Sample Test Reports for efficient registration error analysis and PCB manufacturing process
control
Quantifying different causes of registration errors is the key to effective registration process control.
Separating Causes
Tracking PCB construction variables
Enhanced PerfecTest coupon
measurementsThe basis to identify and quantify registration errors and their causes
Largest registration error on this panel.
Automatically calculated after test data was collected from PerfecTest coupons
Test results from one panel
Fluctuation of Errors on different panels indicate
RANDOM SHIFT ERROR
MAXIMUM TRUE POSITION ERRORS
Largest registration error per panel
Biggest registration error by panel
Identify, separate & correct
EXPANSION ERRORS occur when inadequate scaling factors are applied to theartwork. Expansion registration errors are job specific. They describe the sizeof layers of a specific job. Depending on materials, panel constructions, andfabrication processes, necessary scaling factors will differ with each job.
• SHIFT ERRORS describe the location of inner layers, cores, or panels during thefabrication process. Shift errors are caused by tooling inaccuracies or operatorerrors. Shift error patterns are typically repeated on different jobs.
• Expansion errors are corrected with better scaling factors.
• Shift errors are corrected with tooling adjustments andimproved operating procedures.
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Nominal size
Actual size
Illustration 2Illustration 1
Actual size
Nominal size
- .005”-.005” - .007” - ,003”
Shift targets
Total registration error: - .005” + - .005” = -.010”
negative expansion error onlycorrected with scaling.
Maximum error is 0.005”.
Total registration error:- .007” + - .003” = - .010”
combination of shrinkage & shift errorcorrected with scaling & process
adjustments. Maximum error is 0.007”.
Nominal Location
.002 shift in +X axis
SIZE and SHIFT illustration
Expansion error by layer,Averages of 6 panels
Average Expansion errors
Corrected scaling factors -automatically calculated- adjust for irregular expansion.
NOTE: Scaling artwork will ONLY correct for expansion & shrinkage errors.Repetitive and random shift errors require tooling, process, or operator adjustments.
Corrected scaling
Shift errors averaged over the production lot indicate layer, core, and panel repetitive offset errors
To determine random shift errors refer to individual panel data
Average shift errors
Expansion errors and maximum true position errors are calculated from coupon measurements in Sites 1, 2, 3, 4.
Shift errors are determined by the cross points of the diagonals from Site 1 to Site 3 & Site 2 to Site 4
Site 4 Site 3
Site 1 Site 2
Shift targetMaximum True Position
Error by layer
Calculating expansion & shift errors
Red dots illustrate the average of layers in panel 1
Green dots illustrate the average of layers in panel 2
Blue dots illustrate the average of layers in panel 3
Grey dots illustrate the average of layers in panel 4
Dark green dots illustrate the average of layers in panel 5
Purple dots illustrate the average of layers in panel 6
Average registration errors by panel
Different locations of average shift targets, indicate shift of panels during drilling.
• scattered dots indicate random drilling process errors
• overlapping dots indicate drill offsets
• a combination of random and offset drill errors occurs frequently
Shift targets
Random & repetitive drilling shift errors
Inner layer averages from 11 panels in a production lot
Average inner layer registration
Averages from 11 panels of a production lot with multiple lamination cycles
Comparison of inner layer cores
All inner layers 3
4
5
6
2
9
7
8
Layers 2 & 9 added in second lamination cycle.
Lamination shift registration errors
Random shift on panels from the same production lot. Compare lamination and drilling shifts.
Random rotation of the same inner layer cores on different panels. Random shift of inner
layers and inner layer cores on different panels of the same production lot.
Rotation & shift in - X
Rotation & shift in –x & +y
Inner layer 3
Inner layer 4
Lamination random shift errors
A fully integrated solution to match registration challenges
Predict scaling for new jobs
Factory IntegrationAvailability of precise registration data
when it is needed & where it is needed.
Easy importation of precise or best-match scaling datawhen new jobs are being configured.
View & analyzeRegistration dataOn workstations
AutomaticNew job setup
On workstations
Direct or remote New job setup
on workstations
Automation Script
PerfecTest System
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