About Placement Preferences
Click > 
Options > to set preferences for automatic component placement. The preferences you set apply to all models in the session.
Options > to set preferences for automatic component placement. The preferences you set apply to all models in the session.Your preferences also determine the options in the Component tab, the search sequence for interfaces, and the maximum number of matches listed. Some of these options appear in the Options tab as well. A change made in the Assembly settings during the current session, overrides set configuration options.
• Set Component placement interface control options.
◦ For automatic component placement, use this interface—Select an option for placing components using interfaces:
Default—Uses the default interface.
From List—Uses the interface selected from the list. The Component tab opens.
None—Does not use an interface for placement.
◦ When you select Default or From List, you can also select the Allow creation of temporary component placement interfaces check box. Temporary interfaces are automatically created based on previous assembly instructions.
◦ Place default component interface using—Select an option from the list:
Multiple locations—The Component tab opens and the Auto Place dialog box is open.
Single location—The Component tab opens.
• Set Automatic placement options:
◦ Number of positions displayed in Auto Place dialog box—Sets the maximum number of matches listed. Type a new value to change the default, 5.
◦ Show only matches that do not interfere with other components—Shows only matches that do not interfere with other components.
◦ Check criteria match of a component interface reference during a search—Checks criteria match of interface references.
◦ Include sub-model interfaces as possible references for interface-to-interface placement—Uses interfaces in all sub models.
◦ Ignore non-displayed items during a search—Ignores all items that are not displayed in the graphics window.
◦ Search area size as percentage of component size—Sets the default search area as a percentage of the component size. Select a number from the list.
◦ When dragging single component assemble to the closest component—Automatically uses the closest placement to the drag-and-drop location.