 Dontech’s Optical
Fine Wire (OFW™)
Mesh for EMI/RFI
Shielding
Dontech manufactures a wide variety of woven, fine wire, stainless steel and copper meshes for optical EMI/RFI shielding of electronic displays, instrumentation and enclosures.
Dontech’s mesh counts range from 50 to 255 openings per inch (opi). Standard unplated wire diameter for most mesh counts is 0.0011" with 0.0022" available for 50, 100 and 145 opi mesh. Dontech’s optical fine wire mesh combines excellent shielding effectiveness with optical performance making it ideally suited for electronic displays and optics applications.
| Typical applications for optical fine wire mesh include EMI/RFI shielding of electronic displays and enclosures used in: |
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Military applications – requiring the attenuation of radiated EMI/RFI emissions and susceptibility per MIL-STD-461 |
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Rugged computers, tactical radios, sensors and vehicle mounted displays |
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Secure communication systems to meet tempest and FCC compliance and for homeland security |
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Medical displays – MRI rooms, display and observation windows, shielded electronic equipment cabinets |
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Aircraft Shielding – display and instrument panels, aircraft windows and doors |
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Industrial controls, heavy equipment, shipboard electronic systems |
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Test and measurement equipment – telecommunication, signal analyzers and generators |
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| For OEMs as well as enclosure and membrane switch manufacturers, Dontech's woven fine wire mesh is available unplated, blackened, or silver plated and conductively blackened. Product configurations available include: |
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Rolls |
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Sheets |
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Cut-to-size |
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| Standard Plain Weave Wire Meshes |
Wire Type |
Count |
Diameter (in.) |
Open area (%) |
304 SS |
50 |
0.0012 |
88.4 |
304 SS |
80 |
0.0011 |
83.2 |
304 SS |
100 |
0.0011 |
79.2 |
Copper |
100 |
0.0022 |
60.8 |
316 SS |
100 |
0.0022 |
60.8 |
Copper |
145 |
0.0022 |
46.4 |
304 SS |
150 |
0.0011 |
70.7 |
304 SS |
180 |
0.0011 |
65.5 |
304 SS |
200 |
0.0011 |
62.0 |
304 SS |
230 |
0.0011 |
55.8 |
304 SS |
250 |
0.0011 |
54.0 |
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EMI Shielding Performances
Testing conducted at an independent lab, per IEEE 299 1997. |
Mesh
Composition
Base Material/
(Plated Deposit) |
Openings/
inch |
Wire
Diameter
(inches) |
Open
Area |
H Field |
E |
Plane Wave |
1
MHz |
10
MHz |
100
MHz |
400
MHz |
1
GHz |
10
GHZ |
Stainless Steel1 |
50 |
0.0012 |
88.4% |
63 |
63 |
60 |
59 |
42 |
18 |
Stainless Steel1 |
80 |
0.0011 |
82.0% |
68 |
69 |
70 |
55 |
44 |
26 |
Stainless Steel1 |
100 |
0.0011 |
79.2% |
72 |
71 |
67 |
63 |
52 |
34 |
Copper2 |
100 |
0.0022 |
60.8% |
89 |
90 |
84 |
77 |
62 |
42 |
Stainless Steel2 |
230 |
0.0014 |
46.0% |
97 |
- |
- |
77 |
73 |
62 |
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All Dontech AG-plated and MEM-100 meshes offer resistivity of <0.02 ohms/sq.
Notes:
1 Silver-plated and conductivity blackened
2 Mesh (tested per NSA-65-6 and MIL-STD-285) |
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| Mesh Configurations |
| Product Range: |
Mesh available in Rolls (standard roll size 48"),
Sheets (21.5" x 27.5"), Cut-to-Size, Custom |
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| Dontech OFW Mesh Key Features / Benefits |
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Extra fine wire diameter (0.0011”) provides high light transmission |
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Proprietary silver plating and blackening provides low surface resistivity
(<0.1 ohms/in2) and excellent shielding effectiveness |
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Extensive range of mesh types and configurations |
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| Quality Procedures |
| Every production run of mesh is inspected and measured for transmission, surface resistivity, and plating uniformity. Inspection procedures 5133 for optical defects, color, wire weave quality. |
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Dontech Conductive Plating Process
Dontech Conductive Platings:
• Improve EMI/RFI Shielding
• Improve Galvanic Compatibility
• Improve Optical Properties
To increase the level of shielding and to ensure shielding uniformity, wire meshes (especially stainless steel and phosphor bronze meshes) are conductively plated. Dontech’s standard plating for stainless steel and phosphor bronze meshes is a multilayer plating. After preparation of the base material, Dontech will commonly plate the mesh with silver per Federal Specification QQ-S-365 type 1 grade B with a thickness of .0001” (2.54μm) to .0002” (5.08μm). This silver layer fuses the wire crossover points and also sheaths the wire with a layer of silver. The net result is that the materials’ shielding effectiveness and shielding uniformity are significantly improved. In addition, plating physically holds the wires in place, which results in better consistency of the mesh weave.
Dontech’s proprietary conductive blackening process results in very low diffuse and specular reflection, as well as excellent visual transmission. Unlike corrosion reduction plating, Dontech’s process eliminates discoloration and particle shedding that can occur from handling.
For stability and aesthetics, a multilayer plating (which encapsulates the mesh in a conductive flexible seal) is added. This process prevents silver migration, allows for the desired level of corrosion resistance, and produces the dark outer surface color to minimize reflection and improve light transmission. |
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