Specification_SIPLACE_F5_eng - 第32页

31 Description The optional cop lanarity check fur- ther enhances placeme nt reliabil- ity. Thi s check is al ways co n- ducted right after the devi ation of position is a scertained with the Fine Pitch vision modu le of…

Description

The Flip Chip component vision

module extends the capability of

processing Fine Pitch and Flip Chip

components with extreme fine

lead pitches. This add-on module

for the Fine Pitch component vi-

sion module offers a far higher

resolution. The lighting layout is

fundamentally changed in the pro-

cess. At optimal illumination, the

imaging of the bumps is as large

as possible and the orthogonal dis-

ruptive structures (e.g., chip

printed conductor tracks) are sup-

pressed. In the event of less pro-

nounced disruptive structures, the

intensity can be increased by

combined lighting. This results in a

high recognition reliability even

with usually square surfaces of

bumped Flip Chips in the conduc-

tive adhesive technology.

Special search algorithms are used

to recognize the bumps (balls) in

surroundings where fault condi-

tions usually prevail.

Vision Sensor Technology:

Flip Chip Component Vision Module for the Pick & Place Head

(Option)

Technical Data

Flip Chip size

with single measurement

with multiple measurement

1 x 1 mm

up to max. 7 x 9 mm

max. 20 x 20 mm

Dimensions < 3 x 6 mm

Special nozzle,

feeding tolerance < 0.2 mm edge length

Min. bump diameter 80 µm

Placement cycle

min. 2 s

(depending on number of bumps)

IC-pitch:

Lead pitch

Bump pitch

0.25 mm

0.14 mm

Camera’s field of view 9 x 11.5 mm

Illumination

Front light

(3 freely programmable planes)

Description

The optional coplanarity check fur-

ther enhances placement reliabil-

ity. This check is always con-

ducted right after the deviation of

position is ascertained with the

Fine Pitch vision module of the

Pick & Place head.

The coplanarity module is installed

next to the PCB conveyor along

with the Fine Pitch vision module

of the Pick & Place head.

One of the biggest problems in

Fine Pitch technology, the copla-

narity of leads, can be largely

eliminated by taking one additional

step during inspection. The copla-

narity module is employed to con-

duct a contactless, sequential ver-

tical scanning of the IC lead

structure on the basis of the laser

triangulation principle. The height

profile thus obtained for all of the

rows of leads is used to calculate

placement plane of the IC. The

programmed tolerance band based

on this placement plane then be-

comes effective.

If even one lead is outside this

placement area, the component is

excluded from the placement pro-

cess. It is gently placed back in the

Waffle Pack, entered on the repair

list and automatically repaired.

The component picked up by the

placement head may be crooked,

e.g., because one surface of the

package is not parallel to the row

of leads. The calculation of the

placement eliminates any influ-

ence this might have on

placement however.

As the result of extensive security

measures, the laser can only be

operated in the closed machine. It

then conforms to Safety Class 1

(not dangerous for eyes and skin).

Barring manipulation of the protec-

tive devices, the laser will not op-

erate outside the machine. Fol-

lowing impermissible tampering,

the laser complies with Class B.

On SIPLACE placement systems

the component which is picked up

is placed on the PCB immediately

after the coplanarity check. This

procedure ensures that no change

can occur after the check as the

result of any subsequent mechani-

cal influence. Unlike other designs,

with SIPLACE machines it is not

necessary to pick up the compo-

nent again or to transport it in a

special pick-up movement.

Vision Sensor Technology:

Coplanarity Module for the Pick & Place Head (Option)

Effects of coplanarity (lateral

bending of leads) of a populated

component

Accuracy of the coplanarity module

Uncertainty of checking in case of real components

Dimensions

99.73

[µm]*

32 x 32 mm

55 x 55 mm

21.5

22.7

* Checking uncertainty of a single measurement with a confidence interval of 99.73%

(corresponds to 3

)

Description

Various factors contribute to the

placement accuracy of the

SIPLACE F

machine, e.g., the sta-

tionary PCB during the placement

process. As no accelerations are

acting on the placed components,

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

position 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 revolver

head are positioned by means of

high-resolution glass incremental

panels. The X- and Y-axes are posi-

tioned with the help of the metal

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-

revolver head the placement accu-

racy is ± 70 µm at a statistical reli-

ability of 4 sigma. In other words,

of one million placed components,

60 are outside the specified toler-

ance (= 60 dpm). If the accuracy

value ± 70 µm is divided by the

sigma value 4, the result is the

standard deviation S of 1 sigma =

± 17.5 µm.

A machine capability analysis is

conducted for each machine ac-

ceptance test.

Machine Criteria:

Placement Accuracy

Technical Data Gantry

Drive DC servomotors

Position measuring system (X/Y) Linear scales

Resolution of X-/Y-axis 2.5 µm

Speed of X-axis max. 2 m/s

Speed of Y-axis max. 2.5 m/s

Accuracy

X-/Y- and D-axis offset in optical component and PCB centering

6-nozzle revolver head

Angle accuracy

Placement accuracy

± 0.525° / 3 σ

± 0.70° / 4 σ

± 1.05° / 6 σ

± 67.5 µm/ 3 σ ( ± 45 µm/ 3 σ )*

± 90 µm/ 4 σ ( ± 60 µm/ 4 σ )*

± 135 µm/ 6 σ ( ± 90 µm/ 6 σ )*

Pick & Place-head

Angle accuracy

Placement accuracy

± 0.052° / 3 σ

± 0.07° / 4 σ

± 0.105° / 6 σ

± 37.5 µm/ 3 σ ( ± 30 µm/ 3 σ )**

± 50 µm/ 4 σ ( ± 40 µm/ 4 σ )**

± 75 µm/ 6 σ ( ± 60 µm/ 6 σ )**

* SIPLACE F

with DCA-package

** SIPLACE F

with Flip-Chip-vision module

Standard Deviation - dpm

-4

-3

-2

σσ

2700 dpm

60 dpm

P Point of Inflection