Guide rings
Outer locator rings for cantilever cards. Fine-ground contact faces, micro-chamfered edges so needle tips are never damaged during strip and load.
Guide rings, guide plates and ejector inserts for cantilever and vertical / MEMS probe cards. We currently supply Si₃N₄ probe card ceramics to probe card manufacturers in Taiwan, Japan, Korea and mainland China.
A guide ring or plate positions the needle array over each die and absorbs the Z-axis load of every touchdown. One wafer-sort step can mean hundreds of thousands of touchdowns per week, so the guide wears through needle chatter, planarity loss, particle generation and repeated autoclave / plasma cleaning. When it wears out, needles, PCB and the rest of the ceramics get scrapped with it.
Outer locator rings for cantilever cards. Fine-ground contact faces, micro-chamfered edges so needle tips are never damaged during strip and load.
Multi-hole guide plates for vertical and MEMS probes at fine pitch. Hole arrays held in one grinding setup to keep positional accuracy across the plate.
Ejector inserts and pins that survive repeated touchdowns without mushrooming or shedding debris onto pads.
Also available: insulating sheets, alumina and zirconia guides where the wear data supports them. We recommend the material from your wear data, not the other way around.
| Item | Standard capability |
|---|---|
| Material | GPS-sintered Si₃N₄; density ≥ 3.20 g/cm³, hardness ≥ 1500 HV, flexural strength ≥ 750 MPa. RoHS-compliant, no free silica. |
| Dimensional control | OD / ID tolerances to ±0.005 mm; flatness ≤ 0.003 mm on sealing faces; thickness-matched sets available. |
| Surface finish | Ra ≤ 0.1 µm standard on contact faces; ≤ 0.025 µm lapped on request. Edges micro-chamfered to protect needle tips. |
| Cleanliness | Ultrasonically cleaned and double-bagged — ready for cleanroom introduction without re-cleaning. |
| Inspection | Full CMM report with first articles and per-lot inspection records for production. |
Probe guides fail by a mix of sliding wear and edge chipping. Alumina is hard but brittle — chipped corners are fatal near pads. Zirconia is tough but heavy, and its low thermal conductivity disturbs thermal test heads. Si₃N₄ combines hardness with 6.5–8 MPa·m½ toughness and machines to a fine finish with no conductive coating.
| Property | Si₃N₄ (GPS) | Al₂O₃ 99% | ZrO₂ | Tool steel / POM |
|---|---|---|---|---|
| Hardness (HV) | ~1500–1600 | ~1400–1600 | ~1200–1300 | ≤ 700 / negligible |
| Fracture toughness (MPa·m½) | 6.5–8 | 3–4 | 8–10 | — |
| Wear life as a guide | Baseline (longest) | ≈ 1/3–1/5 of Si₃N₄ | Good, but heavy | Short; swells with humidity |
| Chipping / particle risk | Very low | Higher (brittle) | Low | High (metal debris) |
| Electrical insulation | Insulating | Insulating | Insulating | Steel: conductive |
| Water absorption | 0% | 0% | 0% | POM: yes |
| Density (g/cm³) | 3.20–3.26 | 3.85–3.95 | ≈ 6.0 | ≈ 7.8 / 1.4 |
| Plasma / chemical cleaning | Stable | Stable | Stable | Degrades |
Repeat-order customers typically qualify us with a first-article dimensional and wear trial, then move to scheduled blanket orders on 8–12 week schedules.
Prototype quantities start at 1–10 pcs, so a qualification trial does not require a production commitment.
Probe card guides are not bought in and resold. NitriCeram is a brand of Shandong Dolphin Technology Co., Ltd., operating an integrated line from powder synthesis through forming, gas-pressure sintering, HIP, precision grinding and in-house testing.
We reply within 24–48 hours with a DFM review, recommended grade and price. NDA signed on request before drawings change hands.
Reading first? See the technical article Silicon Nitride Probe Card Guides: Why Leading Probe Card Makers Choose Si₃N₄.
