Specification_SIPLACE_F5_eng - 第24页

23 Description With the SIPLACE F 5 a number of vision module s with a centr al vi- sion system to eval uate the r e- corded image d ata ensure a hi gh placement accuracy . At the machine’s X-gantry the P CB vision modul…

Description

The component changeover tables

can be set up and checked at an

external SIPLACE set-up station

quickly and without machine idle

time. The costs for production in-

volving a great variety of compo-

nents are greatly reduced. During

the bar code check outside the

machine, 10 minutes of machine

standstill are eliminated per set-up

change. All current data from up to

4 lines are accessible over a link to

the line computer via a Local Area

Network (LAN).

In the case of the SIPLACE F

component changeover table is

part of the standard equipment.

Additional changeover tables are

required for optimal use of the set-

up station.

Component Supply:

SIPLACE External Set-Up Station (Option)

Technical Data

Operating system Windows NT 4.0

Set-up check Per bar code scanner

Component table change Time expanded: 2 min / table side

Example for SIPLACE Set-Up Station

Line

LAN

Line Computer

PC for External set-up

LAN Scanner

Serial Interface

Tape Reel

with

Bar Code

Changeover

Table

Changeover Tables

Description

With the SIPLACE F

a number of

vision modules with a central vi-

sion system to evaluate the re-

corded image data ensure a high

placement accuracy.

At the machine’s X-gantry the PCB

vision module finds position off-

sets on the part of the PCB in the

conveyor system. This module is

also required to measure the ma-

chine and/or the feeders on one

side of the table. This vision mod-

ule consists of a single CCD cam-

era with integrated lighting and op-

tics.

The offsets in the position of the

PCBs are determined with the

help of at least two but generally

three reference fiducial marks on

the PCB. When the PCB arrives

the gantry with its PCB vision

module moves to the programmed

mark position. The vision system

compares the recorded video im-

age with the sample stored in the

PCB description.

With the help of the correlation

principle the vision system can de-

termine the correct position even

when fiducial marks are incom-

plete or damaged (actual struc-

tures). It does so by making com-

parisons with programmed

nominal structures. The mark con-

figurations are not fixed; they can

be taught without restriction.

Additional functions of the PCB vi-

sion module are recognition of the

position of the feeders and ce-

ramic substrate (optional) and re-

cording of the machine data in-

cluding mapping.

In addition, the bad board recogni-

tion unit is moved over “ink spots”

with the aid of the PCB vision

module.

Vision Sensor Technology:

PCB Vision Module

Technical Data

Reference marks

Local marks

Library memory

Recognition of poor panels

up to 3 (subpanels and multiple panels)

up to 2 per component

(may be of different type)

up to 255 types of reference marks

per subpanel

Image processing

Correlation principle based on

gray values

Illumination Front light

Recognition time

mark/ink spot 0.8 s

Camera’s field of view 5.7 x 5.7 mm

Correlation Principle

Target Low

Structure Correlation

Actual High

Structure Correlation

Description

Various fiducial mark shapes prove

to be optimal depending on the

condition of the surface.

In the case of bare copper sur-

faces with little oxidation, the sin-

gle cross is particularly recom-

mended because maximum

recognition reliability is achieved as

the result of the high information

content. Rectangle, square and

circle are less “informative”, but

save space, are rugged and can be

used even if oxidation is advanced.

In the case of tinned structures,

circle or square are recommended

because the ratio between fiducial

dimensions and presoldering thin-

ness is then particularly good.

Vision Sensor Technology:

PCB Position Recognition

Fiducial Mark Criteria

Determine 2 fiducials

Determine 3 fiducials

in addition

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

Shear, distortion in X- and Y-direction

Fiducial shapes

Freely definable via teaching, e.g.,

single cross, rectangle, square, circle

Fiducial surface:

Copper

Tin

Without oxidation and solder resist

Warp ≤ 1/10 of structure width, good

contrast with surroundings

Fiducial dimensions:

Single cross

Rectangle/square

Circle

Length and width: 0.9 - 2 mm

Stroke thickness: 0.3 - 1.0 mm

Edge length: 0.5 - 2 mm

Diameter: 0.5 - 2 mm

Fiducial surroundings

No clearance around the fiducial marks

necessary if there is no similar fiducial

structure within the search area

(5.7 x 5.7 mm).

Reference Fiducial

PCB Camera

Field of View

Fiducial to

be Located

Template

Window