Towne Technologies, Inc.
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Towne Technologies, Inc. 
6 - 10 Bell Ave., P.O. Box 460 
Somerville, NJ 08876  USA 
Phone: (908) 722-9500 
FAX: (908) 722- 8394


Precision  APERTURE  and  SLIT  Masks


Towne Technologies' Precision Apertures and Slits are used in a wide variety of applications including Spectroscopes, Endoscopes, Leak Detectors, Lasers, and Many others.   We produce OEM parts for many of the leading manufacturers of  these devices.


       Custom manufactured with single or multiple openings.

        Stock sizes available:  0.375"  (9.5mm) Outside Diameter with a single aperture in a choice of sizes.

        Volume:    Quantities from "Prototypes" for R&D, to "Full production".


ETCHED METAL Apertures and Slits


       Burr Free

       Materials include Molybdenum, Tungsten, Stainless Steel, Copper, BeCu, and others.

       Thickness usually ranges from .001"  (25um) to  .020" (0.5mm), however the smallest aperture should be at least .001" (25um) larger than the material thickness.   For example, a .004" (100um) aperture could be etched in metal ranging from .001" to .003" (25 to 75 um)

        Cross-section:    50/50 etch ratio (etched equally from both sides)  or 90/10 (etched 90% from one side).

 Cross-sectiion of etched holes

       Finish:   Black Chrome Plating (anti-reflective), Gold Plating, or Natural Metal.



ELECTROFORMED Apertures and Slits

(Bi-Metal or Solid Nickel.)


       Minimum Aperture .0006"  (0.15mm)

        Square or Rectangular opening can have either radiused or sharp corners.

        Bi-Metal Construction allows small opening in thick material.  This makes the mask easier to handle and mount.

 Cross-sectiion of Bi-Metal Mask


Bi-Metal Mask Construction:  

1.     The aperture is electroformed in Nickel onto one side of a piece of metal (usually copper or BeCu).   Generally, the nickel thickness is about .0007" (18um).

2.     A larger relief hole is etched on the back side so that the nickel aperture is unobstructed.

3.     The entire part is flashed with nickel.  

4.     The final step (if requested) is to plate both sides of the mask with Black Chrome.


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