JP2994963B2 - Multilayer printed wiring board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer printed wiring board, and more particularly to a multilayer printed wiring board having a fiducial mark for forming a through hole for positioning the multilayer printed wiring board in an inner laminated board.

[0002]

2. Description of the Related Art A conventional multilayer printed wiring board will be described with reference to, for example, a four-layer printed wiring board.

As shown in FIG. 6, a conventional four-layer printed wiring board is provided with an inner layer laminate 2 having an inner layer conductor pattern 1 formed on the front and back surfaces of a base material, and sandwiching the laminate 2 therebetween. And an outer conductor pattern 4 formed on the outer surface of the insulating resin layer 3. The connection between the inner conductor pattern 1 and the outer conductor pattern 4 is connected by through-hole plating 9. Structure.

The laminate 2 is a copper-clad laminate in which a copper foil is adhered to a substrate made of, for example, an epoxy resin material or the like of a glass cloth, and the copper foil is subjected to pattern etching to form an inner conductor pattern. 1 and a reference mark 5 are formed, for example, in a structure as shown in FIG. In the figure, reference numeral 6 denotes an inner layer land. The inner layer land 6 has a diameter larger than the diameter of a through hole hole described later, and is used to conduct the inner layer conductor pattern 1 and the outer layer conductor pattern 4 by through hole plating. Connection part.

[0005] The glass cloth base epoxy resin material comprises a glass cloth base material impregnated with an epoxy resin and cured.

The fiducial marks 5 are provided at both ends of the laminated board 2 and, before forming a through-hole for through-hole plating, an automatic centripetal punching machine (hereinafter, referred to as a hole punching machine) for a multilayer printed wiring board. This is a mark for forming a fixing reference hole for fixing to an "NC drilling machine". The details will be described later.

The insulating resin layer 3 is made of a prepreg made of a sheet-like material obtained by impregnating a base material such as a glass cloth with a resin such as epoxy, polyimide, fluorine or the like and semi-curing the prepreg. Is melted and completely solidified by the thermocompression bonding using a laminating press, thereby forming the insulating resin layer 3.

The outer conductor pattern 4 is made of, for example, copper foil.

The conventional laminating process of the four-layer printed wiring board will be described below.

The four-layer printed wiring board is manufactured by the laminating process shown in FIGS. 6 to 11, and more specifically, the copper foils on the front and back surfaces of the inner layer laminated board 2 are pattern-etched to form the inner layer conductor pattern 1 and the reference. Forming a mark 5 (FIG. 7);
Step of laminating a copper foil layer 4 ′ on both sides of the pattern-etched laminate 2 via a prepreg and thermocompression bonding (FIG. 8)
Forming a reference hole 7 consisting of a through-hole at the position of the reference mark 5 on the wiring board (FIG. 9); and a through-hole 8 for connecting the inner conductor pattern 1 to the copper foil layer 4 '. (FIG. 10), a step of applying copper plating 9 to the entire wiring board (FIG. 11), and forming an outer layer conductor pattern 4 by pattern etching the outer copper foil layer 4 ′ and the copper plating 9. Through the steps (FIG. 6), a four-layer printed wiring board is formed.

The reference hole 7 is provided at the center of each of the reference marks 5 by using an NC drilling machine 11 equipped with an X-ray camera for seeing through the reference mark 5 on the wiring board completed up to the thermocompression bonding step. It is.

As shown in FIG. 10, the through-hole 8 is formed by setting a pin 10 in the previously formed reference hole 7 and mounting the pin 10 on an NC drilling machine 11 to perform NC drilling. In the drawing, reference numeral 12 denotes a discarding plate to be inserted between the wiring board and the NC drilling machine 11, and reference numeral 13 denotes a backing plate applied on the wiring board.

The NC drilling machine 11 comprises a mounting portion for mounting a wiring board, and a drill portion for forming a through-hole 8 facing the mounting portion. Is a hole for inserting and fixing one of the pins 10 and a pin 10
And a groove for fixing a direction perpendicular to the direction in which the two pins 10 are juxtaposed, and the drill portion is fixed at a predetermined position with reference to a hole for inserting and fixing the one pin 10. Multiple drills are arranged. The predetermined position is a position corresponding to the inner layer land 6 when the wiring board is mounted on the NC drilling machine 11.

The positioning between the wiring board and the NC drilling machine 11 uses the reference hole 7. As shown in FIG.
One of the reference holes 7 is fixed by inserting and fixing one end of the pin 10 into a hole provided in a mounting portion of the NC drilling machine 11 through which a pin 10 is inserted.
0 is inserted, and the pin 10 is inserted into a groove indicating the direction of the coordinate axis provided on the mounting portion of the NC drilling machine 11 in order to match the directions of the respective coordinate axes of the NC drilling machine 11 and the wiring board.
Is fixed by fixing.

The through hole 8 is formed by a plurality of drills fixed at predetermined positions with reference to the hole into which the one pin 10 is inserted and fixed.

The connection between the inner-layer conductor pattern 1 and the outer-layer conductor pattern 4 is performed because the inner-layer conductor pattern 1 has an inner-layer land 6 having a diameter larger than the diameter of the through-hole hole 8 at a portion where the through-hole hole 8 penetrates. Then, the inner layer land 6 is exposed on the hole wall of the through-hole hole 8 and copper plating 9 is performed on the through-hole hole 8 so that the inner layer conductor pattern 1 and the outer layer conductor pattern 4 conduct. For this reason, it is important that the through-hole 8 is accurately formed in the area of the inner land 6.

However, at the time of thermocompression bonding in the laminating step,
The resin impregnated in the prepreg glass cloth or the like once melts and generates a stress that tends to shrink when the resin is thermally cured, and this stress also causes the dimensions of the inner layer laminate 2 to shrink and change.

For this reason, the inner conductor pattern 1 which has been dimensionally corrected in advance to allow the dimensional change of the inner conductor pattern 1 before and after lamination so that the dimension of the inner conductor pattern 1 after lamination matches the hole position dimension of the NC drilling. Must be formed.

For example, when the material of the laminated plate 2 is a glass cloth base epoxy resin material, general processing conditions are as follows.
Lamination temperature 170 ° C, time 60 minutes, pressure 40kgf
/ Cm ² , and the dimensional change at this time is 0.02 to
Since it shrinks by 0.04%, it is necessary to form the inner conductor pattern 1 0.03% larger than the dimension after lamination, taking the center.

As another conventional example, as shown in FIG.
A rigid flex wiring board having a partially flexible region, which is a kind of a multilayer printed wiring board, will be described below. Only the differences between the conventional example and the above conventional example will be described.

The rigid-flex wiring board is obtained by using a polyimide film material for a flexible wiring board as a material of the laminated board 2 in place of the above-mentioned glass cloth base epoxy resin material. A cover lay film 14 having an adhesive applied to one side is laminated on the front and back surfaces of the laminate 2, and a substrate made of a glass substrate epoxy resin material is used instead of the above-described conventional copper foil layer 4 '. And an outer layer laminate 15 having a copper foil attached thereto.

The manufacturing process and processing conditions at this time are almost the same, but after the inner layer pattern etching process (FIG. 14) in the manufacturing process, the process of laminating the cover lay film 14 coated with an adhesive on one surface to the polyimide film (FIG. 15) is added. The laminating step is thermocompression bonding, and the laminating temperature is 150 to 1 depending on the type of the adhesive.
80 ° C., time 15-60 minutes, pressure 40 kgf / cm ²
This is the degree of processing conditions. FIG. 16 shows a cross-sectional structure in which a part of the coverlay film 14 is exposed in order to form a flexible portion in the structure after lamination.

As described above, when a polyimide film material for a flexible wiring board is used as the material of the laminate 2, the thermocompression bonding in the laminating step is performed by the coverlay film 14.
And the insulating resin layer (prepreg) 3 twice, and the dimensional change rate due to lamination is about 0.02-0.
Shrink 1%. Therefore, in this conventional example, it is generally necessary to form the inner conductor pattern 1 0.06% larger at the center.

The reason that the polyimide film has a higher rate of change than the glass cloth-based epoxy resin material is that the polyimide film does not contain a glass cloth and the resin is soft.
This is because the dimensional change of the inner layer due to the stress of melting and thermosetting is larger than that of the glass cloth base epoxy resin material, and the difference is also caused by the difference in the area and shape of the copper foil of the inner layer conductor pattern 1. For example, when a large amount of copper foil remains, the amount of dimensional change with respect to stress during lamination becomes smaller. Further, when the signal lines of the inner conductor pattern 1 are arranged in parallel, the dimensional change in the vertical direction is larger than the dimensional change in the parallel direction.

This is because, since the polyimide film is made of a mere soft resin, the shrinkage is particularly high in the portion where the conductor pattern is not formed.

[0026]

However, even when the inner conductor pattern 1 is formed large in advance in accordance with the dimensional change rate, the dimensions of the inner conductor pattern 1 formed before lamination are inappropriate. In addition, when the dimensional change at the time of lamination has a large variation, there is a problem that a predetermined size cannot be obtained after lamination.

In particular, when a polyimide film material for a flexible wiring board is used for the inner laminate 2, the glass cloth is not contained therein and the resin is soft. In addition, the amount of dimensional change of the inner layer due to the stress of thermosetting is large, and the difference is large due to the difference in the area and shape of the copper foil of the inner layer conductor pattern 1. Therefore, it is difficult to accurately predict the dimensional change. .

In addition, the difference between the diameter of the inner layer land 6 and the diameter of the through hole 8 tends to be small due to the increase in the density of the wiring, which also poses a problem.

Hereinafter, these problems will be specifically described.

As an example of the above-mentioned conventional example, for example, the drill diameter of the through hole 8 is 0.35 mm, and the diameter of the inner land 6 connected thereto is 0.75 mm. For this reason, there is only a margin of 0.2 mm per side, and the tolerance of those positional deviations is small. According to the tolerance, the through hole 8 can be formed in the inner land 6 if the finish after lamination is within 500 ± 0.2 mm.

However, in general, the displacement between the reference mark 5 and the reference hole 7, the accuracy of mounting the wiring board on the NC drilling machine 11, the positional accuracy of the NC drilling, and the positional deviation in machining such as bending of the drill. All occur ± 0.1 mm in total. Considering this, 500 ± 0.1 mm (± 0.02
%), Only through-holes 8 can be formed in the inner layer land 6 after the lamination.

Here, when the material of the laminated plate 2 is a glass cloth base epoxy resin material, if the lamination is performed in anticipation of the shrinkage change rate, the variation after lamination is ± 0.01%.
To finish to 0 ± 0.05mm, still ± 0.05mm
The diameter of the through hole 8 and the inner layer land 6
There is no problem with the size of the diameter. However, when the difference between the diameter of the inner land 6 and the diameter of the through hole 8 is 0.1 mm or less, or the distance between the reference marks is 1000 mm or more,
The through hole 8 is formed at a position shifted from the area of the inner layer land 6.

In the case of a polyimide film having a large dimensional change rate, lamination (0.
(Enlarged by 0.6%), the variation after lamination is ± 0.
When the rate of change is large, the through hole 8 is formed at a position deviated from the range of the inner layer land 6. In this case, the through-hole holes 8
It was very difficult to drill. As described above, the drilling position of the NC drilling machine 11 (through hole hole 8
If the position of the inner layer land 6 of the fixed wiring board does not match the position of the fixed inner layer land 6 and the through hole 8 is opened at a position shifted from the area of the inner layer land 6 to be conducted, FIG.
As shown in FIG. 7, the conduction between the copper plating 9 of the through hole 8 and the inner layer land 6 becomes insufficient, and as shown in FIG. 19 and 20 show the state of misalignment of the multilayer printed wiring board. FIG. 19 is a perspective view, and FIG.
0 is a sectional view.

Further, in the conventional method of forming the through hole 8, the position of the drilling of the NC drilling machine 11 and the reference mark 5
Is provided at the end and uses one of the standards,
The tolerance is further narrowed. With this, it is possible to make the ends bear the displacement if the reference is the center.However, if the one end is used as the reference, only the other end has to bear the displacement. The permissible amount of deviation when the reference is set is １ ／ of that when the center is set as the reference.
The above description is based on one end,
It is possible to double the allowance simply by using it as the center.

Therefore, the drilling position of the NC drilling machine 11 and the center of the inner conductor pattern 1 coincide with each other,
This tolerance can be increased by fixing the wiring board so that the difference between the dimensions can be evenly distributed. It is intended to provide a wiring board.

[0036]

According to the present invention, there is provided a multilayer printed wiring board comprising a laminate having a conductor pattern formed on the front and back surfaces of a base material having a predetermined thermal shrinkage, and sandwiching the laminate. In a multilayer printed wiring board comprising: an insulating resin layer formed by thermocompression bonding a substrate impregnated with a thermosetting resin; and an outer conductor pattern formed on an outer surface of the insulating resin layer. At both ends of the same surface of the plate, there are provided reference marks which are provided corresponding to the shrinkage ratio of the laminated plate and serve as a reference for forming a plurality of sets of through-hole holes in which different reference marks are provided,
The reference marks are arranged at positions where lines connecting the reference marks of each set are parallel to each other and the difference between the other reference marks is equally distributed on both sides with respect to the other reference marks. It is a feature.

The inner conductor pattern has a plurality of inner lands provided with through-holes for connection with the outer conductor pattern. The difference is that the difference is provided within a range smaller than a value obtained by subtracting the through hole hole diameter and the permissible hole position shift amount from the inner layer land diameter.

Further, the plurality of sets of reference marks have a different shape for each set.

[0039]

According to the above construction, the multilayer printed wiring board according to the present invention is provided on both ends of the same surface of the laminated board in accordance with the shrinkage of the laminated board, and a plurality of printed wiring boards having different reference marks are provided. It has a reference mark as a reference for forming a set of through-hole holes , and the reference mark is such that lines connecting the reference marks of each set are parallel to each other, and a difference between the other reference marks is set to another reference mark. On the other hand, even if the laminate is shrunk by thermocompression bonding of a base material impregnated with a thermosetting resin, a set of predetermined sets corresponding to the shrinkage rate even if the laminate is shrunk by thermocompression bonding of a base material impregnated with a thermosetting resin. By forming a through hole in the reference mark, a predetermined interval between the reference marks can be obtained.

Also, the difference between the widest and narrowest reference marks of the plurality of sets of reference marks is within a range smaller than the value obtained by subtracting the through hole hole diameter and the permissible hole position shift from the inner layer land diameter. With this arrangement, it can be easily determined whether or not all the through-holes can be drilled within the range of the inner layer land depending on whether or not there is a reference mark for setting the predetermined interval.

Further, by configuring the plurality of sets of reference marks with different shapes for each set, the reference marks of each set can be identified, and the interval between the reference marks before contraction can be known.

[0042]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of a multilayer printed wiring board according to the present invention, a rigid flex wiring board will be described as an example. Note that only the differences between the rigid flex wiring board of the present embodiment and the conventional example will be described.

The rigid flex wiring board of this embodiment is
The lamination plate 2 is formed in an enlarged manner in anticipation of the shrinkage ratio of the lamination plate 2 in the same manner as the conventional example. However, in this embodiment, as shown in FIG. It differs from the conventional example in that a plurality of different sets of reference marks 5 are formed between the reference marks corresponding to (shrinkage ratio). Note that FIG.
FIG. 2 is a perspective view of a laminate 2 used in the present embodiment.

The details will be described below.

The material of the copper-clad laminate 2 used for the rigid flex wiring board is a polyimide film, and the shrinkage change rate in laminating the polyimide film is 0.06.
Expected to be ± 0.04.

For example, the interval between fiducial marks after lamination is 50
In the case of 0 mm, the interval between the reference marks 5 before lamination is 50
It is formed to be enlarged to 0.3. As a result, the variation of the interval between the reference marks after lamination is ± 0.2 mm (± 0.0
4% × 500 mm). Further, the drill diameter of the through hole 8 is 0.35 mm,
Assuming that the diameter is 0.75 mm, simply, the allowable range of positional deviation between the through hole 8 and the inner layer land 6 is 0.4 mm, and a deviation of 0.2 mm per one side can be absorbed. However, as described above, a displacement of about 0.1 mm occurs due to a displacement in machining or the like. For this reason, when the displacement is considered, the variation in the dimensional change of the pattern is recognized up to ± 0.1 mm. Therefore, if the variation after lamination can be made evenly distributed from the center of the wiring board and the hole can be drilled, the displacement after the lamination is within the range of 500 ± 0.2 mm, the positional deviation due to the dimensional change is 0.1 mm or less, The through hole 8 can be formed sufficiently in the area of the inner layer land 6 even if the mechanical displacement occurring during the drilling is included.

However, when the conventional reference hole 7 at one end is used as a reference, the hole is shifted by 0.2 mm to one side, so that the through hole 8 is formed at a position shifted from the inner layer land 6. In view of this, the present invention seeks to uniformly distribute the displacement due to the dimensional change from the center.

As shown in FIG. 2, the reference mark 5 in the conventional example is a normal reference mark 5 '.
Further, a plurality of different sets of auxiliary reference marks 5 ″ are formed between the reference marks within a range corresponding to the dimensional change rate (shrinkage rate).

The interval between the auxiliary reference marks 5 "is set so as to be the interval between the reference marks to be set when the deviation reaches the maximum value, and at least two sets of the auxiliary reference marks 5" are formed. .

For example, as shown in FIG. 3, when the auxiliary reference mark 5 ″ is formed based on the above-described numerical values, the variation in the amount of shrinkage change in the lamination is ± 0.2 mm. The values before lamination are 500.1 mm and 500.5 m so that the reference mark 5 ″ of
Like the regular reference mark 5 ', the wiring is evenly distributed from the center of the wiring board at intervals of m. That is, at least 500.1 mm, 500.
It is formed with an interval of 3 mm and 500.5 mm. Also, if you want to sort more finely, 500.1m
m, 500.2mm, 500.3mm, 500.4m
m, 500.5 mm.

The method of setting the auxiliary reference mark 5 ″ is generally described as follows: difference between adjacent reference marks = allowable dimensional change after lamination of inner conductor pattern = land diameter−drill diameter−machine In addition, when the above-mentioned numerical values are included, 0.2mm = 0.2mm = 0.75-0.35-0.2.

From the above equation, the pitch for increasing or decreasing the interval between the auxiliary reference marks 5 "or the interval between the auxiliary reference marks 5" and 5 "from the interval between the regular reference marks 5 'is obtained. If the pitch is smaller than the required pitch, the shift can be more finely and evenly distributed. Conversely, if the pitch is larger, the through-hole 8 is formed at a position shifted from the inner layer land 6.

The auxiliary reference mark 5 ″ is effective when (land diameter−drill diameter−permissible mechanical hole displacement) / 2 <width of dimensional change after lamination of the inner conductor pattern ( (Difference between the maximum and minimum values of the reference mark spacing) ... And the width of the dimensional change after lamination of the inner conductor pattern (difference between the maximum and minimum values of the reference mark spacing) <land diameter-drill Diameter—the permissible amount of mechanical hole position shift.

Here, the above-mentioned expression stipulates the necessity of the auxiliary reference mark 5 ″. If the dimensional change does not satisfy the expression, the auxiliary reference mark 5 ″ is unnecessary. Also, in the above equation, if the dimensional change is outside this range, the permissible range of the inner layer land 6 is fundamentally exceeded, and drilling is impossible.

The regular reference mark 5 'and the auxiliary reference mark 5 "can be distinguished for each set. For example, as shown in FIG. The reference hole 7 can be drilled by the NC drilling machine 11 based on the image recognition by X-ray fluoroscopy, and it is possible to determine the allowable range of the dimensional variation of the inner conductor pattern 1 ± mm by each mark shape. Can be.

In the wiring board after lamination, first, a reference hole 7 is formed in a regular reference mark 5 ', and the interval between the reference holes 7 is measured. When the measured value is 499.8 mm, since the inner layer conductor pattern 1 is 0.2 mm smaller than the designed value, the reference is made to the auxiliary reference mark 5 ″ of +0.2 mm with respect to the normal reference mark 5 ′. If the holes 7 are formed, the distance between the auxiliary reference holes 7 is approximately 500 mm, and the through holes 8 can be formed in the area of the inner layer land 6 evenly distributed.

If the measured value of the regular reference mark 5 'is 4
If it is smaller than 99.8 mm or larger than 500.2 mm, the permissible range is recognized from the shape of the auxiliary reference mark 5 ″ at the time of X-ray drilling of the reference hole 7 (in this case ± 0.2 mm). ), It can be determined that NC drilling is impossible because it exceeds this.

As described above, the pin 10 is inserted into the drilled reference hole 7 and fixed at the reference position of the NC drilling machine 11.
If the through hole 8 is formed, the displacement between the inner layer land 6 and the through hole 8 does not depend on one side of the wiring board as in the related art (FIGS. 19 and 20) as shown in FIGS. Evenly distributed throughout.

However, when a through hole is formed in the auxiliary reference mark, NC data whose coordinates have been changed corresponding to the auxiliary reference mark is used. Also, since the wiring board is shifted to the left and right as compared with the case where the through hole is formed in the regular reference mark, it is better to prepare a larger size of the abutment plate and the discard plate used for drilling the NC hole. . Furthermore, since the interval between the reference marks is approximately a predetermined interval (500 mm in the above embodiment) even when the auxiliary reference mark is used, the holes through which the pins of the abutment plate and the discard plate are inserted are not changed. , Can be used in case of any deviation.

[0060]

As described above, according to the multilayer printed wiring board of the present invention, after the lamination, if the inner layer pattern is not finished according to the design value, a pattern having an appropriate interval is selected from a plurality of sets of fiducial marks. the Rukoto pierced, it is possible to allocate equally the displacement between the through-hole hole and the inner layer lands. In addition, this reference hole does not require any special device, and can be easily processed by conventional equipment.

The difference between the widest and narrowest reference marks of a plurality of sets of reference marks is set within a range smaller than the value obtained by subtracting the through-hole hole diameter and the permissible displacement of the hole position from the inner-layer land diameter. Therefore, from the shape of the auxiliary reference mark that can be seen when drilling the reference hole, the worker at the processing site can know the tolerance of the wiring board on the spot. Subsequently, the reference hole is measured, and it can be easily determined whether or not the measured value is within the allowable range.

Further, by making the plurality of sets of reference marks different in shape for each set, the shape is confirmed, and the measurement result is re-examined to determine the degree of dimensional deviation of the inner layer pattern of the wiring board. It is possible to judge at a glance the wiring board being processed, and to inspect whether the deviation between the through-hole hole and the inner layer land is close to the limit of the allowable range after drilling the NC hole, and perform an inspection that predicts the degree of risk. .

[Brief description of the drawings]

FIG. 1 is an internal perspective view of a multilayer printed wiring board according to an embodiment of the present invention.

FIG. 2 is a perspective view of a laminate.

FIG. 3 is a plan view showing an example of an interval between reference marks of each set.

FIG. 4 is a plan view showing an example of the shape of each set of reference marks.

FIG. 5 is a sectional view of a multilayer printed wiring board according to one embodiment of the present invention.

FIG. 6 is a sectional view showing a conventional multilayer printed wiring board.

FIG. 7 is a cross-sectional view for explaining a manufacturing process of a conventional multilayer printed wiring board.

FIG. 8 is a cross-sectional view for explaining a manufacturing process of a conventional multilayer printed wiring board.

FIG. 9 is also a cross-sectional view for explaining a manufacturing process of the conventional multilayer printed wiring board.

FIG. 10 is a cross-sectional view for explaining a manufacturing process of the conventional multilayer printed wiring board.

FIG. 11 is a cross-sectional view for explaining a manufacturing process of the conventional multilayer printed wiring board.

FIG. 12 is a perspective view showing an example of a pattern shape of a conventional inner conductor pattern.

FIG. 13 is a sectional view showing another conventional example.

FIG. 14 is a cross-sectional view for explaining a manufacturing process of the conventional example shown in FIG.

FIG. 15 is a cross-sectional view for explaining the manufacturing process of the conventional example shown in FIG.

16 is a cross-sectional view for explaining the manufacturing process of the conventional example shown in FIG.

FIGS. 17A and 17B are plan views for explaining a positional displacement problem between an inner layer land and a through-hole; FIG. 17A shows a state before the hole is drilled, and FIG.

FIGS. 18A and 18B are plan views for explaining another misalignment problem between the inner-layer land and the through-hole, in which FIG. 18A shows a state before the hole is drilled, and FIG.

FIG. 19 is a perspective view showing a misalignment state of a through-hole in a conventional multilayer printed wiring board.

FIG. 20 is also a cross-sectional view showing a state in which a conventional multilayer printed wiring board is misaligned when drilling through-hole holes.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 inner layer conductor pattern 2 laminate 3 insulating resin layer 4 outer layer conductor pattern 5 reference mark 5 ′ regular reference mark 5 ″ auxiliary reference mark 6 inner layer land 8 through hole hole

Claims (3)

(57) [Claims] 1. A laminated board having an inner conductor pattern formed on at least one surface of a substrate having a heat shrinkage of a predetermined width, and a substrate impregnated with a thermosetting resin disposed so as to sandwich the laminated board. and thermocompression bonding was made by forming the insulating resin layer, in a multilayer printed circuit board comprising a layer conductor pattern formed on the outer surface of the insulating resin layer, on both end sides of the same surface of the laminate, the Plural sets of throughs provided corresponding to the shrinkage of the laminated plate and having different reference marks
It has a reference mark which is a reference for forming a hole hole , and the reference mark of each set of reference marks is parallel to each other, and the difference between the reference marks is different from the other reference marks on both sides. A multilayer printed wiring board, wherein the multilayer printed wiring board is disposed at positions evenly distributed over the printed circuit board. 2. The internal conductor pattern has a plurality of internal lands provided with through-holes for connection to the external conductor pattern, and the plurality of sets of reference marks having the widest interval and the narrowest are provided. 2. The multilayer printed wiring board according to claim 1, wherein the difference from the one is set within a range smaller than a value obtained by subtracting a through hole hole diameter and a permissible hole position shift amount from the inner layer land diameter. 3. The multilayer printed wiring board according to claim 1, wherein said plurality of sets of reference marks have different shapes for each set.