Method of making a circuit board having burr free castellated plated through holes

• US 6,105,246 A
• Filed: 05/20/1999
• Issued: 08/22/2000
• Est. Priority Date: 05/20/1999
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Lee, Jeffrey L., Larnerd, James M., Poch, Francis S., Houser, David E.
• Primary Examiner(s): Arbes, Carl J.
• Assistant Examiner(s): Trinh, Minh
• Application Number:
  US09/315,428
• Time in Patent Office: 460 Days
• Field of Search: 29/852, 29/829, 29/846, 427/97, 228/180.21, 174/260, 174/262, 174/265, 174/266
• US Class Current: 29/852
• CPC Class Codes: H05K 2201/09181 Notches in edge pads
• CPC Class Codes: H05K 2203/0228 Cutting, sawing, milling or shearing
• 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 3/0052 Depaneling, i.e. dividing a panel into circuit boards; Working of the edges of circuit boards
• CPC Class Codes: H05K 3/403 Edge contacts; Windows or holes in the substrate having plural connections on the walls thereof H05K3/4092 takes precedence
• CPC Class Codes: H05K 3/42 Plated through-holes or plated via connections
• CPC Class Codes: Y10T 29/49124 On flat or curved insulated base, e.g., printed circuit, etc.
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49165 by forming conductive walled aperture in base

Abstract

The present invention provides a method of creating a circuit board having burr free castellated plated through holes. In particular, the leading edge of the plated through hole, that tends to produce burr formation using conventional profiling methods, is removed or pre-profiled. The pre-profiled plated through hole is then profiled at a distance slightly off-set from the pre-profiled edge to further prevent burr formation.

Claims

1. A method of producing a circuit board having burr free castellated plated through holes, comprising the steps of:

providing the circuit board having at least one plate through hole therein;

removing a lengthwise portion of the at least one plated through hole; and

profiling the at least one plated through hole, leaving a recessed portion at an edge of the circuit board.

2. The method of claim 1, wherein the steps of removing the lengthwise portion of the at least one plated through hole and profiling the at least one plated through hole are performed using the same tool.

3. The method of claim 1, wherein the step of profiling the at least one plated through hole is performed at an off-set distance from an edge created by removing the lengthwise portion of the at least one plated through hole to prevent burr formation.

4. A method of producing a burr free castellated plated through hole, comprising the steps of:

providing a circuit board having at least one plated through hole therein;

removing a lengthwise section of a vertical wall of the at least one plated through hole; and

removing a portion of the at least one plated through hole, leaving a recessed portion within an edge of the circuit board.

5. The method of claim 4, wherein the steps of removing the lengthwise section of a vertical wall of the at least one plated through hole and removing the portion of the at least one plated through hole are performed using the same tool.

6. The method of claim 4, wherein the step of removing the portion of the at least one plated through hole is performed at an off-set distance from an edge created by removing the lengthwise section of the vertical wall of the at least one plated through hole to prevent burr formation.

7. The method of claim 4, wherein the step of removing the lengthwise section of a vertical wall of the at least one plated through hole is performed on a first side of the circuit board, and the step of removing the portion of the at least one plated through hole is performed on a second side of the circuit board.

8. The method of claim 4, wherein the step of removing the portion of the at least one plated through hole is accomplished by nibbling or a series of plunges.