Dek-265GSX-User-Manual - 第267页

Screen Inspection The various screen inspections are shown below. Software Version 6 User Manual 8.3 2Di INSPECTION MODULE OVERVIEW Any change to the area of the screen must be paste , hence the area of smear can be calc…

Operation A Board Inspection Type and a Screen Inspection Type sets the level of

inspection for the board and screen. The following types of inspection are

available:

• None

• Basic

• Advanced

Inspection of the board and screen is licensed as a separate feature for each, and

specifies the maximum level of inspection that may be selected, as follows:

None Basic Advanced

Board No Inspection Paste on Pad Basic + Bridging and Alignment

Screen No Inspection Blockage Basic + Smear

An item only appears in a window while it is appropriate to the current level of

inspection. In particular Paste Volume is only calculated and displayed while

the level of inspection is advanced for both the board and the screen.

Inspection is achieved by image comparison. Prior to printing, an inspection of

the various sites is carried out on the board only, and the image is captured.

This captured image, called a Pre-image is always taken as a set, so that each set

comprises a pre-image of the board at every inspection site. The set may be

taken for just the first board in a batch and applied throughout the batch

(Pre-image set to 1), or a fresh set may be taken as each board is received for

printing (Pre-image set to Every).

Regardless of the setting of Pre-image, the set always comprises all the current

inspection sites. No provision is made to enable individual sites to be selected or

excluded.

8.2 User Manual Software Version 6

2Di INSPECTION

MODULE OVERVIEW

Screen Inspection The various screen inspections are shown below.

Software Version 6 User Manual 8.3

2Di INSPECTION

MODULE OVERVIEW

Any change to the area of the

screen must be paste, hence the

area of smear can be calculated.

This is relative to the area of

white lost in the histogram.

Smear (Advanced)

The position and area of apertures

within the screen site are learnt as

a reference.

Aperture

Screen

Clean Screen

Histogram

Aperture

Any change to the area of the

aperture must be paste, hence the

percentage of blockage can be

calculated. This is relative to the

area of black lost in the

histogram.

Blockage (Basic)

Pa s t e

Figure 8-2 Screen Inspection

Board Inspection The various board inspections are shown below.

NOTE

Uneven tinning of the board and/or misaligned soldermask can be seen as paste,

which can cause false readings. This can be eliminated with the correct lighting

setup.

8.4 User Manual Software Version 6

2Di INSPECTION

MODULE OVERVIEW

The pad on a selected board site is learnt

as a reference for comparison with

inspected sites.

Since the area of the pad is learnt,

and the area of paste can be recognized,

any change in pad area must be paste.

Hence the area of paste present can be

calculated.

The centre of the paste is compared

to the centre of the pad to produce

alignment error information in X and Y.

Since the area of paste can be

recognized, the distance between

two areas of paste (bridging) can

be calculated.

Pa d

Board

Pa s t e

Clean Board

Paste Present (Basic)

Alignment (Advanced)

Bridging (Advanced)

Bridging Distance

Figure 8-3 Board Inspection