JP2018124173A - Inspection method and device for printed circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To establish an inspection procedure for efficiently completing in a short period of time the continuity inspection of a printed circuit board that is performed using a movable probe, and an established inspection procedure.SOLUTION: A procedure is provided that includes: setting a plurality of inspection points on a printed circuit board; dividing all inspection points on the printed circuit board into a plurality of inspection areas so that all inspection points on the printed circuit board are evenly distributed; defining each of the inspection areas so that the number of inspection points included in each of the inspection areas does not exceed a preset value; determining for each inspection area an inspection procedure that includes movement to and inspection of a specific inspection area; and combining a plurality of determined inspection procedures into one inspection procedure. The continuity test of the printed circuit board can be efficiently performed in a short period of time.SELECTED DRAWING: Figure 1

Description

  The present invention relates to the design of an inspection procedure for conducting a continuity inspection of a printed wiring board. More specifically, establishing an inspection procedure for efficiently and quickly completing a printed wiring board continuity inspection performed using a movable probe, and an inspection method and inspection for executing the established inspection procedure Relates to the device.

  In general, a plurality of circuits (nets) electrically connected using a through hole or the like are arranged on one printed wiring board. And about the manufactured printed wiring board, it is necessary to confirm before actually using whether all the circuits arrange | positioned are provided as designed. In other words, it is necessary to confirm in advance that the circuit arranged on the printed wiring board can operate as designed without disconnection and causing poor conduction or short-circuiting with other circuits to cause insulation failure. Inspection is necessary.

  In a continuity test using a movable probe, the probe is moved in parallel along the surface of the printed wiring board to two inspection points in the same circuit (net) on the printed wiring board, and the probe is vertically moved at a predetermined position. The predetermined inspection is performed by moving the probe to contact the inspection point. When the inspection is completed, the probe is moved again in the direction perpendicular to the surface of the printed wiring board to move away from the inspection point, and the probe is moved to another inspection point along the plane. Such an operation is repeated, and all the inspection points on the printed wiring board are determined based on a predetermined threshold value, and the quality of the printed wiring board concerning the inspection target is determined.

  The time required for inspecting one printed wiring board is the total of the probe movement time from one inspection point to another inspection point on the printed wiring board, that is, the total time of probe movement for all inspection points. And the total inspection time at each inspection point. Therefore, the probe moving time to each inspection point, that is, the inspection order is greatly affected.

The problem concerning the determination of the probe destination, that is, the inspection order, can be regarded as a kind of route problem such as Traveling Salesman Problem (hereinafter referred to as TSP). For example, when finding the optimum TSP solution for n destinations (inspection points for printed wiring boards), (n-1)! / It is necessary to calculate two types of tours. For example, when n = 10, it is necessary to calculate 1.81 × 10 ⁵ ways, and when n = 30, it is necessary to calculate 4.42 × 10 ³⁰ routes. Some printed wiring boards have tens of thousands of inspection points as the number of printed wiring boards increases in recent years. For example, when n = 10000, (10000-1)! / 2 It is necessary to calculate two kinds of tours, and since it is impossible to solve the optimal solution of TSP in the case of n = 10000 in a realistic time, an approximate solution with a certain degree of accuracy even if it is not optimal Need to be determined in a short time.

  In this case, it is necessary to consider the following points. After the inspection between one inspection point and another inspection point is completed, it is necessary to move one probe to another inspection point. It is desirable that the probe movement time to the inspection point to be inspected, that is, the movement distance is short. However, in order to evaluate the work efficiency for the inspection of all the inspection points of the printed wiring board, the above (n-1)! / It is necessary to determine the inspection procedure in consideration of the total movement amount of the two routes, that is, the total movement time.

  JP 2013-16430 divides the surface of a circuit board (printed wiring board) provided with probing points (inspection points) into a plurality of grids, and is included in each partitioned area (inspection area). A movement path (inspection procedure) that passes through all probing points is specified for each partition area, and the movement paths specified for each partition area are connected to create a movement path for the entire circuit board.

Then, the inspection of the target circuit board is executed along the created movement path.
As described above, in the technique disclosed in Japanese Patent Laid-Open No. 2013-164308, the surface of a circuit board (printed wiring board) is divided into a plurality of grids to create a movement path (inspection procedure), thereby inspecting the target printed wiring board. There is an effect that the time required for the process can be shortened as a whole. However, when the printed wiring board is divided (divided) into a plurality of areas and sequentially inspected for each divided area, the printed wiring board has a high density area and a low density area of inspection points. In the method of Japanese Patent Laid-Open No. 2013-16430 that simply divides (divides) a printed wiring board into a grid shape, in order to calculate the inspection procedure in the region in the region where the density of inspection points is high (the number of inspection points is large). There is a problem that the amount of time increases synergistically.

  It is an object of the present invention to provide a printed wiring board inspection method and apparatus capable of solving the above problems in the continuity inspection of a printed wiring board using a movable probe.

  That is, the present invention relates to all the inspection points of the printed wiring board, the total value of calculation time required to determine the moving procedure in each divided area, and all the inspection points of the printed wiring board, respectively. The overall inspection procedure for the target printed wiring board is determined in consideration of reducing the total value of both the movement distance between inspection points in the inspection area, that is, the total movement time, and the efficiency. It is an object of the present invention to provide a method and apparatus for inspecting a printed wiring board having high performance.

JP 2013-164308 A

  According to one aspect of the present invention, a printed wiring board inspection method is provided.

The inspection method of the present invention uses the probe to move all the inspections included in the printed wiring board by moving the probe so as to cover a plurality of inspection points included in the circuit provided on the printed wiring board. In an inspection method for conducting a continuity test on a point,
A step of dividing all the inspection points on the printed wiring board into a plurality of inspection regions, wherein the printed wiring board is divided into a plurality of portions so as to equalize the number of inspection points included in each of the divided inspection regions. Dividing into inspection areas;
Determining a procedure for moving the probe to each inspection point within each of the plurality of inspection regions;
A step of determining an integrated movement procedure for all inspection points of the printed wiring board by combining the determined probe movement procedures for each of the plurality of inspection regions.

In a preferred aspect, the step of dividing the plurality of inspection regions includes the step of specifying the positions of all inspection points on the printed wiring board based on coordinates having an X axis and a Y axis perpendicular to the X axis. When,
Setting the number of inspection points included in one inspection region;
A step of demarcating each inspection region so that one inspection region includes the set number of inspection points, and in each inspection region, a straight line in the Y-axis direction passing through the inspection point having the minimum coordinate value in the X-axis Y-axis direction straight line passing through the inspection point having the maximum coordinate value in the X-axis, X-axis direction straight line passing through the inspection point having the minimum coordinate value in the Y-axis direction, and inspection point having the maximum coordinate value in the Y-axis direction Each defining a rectangular inspection region that is surrounded by a straight line in the X-axis direction passing through.

In this case, in a preferred embodiment, the boundary of the target inspection region is changed so as to include an out-of-region inspection point that constitutes a circuit extending beyond the boundary in the X-axis or Y-axis direction of the defined rectangular inspection region. A process,
When the distance from the boundary to the out-of-area inspection point is a ratio of the width of the inspection area in the X-axis or Y-axis direction with a predetermined constant α (0 <α <1) smaller than a preset threshold value, A step of changing a boundary of the inspection area so that the out-of-area inspection point is included in the inspection area as the object.

Further, the step of changing the boundary of the target inspection region so as to include an out-of-region inspection point constituting a circuit extending beyond the boundary in the X-axis or Y-axis direction of the defined rectangular inspection region,
When the distance from the boundary to the out-of-area inspection point is larger than a predetermined threshold value α (0 <α <1) when the ratio of the width of the inspection area in the X-axis or Y-axis direction is larger than a predetermined threshold value And a step of changing the boundary of the inspection region so as to constitute an inspection region in which all inspection regions including the out-of-region inspection point of the circuit extending beyond the boundary are integrated.

  In this case, in a preferred embodiment of the present invention, a circuit extending beyond the boundary is incorporated in the inspection region having the smallest number of inspection points.

  When inspection points of a circuit extending beyond the boundary belong to a plurality of inspection regions, all inspection points of the circuit extending beyond the boundary may be added to any of the inspection point regions belonging to the boundary. .

  Further, when the inspection points of the circuit extending beyond the boundary belong to a plurality of inspection regions, the inspection points of the circuit extending beyond the boundary can be set as a single inspection region.

  Alternatively, at least one inspection point of the circuit extending beyond the boundary may be added to an inspection region other than the inspection region to which the inspection point belongs.

  In this case, the inspection point added to the inspection region other than the inspection region to which one inspection point belongs is the inspection in which the distance from the boundary of all the inspection regions of the plurality of inspection regions is the smallest in the X direction and the Y direction. Is a point.

  It is preferable to set the number of inspection areas so as to minimize the total value of the movement distances of the probe that moves to inspect all inspection points.

According to another aspect of the present invention, in an inspection apparatus that performs a continuity inspection of a printed wiring board using a probe,
Means for setting a plurality of inspection points on the printed wiring board;
A means for dividing all inspection points on the printed wiring board into a plurality of inspection areas, all on the printed wiring board so as to equalize the number of inspection points included in each of the divided inspection areas. Means for dividing the inspection point into a plurality of inspection regions;
Means for defining each inspection area so that the number of inspection points included in each of the inspection areas does not exceed a preset numerical value;
Means for determining an inspection procedure including movement and inspection of the region to a specific inspection point for each inspection region;
A printed wiring board inspection apparatus including means for determining a comprehensive inspection procedure for all inspection points of a printed wiring board by combining the determined plurality of inspection procedures into one inspection procedure is provided. .

In this case, the means for dividing the plurality of inspection areas includes means for specifying the positions of all the inspection points based on coordinates having an X axis and a Y axis perpendicular to the X axis on the printed wiring board. ,
Means for setting the number of inspection points included in one inspection region;
A means for demarcating each inspection area so that one inspection area includes the set number of inspection points, and in each inspection area, a straight line in the Y-axis direction passing through the inspection point having the minimum coordinate value in the X-axis. Y-axis direction straight line passing through the inspection point having the maximum coordinate value in the X-axis, X-axis direction straight line passing through the inspection point having the minimum coordinate value in the Y-axis direction, and inspection point having the maximum coordinate value in the Y-axis direction And a means for demarcating each rectangular inspection region surrounded by a straight line in the X-axis direction passing therethrough.

Further, it is means for changing the boundary of the target inspection region so as to include an out-of-region inspection point that constitutes a circuit extending beyond the boundary in the X-axis or Y-axis direction of the defined rectangular inspection region,
When the distance from the boundary to the out-of-area inspection point is such that the ratio of the width of the inspection area in the X-axis or Y-axis direction is smaller than a predetermined threshold α (0 <α <1) Further, it is possible to provide means for changing the boundary of the inspection area so that the out-of-area inspection point is included in the inspection area as the object.

Furthermore, in another aspect, the boundary of the target inspection region is changed to include an out-of-region inspection point that constitutes a circuit extending beyond the boundary in the X-axis or Y-axis direction of the defined rectangular inspection region. A process,
When the distance from the boundary to the out-of-area inspection point is larger than a predetermined threshold value α (0 <α <1) when the ratio of the width of the inspection area in the X-axis or Y-axis direction is larger than a predetermined threshold value And means for changing the boundary of the inspection region so as to constitute an inspection region in which all inspection regions including the out-of-region inspection point of the circuit extending beyond the boundary are integrated.

  In addition, a circuit extending beyond the boundary may be incorporated in an inspection region having the smallest number of inspection points.

  When the inspection points of a circuit extending beyond the boundary belong to a plurality of inspection areas, all the inspection points of the circuit extending beyond the boundary are added to any of the inspection point areas belonging to the boundary. Also good.

  Further, when the inspection points of the circuit extending beyond the boundary belong to a plurality of inspection regions, the inspection points of the circuit extending beyond the boundary can be set as a single inspection region.

  Alternatively, at least one inspection point of the circuit extending beyond the boundary may be added to an inspection region other than the inspection region to which the inspection point belongs.

  In this case, the inspection point added to the inspection region other than the inspection region to which one inspection point belongs is the inspection in which the distance from the boundary of all the inspection regions of the plurality of inspection regions is the smallest in the X direction and the Y direction. Is a point. It is desirable to set the number of inspection areas so as to minimize the total value of the movement distances of the probe that moves to inspect all inspection points.

  According to the present invention, it is possible to efficiently perform a continuity test on a printed wiring board in a short time.

It is a figure which shows the structural example of the printed wiring board test | inspection apparatus by one embodiment of this invention. It is a flowchart which shows the procedure of the inspection plan of the printed wiring board concerning one Embodiment of this invention. It is a figure which shows all the inspection points on a printed wiring board. It is a figure which shows the state which divided | segmented the test | inspection point of the printed wiring board into two test | inspection area | regions to the X-axis direction. 2 is a view showing an inspection area of a printed wiring board 10. FIG. FIG. 6A is a diagram illustrating a state where a net straddling a boundary line between groups is incorporated into one inspection region when the inspection points of the printed wiring board 10 are divided into inspection groups. FIG. 6B is a diagram when a net straddling a boundary line is incorporated into another inspection region when the inspection points of the printed wiring board 10 are divided into inspection regions. FIG. 7A is a diagram showing a global net in a printed wiring board. FIG. 7B is a diagram showing the state of the printed wiring board excluding the global net. It is a figure which shows the distance relationship between the test | inspection point of a global net, and the test | inspection area | region where a test point does not belong.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this case, in principle, the same members are denoted by the same reference numerals, and repeated description is omitted.

  FIG. 1 shows an overall configuration of a printed wiring board inspection apparatus according to an embodiment of the present invention. The printed wiring board inspection apparatus according to the present embodiment includes, for example, two probes 11, a probe support unit 12, a moving mechanism unit 13, a measurement unit 14, a storage unit 15, a control unit 16, and the like.

  The moving mechanism unit 13 includes various motors and a motor driver that drives the motors. A probe 11 is attached to the moving mechanism unit 13 via a probe support unit 12, and the probe 11 is movable in a parallel direction (XY direction) and a vertical direction (Z direction) with respect to the printed wiring board 10. In the present embodiment, the case where there are two probes 11 will be described as an example. However, the present invention can be applied to the case where there are three or more probes 11.

  The measuring unit 14 includes a voltage source, a current source, a measuring instrument, and the like, and is connected to the probe 11. A circuit in the printed wiring board 10 is supplied by passing a current between the probes or applying a voltage. It is possible to measure the resistance.

  The storage unit 15 is configured by a memory such as a RAM or a hard disk, for example, and temporarily stores a measured value, a calculation result thereof, and the like.

  The control unit 16 includes a CPU, a RAM, a ROM, and the like, and performs a process of determining whether or not the drive control of the moving mechanism unit 13 and the resistance value measured by the measurement unit 14 are defective. The control unit 16 can also be realized by incorporating a program for realizing the above functions and the following operations in a general computer, and the program is read by a computer such as a floppy (registered trademark) disk or a hard disk. It can also be recorded on a possible recording medium. The program can also be read from communication means such as the Internet.

  FIG. 2 is a flowchart for determining an inspection procedure or inspection plan according to an embodiment of the present invention.

  In this example, a printed wiring board to be subjected to a continuity test is divided into a plurality of areas in a planar manner, and all inspection points on the printed wiring board are distributed to a plurality of inspection groups. The continuity test is sequentially performed for each test group.

In this case, a target value of either the number of inspection areas (groups) or the number of inspection points included in one inspection area is set on the printed wiring board. Therefore, the target value of the number of inspection areas formed by dividing all the inspection points of one printed wiring board, the target value of the number of inspection points included in one inspection area, and the target printed wiring board The relationship with the total number of inspection points can be expressed by the following equation (1). (Step 101)

  In order to obtain the inspection time for all inspection points of the target printed wiring board, the continuity test for one inspection point, that is, the time of one continuity inspection, and the time after the end of the inspection to the next inspection point It is necessary to calculate the moving distance of the probe, that is, the moving time. Therefore, when the number of inspection points included in one inspection region increases, the total time for moving the probe in the inspection region increases, so that it takes time to define the inspection procedure for the inspection region. As a result, it takes a long time to define the inspection procedure for the entire printed wiring board. In order to solve this problem and to define an efficient inspection procedure for the entire printed wiring board, the number of inspection points in each inspection area composed of one printed wiring board divided into a plurality of parts is leveled as much as possible. It is desirable to do. In other words, it is desirable that the number of inspection points for all the divided inspection regions be approximately the same.

However, since it is necessary to collect each inspection region for each circuit (net) that is in a conductive relationship with each other, it is difficult to set all the inspection points included in one inspection region to the same number. In this example, an allowable value (ratio (%) with respect to the total number of inspection points) for variation for each inspection group is set in advance, and the number of inspection points included in one inspection region is set. The allowable range of the target inspection score and the relationship between the target inspection score and the allowable value can be expressed by Expression (2). (Step 102)

  For example, if the total number of inspection points of a printed wiring board is 5000, the target number of divisions is 5 and the allowable value is 10%, 5 inspection regions including inspection points of 900 to 1100 inspection points are formed. Will be.

  The target values of the number of divisions and the number of inspection points included in one inspection region are determined based on the attributes of the individual printed wiring boards to be processed.

  Next, a procedure for dividing inspection points to be inspected on an actual printed wiring board into a plurality of inspection groups corresponding to the respective positions will be described.

  The range of each inspection area is set so as to satisfy a predetermined area area set in advance on the target printed wiring board. In this case, basically, all the inspection points of one conduction circuit (net) are set to belong to one inspection region. However, some conductive circuits (nets) may extend across a plurality of inspection regions.

  In this example, as a first stage, it is more efficient to construct an inspection procedure (inspection plan) by including it in one of the inspection areas in a circuit (net) extending over a plurality of inspection groups. Rather than being included in any one inspection area of a circuit (large net) that is considered to be present and one circuit (net) that straddles multiple inspection areas, it is extracted once from the inspection area. In other words, a circuit (global net) that is considered to be more efficient in inspection work as a whole when the inspection procedure is defined by another method is extracted.

  That is, in the first stage of the present invention, a large net is extracted, the inspection area is corrected so as to include the large net, and the global net is extracted to achieve efficient inspection based on the existence of the global net. Thus, the division of the inspection area of the entire printed wiring board 10 is reconfigured.

  As the second stage, an inspection procedure is determined for each inspection area defined in the first stage.

  Then, as a final step, a print in which the inspection procedures (plans) of the inspection area modified to include a plurality of nets and / or large nets and the inspection area reconstructed to include the inspection points of the global net are integrated. An inspection procedure (plan) for the entire wiring board is constructed.

  When the above inspection procedure is executed, the plane on the printed wiring board is coordinated along the X axis direction and the Y axis direction perpendicular to the X axis direction, and is divided based on this data. The inspection procedure for the continuity inspection of the printed wiring board can be efficiently constructed.

The above will be specifically described below.
FIG. 3 is a diagram illustrating a specific example of the inspection points arranged on the printed wiring board.

  The printed wiring board 10 includes a conduction circuit (net) 1 to a conduction circuit (net) 9. Net 1 includes inspection points a and b.

  In FIG. 3, when the inspection points are connected by a solid line, it indicates that a conduction circuit (net) is configured. For example, in the case of the net 1, the inspection point a and the inspection point b are electrically connected, that is, both are in conduction. Similarly, in the net 2, the inspection points c and d are connected and are in a conductive relationship.

  In the net 3, the inspection points e and f are in a conductive relationship. The net 4 includes inspection points g and h. Net 5 includes four test points, test points i, j, k, and l. Net 6 includes inspection points m and n, and net 7 includes inspection points o, p and q. The net 8 includes inspection points r, s, and t, and the net 9 includes six inspection points u, v, w, x, y, and z (FIG. 3).

  As can be seen from FIG. 3, the net 5 extends to the central portion of the printed wiring board 10, and the net 9 extends over a wide range on the printed wiring board.

  FIG. 4 is a diagram for explaining an inspection procedure (plan) when the inspection points of the printed wiring board 10 are divided into two in the X-axis direction as an example. The total number of inspection points of the printed wiring board 10 in the present embodiment is 26 inspection points a to z. As shown in FIG. 4, when the inspection point of the printed wiring board 10 is divided into two in the X-axis direction, the target inspection point number is 26/2 = 13 from the equation (1).

  In this example, the allowable value indicating the range of the difference in the number of inspection points between the inspection regions in the above equation (2) between the inspection regions (groups) of the number of inspection points is 20%.

  Then, since the range of the target value of the number of inspection points in each inspection region is 13 × (100 ± 20) / 100 from the above equation (2), it becomes 10.4 to 15.6.

  In this example, when dividing into two in the X-axis direction, the total number of inspection points of the printed wiring board 10 is 26, so 13 from the inspection point having a small X coordinate become the left group (inspection region 1), and the X coordinate is Thirteen of the large inspection points form the right group (inspection area 2) in the figure.

  Therefore, the inspection area 1 includes 13 inspection points a to j and u to w, and the inspection area 2 includes 13 inspection points k to t and x to z.

  Next, the basic range of the inspection area on the printed wiring board 10 of this example is determined. The basic inspection area is a rectangular area connecting two inspection points having minimum and maximum coordinates in the X-axis direction and two inspection points having minimum and maximum coordinates in the Y-axis direction in the group. Put.

  In this example, the coordinates of the inspection point a on the X axis and the Y axis, that is, the XY coordinates are a (6, 18). Similarly, the XY coordinates of the inspection points b to z are b (17,7), c (19,33), d (19,48), e (13,69), f (13,85), g, respectively. (40, 63), h (56, 63), i (46, 40), j (50, 16), k (60, 36), l (73, 51), m (70, 77), n ( 70, 93), o (100, 22), p (116, 12), q (124, 22), r (104, 63), s (104, 75), t (127, 70), u (22 , 78), v (36, 78), w (40, 51), x (79, 66), y (90, 15), z (117, 42).

  In this example, the minimum coordinate in the X-axis direction of the inspection area 1 is the inspection point a, the maximum coordinate is the inspection point h, the minimum coordinate in the Y-axis direction is the inspection point b, and the maximum coordinate is Inspection point f.

  Therefore, the inspection area in this example is a rectangular area surrounded by two straight lines along the Y axis passing through the inspection points a and h and two straight lines along the X axis passing through the inspection points b and f. Essentially, it becomes the inspection area 1.

  The inspection area 2 is determined in the same procedure. That is, the minimum coordinate value in the X-axis direction of the inspection region 2 is the inspection point k, the maximum coordinate value is the inspection point t, the minimum coordinate value in the Y-axis direction is the inspection point p, and the maximum coordinate value The value is inspection point n.

  Therefore, for the inspection area 2, the area surrounded by the straight line along the Y axis passing through the inspection points k and t and the two straight lines along the X axis passing through the inspection points p and n is the primary inspection. It becomes an area.

  Next, it is investigated whether all the inspection points of each conduction circuit (net) belong to the same inspection area.

  In the case of the printed wiring board 10 in this embodiment shown in FIG. 3, all inspection points are included in the inspection region 1 for the conduction circuits (nets) 1, 2, 3, and 4, and the conduction circuit (net) 6, All inspection points 7 and 8 are included in the inspection region 2.

  On the other hand, the inspection points of the conduction circuit (net) 5 and the conduction circuit (net) 9 exist across both inspection regions 1 and 2. In the case of the conduction circuit (net) 5, the inspection points i and j belong to the inspection region 1, but the inspection points k and l belong to the inspection region 2. As described above, for a net in which inspection points exist across a plurality of inspection areas, the inspection procedure (plan) is examined based on the distance D from the boundary of the inspection area of the inspection points protruding from the inspection area. . In this example, a comparison is made with a preset threshold value for the distance D between the inspection point protruding from the inspection region and the boundary of the inspection region, and different processing is performed depending on the result.

  Hereinafter, the threshold value will be described.

  FIG. 5 is a diagram illustrating the positions of the inspection points of the printed wiring board 10 according to the present embodiment. As described above, the inspection area includes two straight lines along the Y-axis direction passing through the coordinates of the minimum value in the X-axis direction and the inspection point having the coordinates of the maximum value, and the inspection point in the Y-axis direction. This is a rectangular area surrounded by two straight lines along the X-axis direction passing through each of the inspection points having the minimum value coordinate and the maximum value coordinate.

  In FIG. 5, the minimum coordinate value of the inspection point in the X-axis direction is the inspection point a, the maximum coordinate value in the X-axis direction is the inspection point t, and the minimum value in the Y-axis direction is the inspection point b. The maximum coordinate value is the inspection point n. Therefore, a rectangular region surrounded by two straight lines extending along the Y-axis direction passing through the inspection points a and t and two straight lines extending along the X-axis direction passing through the inspection points b and n is the printed wiring board of this embodiment. 10 total inspection areas.

Then, the relationship between the width (W) of the inspection region and the threshold when the inspection region is divided in the X-axis direction can be expressed by Expression (3). Here, α is a constant preset as a parameter (0 <α <1).

Similarly, the relationship between the height (H) of the inspection region and the threshold when the inspection region is divided in the Y-axis direction can be expressed by Expression (4). Here, α is a constant preset as a parameter (0 <α <1).

  In this embodiment, the distance between the inspection area boundary and the inspection point protruding from the inspection area, that is, the distance D from the inspection area boundary to the inspection point protruding in advance, Compare.

  In this case, in the case of a conduction circuit (large net) having a certain size with the distance D from the inspection point protruding from the boundary of the inspection region being less than the threshold value, all the conduction circuits (large nets) The inspection area is reconfigured to include the inspection points.

  On the other hand, a conduction circuit including an inspection point whose distance D to the inspection point protruding from the boundary of the inspection region is equal to or greater than the threshold value is extracted as a circuit (global net) extending across the inspection region. The inspection area including the above is separately reconfigured.

  As described above, in the present embodiment, there are the conduction circuit (net) 5 and the conduction circuit (net) 9 as the conduction circuit (net) that extends over a plurality of inspection groups. Hereinafter, a method of reconfiguring the inspection area when handling the inspection points included in the conduction circuit (net) 5 and the conduction circuit (net) 9 will be described.

  In this case, as a basic idea, inspection points of a conduction circuit (net) having inspection points extending across a plurality of inspection regions are incorporated into any group. If the inspection points of the net extending across the inspection area are included in the group and exist in multiple group areas, they are included in the inspection area with the smallest number of group inspection points and do not exist in any inspection area. In some cases, it is incorporated into an inspection region that is the closest to the boundary among the peripheral inspection regions.

  In the case of FIG. 5, if α = 0.2, in this example, the inspection area is divided in the X-axis direction, and the width (W) of the inspection data area is 121. (X) = 24.2.

  Considering the net 5 when the threshold value is determined in this way, the net 5 includes inspection points i, j, k, and l as described above. Then, the inspection points i and j belong to the inspection group 1 and the inspection points k and l belong to the inspection region 2 in the first stage. That is, the inspection point i and the inspection point j are outside the region of the inspection region 2, and the inspection point k and the inspection point l are outside the region of the inspection region 1.

  In this case, in this embodiment, the distance from the boundary of the inspection area 2 to the inspection point i, the maximum distance from the boundary of the inspection area 2 to the inspection point j, and the boundary of the inspection area 1 to the inspection point k. And the maximum value of the distance from the boundary of the inspection region 1 to the inspection point 1 are calculated and compared with the threshold value.

  The distance from the boundary of the inspection area 2 to the inspection point i is 14, the distance from the boundary of the inspection group 2 to the inspection point j is 10, the distance from the boundary of the inspection area 1 to the inspection point k is 4, and the inspection area 1 Since the distance of the inspection point l is 17, its maximum value is 17. Therefore, since the distance 17 from the boundary of the inspection region 1 to the inspection point l is the maximum value as a result of comparing the distances with the boundaries of the groups in this embodiment, the value is compared with the threshold value 24.2. .

  As a result, it is found that the distance from the boundary of the inspection group region 1 of the net 5 to the inspection point 1 of the specific conduction point (net) 5 to be tested is less than the threshold value. In this example, in such a case, it is assumed that the distance of protrusion or deviation from the boundary of the inspection area is less than the threshold value, and the conduction circuit (net) 5 is a large net and all inspection points included in the conduction circuit (net) 5. Are integrally included in either the inspection region 1 or the inspection region 2.

  Next, a procedure for determining whether moving the large net 5 to the inspection area 1 or 2 is preferable in terms of efficiency of the entire inspection procedure will be described.

  First, as shown in FIG. 6A, an inspection region 1 ', which is an inspection region including all inspection points of the inspection region 1 and the large net 5, is virtually set.

  On the other hand, an inspection region 2 'including all inspection points of the inspection region 2 and the large net 5 as shown in FIG. Then, the amount of increase in each of the inspection region 1 'and the inspection region 2' is compared. The increase amount of the inspection region 1 ′ in the X-axis direction is (73−6) − (56−6) = 17, and the increase amount of the inspection region 2 ′ in the X-axis direction is (127−46). )-(127-60) = 14. Therefore, comparing the increase amounts of both, it can be seen that the inspection region 2 'has a smaller increase amount of the region than the inspection region 1'. This means that if all the inspection points of the large net 5 are included in the inspection region 2 ', the amount of movement of the probe for inspection is small and the inspection efficiency is high. Therefore, in the present embodiment, the inspection areas 1 and 2 are configured such that all inspection points of the net 5 are moved to the inspection area 2 in consideration of inspection efficiency, and all inspection points of the large net 5 are considered. The range of the region is defined.

  Next, how to determine the inspection area of the inspection point included in the net 9 extending beyond the inspection areas 1 and 2 set at the beginning as in the case of the large net 5 will be examined.

  The net 9 includes inspection points u, v, w, x, y and z. Among these, the inspection points u, v, and w are located in the region of the inspection region 1, and the inspection points x, y, and z are included in the region of the inspection region 2. The distance D from the boundary between the inspection point u included in the inspection region 1 and the inspection region 2 is 38 in the X-axis direction, and the distance D from the boundary of the inspection region 2 included in the inspection region 1 is 24, and the distance between the inspection point w included in the inspection region 1 and the boundary of the inspection region 2 is 20. On the other hand, the distance D between the inspection point x and the region boundary of the inspection region 1 is 23, the distance between the inspection point y included in the inspection region 2 and the region boundary of the inspection region 1 is 34, and included in the inspection region 2 The distance D between the inspection point z and the inspection region 1 is 56. The distance between the inspection region 1 and the inspection point z is 61 in the maximum distance between the inspection points and the boundary between the inspection regions 1 and 2. When this distance is compared with a threshold value in the case of α = 0.2 set in advance in this example, the distance D between the inspection region 1 and the inspection point z is larger than the preset threshold value (X) = 24.2. It turns out to be big.

  For this reason, in this example, the distance D between the inspection region 1 and the inspection point z is larger than the preset threshold value (X) = 24.2. From the viewpoint of efficiency, the handling is different from that of the large net 5.

  As one inspection processing method for the global net, an independent inspection region (group) including all inspection points (inspection points u to z in this embodiment) constituting the global net is established.

  That is, as a result of judging the efficiency of the inspection procedure based on a threshold value determined by a preset number of divisions and a preset α, the continuity circuit (global net) 9 is independently traversed by the inspection areas 1 and 2. One inspection area is reconstructed (step 103).

  In this case, the inspection points u, v, and w included in the inspection region 1 are excluded from the inspection procedure for the inspection points in the inspection region 1. Similarly, the inspection points x, y, and z existing in the inspection area 2 are excluded from the inspection procedure for inspection points as inspection objects in the inspection area 2.

  Next, another method for the global net will be described below with reference to FIG.

In the case of the global net 9 (inspection points u to z) in the present embodiment, the inspection points u, v, and w exist in the inspection region 1 ′, so that the inspection points u, v, and w are incorporated into the group 1 ′. In addition, since the inspection points x, y, and z exist in the inspection region 2 ′, the inspection points x, y, and z are incorporated in the inspection region 2 ′. (Step 104)
That is, not all the inspection points included in the global net 9 are integrally configured as an inspection procedure, but first, the global net 9 is divided at the boundary for each inspection region including the inspection points constituting the global net 9. .

  Next, among the inspection points located on both sides of the conductive portion of the global net 9 divided by the boundary, a process of additionally including the inspection point on the side that is not the inspection region to which the inspection point belongs across the boundary do.

The inspection point to be added will be described. In this embodiment, the distance between the inspection point u and the inspection area 2 ′ of the global net 9 is d _u , the distance between the inspection point v and the inspection area 2 ′ is d _v , and the distance between the inspection point w and the inspection area 2 ′ is d _w , the distance between the inspection point x and the inspection area 1 ′ is d _x , the distance between the inspection point y and the inspection area 2 ′ is d _y , and the distance between the inspection point z and the inspection area 1 ′ is d _z ( (See FIG. 8). Then, d _u = 24, d _v = 10, d _w = 6, d _x = 23, d _y = 34, and d _z = 61. Since most things distance is smaller than a result d _u to d _z is d _w, adding a test point w to the group 2 '(Y-axis direction distance between the global net 9 and the inspection area is 0) .

  As described above, in the present embodiment, in order to increase the inspection efficiency, in the present invention, the inspection point w having the smallest sum of the X-axis direction distance and the Y-axis direction distance is selected and the inspection region 1 ′ to which the inspection point w belongs is selected. The inspection point w is added to the inspection region 2 ′ on the opposite side of the boundary of the inspection region.

  Therefore, in the present embodiment, finally, the inspection area 1 ′ includes the inspection points a to h and the inspection points u to w, and the inspection area 2 ′ includes the inspection points i to t and the inspection point w. To z are newly reconstructed.

  In this way, all the inspection points of the target printed wiring board can be formed without configuring all the inspection points of the global net 9 extending across the inspection region 1 ′ and the inspection region 2 ′ as a collective inspection procedure. A continuity test can be performed.

  Next, an inspection procedure, that is, an inspection plan (probe destination and inspection order) is created in each inspection region, and the inspection procedure in each inspection region is performed in an order that minimizes the movement time between the inspection regions. The whole inspection procedure for all inspection points of the target printed wiring board 10 is determined.

  Then, the inspection apparatus inspects the printed wiring board according to the inspection procedure determined in the above procedure for all inspection points of the target printed wiring board 10.

  In the above-described embodiment of the present invention, the inspection area is divided into a plurality of inspection areas so that all inspection points of the target printed wiring board are leveled as much as possible, and the calculation time of the inspection procedure between the inspection areas is calculated. Variation and the calculation time in each inspection region can be shortened, so that the time required to inspect the entire inspection point of the target printed wiring board can be shortened.

  The present invention can be used for an inspection method and an inspection apparatus for continuity inspection of a printed wiring board or the like.

1 Conduction circuit (net)
2 Conduction circuit (net)
3 Conduction circuit (net)
4 Conduction circuit (net)
5 Conduction circuit (large net)
6 Conduction circuit (net)
7 Conduction circuit (net)
8 Conduction circuit (net)
9 Conduction circuit (global network)
DESCRIPTION OF SYMBOLS 10 Printed wiring board 11 Probe 12 Probe support part 13 Movement mechanism part 14 Measurement part 15 Memory | storage part 16 Control part
a ~ q Inspection point

Claims (20)

Inspection that conducts continuity inspection for all inspection points included in the printed wiring board by moving the probe so as to cover a plurality of inspection points included in a circuit provided on the printed wiring board using a probe In the method
Dividing the printed wiring board into a plurality of inspection areas so as to equalize the number of all inspection points on the printed wiring board;
Determining a procedure for moving the probe to each inspection point within each of the plurality of inspection regions;
A step of determining an integrated movement procedure for all inspection points of the printed wiring board by combining the determined probe movement procedures for each of the plurality of regions. The step of dividing into a plurality of inspection regions, the step of identifying the respective positions of all inspection points on the printed wiring board based on coordinates having an X axis and a Y axis perpendicular to the X axis;
Setting the number of inspection points included in one inspection region;
A step of demarcating each inspection region so that one inspection region includes the set number of inspection points, and in each inspection region, a straight line in the Y-axis direction passing through the inspection point having the minimum coordinate value in the X-axis Y-axis direction straight line passing through the inspection point having the maximum coordinate value in the X-axis, X-axis direction straight line passing through the inspection point having the minimum coordinate value in the Y-axis direction, and inspection point having the maximum coordinate value in the Y-axis direction 2. The method of claim 1, further comprising: defining rectangular inspection regions each surrounded by a straight line in the X-axis direction passing through Changing the boundary of the target inspection region to include an out-of-region inspection point that constitutes a circuit extending beyond the boundary in the X-axis or Y-axis direction of the defined rectangular inspection region,
When the distance from the boundary to the out-of-area inspection point is such that the ratio of the width of the inspection area in the X-axis or Y-axis direction is smaller than a predetermined threshold α (0 <α <1) The inspection method according to claim 2, further comprising a step of changing a boundary of the inspection region so that the out-of-region inspection point is included in the inspection region to be the target. Changing the boundary of the target inspection region to include an out-of-region inspection point that constitutes a circuit extending beyond the boundary in the X-axis or Y-axis direction of the defined rectangular inspection region,
When the distance from the boundary to the out-of-area inspection point is larger than a predetermined threshold value α (0 <α <1) when the ratio of the width of the inspection area in the X-axis or Y-axis direction is larger than a predetermined threshold value 3. The method according to claim 2, further comprising a step of changing a boundary of the inspection region so as to constitute an inspection region in which all inspection regions including the out-of-region inspection point of the circuit extending beyond the boundary are integrated. Inspection method.   The inspection method according to claim 4, wherein the circuit extending beyond the boundary is incorporated in an inspection region having the smallest number of inspection points.   When the inspection points of the circuit extending beyond the boundary belong to a plurality of inspection regions, adding all the inspection points of the circuit extending beyond the boundary to any of the inspection point regions belonging thereto The inspection method according to claim 3, wherein:   The inspection point of the circuit extending beyond the boundary is defined as a single inspection region when the inspection point of the circuit extending beyond the boundary belongs to a plurality of inspection regions. Inspection method.   The inspection method according to claim 3, wherein at least one inspection point of the circuit extending beyond the boundary is added to an inspection region other than the inspection region to which the inspection point belongs.   The inspection point added to the inspection area other than the inspection area to which one inspection point belongs is the inspection point whose distance from the boundary between all the inspection areas of the plurality of inspection areas is the smallest in the X direction and the Y direction. The inspection method according to claim 8.   10. The inspection method according to claim 1, wherein the number of inspection areas is set so as to minimize the total value of the movement distances of the probes that move to inspect all inspection points. In an inspection device that performs continuity inspection of a printed wiring board using a probe,
Means for setting a plurality of inspection points on the printed wiring board;
Means for dividing all the inspection points on the printed wiring board into a plurality of inspection areas so as to equalize the number of all inspection points on the printed wiring board;
Means for defining each inspection area so that the number of inspection points included in each of the inspection areas does not exceed a preset numerical value;
Means for determining an inspection procedure including movement and inspection of the region to a specific inspection point for each inspection region;
A printed wiring board inspection apparatus including means for determining a comprehensive inspection procedure for all inspection points of a printed wiring board by combining the plurality of determined inspection procedures into one inspection procedure. Means for dividing the plurality of inspection areas, the means for specifying the positions of all inspection points on the printed wiring board based on coordinates having an X axis and a Y axis perpendicular to the X axis;
Means for setting the number of inspection points included in one inspection region;
A means for demarcating each inspection area so that one inspection area includes the set number of inspection points, and in each inspection area, a straight line in the Y-axis direction passing through the inspection point having the minimum coordinate value in the X-axis. Y-axis direction straight line passing through the inspection point having the maximum coordinate value in the X-axis, X-axis direction straight line passing through the inspection point having the minimum coordinate value in the Y-axis direction, and inspection point having the maximum coordinate value in the Y-axis direction The inspection apparatus according to claim 11, further comprising means for defining rectangular inspection areas each surrounded by a straight line in the X-axis direction passing through the X-axis direction. Means for changing a boundary of a target inspection region so as to include an out-of-region inspection point that constitutes a circuit extending beyond a boundary in the X-axis or Y-axis direction of the defined rectangular inspection region;
When the distance from the boundary to the out-of-area inspection point is such that the ratio of the width of the inspection area in the X-axis or Y-axis direction is smaller than a predetermined threshold α (0 <α <1) The inspection apparatus according to claim 12, further comprising means for changing a boundary of the inspection area so that the out-of-area inspection point is included in the inspection area as the object. Changing the boundary of the target inspection region to include an out-of-region inspection point that constitutes a circuit extending beyond the boundary in the X-axis or Y-axis direction of the defined rectangular inspection region,
When the distance from the boundary to the out-of-area inspection point is larger than a predetermined threshold value α (0 <α <1) when the ratio of the width of the inspection area in the X-axis or Y-axis direction is larger than a predetermined threshold value 13. The apparatus according to claim 12, further comprising means for changing a boundary of the inspection area so as to constitute an inspection area in which all inspection areas including the out-of-area inspection point of the circuit extending beyond the boundary are integrated. Inspection equipment.   The inspection apparatus according to claim 14, wherein the circuit extending beyond the boundary is incorporated in an inspection region having the smallest number of inspection points.   When the inspection points of the circuit extending beyond the boundary belong to a plurality of inspection regions, adding all the inspection points of the circuit extending beyond the boundary to any of the inspection point regions belonging thereto The inspection apparatus according to claim 13, wherein the inspection apparatus is characterized in that   The inspection point of the circuit extending beyond the boundary is defined as a single inspection region when the inspection point of the circuit extending beyond the boundary belongs to a plurality of inspection regions. Inspection device.   18. The inspection apparatus according to claim 13, wherein at least one inspection point of the circuit extending beyond the boundary is added to an inspection region other than the inspection region to which the inspection point belongs.   The inspection point added to the inspection area other than the inspection area to which one inspection point belongs is the inspection point whose distance from the boundary between all the inspection areas of the plurality of inspection areas is the smallest in the X direction and the Y direction. The inspection apparatus according to claim 18.   20. The inspection apparatus according to claim 11, wherein the number of inspection areas is set so as to minimize the total value of the movement distances of the probes that move to inspect all inspection points.

Images