SIPLACE 80 F4_EN.pdf - 第27页

26 Description The component vision module in- tegrated into the placement head perfor ms a critical co ntributi on to placement accur acy and re liabi lity. It dep endably recog nizes all p ack- age forms (= geom etric …

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)

Description

The Fine Pitch component vision

module operates according to a

sophisticated lighting technology

and utilizes diverse analysis algo-

rithms. Despite the great diversity

of components it boasts a very

high recognition reliability with all

SMD modules. Like all other vision

modules, this one is also con-

nected to the station’s vision

processor.

The components are illuminated

from three lighting planes whose

intensity can be adjusted in 256

increments. This enables an opti-

mal illumination of each compo-

nent. The gray-scale picture re-

corded is analyzed on the basis of

the algorithm best suited for the

package form.

ICs, Flip Chips and IC-sockets are

centered on the basis over the

leads or bumps. In the case of

chips, bare chips for subsequent

wire bonding and odd-shaped

components, centering is based

on the outside contour (outline

measurement).

A special inspection mode for the

critical IC lead ends (HALE) pre-

cisely determines the lateral lead

bend as well as pitch error and

lead offset. This greatly reduces

the risk of short circuits.

Beyond this, the rotational angle

deviation and the X-/Y-offset of the

component relative to the nozzle

center is ascertained and factored

in during placement. The X-/Y-

offset also results in the correction

of the pick-up position.

In order to have the vision module

center a component which it does

not yet know, it must first be de-

scribed geometrically in the pack-

age form (GF) file. The component

test makes it possible to check at

the station to determine whether

adjustments, in lighting for exam-

ple, are necessary. These adjust-

ments are automatically assigned

as a file to the pertinent package

form which represents a compo-

nent type. Hence they are valid for

all of the stations in a line. As the

final step, the GF number of the

component type is entered in the

component file.

Vision Sensor Technology:

Fine Pitch Component Vision Module for the

Pick & Place Head

Technical Data

Max. component size

32 x 32 mm (single measurement)

55 x 55 mm* (multiple measurement)

Component range

PLCC, LCCC, QFP, SO, BGA, Flip Chip

components with connections up to

55 x 55 mm (J-leads and gull-wings,

balls, bumps)

Camera’s field of view 38 x 38 mm

Illumination

Front light

(3 freely programmable planes)

Analysis algorithms Compare page 25

* Larger components available on request