M3plus_OperationManual_e - 第222页

B - 9 B Alignment T ype glossar y 2. Alignment T ype glossar y 2.1.2 Detecting the component center and tilt In vision systems, the center position and tilt of a component are detected by several methods according to the…

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Alignment Type glossary

2. Alignment Type glossary

Alignment Group: Connector

• Con-E (Connector E)

This is for components having the same leads only in the E direction.

• Con-NSEW (Connector NSEW)

This setting is suited for components having leads in four directions of N, S, E and W, but the

number of leads and their shape in each direction are different. Only one type of lead shape can be

set for each direction.

• Odd.Con

Use this setting for connectors suitable for "Con-E" having off leads.

• Special

This can be used for components having irregularly arranged leads. For example, components having

leads in four directions of N, S, E and W like "Con-NSEW", but whose number of leads and the

shape in each direction are different. Although "Con-NSEW" allows setting only one type of lead

shape in each direction, "Special" allows setting two types, making it usable for various components

with irregular shapes. This setting cannot be used with the lead coplanarity function.

Alignment Group: Special

• Odd.Chip

This setting automatically determines whether to recognize a component as "white" or "black",

making it suited for components such as bare chips which are difficult to judge as reflective or non-

reflective against the background (PCB). This mode is also appropriate for BGA components with a

light reflective portion on the body.

• AsMark

This setting recognizes components as a mark and is therefore suited for specially shaped compo-

nents.

• Sp. Quad

This is used for square or rectangular components which reflect light at the four sides of the package

making it difficult to distinguish the leads from the package.

• Gravity

This detects the center-of-gravity of a target (black or white) in the specified area, allowing reliable

recognition of various components with irregular shapes. When using this setting, test-mount the

component after setting the data, and check the mounting shift (distance from center of mounting

position to center of the component). Then enter the shift amounts in "Cntr. Offset XYR" of the

Shape parameters.

• Ignore

This does not perform image processing.

Alignment Group: Ball

• Simple BGA

This is specially for BGA components. The number of ball leads can be checked, but the ball lead

positions and nicks are not checked.

• BGA

This is specially for BGA components. The ball lead positions can be edited to check the lead

positions and nicks.

• FlipChip

This is specially for flip chip components and can be used only when a vision camera with a side

lighting unit is used.

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Alignment Type glossary

2. Alignment Type glossary

2.1.2 Detecting the component center and tilt

In vision systems, the center position and tilt of a component are detected by several

methods according to the type of component.

Depending on the component, the center position and tilt of a component found in recog-

nition processing might not always match the center and tilt of the actual component. In

those cases, the detected data must be corrected (offset) based on the library data.

In library data, the center of the dimensional outline is usually defined as the component

center. The positions of leads on all sides of the component are defined based on this

component center. In recognition processing, the component position (hereafter "recogni-

tion center") is usually found as the center-of-gravity position for all component lead

tips.

The center of the dimensional outline of a component such as a QFP matches the recogni-

tion center so the recognition center of these components can be used as the component

center.

The recognition center will not usually match the component center if the left/right and

top/bottom of a component are not symmetrical with each other.

In recognition processing in such cases, the center-of-gravity position (average value for

each X/Y coordinate) for all lead tips is found as the recognition center. The center-of-

gravity positions for all leads and component center offsets are then found beforehand

from the defined component data (library data). Based on this information, the center

positions found from recognition processing are correctly offset to find the component

center. The tilt is found beforehand in the same way by correcting the recognition results

using the offset amount.

So when there is a discrepancy or error between the library data and the actual compo-

nent, that error prevents correctly offsetting the component center position and leads to

problems in component mounting. In components that require offset correction (mainly

asymmetrical components) it is essential that the library data be set correctly.

Offset X

Offset Y

Offset R

Detected angle

Coordinate system

Center of dimensional outline

Center of all lead tips

Component center detection

23B01-5E-20

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Alignment Type glossary

2. Alignment Type glossary

2.2 Using special recognition settings

If a component cannot be recognized with normal "Alignment Type" settings, use special

recognition algorithms. Methods for setting those algorithms are explained below.

2.2.1 QFP recognition mode

Several special recognition algorithms are available for QFP recognition mode.

1. Algorithm: Special 1 (Special QFP recognition 1)

Setting this mode is sometimes useful when edge lead detection is unstable.

2. Algorithm: Special 2 (Special QFP recognition 2)

This mode is used when detecting only horizontal leads with Special QFP recognition 1.

3. Algorithm: Special 3 (Special QFP recognition 3)

This mode is used when detecting only vertical leads with Special QFP recognition 1.

4. Algorithm: Special 4 (QFP recognition with lead length check)

This is a normal QFP recognition mode added with a function to check the lead length. This

function checks whether each lead tip distance is within a specified distance versus a line relative

to each tip. This value is set in Option 3, in hundredths of a millimeter (1/100 mm). Values are

settable from 0 to 127 (0.01 to 1.27 millimeters).

2.2.2 Single connector recognition mode

Several special recognition algorithms are available for connector recognition mode.

1. Algorithm: Special 1 (Special connector recognition 1)

Setting this mode is sometimes useful when edge lead detection is unstable.

2. Algorithm: Special 2 (Special connector recognition 2)

This mode is used when recognizing only multiple leads on both sides of the connector.

3. Alignment Type: Odd. Con

Recognizes connectors having a portion with no leads on unidirectional connectors (connector E).

Recognition method is the same as for unidirectional connectors.

2.2.3 4-way connector recognition mode (Con-NSEW)

Several special recognition algorithms are available for 4-way connector recognition

mode.

1. Algorithm: Special 1 (Special connector recognition 1)

Setting this mode is sometimes useful when edge lead detection is unstable.

2. Algorithm: Special 2 (Recognizing only long connector contours)

This mode is used to recognize only connectors with multiple leads on both sides. In Vision Option

2, set the number of leads to detect on both sides.

3. Compensation type: OffLead

Recognizes components having a portion with no leads on 4-way connectors (Con-NSEW).

Recognition method is the same as for 4-way connectors.