西门子SIPLACE HS 50-设备参数_EN.pdf - 第24页

22 Description The standard component vision module is dire ctly integrated into the Collect & Place Head. While the component is cycling into the next station of the Collect & Place Head, the recorded image is e…

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

Collect & Place Head. For optimal

illumination 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 Collect &

Place Head or via the gantry axes.

From the positions of a number of

components 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 combina-

tion of algorithms, the vision sys-

tem also functions reliably under

the most difficult conditions, e.g.,

in case of different reflection be-

havior 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)

Description

The standard component vision

module is directly integrated into

the Collect & Place Head. While

the component is cycling into the

next station of the Collect & Place

Head, the recorded image is evalu-

ated by the central vision system.

The component rotation is then

corrected by the appropriate angle

based on the position offsets de-

termined with vision inspection.

Vision Sensor Technology:

Standard Component Vision Modules for 12-Nozzle

Collect & Place Head

Standard Component Vision Module for the 12-Nozzle C & P Head

Maximum component size 18.7 x 18.7 mm

Component Range See table on page 6

Camera’s field of view 24 x 24 mm

Illumination Front lighting

(3 freely programmable planes)

Description

Various factors contribute to the

placement accuracy of the

SIPLACE HS-50 machine, e.g., the

stationary PCB during the place-

ment process. As no accelerations

are acting on the placed compo-

nents, their position continues un-

changed. The PCB moves in and

out at a coordinated speed which

is automatically reduced just be-

fore the nominal position is

reached.

A further guarantee for long-term

high placement accuracy is the po-

sition recognition of the axes of

the gantry and placement head by

means of optical scanning by in-

cremental encoders. Revolving star

and segments of the Collect &

Place Head are positioned by

means of high-resolution glass in-

cremental panels. The X- and Y-

axes are positioned with the help

of the linear scales on each gantry

axis.

To determine the placement accu-

racy on SIPLACE machines, highly

precision glass components with

mounted structures are placed on

a dimensionally accurate glass

mapping plate. The results are sta-

tistically evaluated and presented

as a Gaussian standard distribu-

tion. In the case of the 12-Nozzle

Collect & Place Head the place-

ment accuracy is ± 90 µm at a sta-

tistical reliability of 4 sigma. In

other words, of one million placed

components, 60 are outside the

specified tolerance (= 60 dpm). If

the accuracy value ± 90 µm is di-

vided by the sigma value 4, the re-

sult is the standard deviation S of 1

sigma = ± 22.5 µm.

A machine capability analysis is

conducted for each machine ac-

ceptance test.

Machine Criteria:

Placement Accuracy

Technical Data Gantry

Drive Brushless AC

Temperature Controlled Motor (X-axis)

Linear drive (Y-axis)

Position measuring system

(X/Y)

Linear scales

Resolution of X-/Y-axis 1 µm

Speed of X-axis max. 2 m/s

Speed of Y-axis max. 2.5 m/s

Placement Accuracy see table on page 6

Standard Deviation – dpm

-4

-3

-2

2700 dpm

60 dpm

P Point of Inflection