It is often the case that the Fiducial marks do not adequately compensate for errors in the pre-route drilling pattern. In such situations the GSR Edge Detection Vision System can be employed.

1. Getech Edge Detection Vision Alignment
for GSR Routing Process. [Patent Pending.]
Getech Automation Software
Development, March 2014

2. Introduction
Getech Edge Detection Vision Alignment [GDVA software] is a newly
developed system by Getech Automation. Instead of the traditional top
camera ‘view and teach’ method, it works by Back Lighting the PCB held on
the fixture. The Backlight allows the edge of the PCB to be visually detected
by the machines vision system. By detecting the PCB edge before and after
the TAB the machine auto aligns the cutting path for every TAB on a PCB.
The Result is a clean cut edge dimensionally accurate to the PCB Design
outline.

3. Objectives
The objective of this process is to help the end user eliminate over-cutting issues
due to PCB panel inconsistencies and manufacturing defects, eg mis-matching of
overall trace circuits with tooling holes.
Hardware & Software Requirements
 Machine Type : GSR Series with top vacuum configuration
 Spindle Type : Kavo 4041 or 4025
 Camera Type : Fiducial camera ( color or black & white )
 Cutter Type : Diamond flutes for FR4 board ( up-cut )
 Fixture : Dedicated with LED back light beneath PCB
 Software : Getech edge detection software

4. General Setup for Evaluation
List of Equipment.
1. GSR Edge Detection Software with additional [Vision Aligned Line] option.
2. Getech Standard CPK 4up Panel.
3. Dedicated fixture with Back Lighting feature.
4. GSR Standard Fiducial Camera ( color ).
1. GSR edge detection S/W
[cont]

5. 2. Getech CPK Panel
3. Back Light Fixture
4. GSR edge
detection S/W
[cont]

6. Advantages
Traditional Vs Back Light Cutting
 If a batch of PCBs arrive with global mis-matching of trace circuitry relative to
locating holes. [i.e 0.2mm drift in Y direction]
 If this batch of PCBA is uses the traditional method of depanelising [i.e after global
fiducial recognition the system proceeds with the pre-teach (The taught path is
determined from a good panel ). The result will be as shown with an ‘Under-cut’.
Or a worse outcome? Most probably it will be an ‘Over-cut’.
Before Cutting After Cutting

7.  With the Edge Detection option, there is no further concern
about cutting drift.
 The vision system will AUTO ALIGN to
the PCB edge, the routing result will be
as shown – No Over/Under cut
Process

8.  Full PCB Panel Routed with EDGE DETECTION Auto Alignment
 All the cut edges are perfectly FLUSH with the PCB edges regardless of change
in PCB panels or change in PCB vendors.
Results

9.  Full PCB panel depanelised result which purely based on Cad Data input
 Over and Under cut edges can be observed everywhere along the PCB edges,
they vary in locations as raw panel changed.
Results

10. • Cycle time will increase relative to the
number of vision captures on both ‘Start’
and ‘End’ points of the cutting paths.
• The increment will be approximately 0.8s
per cut.
Cycle time considerations

11. Getech Edge Detection Vision Alignment can be considered as an ‘AUTO PILOT’ for the routing
process . It continuously looks at the “Actual Cut Path” needed based on the circuits Actual
Geometry and compensates for any PCB dimensional drift that may impact the process. The
result is clean dimensional stable PCB edge’s regardless of PCB vendors, color or jagged edges.
It provides an Assurance that any change in the circuit as a result of a change in PCB vendors
will not impact the quality of the finished routed PCB. It even helps to minimize or eliminate
tearing, dog bone defects.
Getech Edge Detection Vision Alignment is the next step in machine/process innovation for the
manufacturing company dealing with external quality issues that impact manufacturing.
Note : The lighting level, routing direction etc should be set as per Getech recommendations
.
Conclusions