Fusion PCB Specification

Seeed Fusion Service offers one-stop prototyping service for PCB(printed circuit board) service, PCBA (PCB Assembly) service and other electronic and mechanical customized service (like CNC milling,3D printing, PCB layout service)

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1. PCB Gerber

Gerber format is an open 2D binary vector image file format. It is the standard file used by printed circuit board (PCB) industry software to describe the printed circuit board images: copper layers, solder mask, legend, etc.
Gerber files should be inside a .rar or.zip archive with standard file extensions:
      Extension                                 Layer
  • pcbname.GTL               Top Copper 
  • pcbname.GTS               Top Soldermask
  • pcbname.GTO               Top Silkscreen

  • pcbname.GBL                Bottom copper
  • pcbname.GBS                Bottom Soldermask:
  • pcbname.GBO                Bottom Silkscreen:
  • pcbname.TXT                 Drills
  • pcbname.GML/GKO        Board Outline

  • 4 layer board also need
  • pcbname.GL2                   Inner Layer2
  • pcbname.GL3                   Inner Layer3

Notes:1. Gerber file must be the RS-274x format.  
         2. Drill file(pcbname.TXT) should be Excellon format.

         3. Gerber file and Drill file(pcb name.TXT) must be put in the same file.  
         4. Board outline is must, in Eagle, draw outline in layer 20.

2. PCB Specification 

Unit: mm
Board DimensionMin size: 10*10mm
Max size: 500*500mm

Available Board Layers1-16 layers
Available Board QtyMin:5pcs
Max: 1000pcs
Available MaterialFR-4 TG130
Dielectric Constant4.2-4.7
Dielectric Separation thickness0.075 - 5.0

Available Board Thickness
1-2 layers0.6, 0.8, 1, 1.2, 1.6, 2, 2.5, 3 
4 layers0.8, 1, 1.2, 1.6, 2, 2.5, 3 
6-8 layers1, 1.2, 1.6, 2, 2.5, 3 
10 layers1.2, 1.6, 2, 2.5, 3 
12 layers1.6, 2, 2.5, 3 
14 layers2, 2.5, 3 
16 layers2.5,3 
Available Board Copper Weigh

1oz.  2oz.  3oz.
Copper weightThe Min Track/Spacing 
Board Thickness Tolerance± 10%

Minimum trace width/vias/pads spacing  


Minimum inner trace width(for 4 layers board)


≥8mil (If you chose Min Tracking/Spacing 6mil )
≥6mil (If you chose Min Tracking/Spacing 5mil )
≥5mil (If you chose Min Tracking/Spacing 4mil )  

Minimum silkscreen height/trace width



height ≥0.5842mm /23mil
trace width ≥0.1016mm /4mil


Silkscreen colour  
Silkscreen colour is WHITE   when solder mask is Green, Red, Yellow, Blue, Black

Silkscreen colour is BLACK when solder mask is white  

Minimum distance between pad and silkscreen


Perfect aspect ratio of silkscreen1:5
Outer Layer Copper Thickness(example 4 layers)  0.035-0.07(1oz-2oz)
Inner Layer Copper Thickness(example 4 layers)  0.017(0.5oz)
Drilling Hole Diameter(Mechanical)

0.2 - 6.5mm 
Annular Rings
Diameter Tolerance(Mechanical) ±0.08

Minimum width of the solder mask



Minimum distance between solder mask



Circuit to edge



Minimum distance between inner line/copper and drilling hole


Minimum milling slot≥0.8*0.8mm
Slot Tolerance(Mechanical)±0.15mm

Connection Width to panelize the board


The width of the connection should be 1/3 of the width of the board

Stamp holes
Milled slots( CNC cutting)
The minimum board dimension of V-CUT

The V-cut line only is cut from edge to edge
The maximum board dimension of V-CUT≤380*380mm
The minimum sub-board dimension of V-CUT≥20*20mm
The material of solder maskPhotosensitive ink
PCB production time(build time)3-14 business days

Aluminum Board Specification
Available Board Thickness:1mm, 1.2mm, 1.6mm, 2mm
QTY within:min : 5, max:1000
Board Dimension:min : 10mm*10mm
max : 300*300mm
Available Board Colour:White (Silkscreen is black)
Black (Silkscreen is white )
Copper weight:1oz
Surface Finish:HASL, HASL lead free,  ENIG, OSP
Minimum Trace Width:6mil
Minimum Trace Spacing:6mil
Minimum Drilling Hole:0.3mm
Production Lead Time:5-11 business days

FPC Board Specification
Available Board Thickness:0.1mm,0.15mm
QTY within:min:5,max:100
Board Dimension:max:100mm*100mm
Available Board Colour:Yellow
Copper weight:0.5oz
Surface Finish:ENIG
Minimum Trace Width:0.10mm
Minimum Trace Spacing:0.10mm
Minimum Drilling Hole:0.3mm
Production Lead Time:5-7 business days

3.Panelization Rules:
A.  There is no extra cost for identical design panelization.

When you choose“Panelized PCB” is “1” which mean there is only one design in your Gerber file.

(1)  Please make sure each design is identical when selecting "panelized 1".

(2)  Put the cut lines in outline layer (GKO/GML).

(3)  Highlight the cut lines.

(4)  Put a note beside the V-scoring line if you are using V-scoring for panelized PCB, please see the following picture.

(5)  In Eagel, put in layer 20and46  
(6)  Please note the same sub-boards are over 50pcs (including 50pcs), we will inform you to pay USD10 for the processing fee.   

B. we charge the extra cost for multiple design panelization.
E.g , (1) When you choose“Panelized PCBs” is “2”, it is mean there are 2 designs in your Gerber file and will be requested to pay the panel fee.

※  We will inform your to pay the
corresponding fee if you chose the wrong parameters.
e.g. when there are 3 different sub-boards in Gerber file, you should choose “Panelized PCBs” is “3”.   If you choose “Panelized PCBs” is “1”(for 2 layers), we will inform you to pay USD20 for the panel fee.

Please follow below steps to make the Gerber:
Step 1. Put all designs in one Gerber file.
Step 2. Make sure the cut lines are in outline layer (GKO/GML), and the complete board outline should go all round the edge of the boards.
※    The maximum panelized PCB ( different designs  ) is 9.
        Multi-layer(≥6 layers) board doesn't accept panelization.
Step 3. Choose Panelized PCBs option, ie. 5 different sub-boards = 5 designs
Please note that if there are 2 designs are the same, we still consider that those are 5 designs.  

C. No Panelization

(1) Please make sure the complete board outline should go all round the edge of the boards.
(2) No cut line in Outline layer (GKO/GML), please see the following picture
(3) You will get 1 complete board WITHOUT any cutting no matter you put different designs or same design boards here.

(4) If you want to use silkscreen to separate the boards, put the line in silkscreen layer.
 Tips:  no v-cut line in outline layer by making the line as normal silkscreen

4.The type of panelization

A. V-scoring

(1) The entire board size should be ≥7cm*7cm, ≤38cm*38cm.

(2) The sub-board size should be ≥ 2cm*2cm.

※Please note if the sub-board size is smaller than 2cm*2cm in your PCB Gerber file, we will inform you to pay USD16 for the processing fee.

(3) V-cut line only be a straight line.

(4) V-cut line only be cut from edge to edge.

(5) V-cut line must be zero pitch between sub-boards.

6)The minimum length between circuit wire and the v-cut line as to be ≥ 0.4mm.

(7) The thickness of the board must be ≥ 1.0mm.

B. Stamp holes

C. Milling slots( CNC cutting)

Milling slots ≥ 0.8mm*0.8mm

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