西门子SIPLACE HS 50-设备参数_EN.pdf - 第25页

23 Description Various fa ctors contribute to the placement accuracy of the SIPLACE HS-50 machine, e.g., the stationary PCB during the place- ment process. As no acceler ations are acting on the placed compo- nents, thei…

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

➀ 12-Nozzle Collect & Place Head

➁ X-/Y-Gantry System

➂ Fixed Component Supply

➃ Fixed PCB

Description

In addition to correct positioning,

placement reliability is important.

On the SIPLACE HS-50 this is en-

sured through a number of control

functions, such as vacuum checks

and component vision testing dur-

ing the placement sequence.

Out of tolerance components are

rejected, placed on the repair list

and automatically processed during

a repair cycle. An offset in the po-

sition of the PCB relative to the

conveyor system (PCB vision) and

an offset of the X-axis, Y-axis or ro-

tation of the component relative to

the midpoint of the nozzle (com-

ponent vision) trigger an immedi-

ate correction to ensure placement

accuracy.

Since the PCB is fixed, the com-

ponents remain in the exact posi-

tion they are placed. The stationary

component table ensures a precise

pick up. Options, such as the

component bar code scanner,

can be added to further enhance

reliability.

Placement errors

Placement errorsPlacement errors

Placement errors

Errors that occur after the compo-

nent has been placed on the PCB.

They include:

§ Component is missed on PCB

§ Too many components on PCB

§ Components not placed prop-

erly on PCB

§ Components placed while

standing on edge

Machine Criteria:

Placement Reliability

Placement Principle SIPLACE HS-50