西门子SIPLACE HS 50-设备参数_EN.pdf - 第26页

24 ➀ 12-Nozzle Collect & Place Head ➁ X-/Y-Gantry System ➂ Fixed Component Supply ➃ Fixed PC B Description In addition to c orrect positioning, placement re liability is impor tant. On the SIPLACE HS-50 this is en- s…

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

Description

Slight distortions of the gantry

axes cannot always be avoided de-

spite the highly stable machine

frame. With the aid of the mapping

approach, the high placement pre-

cision of the machine is maintained

throughout its service life.

With this calibrating procedure,

which can be conducted quickly

and easily, the PCB camera recog-

nizes the fiducials on a mapping

calibration plate placed in its oper-

ating area. This board has highly

accurate marks on it. Any distor-

tions are located by comparing the

nominal grid on the mapping board

with the actual grid ”drawn” by

the placement head. These distor-

tions are then considered when

calculating all further positioning of

the X-/Y-axis and are thus compen-

sated for.

Machine Criteria:

Mapping (Option)

Nominal Grid of Mapping Plate and Actual Grid with

Deviations Due to Gantry

Corrected

Position

Technical Data

Dimensions of the mapping

test plate

520 x 460 mm

(for single conveyor)

520 x 215 mm

(for dual conveyor)

Number of measurement

points

13 x 11 (standard resolution)

26 x 21 (high resolution)

Ambient temperature during

calibration + 20° ± 3°C

Components of the option Test plate (special glass)

Calculation data (disk)

Case for secure storage