JP2005072227A - Multilayer circuit board and method for inspecting positional deviation between layers thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the subject that a positional deviation with large error is detected by comparing a periphery with a center in a monitoring range from an aberration, since the monitoring range of a transmitted image by an X-ray is broadened remarkably when a multilayer circuit board is laminated, and the transmitted image is condensed via a lens system and monitored. <P>SOLUTION: For an alignment accuracy a and a first inspecting mark 14 of a diameter L, there are taken as a monitoring range a second inspecting mark 22 of a diameter (2a+L) and a third inspecting mark 32 of a diameter (4a+L), and a diameter (2Na+L) if the multilayer circuit board is laminated to an N layer. Thus, the range includes all the inspecting marks to the N layer. Such an inspecting mark is narrower in the monitoring range than the conventional inspecting mark, and an accurate alignment can be performed with high accuracy and with small aberration. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a multilayer circuit board and an interlayer misalignment inspection method for multilayer circuit boards, and more particularly to an inspection mark produced on a circuit board.

  Conventionally, the interlayer misalignment of a multilayer circuit board constructed by laminating circuit boards is made by transmitting X-rays to inspection marks provided on each layer of the circuit board, monitoring the transmission image with an X-ray camera, and inspecting each layer. The mark position was detected. At this time, if the inspection marks of each layer overlap, it becomes impossible to discriminate the inspection mark for each layer, so that the inspection marks for each layer are shifted in position (see, for example, Patent Document 1).

  FIG. 7 is a diagram for explaining a conventional method of manufacturing so that inspection marks for each layer do not overlap each other, in which three circuit boards are laminated. In addition, the second layer and the third layer inspection mark are produced in the right direction on the paper surface. The inspection mark has the same shape for each layer, and a circular mark is often used for the shape. The mark diameter is L, and alignment accuracy determined by an alignment apparatus such as an exposure apparatus (for example, the manufacturing range of the first layer inspection mark and the maximum deviation amount when the second layer is aligned with the first layer) ) Is a. As shown in FIG. 7A, the first inspection mark 52 and the first inspection mark are produced even if the inspection mark production position of the first layer is produced at the position of the first inspection mark 50 from the inspection mark production accuracy. The mark 54, the first inspection mark 56, and the like may be manufactured. Accordingly, at this time, the range in which the X-ray transmission image is monitored is a range in which the first inspection mark can be produced. Therefore, the one-layer monitor range 55 is within a circle having a diameter (2a + L).

  FIG. 7B is a diagram showing the production position of the second layer inspection mark. The first inspection mark 54 is produced by shifting to the rightmost position on the paper from the position where the first inspection mark is to be produced, and the second inspection mark is further displaced to the rightmost on the paper. This is a case where the inspection mark 64 is prepared. The center position of the second inspection mark needs to be separated from the center position of the first inspection mark 54 by (a + L) so as not to overlap with the inspection mark of the first layer under the alignment accuracy a. The second inspection mark 60 produced at this position is the second inspection mark 60. However, when the alignment accuracy a is taken into consideration, the first inspection mark 54 is produced when it is produced farthest from the first layer. The second inspection mark 64 is (2a + L) away from the center position. At this time, the X-ray transmission image monitoring range is required from the end of the first inspection mark 52 to the end of the second inspection mark 64, and the two-layer monitoring range 65 is within a circle having a diameter (4a + 2L). Become.

  FIG. 7C is a diagram showing the position where the third-layer inspection mark is produced. The first and second inspection marks 54 and 2 are the positions where the first and second-layer inspection marks are shifted to the rightmost on the paper surface. This is a case where the inspection mark 64 is manufactured, and the third inspection mark 74 is manufactured at a position where the inspection mark of the third layer is shifted to the rightmost on the paper surface. The center position of the inspection mark of the third layer needs to be separated from the center position of the inspection mark of the second layer by (a + L) as in the relationship of the position of the inspection mark of the second layer with respect to the inspection mark of the first layer. The third inspection mark produced at this position is the third inspection mark 70. However, the second inspection mark is formed when it is produced farthest from the second inspection mark from the alignment accuracy a. The third inspection mark 74 is (2a + L) away from the center position of 64. At this time, an X-ray transmission image monitoring range is required from the end of the first inspection mark 52 to the end of the third inspection mark 74, and the three-layer monitoring range 75 is within a circle having a diameter (6a + 3L). It becomes.

As described above, when the layers to be aligned are stacked in a state where they are most shifted in one direction, the monitor range diameter increases by (2a + L) for each layer. Therefore, in general, the monitor range when N layers are stacked is within a circle of (2Na + NL).
JP 61-51510 A (page 1-3, FIG. 3)

  However, in the multilayer circuit board having such an inspection mark and the method of inspecting the interlayer misalignment of the multilayer circuit board, the monitor range of the transmitted image by X-rays is dramatically widened as the number of layers increases. Since the transmitted image is collected and monitored by the lens system, the peripheral portion of the monitor range has a large amount of misalignment compared to the central portion due to aberrations (spherical aberration, coma, astigmatism, distortion). There was a problem of detecting.

  The present invention has been made in view of the above problems, and provides a multilayer circuit board and a method for inspecting misalignment of a multilayer circuit board, in which the misregistration of the multilayer circuit board is detected with high accuracy without a large error. For the purpose.

  The multilayer circuit board according to the present invention includes a first circuit board to be aligned with an inspection mark, and an alignment accuracy that is an amount of misalignment that occurs when aligning with the size of the inspection mark on the first circuit board. And a second circuit board that is aligned and stacked on the first circuit board, and a circuit that is aligned when the circuit board is aligned and stacked And a circuit board provided with an inspection mark obtained by adding the alignment amount to the size of the inspection mark on the board.

  By using a multilayer circuit board having such an inspection mark, the inspection mark of the circuit board to be aligned necessarily includes the inspection mark of the circuit board to be aligned. The range to be monitored may be an inspection mark area including all inspection marks. Therefore, the area for monitoring the transmission image may be small, and it is not necessary to monitor the area with large aberration. As a result, it is possible to detect the interlayer displacement of the multilayer circuit board with high accuracy.

  Also, the shape of the inspection mark of the multilayer circuit board of the present invention is circular, the diameter of the inspection mark of the first circuit board is L, the alignment accuracy is a, and the number of circuit boards to be stacked is N. Alignment amount to be

Use a smaller configuration.

  By setting the amount of alignment to determine the shape and size of the inspection mark, the range for monitoring the X-ray transmission image is surely narrow compared to the case where the inspection mark is shifted and manufactured. Become.

  In the multilayer circuit board interlayer misalignment inspection method of the present invention, the first circuit board to be aligned has a first inspection mark, and the second circuit board is aligned and stacked on the first circuit board. Includes a second inspection mark, and the size of the second inspection mark is adjusted to the size of the first inspection mark at least twice the alignment accuracy, which is the amount of misalignment that occurs during alignment. The center position of the second inspection mark overlaps the center position of the first inspection mark when the second circuit board is aligned with the first circuit board, and the circuit board When the circuit board is aligned and laminated, an inspection mark obtained by adding the above-mentioned alignment amount to the size of the inspection mark of the circuit board to be aligned is produced on the circuit board, and the center position of the inspection mark is the first inspection mark. It overlaps with the center position of The X-ray light quantity measuring step for irradiating the inspection mark production range with X-rays and measuring the transmitted light quantity, and the transmitted light quantity classification step for classifying the transmitted light quantity by the transmitted light quantity level divided into (number of circuit boards to be stacked + 1) Calculated in the specific position coordinate calculation step and the specific position coordinate calculation step for obtaining a specific position coordinate of an area that is equal to or higher than each transmitted light amount level by excluding the transmitted light amount level having the largest transmitted light amount level from among the transmitted light amount levels. And an interlayer misregistration amount calculating step for calculating a misregistration amount between layers of the circuit boards stacked by obtaining a distance between specific position coordinates of each region.

  In such a multilayer circuit board interlayer misalignment inspection method, the inspection mark of the circuit board to be aligned is always included in the inspection mark in consideration of the alignment accuracy of the circuit board to be aligned. Then, by forming the center positions of the inspection marks so as to overlap each other, the range to be monitored can be further reduced. Furthermore, since the amount of transmitted X-rays decreases in the portion where the inspection marks overlap, the inspection mark position of each layer can be clearly calculated according to the amount of transmitted X-rays. Then, the specific position of the inspection mark of each layer is determined, its position coordinate is obtained, and the distance between the position coordinates of each layer is obtained, whereby the positional deviation amount of each layer can be easily obtained.

  In addition, the inspection mark preparation range of the multilayer circuit board interlayer misalignment inspection method of the present invention is such that when an N-layer circuit board is stacked, the first inspection mark preparation range is a circle having a diameter (2Na + L). The shape (where N is an integer of 2 or more, a is the alignment accuracy, and L is the diameter of the first inspection mark). By adopting such a method, the largest inspection mark has a minimum circular shape including all the inspection marks in each layer in consideration of alignment accuracy, and the largest inspection mark is always a circle having a diameter (2Na + L). Get inside.

  In addition, the specific position coordinate in the multilayer circuit board interlayer displacement inspection method of the present invention is the center position coordinate of the region. The specific position coordinates may be anywhere as long as they have the same amount of transmitted X-ray light. However, if the area is circular and its center position coordinates, if the longest coordinate interval of the area is obtained, its center can be easily obtained. The position coordinates are determined.

  The multilayer circuit board according to the present invention includes a first circuit board which is provided with an inspection mark and is aligned, and a position at least twice as large as the alignment accuracy, which is the amount of misalignment that occurs when alignment is performed with the size of the inspection mark. The size of the second circuit board that is aligned with the first circuit board and stacked, and the inspection mark of the circuit board to be aligned when the circuit board is aligned and stacked And a circuit board provided with an inspection mark obtained by adding the alignment amount.

  By using a multilayer circuit board having such an inspection mark, the inspection mark of the circuit board to be aligned necessarily includes the inspection mark of the circuit board to be aligned. The range to be monitored may be narrower than that in the prior art. For this reason, it is not necessary to monitor a transmission image in a region with a large aberration, and the interlayer displacement detection of the multilayer circuit board can be performed with high accuracy.

  First, a multilayer circuit board according to an embodiment of the present invention will be described in detail with reference to the drawings.

(Embodiment)
FIG. 1 is a cross-sectional view of a multilayer circuit board according to an embodiment of the present invention. As an example, a state in which three layers of circuit boards are laminated is shown. The first circuit board 100 and the second circuit board 200 are bonded with an adhesive layer 410, and the second circuit board 200 and the third circuit board 300 are bonded with an adhesive layer 420 to form a multilayer circuit board. In addition, an inspection mark preparation region is provided at each end of the circuit board of each layer, the first inspection mark preparation region 110 is provided in the first circuit board 100, and the second inspection mark preparation is provided in the second circuit board 200. The area 210 and the third circuit board 300 are provided with a third inspection mark production area 310. Here, the inspection mark is made of a metal foil such as copper.

  Here, the circuit board is a resin substrate such as a phenol resin, an epoxy resin, or a polyester resin, or an organic film substrate such as a polyimide film or a polyester film.

  2 to 4 are views showing a state of manufacturing the inspection mark of the multilayer circuit board according to the embodiment of the present invention, and show details of the inspection mark manufacturing region of each layer in FIG. FIG. 2 is a view showing an X-ray transmission image showing an overlapping state of the inspection marks of each layer when the three-layer circuit boards are laminated without misalignment. The first inspection mark 10 on the first-layer circuit board has a circular shape with a diameter L and is manufactured with a positioning accuracy a. Therefore, in the left-right direction in FIG. 2, it is produced at any position from the first inspection mark 12 to the first inspection mark 14, but is produced at the position of the first inspection mark 10 if there is no misalignment.

  Next, the second layer inspection mark is produced with the alignment accuracy a with respect to the first layer inspection mark. Therefore, if the diameter of the second layer inspection mark is (2a + L), the first layer inspection mark is necessarily included. The second inspection mark 20 in the second layer is produced with no positional deviation with respect to the first inspection mark 10. Further, since the inspection mark for the third layer is also produced with the alignment accuracy a with respect to the inspection mark for the second layer, if the diameter of the inspection mark for the third layer is (4a + L), the inspection mark for the second layer Must be included. The third inspection mark 30 in the third layer is also produced without positional deviation with respect to the second inspection mark 20. In this way, when the inspection mark is produced up to three layers without positional deviation, the monitoring range of the inspection mark overlapping state may be within a circle of diameter (4a + L).

  FIG. 3 shows a case where three layers of circuit boards are stacked in the same manner as in FIG. 2, and transmission of X-rays representing the overlapping state of inspection marks of the respective layers when the positional deviation of the three layers of circuit boards is greatest in one direction. It is a figure which shows an image. FIG. 3A is a diagram showing a state in which an inspection mark is formed on the first-layer circuit board. The target of the inspection mark on the first-layer circuit board is to be produced at the position of the first inspection mark 10, but the first inspection mark 12, the first inspection mark 14, and the first inspection mark are determined from the alignment accuracy a. An inspection mark 16 or the like is produced in a circle having a diameter (2a + L). Accordingly, the one-layer monitor range 15 is within a circle having a diameter (2a + L). FIG. 3A shows a case where the position is shifted to the rightmost position on the paper surface and the first inspection mark 14 is produced. Here, the first inspection mark 14 is a circular mark, and its diameter is L.

  Next, since the inspection mark for the second layer is produced with the alignment accuracy a with respect to the inspection mark for the first layer, the diameter of the inspection mark for the second layer must be set to include the inspection mark for the first layer. , (2a + L). FIG. 3B shows a case where the second inspection mark 22 is produced with the first inspection mark 14 being displaced to the rightmost on the paper surface. At this time, the range for monitoring the X-ray transmission image is necessary from the end of the first inspection mark 12 to the end of the second inspection mark 22, and the two-layer monitor range 25 is within a circle of diameter (4a + L). Become.

  Furthermore, since the inspection mark for the third layer is also produced with the alignment accuracy a with respect to the inspection mark for the second layer, if the diameter of the inspection mark for the third layer is (4a + L), the inspection mark for the second layer is Always include. FIG. 3C shows a case where the third inspection mark 32 is produced with the second inspection mark 22 being displaced to the rightmost on the paper surface. As described above, when the inspection mark is produced with the positional deviation in the most one direction up to three layers, the range of monitoring the overlapping state of the inspection mark is from the end of the first inspection mark 12 to the third inspection mark. Up to 32 ends are required, and the three-layer monitor range 35 is within a circle of diameter (6a + L).

  FIG. 4 is also a general example in which inspection marks overlap when a three-layer circuit board is laminated. The first inspection mark 18 has a diameter L and is manufactured within a single-layer monitor range 15 that is a manufacturing range of the first-layer inspection mark. Then, a second inspection mark 24 having a diameter (2a + L) including the first inspection mark 18 and a third inspection mark 34 having a diameter (4a + L) including the second inspection mark 24 are produced. The three inspection marks 34 are included in the three-layer monitor range 35 having a diameter (6a + L). Therefore, if the three-layer monitor range 35 is monitored, the overlap of inspection marks can be examined.

  As described above, in the embodiment of the present invention in which the inspection marks of each layer are included, each time the circuit board of one layer is increased, the range of monitoring the overlapping state of the inspection marks is at least twice the alignment accuracy a. What is necessary is just to enlarge 2a which is. Therefore, in the case of FIG. 3 where the monitoring range of the inspection mark is the largest, the monitoring range of the inspection mark overlapping state in the case of stacking N multilayer circuit boards is generally within a circle of diameter (2Na + L). On the other hand, in the method of manufacturing without overlapping the conventional inspection mark, it is within a circle of diameter (2Na + NL).

  Here, the method for producing the inspection mark of the multilayer circuit board according to the embodiment of the present invention obtains the condition that the monitor range becomes narrower than the conventional method. If the added value of the size of the inspection mark is increased to x times the alignment accuracy a, the method according to the embodiment of the present invention monitors the overlap state of the inspection mark when stacking N multilayer circuit boards. The range is within a circle of diameter (2Nax + L), and the monitor range that is expanded every time one layer is added is 2ax. When the range of 2ax is obtained from the condition that the difference between the monitor range (2Na + NL) of the conventional method and the method (2Nax + L) according to the embodiment of the present invention is larger than 0,

It becomes. As described above, the method according to the embodiment of the present invention has a narrower monitor range than the conventional method, so that it is not necessary to monitor a transmission image in a region with a large aberration, and the interlayer positional deviation detection of the multilayer circuit board can be performed with high accuracy. Yes.

  Next, an interlayer misalignment inspection method for multilayer circuit boards according to the present invention will be described.

  5 and 6 are diagrams showing an interlayer misalignment inspection method for a multilayer circuit board according to an embodiment of the present invention. FIG. 5 is a flowchart of the method, and FIG. 6 is a diagram for explaining calculation of specific position coordinates of an inspection mark. is there. FIG. 6 shows a case where three layers of circuit boards are laminated. The first inspection mark 18 includes the second inspection mark 24, and the third inspection mark 34 includes the second inspection mark 24. ing. In addition, a large number of grid points 80 and the like are formed with the vertical and horizontal lines orthogonal to each other. The positions of the grid points are measurement points, and the vertical and horizontal lines are shown for convenience of explanation and are actually formed on the circuit board. Is not to be done. Further, the center position of the second inspection mark 24 on the second circuit board and the center position of the third inspection mark 34 on the third circuit board at the center position of the first inspection mark 18 on the first circuit board. Are produced in such a way that they overlap.

  In the X-ray light quantity measurement step, X-rays are irradiated vertically to the multilayer circuit board in the above-described inspection mark production range of the multilayer circuit board, and the transmitted light quantity of X-rays to each lattice point is measured. Here, the production range of the inspection mark on the multilayer circuit board is as follows. When N is an integer of 2 or more, a is the alignment accuracy, and L is the first inspection mark diameter, This is within a circle having a diameter (2Na + L) with the production range of the inspection mark as one end. If this circle is monitored, all the inspection marks of the N layer are included. In the case of FIG. 6, the amount of transmitted X-ray light at all lattice points in the three-layer monitor range 35 may be measured.

  As the number of inspection marks overlaps, the amount of transmitted X-rays decreases. That is, according to Lambert's law, the amount of transmitted light attenuates as the medium through which X-rays pass becomes thicker. Therefore, the number of transmitted light levels when X-rays are transmitted through the inspection mark production range is (number of circuit boards to be stacked + 1). In FIG. 6, the transmitted light amount level is the largest at the lattice point 82 where the inspection mark is not produced, and is “0”, for example, “0” at the lattice point 80 where only one layer of the inspection mark is produced. “1” is “2” at the lattice point 84 where the two-layer inspection marks overlap, and “3” at the lattice point 86 where the three-layer inspection marks overlap. Thus, in the transmitted light amount classification step, the corresponding transmitted light amount level is calculated from the measured X-ray transmitted light amount for each lattice point.

  When the transmitted light amount level of each lattice point is determined, the transmitted light amount level “0” having the largest X-ray transmitted light amount is excluded in order to exclude the region where the inspection mark is not formed. When M is an integer of 2 or more, the Mth inspection mark includes the (M-1) th inspection mark from the first inspection mark. Include grid points with light level or higher. In FIG. 6, in the third inspection mark 34, the lattice point 80 has the transmitted light amount level “1”, but the transmitted light amount level “2” of the lattice point 84 in the second inspection mark 24 indicates the first inspection. The transmitted light amount level “3” of the lattice point 86 in the mark 18 is included. Therefore, as the center coordinates of the region of the third inspection mark 34, the lattice point with the transmitted light amount level “1”, “2”, and “3” is obtained, and the coordinates of the center lattice point 80C are calculated. Similarly, the center coordinates of the area of the second inspection mark 24 are obtained as lattice points with the transmitted light level “2” and “3”, and the coordinates of the lattice point 84C at the center are determined as the area of the first inspection mark 18. As the center coordinates, the coordinates of the lattice point 86C at the center where the transmitted light amount level is “3” are calculated. In this way, in the specific position coordinate calculation step, center coordinates that are equal to or higher than the respective transmitted light amount levels are calculated and used as the specific position coordinates of the respective inspection marks.

  In the interlayer misregistration amount calculating step, the distance between the calculated center coordinates of each region is obtained. In FIG. 6, the distance between the coordinates of the center lattice point 84C from the center lattice point 84C is obtained, and the amount of displacement of the second layer circuit board relative to the first layer circuit board is calculated. In addition, the distance between the coordinates of the center lattice point 84C from the center lattice point 80C is obtained, and the positional deviation amount of the third layer circuit board with respect to the second layer circuit board is calculated.

  By calculating the amount of misalignment between the layers by the above method, the range for monitoring the inspection mark becomes narrower than in the prior art, and high-accuracy alignment can be realized.

  In the embodiment of the present invention, the shape of the inspection mark has been described as a circle, but it may be a square or a regular polygon, and is not limited to a circle.

  Further, in the embodiment of the present invention, the inspection mark of the circuit board to be aligned is necessarily included in the inspection mark of the circuit board to be aligned. It may be included in the inspection mark of the circuit board to be aligned.

  In the embodiment of the present invention, the lattice points 80C, 84C, and 86C at the center of each inspection mark region are used as the specific position coordinates. However, lattice points 80E, 84E, and 86E at specific ends may be used as the center. It is not limited to coordinates.

  Moreover, since it is necessary to measure the transmitted light amount of X-rays in the present invention, the transmitted light amount of different numbers of laminated circuit boards is set in a range that can be determined.

  The multilayer circuit board and the method for inspecting the interlayer misalignment of the multilayer circuit board according to the present invention eliminates the need to monitor a transmission image in a region having a large aberration, and can detect the interlayer misalignment of the multilayer circuit board with high accuracy. Therefore, it is useful as a multilayer circuit board and a method for inspecting interlayer misalignment between multilayer circuit boards.

Sectional drawing of the multilayer circuit board of embodiment of this invention of this invention The figure which shows the state without the position shift of the inspection mark of the multilayer circuit board of embodiment of this invention. The figure which shows the state with the largest position shift of the inspection mark of the multilayer circuit board of embodiment of this invention. The figure which shows the general state of position shift of the inspection mark of the multilayer circuit board of embodiment of this invention The flowchart which shows the interlayer position shift inspection method of the multilayer circuit board of embodiment of this invention The figure explaining the specific position coordinate calculation of the inspection mark of the interlayer position shift of the multilayer circuit board of embodiment of this invention The figure explaining the method of producing so that the inspection mark for every conventional layer may not overlap

Explanation of symbols

10, 12, 14, 16, 18, 50, 52, 54, 56 1st inspection mark 15, 55 1 layer monitor range 20, 22, 24, 60, 64 2nd inspection mark 25, 65 2 layer monitor range 30, 32, 34, 70, 74 Third inspection mark 35, 75 Three-layer monitor range 80, 82, 84, 86 Grid point 80C, 84C, 86C Center grid point 80E, 84E, 86E End grid point 100 First circuit board 110 First inspection mark production region 200 Second circuit board 210 Second inspection mark production region 300 Third circuit board 310 Third inspection mark production region 410, 420 Adhesive layer

Claims (5)

A first circuit board that is aligned with an inspection mark;
An inspection mark obtained by adding an alignment amount that is at least twice the alignment accuracy, which is an amount of misalignment that occurs during alignment, to the size of the inspection mark on the first circuit board; A second circuit board aligned and laminated to
And a circuit board having a test mark obtained by adding the alignment amount to the size of the test mark of the circuit board to be aligned when the circuit boards are aligned and stacked. The inspection mark has a circular shape, where the inspection mark diameter of the first circuit board is L, the alignment accuracy is a, and the number of circuit boards to be stacked is N, the alignment amount is

The multilayer circuit board of claim 1 that is smaller. The first circuit board to be aligned has a first inspection mark, the second circuit board to be aligned and stacked on the first circuit board has a second inspection mark, and the second circuit board has the second inspection mark. The size of the inspection mark is the size of the first inspection mark plus an alignment amount that is at least twice the alignment accuracy, which is the amount of misalignment that occurs during alignment. When the second circuit board is aligned with the circuit board, the center position of the second inspection mark overlaps the center position of the first inspection mark, and the circuit board is aligned and stacked. An inspection mark obtained by adding the alignment amount to the size of the inspection mark of the circuit board to be aligned is prepared on the circuit board, and the center position of the inspection mark is overlapped with the center position of the first inspection mark. , The inspection And X-ray light amount measuring step of measuring the amount of transmitted light is irradiated with X-rays to produce a range of marks,
A transmitted light amount classification step for classifying the transmitted light amount by a transmitted light level divided into (number of circuit boards to be stacked + 1);
A specific position coordinate calculation step for obtaining a specific position coordinate of an area that is equal to or higher than each transmitted light amount level by excluding the transmitted light amount level having the largest transmitted light amount level from among the transmitted light amount levels;
A multilayer misregistration amount calculating step of calculating a misalignment amount between the layers of the circuit boards stacked by obtaining a distance between the specific position coordinates of each of the regions calculated in the specific position coordinate calculating step. Circuit board interlayer displacement inspection method. The manufacturing range of the inspection mark is a circular shape having a diameter (2Na + L) with the manufacturing range of the first inspection mark as one end when an N-layer circuit board is laminated (where N is an integer of 2 or more, a is the above 4. The method for inspecting an interlayer misalignment of a multilayer circuit board according to claim 3, wherein the alignment accuracy, L is the diameter of the first inspection mark). 4. The method for inspecting an interlayer misalignment of a multilayer circuit board according to claim 3, wherein the specific position coordinates are center position coordinates of the area.

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