Apparatus for optimizing the layout and charge maps of a flowline of pick and place machines

• US 6,275,815 B1
• Filed: 11/03/1998
• Issued: 08/14/2001
• Est. Priority Date: 12/23/1996
• Status: Expired due to Fees

• Current Assignee: Assembleon B.V.
• Original Assignee: Philips Electronics North America Corporation (Koninklijke Philips N.V.)
• Inventors: Mani, Murali, Schaffer, J. David
• Primary Examiner(s): Powell, Mark R.
• Application Number:
  US09/185,025
• Time in Patent Office: 1,015 Days
• Field of Search: 706/13
• US Class Current: 706/13
• CPC Class Codes: G06N 3/126 Evolutionary algorithms, e.g. genetic algorithms or genetic programming
• CPC Class Codes: H05K 13/04 Mounting of components , e.g. of leadless components

Abstract

An apparatus uses a computer-controlled algorithm that enables production of high-quality layouts and charge maps or set-ups for arbitrary printed circuit boards for electronic component placement machines alone or as one of many in a production line. A class of algorithms known as genetic algorithms employing an initial population of chromosomes are used. Each chromosome represents a set of parameters that control how a layout and charge maps are generated. Problem descriptors, based on one time code are generated. An adaptive searcher searches parameters and generates trial solutions as chromosomes and a heuristic layout generator interprets these chromosomes to generate the layout and charge maps using the problem descriptors.

Claims

1. A data processing device comprising

a processor adapted to perform the following operations:

maintaining an internal representation of at least some aspects of a flowline, the flowline including at least first and second respective machines, each respective machine having respective first and second sets of elements, each respective first set of elements being those that are present every time the respective machine runs successfully; and

each respective second set of elements being those that are optional when the respective machine runs successfully, at least one of the first sets of elements containing at least one specific element not present in at least one of the other of the first sets;

conducting an incomplete search of configurations of the second sets of elements together; and

providing a preferred configuration of the flowline based on the incomplete search; and

an output at which the preferred configuration is supplied.

2. The device of claim 1, wherein the flowline comprises at least one pick and place machine and at least one other machine.

3. The device of claim 1, wherein the search is based on a measurement of merit.

4. The medium of claim 3, wherein the search is based on a measurement of merit.

5. The device of claim 1, wherein conducting the incomplete search comprises effecting a genetic algorithm.

6. The device of claim 1, wherein conducting the incomplete search comprises maintaining a heuristic layout generator adapted to simulate configurations and establish a measure of desirability of such configurations.

7. The device of claim 1, wherein the incomplete search comprises:

searching the database to yield partial results; and

simulating configurations based on the partial results.

8. The apparatus of claim 7 wherein the incomplete search further comprises repeating the searching and simulating until a convergence criterion is reached.

9. The apparatus of claim 8 wherein the incomplete search further comprises updating the data base with each repeating.

17. The device of claim 3, wherein the measurement of merit takes into account the differences between the first and second sets.

18. The medium of claim 4, wherein the measurement of merit takes into account the differences between the first and second sets.

10. A medium readable by a data processing device and embodying code for performing the following operations:

maintaining an internal representation of at least some aspects of a flowline, the flowline including at least first and second respective machines, each respective machine having respective first and second sets of elements, each respective first set of elements being those that are present every time the respective machine runs successfully; and

each respective second set of elements being those that are optional when the respective machine runs successfully, at least one of the first sets of elements containing at least one specific element not present in at least one of the other of the first sets;

conducting an incomplete search of configurations of the second sets of elements together; and

providing a preferred configuration of the flowline based on the incomplete search.

11. The medium of claim 10 wherein the flowline comprises at least one pick and place machine and at least one other machine.

12. The medium of claim 10 wherein conducting the incomplete search comprises running a heuristic layout generator to simulate configurations selected from the database.

13. The medium of claim 10 wherein conducting the incomplete search comprises running a genetic algorithm.

14. The medium of claim 10 wherein the incomplete search comprises:

searching the database to yield partial results; and

simulating configurations based on the partial results.

15. The medium of claim 14 wherein the incomplete search further comprises repeating the searching and simulating until a convergence criterion is reached.

16. The medium of claim 15 wherein the incomplete search further comprises updating the data base with each repeating.