 Dontech’s Optical Fine Wire (OFW™) and Micro EMI-Mesh Laminations (MEM-100™) for EMI/RFI Shielding Filters and Windows
Dontech manufactures a wide variety of woven, fine wire, stainless steel, copper and printed silver meshes for optical EMI/RFI shielding of electronic displays, instrumentation and enclosures.
Mesh is typically embedded in glass or plastic substrates such as acrylic, polycarbonate or polyester (PET). The conductive ground plane is then terminated via a perimeter busbar, extended mesh or conductive gasket.
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: |
• |
Military applications – requiring the attenuation of radiated
EMI/RFI emissions and susceptibility per MIL-STD-461 |
• |
Rugged computers, tactical radios, sensors and vehicle-mounted displays |
• |
Secure communication systems to meet tempest and FCC compliance and for homeland security |
• |
Medical displays – MRI rooms, display and observation windows |
• |
Aircraft Shielding – display and instrument panels, aircraft windows and doors |
• |
Industrial controls, heavy equipment, shipboard electronic systems |
• |
Test and measurement equipment – telecommunication, signal analyzers and generators |
| |
|
| Dontech woven fine wire mesh is available unplated, blackened, or silver plated and conductively blackened. In addition, a variety of product configurations are available including: |
• |
Laminated in optical substrates: glass, polycarbonate, acrylic, ADC, PET |
• |
Optical finishes – antiglare, antireflective, chemical/abrasion resistant |
• |
Sheets, cut-to-size |
• |
Applied to metal frames and gasketed |
• |
Applied to touch screens and digitizers |
| |
|
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 |
MEM 100
Printed Mesh |
100 |
0.000075 |
80.0% |
67 |
66 |
56 |
49 |
47 |
24 |
Stainless Steel2 |
230 |
0.0014 |
46.0% |
97 |
- |
- |
77 |
73 |
62 |
|
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) |
| |
| Mesh Configurations |
| Product Range: |
Mesh available in Sheets, Cut-to-Size, Laminated |
| Substrates: |
Glass, Polycarbonate, Acrylic, PET, ADC |
| Size: |
Up to 4 ft. x 8 ft. |
| Thickness: |
0.015 in. to 0.5 in. |
| Optical Finish: |
Clear Glass, Clear Hard Coating (Polycarbonate), 90 Gloss
Anti-Reflective
Anti-Glare
Anti-Reflective/Anti-Glare |
| Design Options: |
Contrast Enhancement
Colors (short pass, long pass, band pass)
Neutral Density, Circular Polarizers
NIR Blocking Filters
Transparent Heaters |
|
| |
| EMI Filter Termination Methods |
|
| |
Dontech Optical Fitting Process and Moire Testing
Because a diffractive interference pattern (moiré) can occur due to the alignment between the wire mesh with the light transmitting pixels of the electronic display, it is often necessary to rotate the mesh to reduce or eliminate this interference. Because most displays have a pixel orientation at 90 degrees, the moiré effect can be minimized by rotating the mesh at a 45 degree orientation. In addition to rotating the mesh, altering the mesh counts, mesh depth in the substrate or surface finish of the substrate can minimize moiré.
In rotating the mesh, Dontech designates mesh orientation as degrees from the positive horizontal axis. Common mesh orientations toreduce moiré include 45 deg., 30 degrees, and 22.5 degrees. As a service, Dontech utilizes both pre-production and in-process testing to verify that mesh orientation does not produce a moiré. |
Company Profile:
Dontech Incorporated is an ISO-9001:2000 designer and manufacturer of optical filters, coatings and enhanced display products for military, medical and industrial applications. For more than 35 years Dontech has provided innovative optical solutions worldwide.
|
|
|
|
|
