VI User Manual - 第192页

Tools library 7 - 30 Vision 2007 4.10 User Manual Re v 01 7.7.3 SO or QFP model edition For SO and QFPs, 2 tools check the presen ce and position of the component as well as an y joints and solder bridges. If you program…

Tools library

Vision 2007 4.10 User Manual Rev 01 7 - 29

7.7 SO or QFP model

7.7.1 Joints detection

Joint inspection is the ability to check if there is solder or not. This tool does not consider quality. The

solder reflect few light to camera when the solder is good, and many when the solder is not good.

Histogram is used to perform joint inspection.

7.7.1.1 Good joint

With solder the reflection is out of the camera, which

causes a black area at the end of lead.

7.7.1.2 Bad joint

The curve of a bad joint weld reflects the major light

flux at the vertical of the solder.

7.7.1.3 No joint

Without solder the reflection is directly inside the

camera which causes a very bright area at the end

of lead.

7.7.2 Solder joint detection

The bridge tool allows inspection of bridges between 2 leads of SO or

QFP components.

Edge is used to perform bridge detection.

There are 2 equation fields in the Edit a model window for de-

tecting joints and solder bridges.

If you want to detect weld joints on small SMCs, like the 0603 or

0402, place a histogram at the end of the component. The equa-

tion in the Joint field will be R2 and R3 if your histograms are pro-

grammed in windows 2 and 3. If you use direct lighting, bad

solder will be very shiny and good welding will be dull.

This enables the presence or absence of joints to be checked.

Tools library

7 - 30 Vision 2007 4.10 User Manual Rev 01

7.7.3 SO or QFP model edition

For SO and QFPs, 2 tools check the presence and position of the component as well as any

joints and solder bridges.

If you program a SO or QFP tool and you want to check the joints and / or welding bridges of

the model, enter 1-J1 in the Joint field, and 1-B1 in the Bridge field. J1 and B1 respectively con-

tain the number of faulty joints and the number of solder bridges detected. The result of the

equation must be positive (> 0) for the test to be considered valid. Therefore, if there are no

faulty joints or bridges (J1 = B1 = 0), the 2 equations are equal to 1.

Vision 2007 sends back solder_afterOven and bridge_afterReflow for these 2 faults.

For these 2 tools, it is very important to define the component size in your .tst file, bearing in

mind the lead length. These tools use the leads to determine the position of the components and

if the leads are outside the camera range, the tool will return a false fault.

We recommend creation of an image representing the component, using BuildModel.

If you draw a TYPE 2 model with BuildModel, the image will contain all the parameters enabling

automatic creation of the SO or QFP model in the library.

7.7.4 Model description tab

On the

Model description

tab, in the

Edit a model

window, click on the button . The .bmp

file name to add in picture list window appears. Select the image on which to load the treatment.

2. Click on Edit area button to define the treatment area.

3. Choose the treatment operation: SO or QFP, a new tab appears (with the inspection tool

name) behind the Model description tab.

4. The software asks if you want to use the

image parameters to create the model.

If you answer no or if you have not cre-

ated an image with BuildModel, the

Specifications of component window

appears to enter the specifications of

your components.

If you have created an image with Build

Model, enter its name in the Model im-

age field of the Model description tab.

After filling in all the fields, click OK and

the model will be initialized automatical-

ly with the parameters you have just en-

tered.

The SO model must be drawn with the leads at the top and bottom

of the image as shown opposite

Gray levels used:

 Body: 30

 Leads: 226

 Background: 128

When you use synthetic model, click on

Auto area

button to define the component size.

SO or QFP model

Tools library

Vision 2007 4.10 User Manual Rev 01 7 - 31

7.7.5 SO

The SO tool returns the (X, Y, θ) position of the component with the joint faults and welding

bridge faults.

7.7.5.1 Body detection

Body detection of the SO

component is performed by

a double transition edge.

The window which appears

when you click on the Body

detection button gives ac-

cess to the parameters of

this edge.

Body detection tab

Position X & Y (A): double

edge position offset.

Width & Length (B): edge

size.

Expected width (C) of the

component body.

Tolerance (D) on the ex-

pected width.

Contrast & Filter Half Size

(E): edge parameters used.

Shift checking tab

This option processing is

used if the component is

shifted by one lead width.

Tick Active Processing (A)

box to activate the process if

you want to check the posi-

tion in X of your component

with the body and not the

lead.

In the Shift checking tab,

Searching area (B) and Pa-

rameters (C) are the same

that for Body detection tab

(see above).

Transition: white

black and black

white

Pos Y1

Pos Y2

Score by size

and contrast

A B

SO or QFP model