YesAX V3.1.2 - Software User Manual - 第158页

11 - 14 3D X-Ray Inspection Methodolo gy During 3D programming it is important to allocate a t least three height reference points per 3D site and make sure each 3D site has the best height reference locations available.…

3D X-Ray Inspection Methodology 11-13

2. When placing laser references on board, it is preferable to put them at the same kind of

surface or layer. It is also better to keep these laser references away from silkscreen,

component names in big white labels and any shinning object, like solder joints and metal

caps. Other than some special devices like PoP (package on package), the laser reference

should be put on the surface of the PCB if possible.

3. If it’s very difficult for user to allocate laser references on top of board surface, it is OK

to put laser references on top of the component or a different surface. Please make sure to

use laser references on same surface for the 3D site and set up the local offset numbers

for those laser references carefully. For laser references reside on same kind of surface,

their local offset should set to same number.

4. If the board is relatively flat (e.g., a fixture is being used to load and unload the board), it

is possible for user to allocate only one laser reference for the 3D site. In this case the

height of this laser reference will be used as the height offset of that 3D site directly.

5. It is OK for user to use 2 laser references for a 3D site, if it is really difficult to find a

good location for the 3

laser pointer.

6. It is not a good idea to use 3 laser references, which is either very close to each other

(lower left image), or almost on the same line (lower right image) for the 3D site. In

either case the height map generated by these three laser references may not reveal the

real tilted situation of the board surface. If user has difficulty locating a third laser

reference, he can either use the force reference 0 option or just use 2 laser references for

current 3D site.

11-14 3D X-Ray Inspection Methodology

During 3D programming it is important to allocate at least three height reference points per 3D

site and make sure each 3D site has the best height reference locations available. YesAX

software has provided user an easy way to tell what height references were used by the current

3D. First, user needs to make sure to run Profile Board Height command once or run the

inspection once to create/refresh the height map. After that if user saves the recipe the latest

reference height information will be saved to ZMap.txt file which is under current recipe folder.

If user only runs Profile Board Height command once, the next thing he needs to do is to switch

to 3D mode, go to first 3D site and then use the >> navigation button inside the 3D control

window and go through the rest of the 3D sites. If user doesn’t want to go through every 3D site,

it is possible for him to only go through those 3D sites which he’s interested. After that all he

needs to do is to maximize the map view window. The window will show extra information

other than the normal blue boxes. Below is a screenshot of part of the window:

3D X-Ray Inspection Methodology 11-15

Other than the blue boxes representing the inspection box and white circle indicating the location

of 3D sites, there will be extra yellow lines connecting center of 3D sites and height references

they’ve been using. By looking at this picture user would be able to check which height

references were being used by which 3D sites. Since the locations of height references are

important for constructing height map of 3D sites, it is advisable for user to check every site

carefully and make sure all 3D sites uses height references in best locations as possible. Once

restore the map view window to its normal size, the background map will be refreshed again and

the yellow lines will disappear.

In situations that certain 3D site doesn’t have the best height references, the user can do the

following: 1. Move the current height reference points to a better location. 2. Add more height

reference points to the recipe. Once user modifies the location of any height reference points,

they need to go through all 3D sites again and then maximize the map view window to see the

updated results.

If the results are still not the best and it seems too difficult to move existing height references

around, one other option available is the force reference function. User needs to go to the 3D site

and launch the Edit 3D Site dialog.