Method and apparatus for affixing components to a substrate when a manufacturing line ceases operation

• US 5,916,513 A
• Filed: 08/04/1997
• Issued: 06/29/1999
• Est. Priority Date: 08/04/1997
• Status: Expired due to Fees

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Neiconi, Ovidiu, Becher, Christopher Lee, Mangold, Richard Lee
• Primary Examiner(s): GRAYBILL, DAVID E
• Application Number:
  US08/905,621
• Time in Patent Office: 694 Days
• Field of Search: 29/25.01, 438/6, 438/107, 438/118, 438/119, 438/907
• US Class Current: 29/25.01
• CPC Class Codes: H01L 21/67121 Apparatus for making assemblies not otherwise provided for, e.g. package constructions
• CPC Class Codes: H01L 21/67144 Apparatus for mounting on conductive members, e.g. leadframes or conductors on insulating substrates
• CPC Class Codes: Y10S 438/907 Continuous processing

Abstract

An apparatus (400) enclosing a portion of a substrate (401) is used for affixing at least one component to a corresponding circuit of the substrate when a manufacturing line (800) ceases to operate. The apparatus includes a conveyor (400), heating elements (102), and a controller (816) for controlling operation of the apparatus (400). The conveyor is used for indexing the substrate periodically through the apparatus. The heating elements are used for dividing the portion of the substrate enclosed by the apparatus into controllable temperature zones (902). The controller is adapted to cause each of the plurality of heating elements to dynamically adjust the temperature of each of the controllable temperature zones upon the indexing process of the manufacturing line (800) ceasing to operate, until at least one component of each circuit enclosed by the apparatus has been adequately affixed to its corresponding circuit.

Claims

1. In an apparatus enclosing a portion of a substrate having a plurality of circuits, a method for affixing at least one component to a corresponding one of the plurality of circuits, comprising the steps of:

indexing the substrate periodically through the apparatus a distance equal to at least one of the plurality of circuits;

dividing the portion of the substrate enclosed by the apparatus into a plurality of controllable temperature zones,

wherein each controllable temperature zone encloses at least one of the plurality of circuits, and

wherein the plurality of controllable temperature zones, under normal operating conditions, maintain different selectable temperature profiles, which together correspond to a predetermined temperature profile adequate for affixing the at least one component to the corresponding one of the plurality of circuits as it is indexed through the plurality of controllable temperature zones; and

dynamically adjusting the temperature of each of the plurality of controllable temperature zones upon the indexing step ceasing to operate, until the at least one component of each circuit enclosed by the apparatus has been adequately affixed to its corresponding circuit.

2. The method as recited in claim 1, further comprising the step of dynamically readjusting the temperature of each of the plurality of controllable temperature zones upon the indexing step being reactivated, until each of the plurality of controllable temperature zones achieves a temperature adequate for affixing the at least one component to its corresponding circuit after the corresponding circuit has been indexed through the plurality of controllable temperature zones.

3. The method as recited in claim 1, wherein each of the plurality of controllable temperature zones apply varying temperatures by way of air convection.

4. The method as recited in claim 1, wherein each of the plurality of controllable temperature zones apply varying temperatures by way of radiation.

5. The method as recited in claim 1, wherein each of the plurality of controllable temperature zones apply varying temperatures by way of conduction.

6. An apparatus enclosing a portion of a substrate having a plurality of circuits for affixing at least one component to a corresponding one of the plurality of circuits, comprising:

a conveyor for indexing the substrate periodically through the apparatus a distance equal to at least one of the plurality of circuits;

a plurality of heating elements for dividing the portion of the substrate enclosed by the apparatus into a plurality of controllable temperature zones, wherein each controllable temperature zone encloses at least one of the plurality of circuits; and

a controller for controlling operation of the apparatus, the controller adapted to;

cause the conveyor to index the substrate through the apparatus;

cause each of the plurality of heating elements, under normal operating conditions, to maintain different selectable temperature profiles, which together correspond to a predetermined temperature profile adequate for affixing the at least one component to the corresponding one of the plurality of circuits as it is indexed through the plurality of controllable temperature zones; and

cause each of the plurality of heating elements to dynamically adjust the temperature of each of the plurality of controllable temperature zones upon the indexing step ceasing to operate, until the at least one component of each circuit enclosed by the apparatus has been adequately affixed to its corresponding circuit.

7. The apparatus as recited in claim 6, wherein the conveyor is a continuous belt conveyor.

8. The apparatus as recited in claim 7, wherein the plurality of heating elements, controlled by the controller, apply varying temperatures by way of air convection.

9. The apparatus as recited in claim 7, wherein the plurality of heating elements, controlled by the controller, apply varying temperatures by way of radiation.

10. The apparatus as recited in claim 6, wherein the conveyor is a vacuum conveyor comprising:

a plurality of pallets for carrying the portion of the substrate enclosed by the apparatus;

first and second linearly slidable tracks for guiding the plurality of pallets, wherein the first linearly slidable track is positioned above the second linearly slidable track;

a first motor for linearly driving at least one of the plurality of pallets in a first direction on the first linearly slidable track;

a second motor for linearly driving at least one of the plurality of pallets in a direction opposite to the first direction on the second linearly slidable track;

a vacuum source;

a plenum coupled to the vacuum source and coupled to at least one of the plurality of pallets for applying adhering forces to the substrate; and

first and second elevators coupled to the first and second linearly slidable tracks for transferring at least one of the plurality of pallets between the first and second linearly slidable tracks.

11. The apparatus as recited in claim 10, wherein each of the plurality of heating elements comprises a corresponding one of the plurality of pallets, and wherein each of the plurality of pallets is electrically coupled to an electrical source, and wherein each pallet is independently controlled by the controller for applying a controllable heat to the portion of the plurality of circuits enclosed by the apparatus.

12. The apparatus as recited in claim 11, wherein each of the plurality of pallets comprises:

a pallet assembly comprising;

a vacuum transfer plate having a first plurality of perforations for coupling to the substrate,

a heater plate having a second plurality of perforations for heating the vacuum transfer plate,

a carrier plate having at least one perforation coupled to the vacuum transfer plate and the heater plate;

a first end of each of a plurality of thermally insulated posts coupled to a bottom surface of the carrier plate; and

a transport plate, wherein a top surface of the transport plate is coupled to an end opposite to the first end of the plurality of thermally insulated posts for transporting the pallet assembly.

13. The apparatus as recited in claim 12, wherein the transport plate has a linear length that is larger than the linear length of the pallet assembly, thereby thermally isolating the plurality of pallets from each other while being carried by one of the first and second linearly slidable tracks.

14. The apparatus as recited in claim 12, wherein the first and second plurality of perforations are substantially aligned to each other.

15. The apparatus as recited in claim 12, wherein at least one thermally insulated post has a cavity extending throughout the at least one thermally insulated post, wherein the cavity of the at least one thermally insulated post is coupled to the at least one perforation and to the plenum for applying a vacuum to the pallet assembly.

16. The apparatus as recited in claim 12, wherein a bottom surface of the carrier plate comprises a plurality of fins for dissipating heat from the pallet assembly.

17. The apparatus as recited in claim 16, further comprising a fan for forcing air flow through the plurality of fins, thereby accelerating dissipation of heat from the pallet assembly.

18. The apparatus as recited in claim 11, wherein for at least one pallet, the vacuum conveyor further comprises an electrical coupling device coupled to the electrical source, wherein the electrical coupling device is used for electrically coupling to the at least one pallet, and for regulating its temperature by way of the controller.

19. The apparatus as recited in claim 11, wherein for at least one pallet, the vacuum conveyor further comprises a thermal sensor coupled to the controller for monitoring the temperature of the at least one pallet.

20. The apparatus as recited in claim 11, further comprising:

a shroud having at least one opening for enclosing a substantial portion of the apparatus;

at least one hose coupled to at least one opening in the shroud for extracting fumes from chemical reactions occurring on a top surface of the substrate caused by heating of at least one of the plurality of pallets; and

at least one fan coupled to at least one opening in the shroud for cooling the top surface of the substrate carried by a corresponding one of the plurality of pallets.

21. A manufacturing line comprising the apparatus of claim 6 for affixing components onto the plurality of circuits of the substrate and for indexing the substrate along the manufacturing line.

22. A manufacturing line comprising the apparatus of claim 11 for affixing components onto the plurality of circuits of the substrate and for indexing the substrate along the manufacturing line.

23. In an apparatus enclosing a portion of a plurality of substrates, each substrate having at least one circuit, a method for affixing at least one component to a corresponding circuit of a substrate, comprising the steps of:

indexing the plurality of substrates periodically through the apparatus a distance equal to at least one of the plurality of substrates;

dividing the portion of the plurality of substrates enclosed by the apparatus into a plurality of controllable temperature zones,

wherein each controllable temperature zone encloses at least one of the plurality of substrates, and

wherein the plurality of controllable temperature zones, under normal operating conditions, maintain different selectable temperature profiles, which together correspond to a predetermined temperature profile adequate for affixing the at least one component to the corresponding circuit of the substrate as it is indexed through the plurality of controllable temperature zones; and

dynamically adjusting the temperature of each of the plurality of controllable temperature zones upon the indexing step ceasing to operate, until the at least one component of each substrate enclosed by the apparatus has been adequately affixed to its corresponding circuit.