SCDQ5541P/Q/R, SCDQ5542P/Q/R, SCDQ5543P/Q/R, SCDQ5544P/Q/R
2006-05-12 11
ESD Protection
The input protection structure of the SCDQ554XX provides signifi-
cant protection ag ai nst E SD dam a ge. It is capab le of wi th s tan ding
discharges greater than 2.0 kV. Take all the standard precautions,
normal for CMOS components. These include properly grounding
personnel, tools, tables, and transport carriers that come in con-
tact with unshi elded parts. If these condi tions are not, or cannot be
met, keep the leads of the device shor ted together or the parts in
anti-static packaging.
Soldering Considerations
The SCDQ554XX can be hand soldered wi th SN 63 sol d er using a
grounded iron set to 260°C.
Wave soldering is also possible following these conditions: Pre-
heat that does n ot e xceed 93°C on t he solder si de of the PC board
or a package surface temperature of 85°C. Water soluble organic
acid flux (except carboxylic acid) or resin-based RMA flux without
alcohol can be used.
Wave temperature of 245°C ± 5°C with a dwell between 1.5 s to
3.0 s. Exposure to the wave should not exceed temperatures
above 260°C for five seconds at 1.59 mm (0.063") below the seat-
ing plane. The packages should not be imm er se d in the wave.
The SCDQ554XR connects to an external connector receptacle
which may be soldered before inserting the SCDQ554XR Display.
In this way, only the connector is subject to the user’s soldering
process. The Molex 52418-0510 receptacle called out in the prod-
uct drawing can be used in solder reflow processes. See Molex for
specifications.
Po st Solder Cl eaning Procedures
The least offensive cleaning solution is hot D.I. water (60°C) for
less than 15 minutes. Addition of mild saponifiers is acceptable.
Do not use commercial dishwasher detergents.
For faster cleaning, solvents may be used. Exercise care in choos-
ing solvents as some may chemically attack the nylon package.
For further information refer to Appnotes 18 and 19 at
www.osram-os.com or in the curren t Short Form Catalogue. See
Appnote 19, Table 2, “Displays–Group 2”.
Optical Considerations
The 3.12 mm (0.123") high character of the SCDQ554XX gives
readability up to five f ee t. Pr oper filte r se lection enha nces reada bil -
ity over this distance.
Using filters emphasizes the contrast ratio between a lit LED and
the character background. This will increase the discriminati on of
different characters. The only limitation is cost. Take into consider-
ation the ambient lighting environment for the best cost/benefit
ratio for filters .
Incandescent (with almost no green) or fluorescent (with almost no
red) lights do not have the flat spectral response of sunlight. Plas-
tic band-pass filters are an inexpensive and effective way to
strengthen contr ast ratios . The SCDQ5542 X is a super-red displa y
and should be matched with long wavelength pass filter in the
570 nm to 590 nm range. The SCDQ5541X/3X/4X should be
matched with a yellow-green band-pass filter that peaks at
565 nm. For displays of multiple colors, neutral density grey filters
offer the best compromise.
Additional contrast enhancement is gained by shading the dis-
plays. Plastic band-pass filters with built-in louvers offer the next
step up in contrast improvement. Plastic filters can be improved
further with anti-reflective coatings to reduce glare. The trade-off is
fuzzy characters. Mounting the filters close to the display reduces
this effect. Take care not to overheat the plastic filter by allowing f or
proper air flow.
Optimal filter enhancements are gained by using circular polarized,
anti-reflective, band-pass filters. The circular polarizing further
enhances contrast by reducing the light that travels through the fil-
ter and reflects back off the display to less than 1%.
Several filter manufacturers supply quality filter materials. Some of
them are: Panelgraphic Corporation, W. Caldwell, NJ; SGL Homa-
lite, Wilmington, DE; 3M Company, Visual Products Division, St.
Paul, MN; Polaroid Corporation, Polarizer Division, Cambridge,
MA; Marks Polarized Corporation, Deer Park, NY, Hoya Optics,
Inc., Fremont, CA.
One last note on mounting filters: recessing displays and bezel
assemblies is an inexpensive way to provide a shading effect in
overhead lighting situations. Several Bezel manufacturers are:
R.M.F. Products, Batavia, IL; Nobex Components, Griffith Plastic
Corp., Burlingame, CA; Photo Chemical Prod ucts of Califor nia,
Santa Monica, CA; I.E.E.-Atlas, Van Nuys, CA.