HomePCB assemblyPCB Assembly Files- PCB Enginner Need To Know

PCB Assembly Files- PCB Enginner Need To Know

Some complex PCBs design be finished,you must take PCB to assembly plant when PCBs get back from PCB manufacturer.That assembly plant need you provide some necessary documents for production.Where the captain guy gave you talk about the PCB assembly when production of documents required,and what the representative of the file is useful.

PCB assembly processing required documents are the following:

1.Stencil file

Stencil file is solder paste file, it used in brush paste when PCB assembly, it can be automatically welded when PCB through high temperature furnace. But stencil file didn’t be included plug-in components information,it’s surface mount components information.What kind of stencil is? The following is a kind of stencil.


Above aperture is exposed for each surface mount components,no components area are covered. And the stencil is a certain thickness,the exposed holes are filled with solder paste when brush paste, then pcb pad coated with solder paste. The solder paste melting to stabilize assembly when soldering in high temperature.

2.Pick Place file

When assembly is processed with a have to tell the machine how to paste the components,which requires the coordinates of the document.Coordinate file also call pick place file,it has the coordinates of each components, layer, rotation angle and other information,the machine will be able to read this information,according to the requirements to paste components. Pick Place file are generally shown below:

Designator Footprint Mid X Mid Y Ref X Ref Y Layer Rotation Comment
U2 USON8_(3×4) 1341.535mil 276.575mil 1294.291mil 229.331mil T 90 MX25R3235F
TP3 TP-L_3D 1066.929mil 60.039mil 1065.945mil 60.039mil B 90 JTAG_TMSC
TP5 TP-L_3D 1121.063mil 125.984mil 1120.079mil 127.953mil B 90 JTAG_TCKC
U4 GNS302uLP_-_BS 645.669mil 308.563mil 645.669mil 618.111mil B 0 GNS302uLP
U5 YFP0025BABD 641.732mil 161.417mil 641.732mil 161.417mil T 360 BQ25120YFPR
L3 0402L_3D 535.433mil 67.913mil 535.433mil 67.913mil T 90 BLM15HG102SN1
C27 0402C_3D 482.284mil 67.913mil 482.284mil 67.913mil T 270 10uF
u1 PVQFN32_3D 1143.701mil 184.055mil 1143.701mil 184.055mil T 0 CC2640RHB
C7 0402C_3D 1024.606mil 335.63mil 1024.606mil 335.63mil T 90 100nF
X2 2.0×1.2×0.6mm_crystal 936.024mil 135.827mil 936.024mil 135.827mil T 90 32.768KHz
C26 0402C_3D 560.039mil 264.764mil 560.039mil 264.764mil T 90 1uF
C25 0402C_3D 721.457mil 104.331mil 721.457mil 104.331mil T 270 1uF
U3 LGA14 1349.409mil 430.118mil 1349.409mil 430.118mil T 180 LSM6DSL
L7 6-0805_L 780.512mil 185.039mil 780.512mil 185.039mil T 270 2.2uH
C1 0402C_3D 1231.299mil 346.457mil 1231.299mil 346.457mil T 90 100nF
C2 0402C_3D 1066.929mil 25.591mil 1066.929mil 25.591mil T 360 100nF
C6 0402C_3D 1183.071mil 346.457mil 1183.071mil 346.457mil T 90 100nF
C13 0402C_3D 1390.748mil 531.496mil 1390.748mil 531.496mil T 90 100nF
C16 0402C_3D 1340.551mil 531.496mil 1340.551mil 531.496mil T 90 100nF
C19 0402C_3D 1380.906mil 117.126mil 1380.906mil 117.126mil T 180 100nF
C20 0402C_3D 1151.575mil 25.591mil 1151.575mil 25.591mil T 360 1uF
C21 0402C_3D 619.095mil 266.732mil 619.095mil 266.732mil T 90 1uF
C22 0402C_3D 710.63mil 272.638mil 710.63mil 272.638mil T 360 10uF
C23 0402C_3D 1380.906mil 167.323mil 1380.906mil 167.323mil T 360 100nF
L2 6-0805_L 1282.48mil 40.354mil 1282.48mil 40.354mil T 180 10uH
R3 0402R-v2_3D 1297.244mil 117.126mil 1297.244mil 117.126mil T 180 56K
R4 0402R-v2_3D 561.024mil 178.15mil 561.024mil 178.15mil T 270 56K
TP1 TP-L_3D 1245.079mil 54.134mil 1245.079mil 54.134mil B 180 JTAG_TDI
C4 0402C_3D 1380.906mil 70.866mil 1380.906mil 70.866mil T 360 10uF
C5 0402C_3D 1380.906mil 26.575mil 1380.906mil 26.575mil T 360 10uF

There are components labels.X,Y coordinates,rotation angle,where level.

3.Component bitmap file

The component bit map file,in fact is the component silkscreen. It’s provided to operate workers to comparison in the production processing.Inspect if there’s any wrong of assembly.The component bitmap is shown below:

Component bitmap file

4.PCB assembly fixture file:

PCB assembly fixture file, it’s used in covering surface mount components and expose plug pin when PCB through reflow welding machine.Because in the production of the first process is surface mount welded,and then the plug-in welding.the plug-in soldering is done with wave soldering, it must be through wave furnace. The fixture is avoid surface mount components be assembled don’t fall when through wave furnace.

PCB fixture-top side

                                                  Top side of PCB fixture

PCB fixture-botside

                                                  Back side of PCB fixture

5.Panel drawing file

If PCB is made from panel,it also need provides panel file.Because the assembly manufacturers need panel drawing to make coordinates files.

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