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Novità ver. 12.0
Design For Fabrication
(DFF) Checks
Design For Fabrication (DFF) Checks provide GerbTool
users with many of the same checks that were previously found only
in tools such as Valor’s Enterprise 3000 and DownStream’s CAM350.
These checks are very important to many designers, as increased
board densities and complexities now mandate verification from a
fabricator’s point-of-view before the layout leaves the designer’s
hands. Additionally, those users that operate GerbTool for actual
fabrication shall benefit from increased verification capabilities
that, in turn, will help to reduce the risk of flaws that result
in scrap boards during the fabrication process. Including the
existing DRC checks, GerbTool now provides a total of 40
verification checks in this release.
DFF Checks offered by GerbTool:
Resist Sliver (Acid Trap)
Detection
A common problem caused by 90-degree bends during
auto-routing is Resist Slivers (sometimes referred to as “Acid
Traps,” depending on your fabrication process). These slivers of
resist material, when too small, will typically flake off the PCB
during fabrication and re-deposit themselves elsewhere on the
board. The results can cause both opens and shorts. Since this is
a totally random situation, troubleshooting is difficult and time
consuming. You will benefit by being able to find potential Resist
Sliver problems prior to fabrication. Once located, the Resist
Sliver can be corrected either by re-routing the traces involved,
or by using the GerbTool’s AutoCorrect feature to fill in the
offending area.
Copper Sliver Detection
Copper Slivers can be found on a variety of layer types; they
are most commonly associated with internal “negative” plane layers
that are using a “paint/scratch” technique for embedding traces
within that layer. Additional instances can also be found on
“positive” trace layers, particularly when “hatch” fills are used
for ground shielding. The small areas of copper (slivers) that
sometimes result in these situations have minimal surface adhering
and can thus flake of during the etch process (similar to that of
a Resist Sliver). While most of the Copper Slivers will dissolve
on the etch tank, some will re-deposit and cause random shorts. You
again benefit by being able to locate potential trouble spots
prior to fabrication, and then eliminate the offending sliver
either manually or via the AutoCorrect feature.
Solder Mask Sliver Detection
Yet another form of slivers, these pertain to solder mask
data. Solder Mask Slivers are most commonly found on fine-pitch,
surface-mounted devices where the webbing between pads is less
that 5 mils wide. Even with Liquid Photo Imageable (LPI) solder
mask technology, fabricators still have issues with producing
areas of solder mask this size. Typically fabricators prefer the
most solder mask coverage possible, but with the largest opening
possible without exposing adjacent data. They will benefit by
using this feature to balance between the largest opening possible
while helping to insure that an abnormally high number of slivers
do not result in the process. Should slivers occur, conductive
pads could become contaminated, thus creating scrap boards just
like a short or open issue could. Another problem here is that, if
not found early, this issue will likely not appear until the
boards are fabricated and out for assembly. Once the boards have
components on them, the cost of scrap increases incrementally.
Solder Bridge Detection
Designed to work hand-in-hand with Soldermask Sliver
Detection, Solder Bridge detection allows you to locate situations
were the soldermask openings are too large. When a mask opening is
too large, it will typically expose adjacent conductive objects,
which can result in shorts during the pre-tin or assembly phase of
manufacturing. Once again the benefit here is to let you balance
between maximum soldermask coverage while maintaining the largest
possible opening for ease in fabrication.
Pin Hole Detection
Similar to Copper Slivers in physical shape, Pin Holes are
actually the reverse. Commonly found in both solid- and
hatched-filled areas, Pin Holes are small pockets or voids within
a given copper area. These voids typically will not fabricate well
for two reasons: A.) either the Resist flakes off or B.) The void
over-etches and becomes larger than normal, thus leaving small
pockmarks in the offending copper area. These Pin Holes are a big
issue within hatch-filled ground shields where hatch lines are
spaced around a border such that they do not touch or close that
area. You benefit by quickly being able to scan any conductive
layer and locate potential Pin Holes, which in turn helps to avoid
costly scrap boards on a given job run. Additionally, you can make
quick corrections to these problems by applying the AutoCorrect
feature found within GerbTool – Pin Holes will be filled and
sealed for a small, clean copper fill.
Starved Thermal Detection
Starved Thermals are one of the biggest issues with Designers,
as most of the CAD system DRC functions do not look to see if a
thermal has been choked off or restricted by adjacent data. This
is because most CAD systems do not provide a “true” representation
of the thermal aperture. GerbTool represents the thermal aperture
shape that will be used during fabrication, and you benefit by
using this feature to validate the thermal connections and their
relationship to adjacent clearances and thermals. If there is an
adjacent object too close to a given thermal, it will starve or
restrict the connection of that thermal to a given plane layer. In
some cases, restrictions are so severe that the thermal loses
connection all together.
Isolated Thermal Detection (Unique
to GerbTool)
Similar to Starved Thermals, and a bigger problem with
Designers, Isolated Thermals are those that have become cutoff
from a given plane layer due to objects that are not directly
adjacent to the thermal. Situations like this are commonly found
in large, multi-pin connector headers where a thermal is buried in
the middle of the connector and the clearances throughout the rest
of the header pins are too large -- which results in the thermal
being cutoff. GerbTool provides you with an automated mechanism
for searching around a thermal for these conditions. In addition,
you can even play “what-if” scenarios and apply a fictitious
“over-etch” amount to increase the effectiveness of this feature.
Soldermask-to-Trace Spacing (Unique
to GerbTool)
Solder Mask-to-Trace Spacing is another feature that allows you
to look for “what-if” conditions. Even LPI soldermasks have a
certain amount of “float” when applied to a job. Usually this
float is very minute -- in the 1-3mil range -- but if you have a
mask opening whose edge is only 2 mils off the edge of a
conductive object, you could end up with a random solder bridge
condition at that location. Allowing you to look for potential
“what-if” conditions provides the added security of knowing that your
job will be as easy as possible for the fabricator to manufacture,
which in turn allows the Designer to benefit from increased
time-to-market and fewer scrap boards.
Layer-to-Layer Registration
More of a sanity check than a full out fabrication check, the
Layer-to-Layer registration feature lets you find situations where
multi-layer jobs no longer stack-up properly. This is a very
common problem within CAD tools, like the PowerPCB product, that
try to be too smart for their own good and register a layer’s data
based upon its physical extents inside a given film size as
opposed to sticking with a fixed origin location. While this
feature is an option for most systems (PowerPCB included), many
users never go in and change the defaults, and simply try to live
with misaligned layers. While gross misalignments are pretty
obvious, it is those jobs that have the ever-so-slight alignment
problems that are the issue. Left untouched, the Designer could
end up getting boards back with weakened annular rings on pads, or
complete break-out conditions. Either way, the boards are scrap,
as even a weakened annual ring is no good – especially in
high-current conditions where the annulus can become a fuse,
depending on the weakened location. GerbTool users benefit by
identifying this situation up-front and rectifying it before the
data leaves their hands.
SMD-to-SMD Spacing & Pitch
Equally useful as both a validation check and an information
check. SMD-to-SMD Spacing & Pitch lets you look for potential
problem areas quickly and efficiently. This check is typically
made during pre-analysis quoting scans. By checking the edge
spacing and pitch of SMD pads, you can tell whether additional
situations might exist, like soldermask and resist slivers.
Enhanced Solder Mask Annular
Ring Checking
While this check already exists, you will benefit from the
additional enhancement of reporting back negative numbers when a
mask clearance actually covers a conductive pad. Most other CAM
tools simply report a “zero” clearance; however what you really
want to know is how much the clearance encroaches upon the pad,
because in certain types of high-density manufacturing it is
actually desirable to have the soldermask on top of the edge of
pads as it helps to keep the pad planted on the circuit board
material. This technique is sometimes referred to as “solder mask
capping.”
Minimum Trace Width, with
Board Average (Unique to GerbTool)
Used for information and checking purposes, Minimum Trace
Width analysis allows you to get a feel for what type of line
width will have to be fabricated on a given job. This can
ultimately affect the costing of a job, as well as the technique
that might be used to perform the fabrication itself. This feature
allows Designers and Fabricators alike to benefit from previewing
the characteristics of a job before it has been fully tooled.
Minimum Air Gap, with Board
Average (Unique to GerbTool)
Like Trace Width checking, Minimum Air Gap also works equally
well as an information and validation feature. It provides you
with insight as to the density requirements of a given job prior
to tooling. This information will again impact both the costing
and fabrication technique of a layout, and is typically used
during quoting or pre-tooling scans.
Silkscreen-on-Pad Detection
While features already exist to fix Solder Masks-on-Pads. the
operator doesn’t know to run the function unless there is
something during the pre-tooling analysis that tells them this
condition exists. None of the PC-based CAM tools do this today --
only the high-end tools from Valor and Barco offer this type of
check. Now GerbTool users benefit from the same pre-tooling
analysis capabilities found within the higher-end products, which
in turn helps to streamline and improve their overall CAM flow.
Flatten Composite
Many difficulties can arise out of composites, not the
least of which are errors due to different interpretations by
various software packages and photo-plotters. As a result, users
have disliked composites almost since there inception. GerbTool
helps you by correctly reading the different types of composites
(274X, Fire900, or Barco DPF), and then flattening that composite
down to a single “positive” image. This single image can then be
processed as a normal layer and allows for easier netlist extraction,
improved analysis, and increased correct-ability during analysis.
This feature is of particular help to to Cadence Allegro users who
are forced to deal with composites whenever they output their
internal plane layers in a 274X format.
DRC/DFF Violations
Stored within Native GTD
With version 12 the GTD format has been expanded in
include DRC/MRC, DFF, and NLC violation information directly within
it. This in turn eliminates the need for a stand-alone file, which
can get lost, and enhances your ability to share and collaborate
with other users. Secondary benefits also come to third party users
that wish to parse error data directly from our database and feed it
back into their system. WISE is currently in negotiations with OEM’s
to add the ability to read the error data to their products.
Fully “Contour” based
Netlist Extraction
GerbTool’s netlist extraction is one of the best on the
market; however the old adage “you can always do better” is true.
With version 12 we have enhanced an already well-respected netlist
extraction by improving our algorithms to leverage our new Polygon
Engine. The result is a fully “contour” based extraction routine. In
terms of user benefit, this means that now internal negative plane
layers can be fully extracted without error; custom apertures can be
taken into consideration using their “true-shape”; and voids within
polygons on positive layers are recognized properly, thus
eliminating erroneous shorts at their locations.
Enhanced Netlist Import
GerbTool’s improved Netlist Import provides full
support for IPC-D-356A, including trace data, as well as the ability
to update Internal Net Names with those of the External Netlist.
Additionally, netlist data is now stored on a new layer type, which
offers two primary benefits: the net points can be truly visualized
and overlaid on their respective conductive layers, and the external
netlist information can be re-aligned to match the actual Gerber
design data.
Graphical Netlist
Compare
Netlist comparison requirements have become an integral
part of both a designer’s and manufacturer’s everyday process.
However, until now they have been forced to deal with substandard
applications that do only a basic comparison and then generate a
simple text report. GerbTool has moved ahead and created the first
Graphical Netlist Compare feature in the PC-based CAM market. You
are able to speed-up and increase the effectiveness of your
comparison process by visualizing the problems graphically. In
addition, all violations are stored internally like DRC/MRC and DFF
violations, which means you can quickly scan through your
connectivity issues like never before. Since violations are stored
within the database, information can also be shared back and forth
from designer-to-designer, designer-to-fabricator,
fabricator-to-designer, and fabricator-to-fabricator. No other CAM
tool offers such flexibility and performance in this price range.
NLC Checks offered by GerbTool:
Net Open
Net opens are conditions where two or more GerbTool nets are
sharing the same coordinates as a single external net. This
condition is typically caused by a missing trace or thermal
connection. GerbTool will highlight the external net while
simultaneously highlighting the internal GerbTool nets, each with
their own unique color. You can quickly isolate the situation
through GerbTool’s unique method of visualizing the problems.
Net Short
Net Shorts are the opposite of net opens; here two or more
external nets are sharing the same coordinates as a single
internal net. This condition can be caused by a myriad of things;
the more common situation is an extra trace that improperly ties
two nets together, or perhaps a thermal connection that is in the
wrong location. For this situation GerbTool will highlight the
internal GerbTool net while simultaneously highlighting the
external nets points in their own unique color (one color per
net). This method of visualization allows you to quickly track
down where the board has been misrouted.
No Copper
No Copper errors indicate that there is an external net but
not corresponding copper at that location. This is typically
caused by a missing pad at a particular location.
No External Net
No External Net errors are the opposite of No Copper: here
there are nets present within the GerbTool design, but there are
no corresponding external nets to validate against. These errors
could occur because someone may have added additional circuitry to
a design after the original netlist was generated, or the external
netlist may only have end-points of nets contained within it.
Display Layers Positive
or Negative
A simple yet effective feature, the display of layers
in a positive or negative state allows you to quickly visualize
layers like internal planes and solder-masks in their native state.
Layers can be toggled at any time through the use of a “hotkey”. All
other viewing modes are supported, such as transparency and outline
viewing.
Enhanced Import Wizard
Reading data correctly is a critical part of any
Designer’s or Fabricator’s process. With other tools, users (especially
Fabricators) can spend as much as 70% of the time on a job just
trying to sort out all the files and their formats. The Import
Wizard helps to eliminate the headaches of loading files by
automatically analyzing all the files within a project directory,
sorting out what is readable, and then detecting their formats.
Close attention has been placed upon format detection, as this is
where many users spend a great deal of “trial-and-error” time. With
this release comes not only detection enhancements, but the
migration from Gerber Wizard to Import Wizard – meaning that the
Wizard now detects Drill, Mill, DXF, HPGL, and databases
automatically. ALL users will benefit from the new Import Wizard.
Enhanced Polygon Pour
Feature
At the heart of version 12.0 is a new Polygon Engine,
which has been instrumental in providing you with features such as
the DFF Checks, Flatten Composites, and Enhanced Netlist Extraction.
Providing maximum benefit from new technology to you is a critical
factor in every release, so with this release comes enhanced polygon
pour functionality. You will immediately notice improved accuracy
while making pours and better handling of small areas that could
result in islands or slivers. Additionally, polygon pour offers a
new feature called “smoothing”, which eliminates sharp cusps by
rounding them off. This smoothing technique dramatically reduces, if
not eliminates, copper sliver issues that could arise during the
manufacturing of a given board.
OTHER ENHANCEMENTS IN PREVIOUS
RELEASES
GerbTool ver.
11.0 |
