INTELLIGENT MILLING PATH CREATION FOR PANELIZATION ABSTRACT

• US 20030167453A1
• Filed: 03/04/2002
• Published: 09/04/2003
• Est. Priority Date: 03/04/2002
• Status: Active Grant

• Current Assignee: Siemens Industry Software Limited (Siemens AG)
• Original Assignee: Mentor Graphics Corporation (Siemens AG)
• Inventors: Mace, Eric C., Smith, Daniel J.
• Granted Patent: US 6,678,878 B2
• Time in Patent Office: Days
• US Class Current: 716/15
• CPC Class Codes: G06F 30/39 Circuit design at the physical level physical level design for reconfigurable circuits G06F30/347
• CPC Class Codes: H05K 2201/09063 Holes or slots in insulating substrate not used for electrical connections
• CPC Class Codes: H05K 2201/0909 Preformed cutting or breaking line
• CPC Class Codes: H05K 3/0005 for designing circuits by computer
• CPC Class Codes: H05K 3/0052 Depaneling, i.e. dividing a panel into circuit boards; Working of the edges of circuit boards

Abstract

A method is disclosed to integrate the creation of a milling path into printed circuit board (PCB) design. The method includes creating keepout regions based on a PCB outline and critical components components placed on the PCB design, calculating support tabs based on the created keepout regions, and then placing the support tabs along the border as calculated. A milling machine may then mill out the support tabs as designed without suffering the potentially undetectable defects in the milling process.

Claims

1. A method to integrate a milling path into a printed circuit board (PCB) design, comprising:

on a PCB design having a PCB outline and critical components placed thereon, creating keepout regions based on the PCB outline and placement of critical components;

calculating support tab placements in accordance with the keepout regions; and

placing support tabs on the PCB design by generating support tabs on the PCB outline based on the calculated support tab placements.

2. The method of claim 1, additionally comprising determining if non-keepout regions of the PCB design have sufficient space for placing support tabs.

3. The method of claim 1, additionally comprising:

a. placing a component on the PCB design;

b. performing stress analysis on the PCB design having the placed component;

c. if stress analysis fails;

i. modifying the placed support tabs; and

ii. repeating the method at 3(b) until stress analysis passes; and

d. repeating the method at 3(a) until there are no more components to be placed.

4. The method of claim 1, additionally comprising defining locations for internal mechanical features, and creating additional keepout regions based on the internal mechanical features.

5. A method to integrate a milling path into a printed circuit board (PCB) design, comprising:

defining a PCB outline of a PCB design;

placing critical components on the PCB design;

creating keepout regions based on the PCB outline and placement of critical components;

calculating support tab placements in accordance with the keepout regions; and

creating pre-routes on the PCB design based on the calculated support tab placements.

6. The method of claim 5, additionally comprising determining if non-keepout regions of the PCB design have sufficient space for placing support tabs.

7. The method of claim 6 additionally comprising:

e. placing a component on the PCB design;

f. performing stress analysis on the PCB design having the placed component;

g. if stress analysis fails;

i. modifying the created pre-routes; and

ii. repeating the method at 3(b) until stress analysis passes; and

h. repeating the method at 3(a) until there are no more components to be placed.

8. The method of claim 5, additionally comprising defining locations for internal mechanical features, and creating additional keepout regions based on the internal mechanical features.

9. The method of claim 8, wherein the internal mechanical features comprise at least one of mounting holes and slots.

10. A method to create pre-routes along the outline of a printed circuit board (PCB) design, comprising:

creating a first set of keepout regions on the PCB design, the first set of keepout regions based on a board outline of the PCB design;

creating a second set of keepout regions on the PCB design, the second set of keepout regions based on placement of critical components on the PCB design;

determining if internal mechanical features exist on the PCB design;

if internal mechanical features on the PCB design exist, determining if they are in critical proximity to the border;

if there are internal mechanical features that are in critical proximity to the border, then creating a third set of keepout regions on the PCB design, the third set of keepout regions based on the internal mechanical features that are in critical proximity to the border; and

calculating support tab placements along the PCB outline in accordance with the first, second, and third set of keepout regions.

11. The method of claim 10, wherein the PCB outline comprises at least one of a line segment and an arc segment, and said calculating support tab placements along the PCB outline comprises:

for each line segment on the outline;

calculating a line segment length; and

calculating a number of support tabs that can be placed on the line segment length given a specified support tab distance between support tabs; and

for each arc segment on the outline;

calculating an arc segment length; and

calculating a number of support tabs that can be placed on the arc segment length given the specified support tab distance between support tabs.

12. The method of claim 11, wherein said calculating a number of support tabs that can be placed on the segment length comprises dividing the segment length by the specified support tab distance.

13. The method of claim 12, wherein if the calculated number produces a modulus, then determining if the modulus is high enough to pass a tolerance threshold.

14. The method of claim 10, additionally comprising determining if any of the placed support tabs are to be removed.

15. An apparatus comprising:

a region protector to create keepout regions along a printed circuit board (PCB) outline of a PCB design having critical components placed thereon;

a support tab calculator to calculate support tab placements along the PCB outline in accordance with the keepout regions; and

a support tab placement to place calculated support tabs along the PCB outline.

16. The apparatus of claim 15, additionally comprising a support tab modifier to enable a user to modify the placement of the support tabs along the PCB outline.

17. The apparatus of claim 15, additionally comprising a region analyzer to determine if there is sufficient area on non-keepout regions to place a minimum number of support tabs.

18. The apparatus of claim 17, wherein the region analyzer determines if there is sufficient area on non-keepout regions to place a minimum number of support tabs within a section of the PCB design.

19. A machine-readable medium having stored thereon data representing sequences of instructions, the sequences of instructions which, when executed by a processor, cause the processor to perform the following:

create a PCB outline of a PCB design;

allow placement of critical components on the PCB design;

create keepout regions based on the PCB outline and placement of critical components;

calculate support tab placements in accordance with the keepout regions; and

create pre-routes on the PCB design based on the calculated support tab placements.

20. The machine-readable medium of claim 19, additionally comprising determining if non-keepout regions of the PCB design have sufficient space for placing support tabs.

21. The machine-readable medium of claim 19, additionally comprising defining locations for internal mechanical features, and creating additional keepout regions based on the internal mechanical features.

22. The machine-readable medium of claim 21, wherein the internal mechanical features comprise at least one of mounting holes and slots.

23. A method to integrate a milling path into a printed circuit board (PCB) design, comprising:

on a PCB design having a PCB outline and critical components placed thereon, the step of creating keepout regions based on the PCB outline and placement of critical components;

the step of calculating support tab placements in accordance with the keepout regions; and

the step of placing support tabs on the PCB design by generating support tabs on the PCB outline based on the calculated support tab placements.

24. The method of claim 23, additionally comprising the step of determining if non-keepout regions of the PCB design have sufficient space for placing support tabs.

25. An apparatus comprising:

means for creating keepout regions along a printed circuit board (PCB) outline of a PCB design having critical components placed thereon;

means for calculating support tab placements along the PCB outline in accordance with the keepout regions; and

means for placing calculated support tabs along the PCB outline.

26. The apparatus of claim 25, additionally comprising means for enabling a user to modify the placement of the support tabs along the PCB outline.

27. The apparatus of claim 25, additionally comprising means for determining if there is sufficient area on non-keepout regions to place a minimum number of support tabs.