Specification-SIPLACE-S25HM-eng - 第28页

26 Description In the cluster technology each subpanel is assigned an ink spot. If this is pres ent during the meas- urement via the PCB vision mod- ule, the corresponding subpanel is populated. It is also possible to ac…

Description

Different reference mark shapes

prove to be optimal depending on

the condition of the surface.

Particularly advisable for bare cop-

per surfaces with little oxidation is

the single cross. Maximum recog-

nition reliability is achieved due to

the high information content. Rec-

tangle, square and circle are less

”informative” but save space, are

rugged, and can even be used

when oxidation is at an advanced

stage.

Advisable for tinned structures are

circle or square because in this

case the ratio of the mark dimen-

sions to the presolder thickness is

particularly favorable.

Vision Sensor Technology:

PCB Position Recognition

Reference Mark Criteria

Locate 2 marks

Locate 3 marks in addition

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

Shear, distortion in X- and Y-direction

Mark shapes Synthetic marks e.g., circle, cross, square,

rectangle, rhombus, circular ring, square

ring, octagonal ring (choose from menu)

Mark surface:

Copper

Tin

Without oxidation and solder resist

Warp

≤ 1/10 of structure width,

both with good contrast to environment

Mark dimensions

Circle

Cross

Rectangle/square

Rhombus

Diameter: 0.3 - 3 mm

Length and width: 0.3 - 3 mm

Line thickness: 0.1 - 1.5 mm

Edge length: 0.3 - 3 mm

Transversal length:0.3 - 3 mm

Mark environment Clearance around reference mark not

necessary if there is no similar mark

structure in the search area

Teach Synthetic Fiducial

Fiducial Editor

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

populated. It is also possible to ac-

complish the population of the

subpanel when the ink spot is

missing. With this function it is

possible to eliminate costs due to

unnecessary population of faulty

subpanels.

Global Ink Spot

Global Ink SpotGlobal Ink Spot

Global Ink Spot

Each bad board evaluation needs

time, so naturally the consumed

time increases with the number of

subpanels per PCB. Using a global

ink spot can result in a significant

reduction of these secondary

times.

The PCB vision module searches

at positions taught before for the

defined fiducial. In case of recogni-

tion there is no following evalua-

tion of subpanels. The system al-

lows the customer to choose also

the opposite interpretation.

Position Recognition of Feeder

Position Recognition of FeederPosition Recognition of Feeder

Position Recognition of Feeder

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:

Bad Board Recognition

Position Recognition of Feeder

Ink Spot Criteria

Evaluationmethod

for fiducials

for structures

brightness method

contrast method

Shapes and sizes of

fiducials/structures for

brightness method

contrast method

square or circular forms

edge length/diameter 0.3 - 5 mm

rectangular forms

edge length 0.3 - 5 mm

Masking material mat dark (light-absorbing)

not recommended: white or shiny

Ink spot recognition time 0.3 s for each method

Description

The component vision modules

perform 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 a

number of planes. To illuminate

each component optimally, the

luminosity of the individual planes

can be adjusted 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

Collect & Place Head or via the

gantry axes. A relevant X-/Y-pick-

up offset is calculated from the

positions of a number of compo-

nents from one track. This is fac-

tored in accordance with the self-

learning principle during the sub-

sequent 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, to which all other vision

modules are connected, analyzes

the gray-scale picture of the com-

ponent vision module. To this end,

suitable algorithms 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.

The algorithms are used for all

component vision modules.

Vision Sensor Technology:

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

Rotation Angle of Components

Algorithm Component Determined on the basis of

Size Driven Chip the component’s outline

(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/Bump BGA, µBGA,

Flip Chip

all defined balls and bumps

(gradients/ball or bump centering)