A10011-ASM-T45-EN-Spec-E_DMS - 第31页

31 Vision Sensor Technology PCB Position Recognition Bad Board Recognition Ink spot crite ria Methods • Synthetic fidu cial recognition method • Mean gray scale value • Histogram method • Template matching Shapes and siz…

Vision Sensor Technology

PCB Position Recognition

Description

The optimum fiducial shapes

vary according to the condi-

tion of the surface. When

using bare copper surfaces

with low oxidation, it is advis-

able to take the single cross,

as the high amount of infor-

mation provided helps

achieve the greatest

accuracy. Rectangle, square

and circle are less "informa-

tive" but save space and can

even be used when oxidation

is at an advanced stage. Cir-

cle or square are advisable

for tin-plated structures as

the ratio of the fiducial

dimensions to the presolder

thickness is particularly

favorable.

Fiducial criteria

Locate 2 fiducials

Locate 3 fiducials

X-/Y-position, rotation angle, mean PCB distortion

additional: shearing, distortion separately in X and Y direc-

tion

Fiducial shapes Synthetic fiducials: circle, cross, square, rectangle, dia-

mond, circular, square and rectangular contours, double

cross, pattern: any

Fiducial surface

Copper

Tin

Without oxidation and solder resist

Warpage of fiducial ≤ 1/10 of structure width, both with good

contrast to environment

Dimensions of patterns

min. size

max. size

0.5 mm

3 mm

Fiducial environment Clearance around reference fiducial not necessary if there

is no similar fiducial structure in the search area

Dimensions of synthetic fiducials

Min. X/Y size for circle and rectangle 0.25 mm

Min. X/Y size for annulus and rectangle 0.3 mm

Min. X/Y size for cross 0.3 mm

Min. X/Y size for double cross 0.5 mm

Min. X/Y size for diamond 0.35 mm

Min. frame width for annulus and rectangle 0.1 mm

Min. bar width / bar distance for cross, double-cross 0.1 mm

Max. X/Y size for all fiducial shapes 3 mm

Max. bar width for cross/double-cross 1.5 mm

Minimum tolerances generally 2% of nominal dimension

Max. tolerances generally 20% of nominal dimension

Vision Sensor Technology

PCB Position Recognition

Bad Board Recognition

Ink spot criteria

Methods • Synthetic fiducial recognition method

• Mean gray scale value

• Histogram method

• Template matching

Shapes and sizes of fiducials/structures for

synthetic fiducials

other methods

For dimensions of synthetic fiducials, see page

min. 0.3 mm

max. 5 mm

Masking material Good coverage

Recognition time Depends on the method: 20 ms - 200ms

Description

In the cluster technology

each subpanel is assigned

an inkspot. If this is present

during the measurement via

the PCB vision module, the

corresponding subpanel is

populated. This function

helps prevent unnecessary

costs caused by placement

of defective panels.

Technical data for PCB position detection

PCB fiducials

Local fiducials

Library of bad panel recognition

Up to 3 (subpanels and multiple panels)

Up to 6 for the long board option (optional PCB fiducials

are output by the optimization.)

Up to 2 per PCB (may be of different type)

Up to 255 fiducial types per subpanel

Image analysis Edge detection method (singular feature) based on gray

scale values

Illumination type Front lighting

Fiducial recognition time 0.1 s

Field of vision 5.78 mm x 5.78 mm

Vision Sensor Technology

Reading the Barcode and Data Matrix Code with a

PCB Camera

Description

The PCB camera can read

either a barcode or a data

matrix code. The data can be

used for traceability pur-

poses.

The barcode can be on the

board itself or on a compo-

nent. In addition, it is also

possible to attach a barcode

label to a board or a compo-

nent and to then read this

barcode label with the PCB

camera, directly after place-

ment. The focal height must

be taken into account during

reading, if there is a barcode

or barcode label on the top of

a component.

Data Matrix Codes

Code types supported Only Data Matrix ECC 200 is supported.

No. rows/columns All combinations of rows/columns as defined in the standard will be

accepted, including rectangular symbols and large symbols with multi-

ple data areas.

Minimum dot size 50 µ

Maximum size of data matrix

codes

≤ 30 mm and Y ≤ 30 mm, or

≤ 10 mm and Y ≤ 100 mm, or

X ≤ 100 mm and Y ≤ 10 mm

Symbol angle All symbol angles will be accepted.

Inverse symbols Inverse symbols (light modules on a dark background) will be

accepted.

Mirrored symbols Mirrored symbols will be accepted.

(Station software version 707.1 SP2 or higher required)

Ratio of column width to row

height

1/2

≤ (column width) / (row height) ≤ 2

Region of Interest (ROI) The area in which the barcode is searched for (ROI) should not

exceed the following values:

Width of ROI

≤ 6 * width of barcode symbol

Height of ROI

≤ 6 * Height of barcode symbol

Contrast Minimum 20 gray values.

Print growth The size of a module must be at least 1/3 of the cell size in the data

matrix grid.

The size of a module must be at most 5/3 of the cell size in the data

matrix grid.