Circuit board component ambient moisture exposure monitoring

• US 20050184723A1
• Filed: 02/20/2004
• Published: 08/25/2005
• Est. Priority Date: 02/20/2004
• Status: Active Grant

• Current Assignee: Accu-Assembly Incorporated
• Original Assignee: Accu-Assembly Incorporated
• Inventors: Michael Kou, Yuen-Foo
• Granted Patent: US 7,164,281 B2
• Time in Patent Office: Days
• US Class Current: 324/750.300
• CPC Class Codes: H05K 1/0266 Marks, test patterns or identification means
• CPC Class Codes: H05K 2201/09927 Machine readable code, e.g. bar code
• CPC Class Codes: H05K 2203/1476 Same or similar kind of process performed in phases, e.g. coarse patterning followed by fine patterning
• CPC Class Codes: H05K 2203/1572 Processing both sides of a PCB by the same process; Providing a similar arrangement of components on both sides; Making interlayer connections from two sides
• CPC Class Codes: H05K 2203/163 Monitoring a manufacturing process
• CPC Class Codes: H05K 3/3415 on both sides of the substrate or combined with lead-in-hole components
• CPC Class Codes: H05K 3/3494 Heating methods for reflowing of solder using integral heating means H05K1/0212
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A method of assembling multiple electronic components to a circuit board includes securing one electronic component to the circuit board, then, creating an association between that electronic component and an environmental condition recorder. The method further includes recording data from the environmental condition recorder. The recorded data indicates exposure of the secured electronic component to an environmental condition over time. The method also includes determining, based on the stored data, whether the secured electronic component is suitable for exposure to conditions associated with securing a second electronic component to the circuit board.

Claims

1. A method of assembling multiple electronic components to a circuit board, the method comprising:

securing an electronic component to the circuit board;

creating an association between the secured electronic component and an environmental condition recorder;

recording data from the environmental condition recorder, the data indicating exposure of the secured electronic component to an environmental condition over time; and

determining, based on the recorded data, whether the secured electronic component is suitable for exposure to conditions associated with securing a second electronic component to the circuit board.

2. The method of claim 1 further comprising, for a secured electronic component found suitable, exposing the suitable secured electronic component to conditions associated with securing a second electronic component to the circuit board.

3. The method of claim 1 further comprising maintaining the association between the secured electronic component and the environmental condition recorder from shortly after securing the electronic component until determining suitability.

4. The method of claim 1 wherein the environmental condition recorder is adapted to continually monitor and periodically record an ambient environmental condition.

5. The method of claim 1 wherein the environmental condition recorder is adapted to automatically record an ambient environmental condition over time.

6. The method of claim 1 wherein the conditions associated with securing a second electronic component to the circuit board comprise exposing the secured electronic component to conditions associated with reflow soldering the second component to the circuit board.

7. The method of claim 1 wherein the conditions associated with securing the second electronic component to the circuit board comprises exposing the secured electronic component to an elevated temperature.

8. The method of claim 1 wherein recording the data from the environmental condition recorder comprises storing data that is indicative of the secured electronic component'"'"'s exposure to atmospheric moisture content.

9. The method of claim 8 wherein the data indicative of atmospheric moisture content comprises temperature measurements and percent relative humidity measurements collected by the environmental condition recorder over time.

10. The method of claim 1 wherein creating the association between the secured electronic component and the environmental condition recorder comprises physically attaching the environmental condition recorder to the circuit board.

11. The method of claim 1 wherein creating the association between the secured electronic component and the environmental condition recorder comprises creating a logical association between the secured electronic component and the environmental condition recorder in a computer database.

12. The method of claim 1 wherein an identification code is positioned on the circuit board, the identification code providing sufficient information to enable identification of the secured component and the circuit board and wherein creating the association comprises logically linking, in a computer database, the secured electronic component and the circuit board, based on information provided by scanning the identification code.

13. The method of claim 12 wherein the identification code positioned on the circuit board is based on bar code technology.

14. The method of claim 12 wherein the identification code is based on radio frequency technology.

15. The method of claim 1 wherein recording the data from the environmental condition recorder comprises recording the data to a memory storage unit within the environmental recorder.

16. The method of claim 15 further comprising accessing the recorded data from the memory storage unit, for the suitability determination over a communication channel.

17. The method of claim 1 wherein recording data from the environmental condition recorder comprises recording data to a memory storage unit that is located external to the environmental condition recorder.

18. The method of claim 1 further comprising estimating a cumulative effect that exposure to the recorded environmental conditions would have on the secured component.

19. The method of claim 18 wherein estimating the cumulative effect that exposure to the recorded environmental conditions would have approximates integrating effects of exposure to the recorded environmental conditions over time.

20. The method of claim 18 wherein estimating the cumulative effect that exposure to the recorded environmental conditions would have comprises referencing industry standard guidelines related to expected total floor life for the secured electronic component under particular environmental conditions.

21. The method of claim 1 wherein the environmental condition recorder comprises:

a sensing element responsive to an environmental condition;

a memory storage unit in electronic communication with the sensing element and adapted to store environmental condition data sensed by the sensing element; and

a processing unit in electronic communication with the sensing element and the memory storage unit.

22. The method of claim 21 wherein the processing unit is adapted to record the data from the environmental condition recorder by periodically sampling the sensing element and electronically storing the sample in the memory storage unit.

23. The method of claim 22 wherein the processing unit is adapated to determine whether the secured component is suitable for exposure to conditions associated with securing a second electronic component to the circuit board by evaluating the sample, stored in the memory storage unit.

24. A method of securing multiple sets of electronic components to a circuit board, the method comprising:

reflow soldering a first set of electronic components to a circuit board;

creating an association between the first set of electronic components and an environmental condition recorder;

collecting environmental exposure data with the environmental condition recorder, the environmental exposure data being associated with the first set of electronic components during consecutive time periods before reflow soldering a second set of electronic components to the circuit board;

storing the collected data in the environmental condition recorder;

estimating, with the environmental condition recorder, a cumulative effect of the environmental exposure on each electronic component of the first set, based on the stored data; and

evaluating, with the environmental condition recorder, whether each electronic component of the first set is suitable for exposure to environmental conditions associated with reflow soldering the second set of electronic components to the circuit board.

25. The method of claim 24 further comprising reflow soldering the second set of electronic components to the circuit board depending on whether each electronic component of the first set is suitable for exposure to environmental conditions associated with reflow soldering the second set of electronic components to the circuit board.

26. The method of claim 24 wherein the conditions associated with reflow soldering a second set of electronic components to the circuit board comprise an elevated temperature.

27. The method of claim 24 wherein collecting environmental exposure data comprises collecting temperature measurements and relative humidity measurements.

28. The method of claim 24 creating the association comprises attaching the environmental condition recorder to the circuit board.

29. The method of claim 24 wherein creating the association comprises scanning a bar code affixed to the circuit board, the bar code identifying each electronic component of the first set of components secured to the circuit board.

30. The method of claim 24 wherein storing the collected data comprises storing the collected data in a memory storage unit within the environmental condition recorder.

31. The method of claim 24 wherein the collected data comprises temperature measurements and relative humidity measurements collected over time and wherein estimating the cumulative effect of the environmental exposure comprises integrating the temperature measurements and relative humidity measurements with respect to time.

32. The method of claim 24 wherein evaluating whether each electronic component of the first set is suitable for exposure to environmental conditions associated with reflow soldering the second set of electronic components to the circuit board comprises referencing industry standard guidelines.

33. The method of claim 24 wherein collecting the environmental exposure data associated with the first set of electronic components comprises using an environmental condition recorder to continually monitor and periodically and electronically record an environmental condition.

34. The method of claim 24 wherein collecting the environmental exposure data associated with the first set of electronic components comprises using an environmental condition recorder to automatically record environmental condition data.

35. The method of claim 24 wherein the environmental condition recorder comprises:

a sensing element responsive to an environmental condition;

a memory storage unit in electronic communication with the sensing element and adapted to store environmental condition data sensed by the sensing element; and

a processing unit in electronic communication with the sensing element and the memory storage unit.

36. The method of claim 35 wherein the processing unit is adapted to collect environmental condition exposure data by periodically sampling the sensing element and electronically storing the sample in the memory storage unit.

37. The method of claim 35 wherein the processing unit is adapated to evaluate whether each electronic component of the first set is suitable for exposure to conditions associated with securing a second electronic component to the circuit board by evaluating the sample, stored in the memory storage unit.