What BC412 is
BC412 is a linear barcode symbology developed by Intel and standardized by SEMI (Semiconductor Equipment and Materials International) as SEMI T1-95, used to mark and identify silicon wafers and reticles during semiconductor manufacturing. bwip-js draws its bars directly using its own 35-character alphabet and encoding tables -- confirmed directly: bwipp_bc412 computes its own checksum and calls bwipp_renlinear() itself, with no delegation to another symbology's encoder.
Generate it now
Enter a value using digits and capital letters (except O) to see a live preview.
Valid input
The value must be 1 to 500 characters, using only BC412's own 35-character alphabet: digits 0-9 and capital letters A-Z except O (confirmed directly against bwipp_bc412.globals.bc412_barchars, the literal string "0R9GLVHA8EZ4NTS1J2Q6C7DYKBUIX3FWP5M") -- any other character is rejected ("BC412 must contain only digits and capital letters except O"). A separate "semi" mode (SEMI T1-95's own alternate encoding) restricts length to 7-18 characters (8-19 with an existing check character) and uses a different checksum algorithm.
Key options
Supported options include includetext, height, includecheck, validatecheck, includecheckintext, and semi. Real, literal defaults: includetext false, includecheck false (no check character drawn unless requested), validatecheck false (a check character is computed and appended rather than verified), semi false (standard mode, not SEMI T1-95's alternate length/checksum rules).
Output and printing
Export SVG for vector-precise direct part-marking artwork or PNG for a quick proof.
Common uses
BC412 appears on silicon wafers and reticles in semiconductor fabrication facilities, where wafer-tracking equipment reads it to identify individual wafers through processing.
Example
See the live preview above, seeded with a bwip-js-verified valid value.
Size guidance
Bar height has no auto-computed adaptation to data length -- the same fixed default height applies regardless of value length; use the height option to fit a specific wafer-marking station's requirements.
Troubleshooting
A rejected value usually means a character outside BC412's own 35-character alphabet (most commonly the letter O, which is deliberately excluded), a length outside 1-500 characters, or -- in semi mode -- a length outside 7-18/8-19 characters.
Related formats
BC412 is a distinct, dedicated semiconductor-industry symbology with its own alphabet and checksum -- it is not a variant of Code 39 or any other already-covered symbology in this catalog, despite superficially resembling a simple alphanumeric linear code.
FAQ
Why was the letter O rejected?
BC412's own 35-character alphabet deliberately excludes the letter O (to avoid confusion with the digit 0) -- only digits 0-9 and capital letters A-Z except O are accepted.
What is "semi" mode?
SEMI T1-95's own alternate encoding mode: a different length range (7-18 characters, or 8-19 with an existing check character) and a different weighted odd/even checksum algorithm than the standard mode's plain positional sum. Both modes share the same 35-character alphabet and bar patterns.