Multilevel circuit board precision positioning

• US 5,008,619 A
• Filed: 11/18/1988
• Issued: 04/16/1991
• Est. Priority Date: 11/18/1988
• Status: Expired due to Fees

• Current Assignee: Amp-Akzo Corporation
• Original Assignee: Amp-Akzo Corporation
• Inventors: Morino, Ronald, Burr, R. Page, Keogh, Raymond J.
• Primary Examiner(s): Snow, Walter E.
• Application Number:
  US07/272,929
• Time in Patent Office: 879 Days
• Field of Search: 324/207, 324/208, 324/226, 324/262, 324/207.11, 324/207.13, 324/207.14, 324/207.15, 324/207.16, 324/207.17, 324/207.22, 324/207.24, 336/115, 29/825, 29/830-832, 29/834, 29/846, 29/850
• US Class Current: 324/207.17
• CPC Class Codes: G01B 7/14 for measuring distance or clearance between spaced objects or spaced apertures G01B7/30 takes precedence
• CPC Class Codes: G01B 7/31 for testing the alignment of axes
• CPC Class Codes: H05K 1/0268 for electrical inspection or testing
• CPC Class Codes: H05K 2203/101 Using electrical induction, e.g. for heating during soldering
• CPC Class Codes: H05K 2203/166 Alignment or registration; Control of registration
• CPC Class Codes: H05K 3/4638 Aligning and fixing the circuit boards before lamination; Detecting or measuring the misalignment after lamination; Aligning external circuit patterns or via connections relative to internal circuits
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

In a system for determining the relative position of a first object with respect to a second object, electrical detection of registration is achieved. This registration can be used during the manufacture of printed circuit boards or discrete wiring boards to determine the registration between layers of wiring, or between wiring layers and printed circuit layers. The system introduces an a.c. current at a suitable frequency into at least one first conductive pattern wired or etched or otherwise provided near the perimeter of a printed or wired first layer of a circuit board panel. The panel having the first pattern is moved relative to similarly wired second conductive patterns on a second layer or base plate, mounting table, etc., to which detection circuits are connected. Voltage induced in the second patterns is detected and indicates the positional relationship between the first and second conductive patterns and, hence, objects associated with such patterns. The system is well adapted for use in the manufacture of circuit boards, with errors between a distorted panel layer and the next succeeding layer may be evenly distributed or averaged to produce optimum results.

Claims

1. An apparatus for determining the relative position of at least a first object with respect to a second object, the first object being a layer of a circuit board and the second object being a surface associated with a machine for making circuit boards or a second layer of a circuit board, the apparatus comprising:

a first geometric pattern of conductive material disposed on the first object;

a second geometric pattern of conductive material which is disposed on the second object in juxtaposition with the first, such that the perpendicular projection of said second geometric pattern on the first object is centered on about said first geometric pattern;

means for applying a predetermine value of alternating current to said first pattern to establish an electromagnetic field surrounding said first pattern;

means for detecting the magnitude of the voltage induced in said second pattern by the field established by said first pattern;

whereby the position of the first object relative to the second object is indicated by the magnitued of the detected voltage resulting from the said predetermined value of alternating current.

2. The apparatus according to claim 1 wherein a predetermined position of the first object relative to the second object is indicated by the peak voltage detected by said detecting means.

3. The apparatus according to claim 1 wherein said second pattern includes two parallel legs connected to each other, said detector means being connected to said legs and a predetermined position of the first object relative to the second object being indicated by a null voltage.

4. The apparatus according to claim 1 wherein said detecting means include an amplifier and a display means connected to said second pattern.

5. The apparatus according to claim 1 wherein said means for applying a predetermined value of alternating current includes an oscillator and an amplifier.

6. The apparatus according to claim 1 further comprising at least two first patterns disposed orthogonally to one another and at least two second patterns disposed orthogonally to one another.

7. The apparatus according to claim 6 wherein the conductive material of said first patterns is an insulated wire which forms a bow-tie shaped pattern having a cross-over point.

8. The apparatus according to claim 7 wherein the second patterns include substantially rectangular shaped coils.

9. The apparatus according to claim 1 wherein the conductive material of said first pattern is a metallic etching which forms a bow-tie shaped pattern not including a cross-over point.

10. The apparatus according to claim 9 wherein the conductive material of said first pattern is conductive ink.

11. The apparatus according to claim 9 wherein said second patterns include substantially rectangular shaped coils having insulated cross over points.

12. The apparatus according to claim 1 wherein a plurality of said first pattern geometric patterns ar disposed around the periphery of the first object and a plurality of said corresponding second patterns are disposed around the periphery of the second object, each of said second patterns having detecting means connected thereto.

13. The apparatus according to claim 1 wherein the first and second objects are layers of a circuit board.

14. A method of establishing the registration of a layer of a discrete wiring board to a surface associated with a wire scribing machine surface which comprises the steps of:

(a) forming a plurality of first patterns of linear conducting material at a plurality of locations on a panel, said panel being a layer of a discrete wiring board;

(b) wire scribing a plurality of corresponding second patterns on a surface associated with the wire scribing machine;

(c) connecting detecting means to said wires second patterns;

(d) connecting a source of alternating current to said first patterns on said panel;

(e) translating said panel relative to said surface until said detecting means detects a predetermined condition.

15. A method of establishing at least one wire scribed conductor on a substrate in registration to the conductive pattern of the substrate, which method comprises the steps of:

a. wire scribing a plurality of first datum reference conductive patterns on a surface associated with and in fixed relation to the table of a wire scribing machine;

b. connecting detecting means to said first wire scribed pattern;

c. providing a substrate having a corresponding plurality of second datum reference conductive patterns on an insulating base;

d. connecting a source of alternating current to said second corresponding datum reference patterns on the insulating base;

e. placing the insulating base on the table of the wire scribing machine;

f. moving the insulating base relative to the table in response to signals from said detecting means until optimum registration between said first and second datam reference conductive patterns is obtained;

g. wire scribing a conductor layer on the substrate.