00195941-03-UM SiplaceCA-EN - 第188页
3 Technical Data User Manual SIPLACE CA 3.8 Placement Heads Edition 08/2011 EN 188 3.8.3.2 Control and Self-Learning Functions Control and self-learning functi ons enhance the reliability of th e 20 segment Collect&P…
User Manual SIPLACE CA 3 Technical Data
Edition 08/2011 EN 3.8 Placement Heads
187
3.8.3.1 Description
The 20 segment Collect&Place CA head functions according to the Collect&Place principle i.e.
that twenty components are picked up from the placement head within each cycle. At the pickup
and placement position the component sensor checks that the component is present at the noz-
zle. On their way to the placement position the components are optically centered and rotated into
the required placement angle. Finally forced air sets down the component gently and accurately
on the board.
The C&P20CA placement head is an advanced design which significantly increases the perfor-
mance of the placement head and of the whole machine. The compact structure of the C&P20CA
head makes very short cycle times possible. In this case, the star axis is at an angle to the PCB
level. This geometry allows the segments to be arranged in a very small space.
The component camera is still integrated into the C&P20CA head. This saves additional travel-
ing distances to external centering cameras. Each segment also has a separate DP drive for ro-
tating the nozzle. The nozzles are therefore no longer rotated into the correct position at a single
head station. They can be rotated into their placement position at any time and independently of
one another.
Each segment has a separate vacuum generator. This greatly reduces the time taken to switch
between vacuum and air kiss. It also allows a vacuum check to be carried out in the holding circuit
for each individual nozzle.
The Z drive for the segments is implemented with a linear motor with linear path measuring sys-
tem, and is thus extremely precise. In the pickup/placement position, the Z drive moves the seg-
ments up or down in the vertical direction.
3 Technical Data User Manual SIPLACE CA
3.8 Placement Heads Edition 08/2011 EN
188
3.8.3.2 Control and Self-Learning Functions
Control and self-learning functions enhance the reliability of the 20 segment Collect&Place CA
head.
– The vertical axis for picking up and placing components is driven by a linear motor. The
travel range is recorded opto-electronically by a linear path measuring system. A sensor
registers the relative movement between the nozzle and the segment when components
are placed and sends a signal to the position control axes. With this sensor stop method,
differences in height during pickup and any unevenness of the board surface are com-
pensated during placement. The average of the deviations during the last 10 placement
operations is taken into account when adapting the further stroke and placement speeds.
The programmed placement force always remains constant.
– To further increase placement reliability, a component sensor has been installed on the
20 segment Collect&Place CA head. At the pickup and placement position, it checks that
the component is present at the nozzle and in addition the component edge ratio. In this
way it is possible to determine whether the component was picked up by the nozzle
transversely or on edge. The beam intensity is also checked regularly to avoid false mea-
surements.
– The package form is also checked and the component is not placed if the geometric data
thus determined differs from the programmed data.
– A digital component camera on the placement head determines the precise position of
each component at the nozzle. The standard camera, type 23 of the 20-Segment Col-
lect&Place-CA heads can optical center modules of the sizes 0,2 mm x 0,2 mm up to 6
mm x 6 mm. Variations of the transfer position are corrected already before placing.
When a component is picked up, the average of the deviations for the last 10 placement
operations is taken into account, thus increasing the pickup accuracy.
3.8.3.3 Functional Description
The 20 segment Collect&Place CA head consists of three axes, the DR or star axis, the Z-axis
and the DP axis.
User Manual SIPLACE CA 3 Technical Data
Edition 08/2011 EN 3.8 Placement Heads
189
3
Fig. 3.8 - 5 Functional Description
(1) Component pickup position, placement position, reject position, component check with com-
ponent sensor
(10)Vacuum check of the nozzle in the holding circuit, with or without component
(11) Position for the optical centering of the components
Star rotation
Star axis
DP drive (segment)
Nozzle
Z axis
Check pick up, place or
reject component with com-
ponent sensor
DP axis
Each sleeve can be rotated
individually.
Component
camera for optical
centering
Vacuum- check
of nozzle in hold-
ing circuit