low pressure
- Continue blowing air on the probe face until it is visibly dry, approximately 30-60 seconds
- Return to Step 1: Inspecting the Core, and repeat steps 2, 3 and 4 until all particles have been removed
That should do it. You should be left with a clean Pyramid Probe card. If you have any questions please leave a comment below and we’ll get back to you. You can also reference a detailed off-line probe card cleaning guide that has some visuals which may be of help.
