Specification_SIPLACE_S23HM_eng.pdf - 第21页

20 Description The component vision module is directly integrated into the revolver head and it takes a picture of the pertinent component. This image is analyzed b y the central vision system while the component i s cyc…

Description

In cluster technology, each sub-

panel is assigned an ink spot. If

this is present when the PCB vi-

sion module conducts the meas-

urement, the pertinent subpanel is

not populated.

Naturally, it is also possible to pre-

vent the population of the sub-

panel when the ink spot is miss-

ing.

This function can be used to pre-

vent costs incurred by unneces-

sarily populating faulty subpanels.

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The pick-up position of the com-

ponents can be determined pre-

cisely with the aid of the position

recognition of the feeder. It is acti-

vated each time after a change of

feeder or component table. The

offset in position relative to the

stored ideal position is determined

on the basis of fiducials on the

feeder modules using the PCB vi-

sion module. This provides a very

high pick-up reliability even for the

very first component. This is par-

ticularly important with small com-

ponents.

Vision Sensor Technology:

Recognition of Faulty PCBs via Ink Spots

Position Recognition of Feeder

Ink Spot Criteria

Mark shapes Single cross (recommended because

of lowest susceptibility to problems),

rectangle, square, circle, etc.

Masking material Mat dark (light-absorbent)

Not advisable: white or glossy

Size of mark masking

Circular: Diameter ≥ 8.1 mm

Square: Edge length ≥ 5.7 mm

Mark recognition time

(Travel > 100 mm)

Mark masked: 1.2 s

Mark not masked: 0.4 s

Description

The component vision module is

directly integrated into the revolver

head and it takes a picture of the

pertinent component. This image

is analyzed by the central vision

system while the component is

cycling into the next station, where

the position of the component is

corrected in accordance with the

offsets in position discovered.

Vision Sensor Technology:

Component Vision Module on the 12-Nozzle Revolver Head

Technical Data

Maximum component size 18.7 x 18.7 mm

Recognizable spectrum

of components

0402 to PLCC44

incl. BGA, µBGA, Flip Chip, TSOP,

QFP, PLCC, SO to SO32, DRAM

Lead pitch

min. ≥ 0.5 mm

Camera’s field of view 24 x 24 mm

Type of lighting Front lighting

(3 freely programmable planes)

Description

The component vision module in-

tegrated into the placement head

significantly contributes to place-

ment precision and reliability. It

dependably recognizes all package

forms (= geometric dimensions of

the component) which are illumi-

nated at various angles from three

planes in the case of the 12-nozzle

revolver head. For optimal illumina-

tion of each component, the

brightness of the lighting of the

planes can be adjusted individually

in 256 increments.

Aside from the dimension of the

SMD module, the vision system

determines the number of leads

and their pitch (lateral IC lead bend)

as well as the offset of the place-

ment angle and the X-/Y-axis. Un-

suitable components are rejected

and automatically added later in a

repair cycle. Offsets in placement

angle and X-/Y-axis are corrected at

the turning station of the revolver

head or via the gantry axes. From

the positions of a number of com-

ponents in one track a relevant

offset in the pick-up position on

the X-/Y-axis is calculated. This off-

set is taken into account during

subsequent component pick-up

steps due to the self-learning prin-

ciple.

Prior to placement, the required

geometric dimensions of a com-

ponent type are entered into the

GF editor, creating a synthetic

model of the SMD chip. This task

is facilitated by the extensive on-

line information and help system.

The central SIPLACE vision sys-

tem, to which the other vision

modules are also connected, sub-

sequently analyzes the gray-scale

value of the component vision

module. Algorithms suitable for

the specific package form are used

for this purpose. Due to the com-

bination of algorithms, the vision

system also functions reliably un-

der the most difficult conditions,

e.g., in case of different reflection

behavior on the part of the leads or

interference from outside.

Vision Sensor Technology:

Algorithms to Determine the X-/Y-Position and the

Placement Angle

Algorithm Component Analysis based on

Size Driven Chip the component contour (pro-

file/gradient)

Row Driven IC Several component leads (correla-

tion method)

Corner Driven IC all component leads

(correlation method)

Lead Driven Complex IC Each component lead (High-

Accuracy-Lead-Extraction method)

Grid/Ball

BGA, µBGA,

Flip Chip

all defined balls

(gradients/ball centering)