YesAX V3.1.2 - Software User Manual.pdf - 第211页

SPC Data Logg ing 15 -7 Mark1 Mark2 Using Edge Locators for Position Tracking In addition to using pattern matching you can also use the Edge Locator algorithm for position tracking. Edge locator provides more accurate p…

15-6 SPC Data Logging

The position tracking is OFF by default. To turn it on, go to Vision>Recipe Option and select

the Track XY Position to ODBC Database Table checkbox. Only templates with “Check Pos.”

turned on in the Mark Parameters dialog will have their XY position tracked.

Sample Data Output

The XY Positions are sent via the ODBC to a separate table named XYPosTrack. The table has

the following fields:

Assy

Recipe Name

IDate

Inspection date and time stamp.

Serial number of the board inspected.

RefID.

Reference designator for the part

X reference position for the first mark

Y reference position for the first mark

DX1

X Offset position for the first mark

DX2

Y Offset position for the first mark

X reference position for the second mark of the same part

Y reference position for the second mark.

DX2

X Offset position for the second mark.

DY2

Y Offset position for the second mark.

WorkOrder

 NOTE

All positioning units are in microns.

Here is a sample output.

Operational Details

Marking inspection uses a search algorithm called Normalized Grayscale Correlation or in

layman terms “template matching”. All successful template matches generate an XY position of

the successful match. We call this XY position the “Found” position. A deviation is calculated

by subtracting the trained position from this found position. It is this deviation that gets stored

into the database as X and Y.

Each part can have one or more mark inspection boxes. If the part has only one mark inspection

box, only the X1 and Y1 fields in the database table will be filled. X2 and Y2 are for the second

mark inspection box. Having a pair of XY data points allows for the calculation of the rotational

deviation of a placement.

SPC Data Logging 15-7

Mark1 Mark2

Using Edge Locators for Position Tracking

In addition to using pattern matching you can also use the Edge Locator algorithm for position

tracking. Edge locator provides more accurate position tracking on targets with clear and well

defined horizontal and vertical edges. To use Edge locator for position tracking, train two marks

with the Edge Locator algorithm. The first mark should be trained to locate a vertical edge or

strip and the second mark should be trained to locate a horizontal edge or strip. The first mark

will provide the X position plus the angle data and the second mark provides the Y position data

to the database.

15.5 Robust Mode for Data Logging

In the normal operating mode for data logging, the software opens a link to the database during

software start-up and assumes the link to be there for all the subsequent data logging operations.

This mode of operation works well for most of the network environment. In environments where

the network traffic is heavy and a prolong connection to one computer cannot be guaranteed, the

YesAX software offers a more robust mode of data logging. In the Robust Mode, the software

tests the database connection before each batch of data logging operations. It is slightly slower

but far more reliable. To enable Robust Mode, edit the YesAX.ini file:

[ODBC_Report]

RobustMode=1

15.6 Process Alarm

YesAX allows users to setup various trigger conditions to raise process alarms. There are

currently two types of alarms, rate alarms and defect alarms. The rate alarm triggers when the

defect rate or the false call rate exceeds a preset level. The defect alarm triggers when a user-

specified defect condition has been reached.

15.6.1 Rate Alarms

The Rate Alarm triggers when the defect rate or false call rate exceeds the preset level. The

defect rate is measured as PPMO (Part Per Million Opportunities) and is calculated as:

Defects

-------------------------------- * 1,000,000

Opportunity for Defect

The opportunity for defects is the total number of tests performed. It is usually the sum of

Marking, Lead Bank, and Solder inspections.

The false call rate is also measured as PPMO and is calculated as:

False Call Count

-------------------------------- * 1,000,000

Opportunity for False Call

15-8 SPC Data Logging

On a board with no real defects, the opportunity for false calls is the same as the opportunity for

defects. To simplify the calculation we assume the opportunity for false calls also as the sum of

Marking, Lead Bank, and Solder inspections.

A high defect rate would indicate problems upstream. A high false call rate may indicate the

inspection recipe should get additional tweaking.

15.6.2 Defect Alarms

The defect alarm triggers when the user-specified defect conditions are exceeded. There are 10

defect alarms. You can set one defect alarm to trigger when there are more than 3 part defects in

the last 5 runs of boards. You can set another defect alarm to trigger when there are more than 10

solder defects in the last 3 runs of boards.

The first step to setup a defect alarm is to group the defects into classes. This is done by editing

the defect.ini file. Use the @C# notation to assign a class to each defect. The class number starts

with 1 and ends with 9. Defects with no class assignment default to class 0. Here is a sample

defect.ini file with the class assignment.

[01] Unclassified

[02] Missing Part@S@C2

[03] Wrong Part@S@C1

[04] Tombstone Part@S@C4

[05] BillBoard Part@S@C2

[06] Skew Part@C2

[07] Wrong Polarity@S@C3

[08] Lead Solder Bridge@C4

[09] Bend Lead@C4

[10] Insufficient Solder@C4

[11] Solder defects@C4

[12] False Call

After setting the defect classes, setup the trigger condition by selecting Process Alarm.. from the

System menu. The Process Alarm Setup dialog displays.