Custom Sample Holders, Mask Frames & Thin-Film Fixtures — How to Specify Designs

Sample holders and mask frames are critical in:

• Thermal evaporation
• Sputtering (DC / RF / magnetron)
• E-beam & PVD systems
• CVD processes
• Photolithography alignment
• High-temperature furnace experiments
• Optical & spectroscopy systems
• Microfabrication and device prototyping

Unlike standard commercial holders, research applications almost always require custom geometry, specific substrate sizes, alignment structures, and vacuum/high-temperature compatibility.

This guide summarizes everything customers must specify when ordering custom fixtures.

SECTION A — Choosing the Right Material

Material choice depends on temperature, vacuum, and mechanical load.

✔ Metals (Vacuum & High-Temperature Safe)

✔ Ceramics / High-Temp Materials

✔ Plastics (Low-temp or atmospheric)

• Nylon, PC, PETG → mechanical jigs
• Resin/SLA → precision alignment tools
• CF-Nylon → strong and stable for ~120°C
• Not suitable for high vacuum unless baked

SECTION B — Dimensions & Tolerances (Critical)

✔ Provide:

• Substrate size（e.g., 10×10 mm, 1", 2", 4" wafer）
• Frame outer size
• Slot/step width
• Clamping mechanism dimensions
• Thickness tolerances
• Center opening diameter
• Mask–substrate spacing (for shadow mask use)

✔ Recommended tolerances:

Shadow mask applications often require tight uniform spacing.

SECTION C — Alignment Requirements

Most sample holders & mask frames require precision alignment features:

✔ Alignment Methods

• Alignment pins
• V-groove seats
• Step-style recess
• Screw-based micro-adjust
• Kinematic mounts
• Magnetic registration (for low-temp only)

✔ For shadow mask alignment:

• Add 2–4 dowel holes
• Include global + local alignment fiducials
• Ensure flatness of the frame
• Keep mask–substrate parallelism within 0.05–0.1 mm

✔ For multi-layer deposition

• Repeatable rotational alignment (+/– 0.1°)
• Reference edge or notch
• Substrate corner keys

SECTION D — Temperature & Vacuum Requirements

✔ Provide:

• Maximum temperature (e.g., 150°C / 600°C / 1200°C / 1600°C)
• Vacuum level (10⁻³ / 10⁻⁵ / 10⁻⁶ / 10⁻⁸ Torr)
• Reactive gases (O₂, N₂, H₂, Ar)

Compatibility example:

For PVD:
➡ avoid plastics unless used outside of vacuum.

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SECTION E — Mask–Substrate Spacing (Shadow Mask Applications)

Spacing determines:

• Feature fidelity
• Edge sharpness
• Deposition uniformity
• Step coverage

Recommended spacing:

• Contact mode: 0–20 µm (highest resolution)
• Near-contact: 50–200 µm (reduces sticking)
• Lift-off style: 200–500 µm

Spacing should be specified in:

• Microns if precision is needed
• Millimeters for general fixtures

SECTION F — Clamping & Mounting Mechanisms

Options include:

• Screw clamps
• Spring clips
• Vacuum chuck
• Drop-in holders
• Magnetic clamps（not for vacuum）
• Edge clips
• Kinematic three-point clamps
• Step-clamp system

Your manufacturing options support machined metal + high-temp ceramics + sapphire/quartz windows for optical access.

SECTION G — What Customers Must Provide Before Ordering

✔ 1. Material choice

Metal / ceramic / plastic / hybrid.

✔ 2. Substrate specifications

Size, thickness, shape.

✔ 3. Alignment requirements

Pins, holes, tolerances, multi-layer alignment.

✔ 4. Operating environment

Temperature, vacuum, gases.

✔ 5. Coating or finishing needed

Polishing, anodizing, passivation.

✔ 6. Assembly specifications

Screws, threads, inserts, mating parts.