https://nanyte.com/photoresists/riston-di9500m · last updated 2026-10-15
- Manufacturer
- DuPont
- Tone
- negative
- Chemistry
- Photopolymer
- Thickness
- 15–38 µm
- Developer
- Na2CO3 anhydrous 0.85-1.0 wt% (0.85 preferred), or Na2CO3 monohydrate 1.0-1.1 wt% (1.0 preferred), or K2CO3 1.0-1.1 wt% (1.0 preferred)
- Applications
- Etch mask
Cross-checked — the spin curve (where published) and the single-value figures were read twice, independently, from the datasheet, with any disagreement settled against it.
- Substrate
- Resist
- Exposed
Coating — dry-film lamination
Riston DI9500M is supplied as a pre-cut dry-film sheet and applied by hot-roll lamination — it is not spin-coated. Thickness is fixed per sheet, 15–38 µm, selected by sheet rather than by spin speed.
- Riston is hot-roll laminated onto copper-clad panels, so thickness is set by the sheet, not by a spin speed.
- Conditions given for a DuPont ASL-24 / ASL-24 Yieldmaster film laminator (p.3): lamination temperature 100 ± 10 °C, laminating-roll pressure 3.0-5.0 bar (43-72 psig), seal bar 60 ± 10 °C at 3.5-4.5 bar with a 1-4 s seal time, line speed 1.5-3 m/min (5-10 ft/min); pre-heat is optional.
- Yieldmaster models also run a water feed of 30 cc/min per valve.
- Let the panel cool to room temperature (about 30 minutes) before exposing it.
- For the best tenting, keep the hold between lamination and development short: the sheet's guideline limits are 24 hours after wet lamination and up to 3 days after dry lamination, and the film should be stripped within 5 days of lamination.
- Copper preparation before lamination (p.2) is by pumice or aluminium-oxide scrub, pad or bristle brushing, or a chemical or electrochemical clean plus microetch, checked by a water-break time of at least 30 s and a surface roughness of Ra 0.1-0.3 µm, Rz 2-3 µm.
- Racking and stacking of laminated panels is also covered on p.3; vertical racking is preferred.
- Adhesion
- No adhesion promoter is mentioned. Adhesion is managed through copper surface preparation (p.2): scrubbed copper should pass a water-break test of at least 30 s with Ra 0.1-0.3 µm and Rz 2-3 µm; double-treated copper normally needs no pre-lamination cleaning beyond tacky-roller particle removal.
Soft bake
- Soft bake
- Not published — characterize on-tool
- Notes
- No bake between lamination and exposure. The sequence on pp.3-5 goes lamination, cool-down, exposure, hold, develop.
SOURCE: Lamination and Exposure sections, pp.3-4
Exposure dose
Riston DI9500M's dose is published per sheet thickness, not as a single number. Read the row for the sheet you laminate and run a dose array around it.
- As published
- Dose follows the sheet and the laser: at 405 nm a 15 µm sheet takes 10-23 mJ/cm² and a 38 µm sheet 15-31; at 355 nm the same sheets take 8-20 and 14-29, aimed at 6-12 steps held.
| Sheet | Dose |
|---|---|
| 15 µm | 8–20 mJ/cm² |
| 18 µm | 10–22 mJ/cm² |
| 20 µm | 11–23 mJ/cm² |
| 25 µm | 12–25 mJ/cm² |
| 30 µm | 13–27 mJ/cm² |
| 38 µm | 14–29 mJ/cm² |
SOURCE: 'Exposure Energy vs "Steps Held" For Recommended Exposure…
'Exposure Energy vs "Steps Held" For Recommended Exposure Range' tables, p.4 — the '355nm LDI mJ/cm2' rows, one column per grade DI9515M-DI9538M. Each range is the recommended energy for a 6-12 'RST' steps-held window.
| Sheet | Dose |
|---|---|
| 15 µm | 10–23 mJ/cm² |
| 18 µm | 11–24 mJ/cm² |
| 20 µm | 12–25 mJ/cm² |
| 25 µm | 13–27 mJ/cm² |
| 30 µm | 14–29 mJ/cm² |
| 38 µm | 15–31 mJ/cm² |
SOURCE: 'Exposure Energy vs "Steps Held" For Recommended Exposure…
'Exposure Energy vs "Steps Held" For Recommended Exposure Range' tables, p.4 — the '405nm LDI mJ/cm2' rows, one column per grade DI9515M-DI9538M. Each range is the recommended energy for a 6-12 'RST' steps-held window.
Development
- Developer
- Na2CO3 anhydrous 0.85-1.0 wt% (0.85 preferred), or Na2CO3 monohydrate 1.0-1.1 wt% (1.0 preferred), or K2CO3 1.0-1.1 wt% (1.0 preferred)
- Method
- spray
- Rinse
- Hard-water rinse (150-250 ppm CaCO3 equivalent) at 15-25 °C and 1.4-2.4 bar with direct-fan nozzles over a third to a half of the chamber length (more than half preferred); softer water can be hardened with calcium chloride or magnesium sulfate, or followed by a dilute acid rinse. Blow dry, hot air preferred.
- Developer family
- Buffered alkaline
Not published for this resist: Dilution, Time — characterize on-tool.
SOURCE: Development section, pp.4-5 (chemistries, development conditions, dwell time, rinsing and drying)
Hard bake, etch & strip
- Etch resistance
- Compatible with most acid etchants: cupric chloride (free HCl up to 3.0 N), H2O2/H2SO4 and ferric chloride (Etching, p.6).
- Stripper
- Aqueous caustic, conveyorized spray: 3.5 wt% NaOH at 55 °C and 1.7 kg/cm² (25 psig). Time to strip by sheet: 15 µm 8 s, 18 µm 10 s, 20 µm 13 s, 25 µm 20 s, 30 µm 29 s, 38 µm 44 s, from lab testing across the recommended exposure range. Stripped particles are sheet-like, insoluble and non-sticky; KOH gives smaller skins than NaOH. Strip time rises with white-light exposure (about 20 % after 8 days is called not unusual) and slightly with higher exposure dose. Keep stripper loading below 0.4 mil-m²/L with continuous feed and bleed, or up to 0.5 mil-m²/L in batch with the breakpoint held at 50 % or lower (Stripping, pp.6-7).
- Storage
- Store at 5-21 °C (40-70 °F) and 30-70 % relative humidity (Storage, p.1). Handle under yellow, amber or gold safe lights; the film needs protection from UV and visible light up to 450 nm through lamination and development (Safe Lighting, p.7).
Not published for this resist: Hard bake, Descum — characterize on-tool.
SOURCE: Development and Etching sections, pp.5-6
Where it's used
Practical notes from the datasheet
A thin-film print-and-etch resist for copper panels exposed on laser direct-imaging machines rather than through a phototool. The datasheet's resolution figures are 20 µm line/space on a 25 µm sheet in an optimized production environment (hard contact, high intensity), and 15 µm line/space on a 25 µm sheet on either 355 nm or 405 nm LDI in the lab. It is also stated to work on thin core laminate and flexible substrates. The vendor sells the series as a system: sheet grade, exposure energy and developer dwell all scale together, so pick the grade first and read the dose and dwell off its column. All numbers are lab-test values on copper and vary with panel preparation, tool and developer condition, so confirm steps held on the actual line.
Troubleshooting
Common failure modes for Riston DI9500M, answered from the manufacturer's datasheet and application notes. These are starting points — your substrate, tooling and environment shift the specifics, so calibrate on-tool.
Tented holes are breaking in the developer. What does the datasheet suggest?
Two things. Keep the hold between lamination and development as short as practical, since a short hold gives the best tenting. And if tents still break in the spray, a mix of cone and fan nozzles may work better than all high-impact direct-fan nozzles. Do not drop the spray pressure below the 1.0-2.0 bar window to be gentle on the film.
SOURCE: Riston DI9500M Data Sheet (07/30/2021) — Post-Lamination Hold Time, p.3; Development conditions and Controls, p.5
Steps held change between runs at the same energy. Where does the variation come from?
The sheet lists three sources. The development breakpoint can shift steps held by about one step either way. Strong yellow safe lighting also changes steps held, so keep the room lights dim. And the dose ranges themselves came from lab testing, so an in-house calibration on your tool is expected rather than optional.
SOURCE: Riston DI9500M Data Sheet (07/30/2021) — Exposure Energy vs 'Steps Held' note, p.4; Safe Lighting, p.7
Sources & disclaimer
- DuPont — Riston DI9500M datasheet (07/30/2021 (printed in the footer of every page, 'DI9500M DataSheet 07/30/2021'; the 2026/10 in the hosting URL is an upload path, not the revision date)) · accessed 2026-10-15
Manufacturer datasheet values are starting points; optimal parameters depend on your substrate, equipment and environment. Product names and trademarks belong to their respective owners. NANYTE is not affiliated with the manufacturers listed. Last updated 2026-10-15.