Dek-265GSX-User-Manual - 第264页

在线预览 Dek-265GSX-User-Manual PDF 文档。

CHAPTER 8

2Di INSPECTION

MODULE OVERVIEW

Introduction The vision system of the screen printing machine is used to both align the screen

to each board before it is printed and, when enabled, inspect the screen and

board. This module describes how this is achieved.

Purpose 2D inspection (2Di) ensures the quality of the print by monitoring the printing

process, to determine when a screen clean or paste dispense is required and if

licensed and selected, to warn for bridging, misalignment and reduced paste

volume. 2Di optimizes the cycle time by eliminating unnecessary screen

cleaning and paste dispensing operations. To achieve this the system inspects

various areas of the board and/or screen (sites) to detect the following:

• Screen Blockage - solder paste remaining inside screen apertures.

• Screen Smear - solder paste on the screen.

• Board: Paste Present - amount of the pad covered by solder paste, as a %

of the aperture size.

• Board: Alignment - accuracy of paste positioning compared to the learnt

site image.

• Board: Bridging - distance between adjacent deposits of paste.

Using the screen aperture, blockage and paste present information the system

can calculate the following:

• Board: Paste Volume - volume of paste on the pad.

Software Version 6 User Manual 8.1

2Di INSPECTION

MODULE OVERVIEW

Paste on screen

(smear)

Pa s t e o n b o a r d

(bridging)

Paste Present

and

Paste Volume

Screen apertureBoard pad

Underside of screen

Top of board

Paste in aperture

(blockage)

Figure 8-1 Paste on Board and Screen