Infinity EX Screens and Screen Images.pdf - 第5页
INFINITY EX SCREE NS AND SC REE N IMAGE S IMAGE POSITIONING Chapter Issu e 1 Mar 01 Technical Reference Manual 26.5 Figure 26-2 DEK Scr een - Front Edge J ustif ied Figure 26-3 DEK Scr een - Centre J ustif ied Machine Ce…
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SCREENS AND SCREEN IMAGES
IMAGE POSITIONING
26.4 Technical Reference Manual Chapter Issue 1 Mar 01
IMAGE POSITIONING
To allow the screen printer to be set up consistently, it is important that the image
in the screen frame is accurately positioned.
The screen image can be either centre or front justified.
The Figures on the following pages, show the required dimensions.
It is imperative that the image is placed squarely in the screen frame within the
given dimensions.
At the end of this section an example is given for artwork positioning of a front
justified image on a DEK 265 screen frame.
Image Positioning
Data
The position of the image on the screen is accessed using information from the
product file created by the operator and from data stored during machine
configuration.
The information required to set the correct position is as follows:
Image Justification
Centre Justified The image is positioned on the screen such that the centre of the board coincides
with the centre of the screen as indicated in the figure DEK Screen - Centre
Justified.
Front Edge Justified The image is positioned on the screen such that the front edge of the board is as
indicated in the figure DEK Screen - Front Edge Justified.
Y Axis Positioning The important dimension to adhere to is the position of the artwork in the Y
direction. This dimension shows the position of the inner edge of the front rail
relative to the outer edge of the screen frame when the screen parameters are set.
On most artwork there are usually corner alignment marks showing the board
outline. These can be used to specify the positioning of the artwork relative to
the outer edge of the screen frame.
All dimensions are specified to ±1mm.
It is usual practice to measure from the nearest pad to the edge of the board and
to specify which pad the dimension has been measured.
X Axis Positioning The artwork is positioned centrally on the board therefore positioning of the
artwork in the X direction is achieved by placing the centre of the image about
the centre of the screen frame. This position should be specified to ±1mm.
Parameter Options Accessed
Screen Type DEK 265 - 29
″x 29″
DEK 249/UIC Fuji
4000 Sanyo
Entered in the Set Preferences option of the
Maint. function.
Image Justification Centre Justified or
Edge Justified
This parameter is programmed into each
particular board file for each product.
INFINITY
EX
SCREENS AND SCREEN IMAGES
IMAGE POSITIONING
Chapter Issue 1 Mar 01 Technical Reference Manual 26.5
Figure 26-2 DEK Screen - Front Edge Justified
Figure 26-3 DEK Screen - Centre Justified
Machine CentreLineReference
Board
Metal Mask
Supporting Mesh
ScreenFrame
Artwork Position
Relativeto
Board FrontEdge
A
B
Enlarged View
622.0mm
+/- 1.0mm
NOTE
For ScreenProductionthe Following Information is Required:
1. Overall dimension of board i.e.length and width
2. Dimensions and (see EnlargedView)AB
Machine Centre Line Reference
Machine CentreLine
Reference
NOTE
The centrelinedimensions quoted must take into account the frametolerances.
Board
Metal Mask
Supporting Mesh
Screen Frame
Centre point
X = 368.3 mm
Y= 368.3 mm
Y
X
INFINITY
EX
SCREENS AND SCREEN IMAGES
IMAGE POSITIONING
26.6 Technical Reference Manual Chapter Issue 1 Mar 01
Custom Screen
Image
User definable screen image positions are accommodated for with the Custom
Screen menu parameter.
Selecting Custom Screen activates the following menu parameters:
• Print Area Length
• Print Area Width
• Distance to Image
Print Area Length The Print Area Length parameter is used to control the board width ranges. This
is the maximum printable distance in the Y direction, ie the maximum distance
the squeegee can travel, front to back.
Print Area Width The Print Area Width is used to control the board stop position and the paste
dispenser start and stop positions. For certain screen widths a warning is
displayed that the screen clean unit should not be used. This is the maximum
length of squeegee that could be fiited to the printer, taking into account screen
frame and the amount of mesh surrounding the mask. This is also the maximum
length of paste that can be dispensed.
NOTE
When setting ‘print area’ parameters, care must be taken to ensure that a large
enough safety margin is maintained between the board edges and inside edges
of the screen frame. An adequate safety margin prevents any process problems
and allows for squeegee movement and screen alignment. A distance of at least
60mm is usually acceptable.
Distance to Image The parameter has two meanings depending on whether Centre Justified or Edge
Justified image is selected.
For a Centre Justified image the Distance to Image measurement is the distance
from the outside rear of the screen frame to the centre of the image.
For an Edge Justified Image the Distance to Image measurement is the distance
from the outside rear of the screen frame to the front edge of the board. Care
must be taken to ensure that this measurement is to the edge of the board, not the
front of the image. Add the distance between the front edge of the board and the
foremost aperture, to the distance between the outside rear of the screen frame
and the front edge of the foremost aperture.
X Axis Offset The setting of the Custom Screen parameters only effects the Y screen load
position. Any offset in the X direction must be adjusted by offsetting the board
stop position.