SIPLACE 80 F4_EN - 第26页

25 Description The component vision module is integrated dir ectly into the rev olver head and images the component in question. While the component is cycl ing onwa rd into the nex t sta- tion of the revolver head, the …

Description

In the cluster technology each

subpanel is assigned an ink spot.

If this is present during the meas-

urement via the PCB vision mod-

ule, the corresponding subpanel is

not populated. Naturally it is also

possible to prevent the population

of the subpanel when the ink spot

is missing.

With this function it is possible to

prevent costs arising due to un-

necessary population of faulty

subpanels.

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The pick-up position of the com-

ponent 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

Fiducial shapes

Single cross (recommended because

susceptibility to disruption lowest)

rectangle, square, circle, etc.

Masking material

Mat dark (light-absorbing)

Not recommended: white or shiny

Size or fiducial masking

Circular: Diameter ≥ 8.1 mm

Square: Edge length ≥ 5.7 mm

Fiducial recognition time

(travel > 100 mm)

Mark masked: 1.2 s

Mark not masked: 0.4 s

Description

The component vision module is

integrated directly into the revolver

head and images the component

in question. While the component

is cycling onward into the next sta-

tion of the revolver head, the re-

corded image is being evaluated

by the central vision system. The

component is then corrected by

the appropriate angle in this sta-

tion on the basis of the position

offsets determined.

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 including BGA,

µBGA, Flip Chip, TSOP, QFP, PLCC,

SO to SO32, DRAM

Lead pitch

≥ 0.5 mm

Camera’s field of view 24 x 24 mm

Illumination

Front light

(3 freely programmable planes)

Description

The component vision module in-

tegrated into the placement head

performs a critical contribution to

placement accuracy and reliability.

It dependably recognizes all pack-

age forms (= geometric dimen-

sions of the component) illumi-

nated at various angles from three

planes. To illuminate each compo-

nent optimally, the luminosity of

the individual planes can be ad-

justed individually in 256 levels.

Aside from the dimension of the

SMD component, the vision sys-

tem determines the lead number

and pitch (lateral IC lead bend) as

well as the rotation angle and X-/Y-

offset. Components which are not

suitable are rejected and automati-

cally corrected in a repair cycle.

Rotational and X-/Y-offsets are cor-

rected at the turning station of the

revolver head or via the gantry

axes. A relevant X-/Y-pick-up offset

is calculated from the positions of

a number of components from one

track. This is factored in accor-

dance with the self-learning princi-

ple during the subsequent pick-up

of components.

Prior to placement the required

geometrical dimensions of one

component type are entered into

the package form (GF) editor, cre-

ating a synthetic model of the

SMD module. This task is simpli-

fied by the comprehensive on-line

information and Help system.

Later the central SIPLACE vision

system, which all other vision

modules are connected, analyzes

the gray-scale picture of the com-

ponent vision module. To this end,

suitable logarithms are used for

the pertinent package type. Due to

the combination of algorithms, the

vision system also functions relia-

bly under the most difficult condi-

tions, e.g., in the case of different

reflection behavior by the leads or

disruptive influences from the out-

side.

Vision Sensor Technology:

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

Rotation Angle

Algorithm Component Determined on the basis of

Size Driven Chip

the component’s out line

(profile/gradients)

Row Driven IC

several component leads

(correlation method)

Corner Driven IC

all component leads

(correlation method)

Lead Driven Complex IC

each component connection

(High-Accuracy-Lead-Extraction method)

Grid/Ball

BGA, µBGA,

Flip Chip

all defined balls

(gradients/ball centering)