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If you see an error contact:
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inform@xtronics.com
Gerbview
Loading in finished Gerbers for checking is a last step in designing a PCB.
Related kicad pages
-
EE CAD Terminology
-
kicad Navigator - the kicad project Manager
-
eeschema - the schematic editor
-
cvpcb - the component to module (AKA foot-print) editor
-
pcbnew - the PCB layout program
- Gerbview - the Gerber file viewer and production notes
-
Bitmap2Component Converts bitmap images to filled polygons
-
wings3d - 3d view - good way to waste a lot of time..
Similar Gerber viewer
In Debian install gerbv - it has differnet features - some better some worse than gerbview
Checklist
- Super Money saving tip: print out the artwork on
card-stock 1:1 and poke holes and stuff it like a real PCB - find errors
- fix them and rework for pennies all the same day..
Part Placement
- SMD component orientation consistent
- Clearance for IC extraction tools, heatsinks etc.
- Polarization of components checked
- Are components on grid ?
- Check the orientation of all connectors - is Pin #1 where you expect it?
- minimum component body spacing
- Bypass capacitors located close to IC power pins
- Series terminators are located near the source
- I/O drivers near where their signals leave the board
- PCB has ground turrets, power rail test points, and test points for important signals, all labeled
- EMI and RFI filtering as close as possible to exit and entry points in shielded areas
- Potentiometers should increase controlled quantity clockwise
- Mounting holes electrically isolated or not?
- Mounting hole clearance for hardware
- SMD pad shapes checked
- Tooling holes for automated assembly
- Extra clearance for socketed ICs
- Pin one pad indicators
Routing
- Digital and analog signal commons joined at only one point - net tie - ground
Pavilion
- Check for traces running under noisy or sensitive components
- No vias under metal-film resistors and similar poorly insulated parts
- Traces spaced to max where possible
- Check for dead-end traces, unless used on purpose
- Ensure schematic software did / did not separate Vcc from Vdd,
Vss from GND as needed (Not a problem if you don't use invisible
connections - it really doesn't save time in the long run )
- Multiple vias for high current and/or low impedance traces - check the current ratings of your via size
Current rating of Traces, viass
-
- Component and trace keepout areas observed
- Ground planes where possible
Dimensions
- Hole diameter on drawing are finished sizes, after plating.
- Finished hole sizes are >= 0.25mm larger than lead
- Silkscreen legend text weight, spacing
- Pads >=0.37mm larger than finished hole sizes
- Components spacing from edge of PCB
- Traces to board edge spacing
- Consider Drill size tolerance
- Soldermask clearance and tolerance - often board houses want zero clearance.
- High voltage traces need extra spacing
Text on Silk Screen and other Layers
- Allign legend text tp read from one or two orientations
- Logo in silkscreen legend
- Copyright notice
- PCB part number and version
- Do parts cover Legend
- Label all layers - Mirror text on back
- Pin one indicators
- High pin count parts can have corner pins numbered for ease of location
- Silk screen tick marks for every 5th or 10th pin on high pin count Parts
Other
- CAD design rule checking must be turned on
- High frequency circuitry precautions observed
- ReadMe for PCB house see
Gerbview#What_to_send_the_PCB_house checklist
- Thermal reliefs for internal power layers
- Solder paste mask spacing
- Blind and buried vias on multilayer PCB
- PCB layout panelization
Standard Sizes
Gerber file names
- x.gba Bottom Adhesive
- x.gbl Bottom copper
- x.gbo Bottom Silk-screen
- x.gbp Bottom Solder-Paste
- x.gbr board outline - edges
- x.gbs Bottom Solder-mask
- x.gko keep out ( Not yet implemented 2013-07 )
- x.gta Top Adhesive
- x.gtl Top copper
- x.gto Top Silk-screen
- x.gtp Top Solder-Paste
- x.gts Top Solder-mask
Inner Layers
- x.gp1 - inner plane 1 - Negative
- x.gp2 - inner plane 2 - Negative
- x.g1 - inner routing layer 1
- x.g2 - inner routing layer 2
What to send the PCB house
All the gerbers and a README.txt are packed up into a tar. ark is a great tool for this.
The README.txt should look something like this:
Contact name
phone
email
address
>>>- hole dimensions are finished size- <<<<<
-PCB Name and revision number: DC_UPS3.1
Use this name on invoices
-We provide Gerber files including drill layer
Pads 23 Through vias 16 Smallest hole .025" (0.64mm) Specified finished size. 39 holes
-FR406 or 370HR 1.57mm[.062"] IPC-4101C Sheet 24
-Copper thickness 0.0347mm [1oz]
-Quantity 4
-Sides 2
-HASL
-Silk Screen 2 sides (white or yellow)
-Solder Mask 2 sides green/matte finish SR1000 over bare copper (same art work) to IPC-7351
-Size 50 x 65mm
-To IPC specifications
- For productions quantities please Quote -
Solder resist (solder mask) is required on both external faces of the printed board, it shall meet
the qualification/conformance IPC-SM-840. Coverage, cure and adhesion shall be as defined in
paragraphs 3.8.1 to 3.8.3 of IPC-6012, except that no encroachment of solder resist is allowed on
any surface mount or ball grid lands, and that ALL pad patterns have solder resist slivers between
individual pads. The height of the solder resist should not cause any mounting problems for
surface-mount components.
Solder resist data is provided as per IPC-7351 standard, 1:1 with the land size, the manufacturer
is to oversize these solder resist openings commensurate with their manufacturing procedures ensuring
that ALL the above requirements are met, the amount of oversize to take into account the minimum track
and gap dimensions as shown on the Printed Boards Master Drawing. Solder resist not related to a
component pad is not to be enlarged.
Things to have in the readme :
- Name with version of the board: widget2.3
- Quantity
- Size - outer rectangle dimensions
- Sides 1,2,4 or more..
- plate finish : HASL works for leaded solder - fancy expensive stuff for the insane RoHS
- LPI Silk Screen 2 sides (white or yellow) 1mm tall 0.1mm wide
- LPI Solder Mask 2 sides green/matte finish SR1000 over bare
copper (same art work) to IPC-7351 - we provide it with .05mm clearance
[0.002"]
- IPC-4101C Sheet 24 - This is a common way to try to get good material
- 1.57mm,[.062"] You need to specify how thick the board is.
- FR4 is the common epoxy fiberglass material, FR406 has replaced it and 370HR is often used for no lead
- Copper thickness 0.0347mm [1oz]
- Quality specifications.
Laminate quality can be important particularly if the board is worth
reworking. One way to explain this is to look at some quality material.
Look at a [1] data sheet. Here is their
product selector
Notes about Minimum feature sizes
- The days of .25mm[10mil] traces with 250mil spacing are long
over. Today (2011 ) Trace minimum of 0.100mm is standard and 0.075
-0.080mm can be had without a premium. Premium minimum air spacings are
about 0.050mm[2]. The minimum depends on copper weight - below are
approximate limits if you want to pay extra.
- 0.100mm[4] at 17.35um[1/2oz]
- 0.125mm[5] at 34.7um[1oz]
- 0.150mm[6] at 69.4um[2oz]
- Eeschema now has a built-in calculator for trace width and
other features. The following link is for an older tool. Also, SaturnPCB
has a free calculator that includes differential traces, but runs only
on Windows.
-
Trace width / current calculator
- Annular ring of 0.5mm[20mil]minimum is a good idea for through
hole, but many board houses can go as low as 0.075mm[3mills] Best not to
go under 0.25mm[10] without good reason. A 0.457mm[18] pad x
0.200mm[8]hole is usually without extra charge. Be sure to calculate
Current ratings of your Vias.
via-calculator
- Why not use the smallest size the shop offers at your price
point? Because especially at discount houses there are tolerance issues
in aligning layers and in drilling. You may find traces disconnected
from their vias if the drill was a little off center, or if the etch was
a little uncontrolled. Doubly important if you are not paying for full
electrical testing.
- Don't use minimum Vias without good reason
- start with Vias 0.75mm[30mil] with a 0.457mm[18mil] drill for simple signal traces.
- Minimum micro via 0.46mm[18]pad x 0.200mm[8]hole
- Minimum coper to board edge - normally .25mm[10]
- Hole size tolerances are usually +/-0.075mm[3] to +/-0.125mm[5] specified finished size.
- Minimum hole size 0.200mm[8] - smaller can be LASER drilled for a price if you really need it.
- Minimum slot width 0.80mm[31]
- Minimum Solder mask Clearance 0.05mm [2] - special deals can do 0.025mm[1]
- Minimum Silk screen
- This is a bit complicated - the size is three numbers H x W x T
(where T is line thickness). It is common to see the limit on line
thickness 0.100 - 0.125mm[4-5] but the real limit seems to be
0.075mm[3]. What I recommend is not to IPC specification, but if the
idea is to have useful information available for trouble shooting and
debugging modern SM, then we need to find the limit and the IPC might
catch up with us someday. When going smaller One does need a magnifier
to read, but one needs a magnifier to see the components as well! (I'm looking through a 7 or 10 power
Optivisor or a Stero-zoom anyway! )
- Some places will say their LPI is limited to a line width of
0.100mm[4] and with that you can get down to a letter size of about 0.9
x 0.7 x 0.1mm
- You can push it by going to 0.075mm[3] line width - and ending up with a 0.8 x 0.9 x 0.075mm
- Anything smaller and you might as well leave it off the board
and look at an assembly drawing show the detail. That's just the
practical side of it. I will use the above with my 1005M[0402]'s, but
that seems to be todays limit. I don't care if a few end up unreadable,
at least there is a clue with the small ones.
- So here is what I suggest - make your library foot-prints with
1.0 x 0.9 x 0.1 mm reference designators and if you have a place where
you need something smaller use 0.8 x 0.9 x 0.075mm
If you are using a supper cheap shop that is using obsolete silk screen - you will want to double the size 2.0 x 1.8 x 0.125 mm
Send Off Check List
Pre Gerber
- Version strings on the PCB
- Readme.txt quantity and specifications
- Schematic Electrical Rules Check
- PcbNew Design Rules Check
- edit/Clean_tracks_and_vias
PCB Board houses
Picking a board house depends on what is needed. Cheap boards that
have the copper glued on instead of laminated at the same time that they
heat cure the epoxy - cheap board traces will come off with just the
slightest amount of rework. If they don't spec the Tg of the material,
you are getting really cheap junk. Put your favorite place here and add
comments - don't delete or reorder other PCB houses with out leaving a
good reason on the discussion page or your edit will just get reverted.
E-teknet
The cheapest laminate disappointed me (traces lift if they even see a
soldering iron.) - go with the FR406 and 1oz copper. The cheapest
laminate could be used for very low cost for things that will never be
reworked.
They now offer several laminates and copper thicknesses.
megacircuit.com
They can do very good work - a bit pricey, but they offer good laminate.
eFABPCB
http://www.efabpcb.com Ok to work with
Bittele.com / 7pcb.com
Provides good quality in affordable cost. Uses FR4 Tg170(S1000-2) and FR4(S1141). Complies with IPC600F standard.
A second review: excellent quality, very low cost for small
production runs. Typically $300-400 per batch, ~2 weeks to complete.
Ships from China, with a business office near Toronto. ENIG, multilayer,
heavy copper are all readily available. Also offers turn-key assembly
at reasonable rates, with parts ordered from Digikey and similar
suppliers. I'm very pleased with their automated SMT assembly, but was
not happy with the quality of the more labor-intensive manual assembly
of thru-hole PCBs.
Seeed Studio
Located in Hong Kong. Offers single and double sided PCBs with solder
mask and silkscreen, a variety of thicknesses and finish colors on
quality FR4 material. The quality of the PCBs I've ordered has been as
good as anything I've worked with and the price was extremely
competitive for small batches of boards. Not particularly fast, takes
about a month from submission to receive finished PCBs. Max size offered
is 20cm x 20cm.
- Ajo: worked good for me they needed 2 weeks to ship. Board
quality was good for the price, tracks tend to tear off easily with too
much hot (faster than other pcbs i've used).
SINOMICRO PCB
Low Cost PCB Prototype,PCB manufacture,PCB Assembly and PCB Design
- No experience listed by any users
OSHPARK
https://www.oshpark.com
Formerly known as DorkbotPDX PCB order. Shared PCB orders for hobbyists.
Very good quality. ENIG finish, purple solder mask. Orders in
multiple of 3 boards. Cost: 5$ per square inch for 3 boards (2 layers,
prototype run). They can do 4 layers and higher volume as well. Free
international standard shipping. Shipping times to the EU vary. The
longest time I've had to wait for my boards was 6 weeks: about 10 days
for fabrication + 4 weeks shipping time including a hefty customs
processing delay. Laen (the owner) told me he's working on improving
international shipping times to the EU.
BatchPCB
- Was taken over by OSHPARK in 2013
goldphoenixpcb
Haven't used - probably too cheap to be high quality. Taiwan laminate - fails to specify Tg - or IPC-4101C
- No experience listed by any users
I used them - they have a Canadian (Oakville Ontario) contact
address. I thought the boards (double side, solder mask, silkscreen,
about 2 x 3 inch) were pretty good quality, especially given the price.
No problem with the boards or assembly, but I didn't have any real small
components. Turnaround was a couple weeks. I figure they are like Seeed
but more expensive.
Multilayer Technology
Olimex
Taiwan laminate - fails to specify Tg - or IPC-4101C
- No experience listed by any users
ellwest-pcb
San Francisco Circuits
PCB Fab Express
Advanced Circuit
Speedy PCB Prototype
AP Circuits
Bare Bones PCB
PCBPro
PCB Express AKA Sunstone
Sierra Proto Express
Technotronix
Sun Stone Circuits
Quick-teck PCBs
- UK based PCB manufacturer,guaranteed delivery date. Online instant quote, reasonable prices.
- No experience listed by any users
Custom Circuit Boards
Good USA PCB manufacturer. Fast quick turn prototypes, but you need
to have a min lot of a panel. Good selection of board materials with
extensive capabilities.
- No experience listed by any users
Sinofast
We can produce single-side, double-side, multi-layer, Copper and
aluminum-based, flex board PCB, and Printed Circuit Boards assembly.
http://www.alpcb.com.cn/
- No experience listed by any users
Peakpcb
ShenZhen2U
Instant quote online,really low price but high quantities. Supported panel board and solder paste stencil.
Fast Circuits
IteadStudio
Really cheap prototypes in limited quantities. You get to boards free
if is an OpenSource Project. Their quality is not the best but is not
bad. As far as my experience they provide relative good support.
Elecrow
Similar to Itead and Seeedstudio, with choice of soldermask colour at
no additional cost. Very quick manufacturing, I submitted my files on
a Friday evening and the boards were ready by Tuesday morning. (Of
course standard registered mail ensured a few weeks before I actually
got the boards). They provide good feedback during the process, sending
photographs of the completed boards and package before shipping.
Quality is as good as that of the other Chinese manufacturers.
Hackvana
I ordered several boards of the cheapest type and all were fine. (As
for delivery times, I only tried express shipping, which is more
expensive but fast.)
PCB Train
Not the cheapest but always quality and reliable PCBs. Offer a
special 24 hour delivery service called 'PCB Train Express' for fast
turnaround prototype PCBs.
JOGA PCB
Not the fastest one, but really reasonable combination of price and Quality.
PCBShopper
Not a board house, but a price comparison site for PCB manufacturing.
Enter your board's size, number of layers, solder mask and silkscreen
options, the quantity you want, and how quickly you want them, and
PCBShopper shows you prices from over 20 different manufacturers in
China, North America, and Europe.
Stencil houses
Stencils Unlimited
SunStone
Board Stuffers / Assembly House
eCircuits
sales@ecircuitsusa.com Kansascity Area
Lonnie Smith (816)224-6611 ext. 211
Can source parts for turnkey - leaded and noleaded - Surface Mount Technology
Through Hole and SM - Conformal Coating - Potting - Electromechanical Assembly
Box Build - Serial Number Tracking -Full ESD Control -Automated Optical Inspection
Screaming Curcuits
Technotronix
Technotronix is professional PCB Manufacturer in USA offering
PCB manufacturing, assembly, fabrication and PCB Prototype service as per customer requirement.
Asian Circuits
4pcbassembly
Email