Apparatus and method for inspecting wiring on board
First Claim
1. A wiring inspection apparatus for inspecting wirings of a board, including first and second wirings, each of which has first and second ends, in a condition that both first ends of said first and second wirings are electrically coupled to each other, comprising:
- magnetic field applying means for applying a magnetic field to said first and second wirings on the first ends side of said first and second wirings;
magnetic field controlling means for supplying a signal to said magnetic field applying means so that the magnetic flux of the magnetic field changes with time;
current detection means for detecting a current which flows between said first and second wirings as the magnetic flux changes with time; and
defect judging means for judging whether said first and second wirings are defective based on a detection result which is obtained by said current detection means.
1 Assignment
0 Petitions
Accused Products
Abstract
A magnetic field applying portion is positioned above a magnetic field applied region, and applies a magnetic field to the magnetic field applied region. Among probes which are abutted against ball grids of wirings, two probes are selectively connected electrically to a current detector section whereby a closed circuit is formed. This causes the closed circuit to carry an induced current as the magnetic flux through the magnetic field the magnetic field applied region changes with time. A current detector of the current detector section detects the value of the induced current, and whether there is a short-circuit is judged based on the detected current value.
28 Citations
30 Claims
-
1. A wiring inspection apparatus for inspecting wirings of a board, including first and second wirings, each of which has first and second ends, in a condition that both first ends of said first and second wirings are electrically coupled to each other, comprising:
-
magnetic field applying means for applying a magnetic field to said first and second wirings on the first ends side of said first and second wirings;
magnetic field controlling means for supplying a signal to said magnetic field applying means so that the magnetic flux of the magnetic field changes with time;
current detection means for detecting a current which flows between said first and second wirings as the magnetic flux changes with time; and
defect judging means for judging whether said first and second wirings are defective based on a detection result which is obtained by said current detection means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
the first end surface is located over the first ends of said first and second wirings on one side of a board in which the first ends of said first and second wirings are formed on the same plane, and on the other side of said board, the second end surface is located facing the first end surface across said board.
-
-
3. A wiring inspection apparatus in accordance with claim 1, wherein said current detection means comprises specified resistor means whose resistance is known in advance and a current detector, and
said specified resistor means and said current detector are connected in series between the second ends of said first and second wirings. -
4. A wiring inspection apparatus in accordance with claim 1, further comprising a magnetic path generation plate which is formed by a soft magnetic material, wherein
said magnetic field applying means comprises: - a core which is entirely formed by a soft magnetic material and includes a first leg portion with a first end surface, a second leg portion with a second end surface and a link portion which links said leg portions to each other; and
a coil which is wound around said core, andsaid core is disposed on one side of a board in which the first ends of said first and second wirings are formed on the same plane while said magnetic path generation plate is disposed parallel to said board on the other side of said board so that the magnetic flux which exits at one of the two end surfaces of said core is guided to the other one of the two end surfaces of said core, whereby a magnetic circuit is formed.
- a core which is entirely formed by a soft magnetic material and includes a first leg portion with a first end surface, a second leg portion with a second end surface and a link portion which links said leg portions to each other; and
-
5. A wiring inspection apparatus in accordance with claim 4, wherein
said board is structured as a work in which a plurality of work pieces are formed continuous and integrated with each other in a plane, the first and second end surfaces of said core are spaced sufficiently to be faced with first ends of said wirings of different ones of said work pieces, and whether each one of said work pieces with which the end surfaces of said core are faced is defective or not is judged. -
6. A wiring inspection apparatus in accordance with claim 1, wherein said magnetic field applying means comprises:
- a core which is formed by a soft magnetic material and has a first end surface and a coil which is wound around said core, and
the first end surface of said core is located over the first ends of said first and second wirings.
- a core which is formed by a soft magnetic material and has a first end surface and a coil which is wound around said core, and
-
7. A wiring inspection apparatus in accordance with claim 6, further comprising a guide member for guiding the magnetic field applied from said magnetic field applying means in a predetermined direction and accordingly limits the range of the magnetic field which is applied to said first and second wirings.
-
8. A wiring inspection apparatus in accordance with claim 6, wherein a portion of said core which is close to the first end surface tapers toward the first end surface in a direction which is approximately perpendicular to a direction in which said first and second wirings are arranged.
-
9. A wiring inspection apparatus for inspecting wirings of a board, which inspects first and second wirings, each of which has a first end, in a condition that both first ends of said first and second wirings are electrically connected to each other, comprising:
-
magnetic field generation means for generating a magnetic field;
positioning means for positioning said first and second wirings relative to said magnetic field generation means such that said first and second wirings intersect the magnetic flux of the magnetic field on the first ends side of said first and second wirings;
magnetic field controlling means for supplying a signal to said magnetic field generation means so that the magnetic flux changes with time;
current detection means for detecting a current which flows between said first and second wirings as the magnetic flux changes with time; and
defect judging means for judging whether said first and second wirings are defective based on a detection result which is obtained by said current detection means.
-
-
10. A wiring inspection apparatus for inspecting wirings of a board, which inspects first and second wirings, each of which has first and second ends, in a condition that both first ends of said first and second wirings are electrically connected to each other, comprising:
-
current detection means which is inserted between the second end of said first wiring and the second end of said second wiring to thereby form a closed circuit, and which detects a current which flows through the closed circuit;
induced current generation means for generating an induced current within the closed circuit; and
defect judging means for judging whether said first and second wirings are defective based on the value of the induced current which is detected by said current detection means. - View Dependent Claims (11)
-
-
12. An apparatus for inspecting wirings of a board which is structured as a work in which a plurality of work pieces are formed continuous and integrated with each other in a plane, said apparatus inspecting first and second wirings, each of which has a first end, in a condition that the first ends of said first and second wirings of each said work piece are electrically connected to each other, comprising:
-
(a) magnetic field applying means which comprises;
(a-1) a core which is entirely formed by a soft magnetic material and includes a first leg portion with a first end surface, a second leg portion with a second end surface and a link portion which links said leg portions to each other, said core being located on one side to said work, the first and second end surfaces of said core being faced respectively with the first ends of said wirings of different ones among said work pieces;
(a-2) a coil which is wound around said link portion; and
(a-3) a magnetic path generation plate which is formed by a soft magnetic material, said magnetic path generation plate being disposed parallel to said work on the other side of said work so that the magnetic flux which exists at one of said end surfaces of said core is guided to the other one of said end surfaces of said core and a magnetic circuit is consequently formed, said magnetic field applying means applying a magnetic field simultaneously to said work pieces which are faced with the first and second end surfaces of said core;
(b) magnetic field controlling means for supplying a signal to said magnetic field applying means so that the magnetic flux of the magnetic field changes with time;
(c) current detection means for detecting a current which flows, in accordance with a change in the magnetic flux, between said wirings of said work pieces which are faced with the first and second surfaces of said core; and
(d) defect judging means for judging, with respect to each of the said work pieces which are faced with said first and second end surfaces of said core, whether said wirings are defective based on a detection on the current which is detected by said current detection means. - View Dependent Claims (13)
-
-
14. A method of inspecting wirings of a board, which inspects first and second wirings, each of which has a first end, in a condition that the first ends of said first and second wirings are electrically connected to each other, comprising the steps of:
-
a magnetic field applying step of applying a magnetic field to said first and second wirings on the first ends side of said first and second wirings while changing the magnetic flux with time;
a current detecting step of detecting a current which flows between said first and second wirings as the magnetic flux changes; and
a defect judging step of judging whether said first and second wirings are defective or not based on a detection result.
-
-
15. A method of inspecting first and second wirings of a board which is structured as a work in which a plurality of work pieces are formed continuous and integrated with each other in a plane, each of said first and second wirings having a first end, the first ends of said first and second wirings of each said work piece being electrically connected to each other, said method comprising the steps of:
-
a first step of preparing a core which is entirely formed by a soft magnetic material and includes a first leg portion with a first end surface, a second leg portion with a second end surface and a link portion which links said leg portions to each other;
a second step of positioning the first and second end surfaces of said core on one side of said board such that the first and second end surfaces of said core are faced respectively with the first ends of said first and second wirings of different ones among said work pieces;
a third step of disposing a magnetic path generation plate made of a soft magnetic material parallel to said board on the other side of said board;
a fourth step of supplying a signal to a coil which is wound around said link portion to thereby apply a magnetic field simultaneously to said work pieces which are faced with the first and second end surfaces of said core while changing the magnetic flux with time;
a fifth step of detecting a current which flows, in accordance with a change in the magnetic flux, between said first and second wirings of said work pieces which are faced with the first and second end surfaces of said core; and
a sixth step of judging, with respect to each one of said work pieces which are faced with the first and second end surfaces of said core, whether said first and second wirings are defective or not based on the current which is detected by said current detection means. - View Dependent Claims (16, 17, 18)
said sixth step includes simultaneously judging whether said first and second wirings are defective or not, simultaneously with respect to said work pieces which are faced with the first and second end surfaces of said core, based on detection results which are detected simultaneously at said fifth step. -
17. A wiring inspection method in accordance with claim 15, wherein said fifth step includes sequentially detecting the currents, one at a time, which flow between said first and second wirings in said work pieces which are faced with the first and second end surfaces of said core, and
said sixth step includes judging whether said first and second wirings of each one of said work pieces which is under current detection is defective or not every time the current is detected at said fifth step. -
18. A wiring inspection method in accordance with claim 15, wherein upon completion of said sixth step of judging whether said wirings are defective or not in a pair of said work pieces, the first and second end surfaces of said core are faced against a different pair of said work pieces at said second step.
-
-
19. A wiring inspection apparatus for inspecting conductivity of a first and second wirings on a circuit board, each of the first and second wirings having a first and second ends, and the inspection being made with the first ends of the wirings being connected with each other, the apparatus comprising:
-
a current detector to be interposed between the second ends of the wirings to form a closed circuit with the wirings and detect the current running through the closed circuit;
a current inducing unit for inducing electric current in the closed circuit; and
a conductivity detector for detecting the conductivity of the wiring in accordance with the output of the current detector. - View Dependent Claims (20, 21, 22, 23, 24, 25)
-
-
26. A method of inspecting wirings on a circuit board with a circuit board testing apparatus, the circuit board to be tested being structured as a work including a plurality of work pieces formed continuous and integrated with one another in a plane, each of the work pieces having a first and second wirings, each of the wirings having a first and second ends with the first ends of the wirings being connected with each other, the testing apparatus including a core having a first leg portion with a first end plane, a second leg portion with a second end plane, a link portion interconnecting the first and second leg portions, a coil wound around the link portion, and a current detector, the method, comprising the steps of:
-
positioning the core to face the first and second end planes to the first and second wirings of different work pieces on one side of the circuit board;
disposing a magnetic path forming plate on the other side of the circuit board than the side where the core is disposed;
connecting the current detector between the second ends of the wirings to form a closed circuit;
supplying to the coil electric current which changes with time, to cause time changing magnetic flux in the core, with the flux being supplied to the closed circuit to thereby induce electric current in the closed circuit; and
measuring the induced current by the current detector to determine the conductivity of the wirings.
-
-
27. A wiring inspection apparatus for inspecting wirings formed on a board, each wiring having first and second ends, with the first ends being formed on the same plane of the board, the inspection being made with respect to selected first and second wirings with the first ends of wirings being connected with each other, the apparatus comprising:
-
a magnetic field applier including a core formed by a soft magnetic material and having a first leg portion with a first end surface, a second leg portion with a second end surface and a link portion which links said leg portions to each other, and a coil which is wound around said core, said first and second end surfaces being on the same side of the board where the first ends of the wirings are formed such that at least one of the first and second end surfaces opposes the first ends of the wirings;
an electric current supplier for supplying time-changing electric current to said coil such that the magnetic flux caused by the magnetic field appliers changes with time;
a magnetic path plate formed by a soft magnetic material and disposed on the opposite side of the board from the first and-second end surfaces of the magnetic field applier to guide the magnetic flux exerted from the first end surface and passing through the board, to the second end surface through said magnetic path plate;
a current detector connected between the second ends of the first and second wirings for detecting a current induced in the first and second wirings by the magnetic flux changing with time; and
a defect judger for judging the defect of the first and second wirings based on the current detected by the current detector.
-
-
28. An apparatus for inspecting wirings of a board which is structured as a work in which a plurality of work pieces are formed continuous and integrated with each other in a plane, said apparatus adapted to inspect first and second wirings, each of which has a first end, in a condition that the first ends of said first and second wirings of each said work piece are electrically connected to each other, comprising:
-
(a) magnetic field applying means which comprises;
(a-1) a core formed entirely of a soft magnetic material and includes a first leg portion with a first end surface, a second leg portion with a second end surface and a link portion which links said leg portions to each other, said core being located on one side to said work, the first and second end surfaces of said core being faced respectively with the first ends of said wirings of different ones among said work pieces;
(a-2) a coil which is wound around said link portion; and
(a-3) electric current supplying means for supplying time-changing electric current to said coil such that the magnetic flux caused by the magnetic field appliers changes with time;
(a-4) a magnetic path generation plate formed by a soft magnetic material and disposed parallel to said work on the other side of said work so that the magnetic flux which exists at one of said end surfaces of said core is guided to the other one of said end surfaces of said core and a magnetic circuit is consequently formed, said magnetic field applying means applying a magnetic field simultaneously to said work pieces which are faced with the first and second end surfaces of said core;
(b) magnetic field controlling means for supplying a signal to said magnetic field applying means so that the magnetic flux of the magnetic field changes with time;
(c) current detection means for detecting a current which flows, in accordance with a change in the magnetic flux, between said wirings of said work pieces which are faced with the first and second surfaces of said core; and
(d) defect judging means for judging, with respect to each of the said work pieces which are faced with said first and second end surfaces of said core, whether said wirings are defective based on a detection on the current which is detected by said current detection means.
-
-
29. A wiring inspection apparatus for inspecting conductivity of a first and second wirings on a circuit board, each of the first and second wiring having a first and second ends, and the inspection being made with the first ends of the wirings being electrically connected to each other, comprising:
-
a current detector interposed between the second ends of the wirings to form a closed circuit and detects a current running through the closed circuit;
a current inducing unit for inducing electric current in the closed circuit wherein, said unit includes an electromagnetic member for applying to closed circuit a time-varying magnetic flux, said electromagnetic member including a core made of a soft magnetic material, a coil wound around the core and a current supply for supplying a time-varying electric current to the coil wherein said core has a first leg portion with a first end surface, a second leg portion with a second end surface, and a link portion for interconnecting the first and second leg portions, the coil is wound around the link portion, and the first and second ends are to face the circuit board on the same side of the board;
a conductivity detector for detecting the conductivity of the wiring in accordance with the output of the current detector; and
a magnetic path providing plate made of a soft magnetic material and disposed in parallel with the circuit board on the opposite side of the circuit board from the first and second ends of the core to guide the magnetic flux exerted from the first end of the core to the second end of the same.
-
-
30. A wiring inspection apparatus for inspecting the conductivity of first and second wiring patterns on a circuit board, each of the first and second wiring patterns having first and second ends and the inspections being made with the first ends of the wiring patterns being connected with each other by a removable common wiring, the wiring inspection apparatus comprising:
-
a current detector unit to be interposed between the second ends of the wiring patterns including a pair of probes for electrically contacting the second ends of the first and second wiring patterns to form a closed circuit with the wiring patterns, the current detector unit detects current running through the closed circuit and provides an output signal;
an electromagnetic member for applying, on one side of the closed circuit, a magnetic field which changes over a predetermined time period to induce an electric current in the closed circuit;
a magnetic field guide member positioned on the other side of the closed circuit from the electromagnetic member for guiding the magnetic field applied to the closed circuit and limiting the range of the magnetic field; and
a controller unit for receiving the output signal and providing an indication of the conductivity of the first and second wiring patterns.
-
Specification