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3 Technical data User manual SIPLACE HF series 3.7 Placement heads S oftware Version SR.50x.x x 01/2006 US Edition 120 They are then set down gentl y and accu rately on the P CB with a blas t of air . The twe lve nozzle …

User manual SIPLACE HF series 3 Technical data

Software Version SR.50x.xx 01/2006 US Edition 3.7 Placement heads

119

Fig. 3.7 - 4 12-segment Collect&Place head - Function groups, part 2

(1) Intermediate distributor board (beneath the cover)

(2) Star drive - DR motor

(3) Z axis motor

(4) Valve adjustment drive

(5) 24 x 24 component vision camera

3.7.2.1 Description

The 12-segment Collect&Place head works on the Collect&Place principle. This means that,

within each cycle, twelve components are picked up by the placement head, are optically cen-

tered on the way to the placement position and are rotated into the required placement angle.

3 Technical data User manual SIPLACE HF series

3.7 Placement heads Software Version SR.50x.xx 01/2006 US Edition

120

They are then set down gently and accurately on the PCB with a blast of air. The twelve nozzles

on SIPLACE Collect&Place heads turn about a horizontal axis, in contrast to conventional chip

shooters. This does not simply save space: the small diameter means that substantially smaller

centrifugal forces occur in comparison to conventional chip shooters. This largely eliminates the

risk of components slipping during transportation. 3

And there is yet another benefit: the cycle time of the Collect&Place head is the same for all com-

ponents, which means that the placement rate is not dependent on the component size. 3

Checking and self-learning functions 3

The reliability of the Collect&Place head is increased by various checking and self-learning func-

tions. 3

– For example, vacuum checks at the nozzles indicate whether the component was picked up

or set down correctly.

– A mark on the feeder is used to determine the precise component pick-up position on the

feeder.

– A camera on the placement head determines the precise angle of each component on the

nozzle. Any deviations from the required pick-up position are corrected before placement

takes place. When further components are picked up, the average of the deviations for the

last 10 placement operations are taken into account, thus further increasing pick-up accuracy.

– The package form is also checked, and the component is not placed if the geometric data thus

determined differs from the programmed data.

– The vertical axis (Z axis) for picking up and placing the component works in sensor stop

mode, in which differences in height during pick-up and any unevenness of the PCB surface

are compensated during placement. The average of the deviations during the last 10 place-

ment operations is also taken into account when adapting the further stroke and placement

speeds. The programmed placement force always remains constant.

– A component sensor may be installed on the C&P head in order to increase placement reli-

ability. The component sensor checks the edge ratio of the components, in addition to

whether the component is present at the nozzle. In this way it is possible to determine

whether the component was picked up by the nozzle transversely or on edge.

– The 12-segment Collect&Place head can optically center and place components from 0.6 x

0.3 mm² to 13 x 13 mm² using the optional DCA vision module. The DCA vision module opti-

mizes the speed and accuracy when placing high-speed flip-chips and bare die components

The values are shown in the table on page 122

3.7.2.2 Description of the functions

The 12-segment Collect&Place head has three axes - the DR or star axis, the Z axis and the DP

axis. 3

User manual SIPLACE HF series 3 Technical data

Software Version SR.50x.xx 01/2006 US Edition 3.7 Placement heads

121

The star rotates about the star axis with its 12 segments. The segments hold the sleeves. There

is a nozzle seated on every sleeve, which sucks up the components, and transports them from

the pick-up/placement position (1) to the reject position (3), to the optical centering position (7) or

to the turning position (9). 3

The Z axis performs a vertical movement. Every sleeve that is in the bottom star position (1) is

raised or lowered by this axis, thus picking up the components from the feeder modules and set-

ting them down on the PCB. The Z axis is an "intelligent axis". It "notes" the pick-up height of

each conveyor track and the placement height for each component. This can speed up the place-

ment process. The programmed placement force remains constant. 3

Fig. 3.7 - 5 Description of the functions

The DP axis rotates the optically centered component to the desired placement angle. The se-

quences of movements of the rotation and translation axes are controlled by control circuits. Po-

sition and speed sensors send the actual values for the axis movement to the axis control. The

setpoint and actual values are compared and used to determine the force and speed parameters

for the servo amplifier, and thus the axis movement to be performed. The vacuum values at the

Component camera

DP axis

Rotate component

into placement position

Remove sleeve

or insert

Z axis

Pick up component

or place it

Star axis

Star rotation

Reject component