Transfer fluxing method and apparatus for component placement on substrate

• US 6,471,117 B1
• Filed: 11/04/1999
• Issued: 10/29/2002
• Est. Priority Date: 01/12/1998
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Slesinger, Kris Allen, Davis, John Gillette, Mays, Allen Thomas
• Primary Examiner(s): Dunn, Tom
• Assistant Examiner(s): DUNN, COLLEEN P
• Application Number:
  US09/434,576
• Time in Patent Office: 1,090 Days
• Field of Search: 228/223, 228/102, 228/19, 228/35, 427/282, 427/310, 427/58, 427/126.1
• US Class Current: 228/223
• CPC Class Codes: B23K 3/082 Flux dispensers; Apparatus for applying flux

Abstract

A transfer fluxing apparatus is provided. The apparatus is a flux reservoir for holding flux, a compliant pad attached to an opening in the flux reservoir and a means for controlling deposition of flux onto the compliant pad. The apparatus can be attached to an automated component placement machine. In the preferred embodiment of the invention, the control means is a valve located within the flux reservoir. The valve is opened by applying pressure to a plunger that extends through the compliant pad. When the plunger is pressed, the valve opens, and flux falls onto the compliant pad. Flux then passes through the pad to a component placement site. A method for automated fluxing and to component placement also is provided.

Claims

1. A method for transfer fluxing, comprising the following steps in the following order:

loading a product program;

acquiring a fluxing tool comprising a flux reservoir on a first robot head of an automated component placement machine;

attaching a compliant pad to an opening in the flux reservoir;

controlling the deposition of flux onto the complaint pad;

acquiring a component on a second robot head of the automated component placement machine;

identifying a target placement location for the component on a substrate;

identifying a position of the component on the second robot head;

determining a component placement site for the component on the substrate based on the identifying of the target placement location on the substrate and on the identifying of the position of the component on the second robot head;

moving the first robot head carrying the fluxing tool to the component placement site;

applying flux to the component placement site with the fluxing tool;

placing the component on the substrate using the second robot head; and

determining if additional components need to be placed and, if so, repeating the steps from acquiring the component; and

if not, ending the process.

2. The method of claim 1, further comprising, after any step in the method following the step of acquiring the fluxing tool, the following additional steps:

determining if the fluxing tool needs refilling;

when the fluxing tool does need refilling, then placing the fluxing tool into a refill dock and refilling the flux reservoir; and

when the fluxing tool does not need refilling, continuing to the next step of the method.

3. The method of claim 1, wherein the step of applying flux further comprises:

defining a contact force and a dwell time between the fluxing tool and the

component placement site to control flux flow.

4. The method of claim 1, further comprising attaching the fluxing tool to said automated component placement machine.

5. The method of claim 1, further comprising attaching the flux tool to a robotic arm of said automated component placement machine.

6. The method of claim 5, wherein the attachment of said fluxing tool is effected at an end-of-arm interface.

7. The method of claim 1, further comprising:

providing a docking station; and

effecting the steps of holding the flux reservoir in the docking station.

8. The method of claim 7, wherein the flux reservoir is held by springs in the docking system.

9. The method of claim 8, further comprising:

correctly positioning the flux reservoir in the docking station through the interposition of guide pins.

10. The method of claim 1, wherein controlling the deposition of flux onto the compliant pad comprises the steps of:

causing a valve upon being closed preventing flux from being deposited onto the compliant pad; and

upon opening of the valve permitting flux to fall onto compliant pad.

11. The method of claim 10, wherein the step of opening said valve is implemented by a plunger extending from the compliant pad to the valve.

12. The method of claim 1, wherein flux refilling is implemented by a refill syringe extending through a wall of the flux reservoir.

13. The method of claim 12, wherein the further step of flux refilling refills the flux reservoir at specified time intervals or number of fluxing cycles.