The following operators can be used to better focus your queries.
( ) , AND, OR, NOT, W/#
? single char wildcard, not at start
* multi char wildcard, not at start
(Cat? OR feline) AND NOT dog?
Cat? W/5 behavior
(Cat? OR feline) AND traits
Cat AND charact*
This guide provides a more detailed description of the syntax that is supported along with examples.
This search box also supports the look-up of an IP.com Digital Signature (also referred to as Fingerprint); enter the 72-, 48-, or 32-character code to retrieve details of the associated file or submission.
Concept Search - What can I type?
For a concept search, you can enter phrases, sentences, or full paragraphs in English. For example, copy and paste the abstract of a patent application or paragraphs from an article.
Concept search eliminates the need for complex Boolean syntax to inform retrieval. Our Semantic Gist engine uses advanced cognitive semantic analysis to extract the meaning of data. This reduces the chances of missing valuable information, that may result from traditional keyword searching.
Segments of dummy signal lines are added to a signal plane in areas of low wiring density to obtain a uniform subtractive etch rate across the entire printed circuit with low and high density copper areas.
English (United States)
This text was extracted from a PDF file.
100% of the total text.
Page 1 of 1
Subtractive Etch Promoting Dummy Lines
Segments of dummy signal lines are added to a signal plane in areas of low
wiring density to obtain a uniform subtractive etch rate across the entire printed
circuit with low and high density copper areas.
Dense signal wiring areas on signal planes have a lower etch rate than
unpopulated areas. A signal line in unpopulated areas is easily overetched,
since the etch solution is capable of penetrating the few signal lines unimpeded,
causing them to be overetched to an extent that opens occur.
To overcome these disadvantages, the dummy line segments are arranged in
such a manner that they do not influence the signal line characteristics nor the
yield through shorts in the actual signal lines. The dummy signal lines afford a
uniform etch rate in all areas of a signal plane, thus improving the product yield
and electrical characteristics. The signal line width distribution is narrower owing
to the smaller signal line width tolerance of a signal plane. A dynamic dummy
signal line segment installed in the automatic wiring program can be
automatically placed at defined grid points in areas of low density.