JPWO2015166587A1 - Circuit board manufacturing method - Google Patents

Abstract

The method for manufacturing a circuit board according to the present invention includes a through hole forming step of forming a through hole (62) in a multilayer wiring board (20) having a pad layer (26) and an internal conductor layer (50, 52, 54, 56). A preparation step of inserting a metal pin (64) into the through hole (62) and bringing the metal pin (64) into contact with a target internal conductor layer (54) of the internal conductor layer, and a drilling machine The drill blade (12) driven to the multilayer wiring board (20) is pressed using (10) to advance the drilling process, and the drill blade (12) and the target internal conductor layer (54) come into contact with each other to conduct Is detected through the metal pin (64), the drive of the drill blade (12) is stopped, and the non-through hole (68) extending from the outer conductor layer (24) to the target inner conductor layer (54) And a non-through-hole forming step for forming.

Description

  The present invention relates to a method for manufacturing a circuit board, and more particularly to a method for manufacturing a circuit board including a step of forming a non-through hole.

  In a multilayer circuit board, so-called blind via holes are known as vias that connect only specific layers. In this blind via hole, for example, a non-through hole extending from the outer conductor layer to the inner conductor layer is formed, and plating is performed over the inner wall of the non-through hole, the outer conductor layer, and the inner conductor layer. Is formed. As a method for manufacturing a multilayer circuit board having such blind via holes, for example, a method for manufacturing a multilayer wiring board as shown in Patent Document 1 is known.

  In the manufacturing method of Patent Document 1, unnecessary copper foil is removed by etching using a copper-clad laminate to form an internal conductor layer having a predetermined shape, and a desired non-through hole is formed on the internal conductor layer. A non-through hole is provided by forming an insulating layer except for a predetermined region, and a plating process is applied to the inside of the non-through hole and the outer surface of the insulating layer to connect the blind via hole and the external conductor layer having a predetermined pattern connected to the blind via hole It is characterized by forming.

  By the way, in the case of the manufacturing method of Patent Document 1, it is necessary to form an insulating layer by performing masking or the like so that the insulating layer is not formed in the non-through-hole formation scheduled region. In order to form such an insulating layer, a special insulating material must be used, which increases the manufacturing cost.

  On the other hand, in order to reduce the manufacturing cost of a multilayer circuit board, a method of forming a non-through hole by drilling is also known. In this method, a multilayer wiring board manufactured in advance is prepared, and a non-through hole extending between specific layers is drilled in the multilayer wiring board using a drill. In the case of this method, it is not necessary to use a special insulating material, and since the hole formation is simple and the productivity is excellent, the manufacturing cost of the circuit board can be suppressed lower than the manufacturing method of Patent Document 1. it can.

  In this method of manufacturing a circuit board with drilling, a drill blade that rotates from an external conductor layer located on the surface of a multilayer wiring board is inserted, and a target internal conductor layer (hereinafter referred to as the following) among the internal conductor layers. A non-through hole reaching the target pad layer) is formed. Then, plating is performed over the inner wall of the formed non-through hole, the external conductor layer, and the target pad layer, and the external conductor layer and the target pad layer are electrically connected.

  When the non-through hole is formed by the drill as described above, the tip of the drill blade needs to be stopped (positioned) with high accuracy at the position of the target pad layer. This positioning is performed by detecting a state in which the tip of the drill blade and the target pad layer are in contact with each other and the drill blade and the target pad layer are electrically connected by a drill position detection device attached to the hole processing machine. In order to detect such a conduction state, in the drill position detecting device, it is necessary to electrically connect one input end to the drill and to electrically connect the other input end to the target pad layer. At this time, since the target pad layer exists inside the multilayer wiring board, the target pad layer is connected to the surface layer portion of the multilayer wiring board so that it can be electrically connected to the drill position detection device outside the multilayer wiring board. It is necessary to form a connection pad portion. Therefore, normally, a plating through hole for electrical connection is formed at a predetermined position of the multilayer wiring board in order to connect the connection pad portion and the target pad layer.

The plated hole for electrical connection is formed as follows, for example.
First, when the multilayer wiring board is viewed in the thickness direction, a part of the target pad layer inside the multilayer wiring board is located below a part of the outer conductive layer that can be used as a connection pad portion in the outer conductive layer on the surface layer. A through hole is drilled at a predetermined position where there is. Thereby, this through-hole extends along the thickness direction of the multilayer wiring board, the connection pad portion is located at the periphery of the opening end, and the target pad layer is exposed on the inner wall thereof.

  Next, the multilayer wiring board having such a through hole is subjected to a plating treatment to form an in-hole plating layer on the inner wall. In this way, a plated through hole for electrical connection is formed. The plating through hole for electrical connection is electrically connected to the target pad layer by the in-hole plating layer.

  Next, a procedure for forming non-through holes in a multilayer wiring board having such plated holes for electrical connection will be described below.

  First, a drilling machine equipped with a control device that controls the driving of a drill blade and a drill position detection device that detects the position of the drill is prepared. And the drill blade of a drilling machine is electrically connected to one input end of a drill position detection apparatus via a lead wire. Further, the other input end of the drill position detecting device and the connection pad portion on the surface of the multilayer wiring board are connected via a lead wire. Thereby, the target pad layer is electrically connected to the other input end of the drill position detecting device via the in-hole plating layer, the connection pad portion, and the lead wire.

  When such a drilling machine is used to push a rotating drill blade into a position where a non-through hole is to be formed in a multilayer wiring board, a hole is drilled as the drill blade advances. When the drill blade reaches the target pad layer and the drill blade and the target pad layer come into contact with each other, the drill position detecting device detects the continuity of the drill blade, and the control device stops the drilling machine based on this continuity information. Let As a result, the drill stops at the target pad layer, so that the drill is positioned with high accuracy. In this way, a non-through hole extending to the target pad layer is formed.

  The multilayer wiring board in which the non-through holes are formed is subsequently subjected to a plating process for forming blind via holes. Thereafter, the multilayer wiring board having the blind via hole becomes a circuit board having a circuit pattern formed on the surface thereof through an etching process or the like.

JP 09-162550 A

By the way, in the method of manufacturing a circuit board in which a non-through hole is formed by a drill as described above and a blind via hole is formed, a plating layer is formed when forming an in-hole plating layer of a plating through hole for electrical connection and into the non-through hole. A total of two plating processes are required when forming the film. Since these plating processes are performed over the entire multilayer wiring board, the plating layer is formed twice on the external conductor layer, so that the thickness of the external conductor layer is increased. As described above, when the thickness of the external conductor layer is increased, the circuit forming property of the surface layer by etching is deteriorated. For this reason, it is difficult to reduce the circuit width, it is difficult to increase the density of the circuit, and the variation in the circuit width also increases, so that the impedance characteristics of the circuit board deteriorate.
Therefore, it is desired to develop a method of manufacturing a circuit board that can reduce the number of plating treatments and can maintain the positioning accuracy of the non-through holes in the depth direction.

  The present invention has been made on the basis of the above circumstances, and the object of the present invention is to reduce the number of plating treatments compared to the prior art, and to improve the positioning accuracy of the non-through holes in the depth direction. An object of the present invention is to provide a method of manufacturing a circuit board that can be maintained.

  In order to achieve the above object, according to the present invention, an insulating substrate, a number of internal conductor layers provided inside the substrate, an external conductor layer provided on a surface portion of the substrate, and A through-hole forming step of preparing a multilayer wiring board having a pad layer, and forming a target internal conductor layer among the internal conductor layers and a through-hole penetrating the pad layer in the multilayer wiring board; A drill blade drive device for driving the blade, a drive control device for controlling the drill blade drive device, a first input end to which the drill blade is electrically connected, and a second input end to which the detection target is to be connected. A continuity that can detect continuity between the first input end and the second input end, and when detecting continuity between the drill blade and the detection target, continuity to send the detection information to the drive control device. The detection device and the object to be processed by the drill blade A drilling machine having a holding jig is prepared, the multilayer wiring board is held by the jig, the pad layer and the second input end are electrically connected, and the through hole is electrically conductive. A preparation step of inserting a conductive object and bringing the conductive object into contact with the target internal conductor layer and the pad layer, and using the drilling machine, in the portion of the external conductor layer of the multilayer wiring board, The drill blade is pressed to drive the drill, the tip of the drill blade contacts the target internal conductor layer, and conduction between the target internal conductor layer and the drill blade is detected by the conduction detector. Sometimes the drive control device stops the drill blade driving device based on the detection information from the continuity detection device, and forms a non-through hole extending from the external conductor layer to the target internal conductor layer Forming process; Includes, method of manufacturing a circuit board is provided.

  According to the circuit board manufacturing method of the present invention, the number of plating treatments can be reduced as compared with the prior art, and the positioning accuracy of the non-through holes in the depth direction can be maintained.

It is a top view which shows the work board which concerns on the 1st Embodiment of this invention. It is the top view which showed the multilayer wiring board which concerns on the 1st Embodiment of this invention with the structure of the non-through-hole processing machine. It is sectional drawing which showed the aspect which provides a through-hole in a multilayer wiring board and inserts a metal pin in a through-hole. It is sectional drawing which showed the state which has drilled the multilayer wiring board. It is sectional drawing which showed the state which the drill blade reached | attained the target internal conductor layer. It is sectional drawing which showed the aspect which extracts a drill and a metal pin from a multilayer wiring board, and performs a plating process after that. It is sectional drawing which showed the multilayer wiring board which concerns on the 2nd Embodiment of this invention. It is sectional drawing which showed the state which has drilled to the multilayer wiring board which concerns on the 2nd Embodiment of this invention. It is sectional drawing which showed the aspect which extracts a drill about the multilayer wiring board which concerns on the 2nd Embodiment of this invention, and performs a plating process after that. It is sectional drawing which showed the multilayer wiring board which concerns on the 4th Embodiment of this invention. It is sectional drawing which showed the multilayer wiring board which concerns on the 5th Embodiment of this invention. It is sectional drawing which showed the multilayer wiring board which concerns on the 6th Embodiment of this invention.

(First embodiment)
A method for manufacturing the circuit board 1 according to the first embodiment of the present invention will be described below with reference to the drawings.

  A plurality of circuit boards 1 are built in the work board 2. Specifically, as shown in FIG. 1, the work board 2 is a substrate having an outer frame portion 4 on the periphery, and a plurality of (four in FIG. 1) sheets 6 are placed inside the outer frame portion 4. Contains. Each sheet 6 has a discard frame portion 8 on each periphery, and a plurality (two in FIG. 1) of circuit boards 1 are included inside the discard frame portion 8. A plurality of circuit boards 1 are manufactured simultaneously in units of work boards. Since these circuit boards 1 are the same, only one circuit board 1 will be described.

  First, in manufacturing the circuit board 1, a drilling machine (hereinafter referred to as a non-through hole processing machine) 10 used for forming a non-through hole is prepared. As shown in FIG. 2, the non-through hole processing machine 10 detects the position of the drill blade drive device 14 that drives the drill blade 12, the drive control device 16 that controls the drill blade drive device 14, and the drill blade 12. A drill position detection device (continuity detection device) 18 for sending a position detection signal to the drive control device 16 is included. Here, before describing the connection mode of the non-through hole processing machine 10, the multilayer wiring board 20 which is an intermediate product of the circuit board 1 shown as a plan view together with the non-through hole processing machine 10 in FIG. 2 will be described. . The multilayer wiring board 20 includes an external conductor layer 24 and a pad layer 26 formed on the surface layer, and a plurality of internal conductor layers formed inside. The external conductor layer 24 is a region where a circuit pattern is formed on the surface layer. On the other hand, the pad layer 26 is an area to which the lead wire of the drill position detecting device 18 is connected as will be described later. A groove 28 is provided between the external conductor layer 24 and the pad layer 26, and the external conductor layer 24 and the pad layer 26 are electrically separated. Each cross-sectional view used in the following description is a cross-sectional view at a position corresponding to the cross-section shown along the line AA in FIG.

  In the drill position detection device 18, one first input end 30 is electrically connected to the drill blade 12 via a first lead wire 32, and the other second input end 34 is connected via a second lead wire 36. Are electrically connected to the pad layer 26 of the multilayer wiring board 20. When the first input end 30 and the second input end 32 are conducted, the drill position detection device 18 detects conduction and transmits a conduction detection signal as a drill position detection signal to the drive control device 16.

  When receiving the drill position detection signal, the drive control device 16 transmits a drill blade stop signal to the drill blade driving device 14.

  The drill blade drive device 14 is a device that drives the drill blade, and stops driving the drill blade when receiving a drill blade stop signal.

  Here, the drill position detection device 18 and the drive control device 16 are connected by a signal line 38, and the drive control device 16 and the drill blade drive device 14 are connected by a signal line 40. Further, the drill blade driving device 14 and the drill blade 12 are connected by a driving force transmitting means 42.

  Furthermore, a multilayer wiring board 20 as shown in FIG. The multilayer wiring board 20 includes an insulating substrate 48 having an upper surface (first surface) 44 and a lower surface (second surface) 46. The insulating substrate 48 is not particularly limited as long as it has insulating properties. For example, a glass epoxy substrate in which an epoxy resin is impregnated on a glass fiber cloth is cited. It is done. The insulating substrate 48 has external conductor layers 24 and 24 on an upper surface 44 and a lower surface 46, respectively, and includes four internal conductor layers 50, 52, 54, and 56 therein.

  As described above, the upper surface 44 includes the external conductor layer 24 and the pad layer 26, and a groove 28 is formed between the external conductor layer 24 and the pad layer 26. As is clear from FIG. 3A, a non-through hole formation scheduled region 58 is set at a predetermined position corresponding to the external conductor layer 24, and is set at a predetermined position corresponding to the pad layer 26. A through-hole formation scheduled area 60 is set.

  Of the internal conductor layers 50, 52, 54, and 56, the target internal conductor layer (target pad layer) 54 is the third layer from the upper surface 44 side. The target pad layer 54 is formed so as to intersect the non-through hole formation planned region 58 and the through hole formation planned region 60. On the other hand, the internal conductor layers 50, 52, and 56 other than the target pad layer 54 are designed in advance so as to avoid the non-through hole formation planned region 58 and the through hole formation planned region 60.

  The multilayer wiring board 20 prepared in this way is drilled in the through-hole formation scheduled region 60 by a general drilling machine to form a through-hole 62 (see FIG. 3B).

  As shown in FIG. 3C, the multilayer wiring board 20 in which the through holes 62 are formed is disposed on a resin jig 66 of the non-through hole processing machine 10 and fixed by a fixing means (not shown). Metal pins 64 that are metal pins are inserted into the through holes 62 of the multilayer wiring board 20 in this state. The metal pin 64 has a cylindrical shape having an outer diameter dimension substantially equal to the inner diameter dimension of the through hole 62, and comes into contact with the target pad layer 54 and the pad layer 26 by being inserted into the through hole 62. Electrically connected to the layer.

  Next, as shown in FIG. 4, the tip of the second lead 36 in the drill position detection device 18 of the non-through hole processing machine 10 is electrically connected to the pad layer 26. In this state, the driven drill blade 12 is pressed against the non-through hole formation scheduled region 58 of the multilayer wiring board 20 to perform drilling. As the drill blade 12 advances into the multilayer wiring board 20, non-through holes 68 are formed. As shown in FIG. 5, when the tip of the drill blade 12 reaches the target pad layer 54, the drill blade 12 and the target pad layer 54 are electrically connected. That is, in the drill position detection device 18, the first terminal 30 and the second terminal 34 connect the first lead wire 32, the drill blade 12, the target pad layer 54, the metal pin 64, the pad layer 26, and the second lead wire 36. Are electrically connected to each other through a conductive state. As a result, the drill position detection device 18 detects that the tip of the drill blade is positioned at the portion of the target pad layer 54, and transmits a drill position detection signal to the drive control device 16. The drive control device 16 that has received the drill position detection signal transmits a drive stop signal for the drill blade 12 to the drill blade drive device 14. The drill blade driving device 14 that has received the drive stop signal stops driving the drill blade 12. Thereby, the drill blade 12 can be positioned with high accuracy, and the non-through hole 68 to the target pad layer 54 is formed.

  In the multilayer wiring board 20 in which the non-through holes 68 are formed, the drill blade 12 is pulled out and the second lead wire 36 is removed as shown in FIG. 6A. Further, as shown in FIG. After the metal pin 64 is pulled out, it is removed from the resin jig 66 and plated. For the plating treatment here, electroless plating of copper is suitably used. At this time, copper electroplating can also be employed.

  The conditions for the plating treatment here are not particularly limited, and it is preferable to adopt conditions under which a plating layer 70 having a desired thickness can be formed.

  By the above plating process, the plated layer 70 is formed in the non-through hole 68, and the multilayer wiring board 20 having the blind via hole 72 as shown in FIG. 6C is obtained.

  The multilayer wiring board 20 having such a blind via hole 72 is subsequently subjected to an etching process or the like, thereby becoming a circuit board 1 having a desired wiring pattern.

  Here, in the first embodiment, the groove 28 is coated with a plating resist so that plating is not performed even in the above-described plating process. However, the present invention is not limited to this mode. The plating resist is not applied to the groove 28, the groove 28 is filled with the plating layer 70, the pad layer 26 is etched, and the wiring pattern is formed. May be formed.

  According to the method for manufacturing the circuit board 1 of the present invention as described above, the plating process for forming the plating through hole for electrical connection as in the prior art can be omitted. It is possible to perform only one plating process on the non-through hole 68 for forming. For this reason, since the thickness of the surface metal layer 74 formed by combining the external conductor layer 24 and the plating layer 70 can be made thinner than before, the width of the wiring pattern can be reduced and the variation can be reduced. . As a result, the wiring pattern can be densified, the impedance characteristics of the circuit board can be improved, the rate of occurrence of defects such as disconnection and short circuit in circuit formation can be reduced, and the yield of products can be improved. In addition, the manufacturing cost can be reduced by reducing the number of plating treatments.

(Second Embodiment)
In the second embodiment, a conductive paste 76 is filled in the through holes 62 instead of the metal pins 64, and an electrical connection structure between the target pad layer 54 and the pad layer 26 is formed by the conductive paste 76. Except for this, it is the same as the first embodiment. Therefore, the same members as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof will be omitted, and only portions different from those of the first embodiment will be described.

  In the second embodiment, as shown in FIG. 7, the multilayer wiring board 20 (see FIG. 3B) in which the through holes 62 are formed is fixed on the resin jig 64 of the non-through hole processing machine 10. Thereafter, the conductive paste 76 is filled into the through hole 62. The conductive paste 76 is not particularly limited, and, for example, an epoxy resin containing silver powder is preferably used.

  As shown in FIG. 8, the multilayer wiring board 20 in which the conductive paste 76 is filled in the through holes 62 is caused by the rotating drill blade 12 being advanced into the multilayer wiring board 20 by the non-through hole processing machine 10. A non-through hole 68 is formed. In the case of the second embodiment, as shown in FIG. 9A, in the multilayer wiring board 20 after the drill blade 12 has been pulled out, the conductive paste 76 is not pulled out and is inserted into the through hole 62. Keep holding. Then, by performing a plating process on the multilayer wiring board 20 in this state, blind via holes 72 are formed as shown in FIG.

  In the multilayer wiring board 20 in the second embodiment, the portion filled with the conductive paste 76 is used as a conductive via that connects the pad layer 26 on the upper surface 44 side and the external conductor layer 24 on the lower surface 46 side. It is possible to prevent the through hole 62 from being wasted. Further, in the second embodiment, since the conductive paste 76 has viscosity, it can match the shape of the target pad layer 54 and the fine missing portion of the pad layer 26, and has good electrical connectivity. Can be demonstrated. Here, the through-hole 62 is formed using a drilling machine. At this time, the pad layer 26 positioned at the opening end of the through-hole 62 is likely to be turned or missing as the drill blade is processed. For this reason, even if a contact failure occurs in the straight metal pin 64 as in the first embodiment, the conductive paste 76 of the second embodiment has good electrical connectivity with the pad layer 26. There is a merit that can be secured.

(Third embodiment)
In the third embodiment, the outer diameter dimension of the metal pin 64 is larger than the inner diameter dimension of the through hole 62, and when the metal pin 64 is inserted into the through hole 62 as shown in FIG. Except for press-fitting the pin 64 into the through-hole 62, this is the same as in the first embodiment.

As described above, the pad layer 26 positioned at the opening end of the through-hole 62 is likely to be turned over or missing, and the electrical connectivity between the pad layer 26 and the metal pin 64 tends to be unstable. For this reason, the press-fit of the metal pin 64 into the through hole 62 increases the adhesion between the pad layer 26 and the metal pin 64.
According to the third embodiment, since the contact failure between the pad layer 26 and the metal pin 64 is suppressed, the accuracy of position detection of the drill blade 12 is further improved as compared with the first embodiment.
(Fourth embodiment)

  FIG. 10 shows a fourth embodiment. As is apparent from FIG. 10, the fourth embodiment, except that the head of the metal pin 64 and the surrounding pad layer 26 are electrically connected with the conductive tape 80, The same as in the first embodiment. Therefore, the same members as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof will be omitted, and only portions different from those of the first embodiment will be described.

  In the fourth embodiment, as shown in FIG. 3 (c), after inserting the metal pin 64 into the through hole 62, the surrounding pad layer is formed from the head of the metal pin 64 as shown in FIG. 26, a conductive tape 80 is applied. Thereafter, the non-through hole 68 is formed using the non-through hole processing machine 10.

  As described above, the pad layer 26 positioned at the opening end of the through-hole 62 is likely to be turned over or missing, and the electrical connectivity between the pad layer 26 and the metal pin 64 tends to be unstable. For this reason, electrical connectivity can be complemented by sticking the conductive tape 80.

  According to the fourth embodiment, since the contact failure between the pad layer 26 and the metal pin 64 is suppressed, the accuracy of position detection of the drill blade 12 is further improved as compared with the first embodiment.

(Fifth embodiment)
FIG. 11 shows a fifth embodiment. As apparent from FIG. 11, the fifth embodiment is the same as the first embodiment except that a tapered pin 82 having a tapered shape is used instead of the metal pin 64. is there. Therefore, the same members as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof will be omitted, and only portions different from those of the first embodiment will be described.

  In the fifth embodiment, as shown in FIG. 11, after fixing the multilayer wiring board 20 with the through holes 62 as shown in FIG. 3B on the resin jig 66, The taper pin 82 is inserted into the through hole 62 and pushed slightly. Thereafter, the non-through hole 68 is formed using the non-through hole processing machine 10.

  As described above, the pad layer 26 positioned at the opening end of the through-hole 62 is likely to be turned over or missing, and the electrical connectivity between the pad layer 26 and the straight metal pin 64 tends to be unstable. . Therefore, a taper pin 82 having a tapered shape is used, and the taper pin 82 is pushed in. Thereby, the taper part in the periphery of the head part of the taper pin 82 can expand the opening end of the through-hole 62 slightly, and the adhesiveness of the taper pin 82 and the pad layer 26 can be improved.

  According to the fifth embodiment, since the contact failure between the pad layer 26 and the taper pin 82 is suppressed, the position detection accuracy of the drill blade 12 is further improved as compared with the first embodiment.

(Sixth embodiment)
FIG. 12 shows a sixth embodiment. As apparent from FIG. 12, the sixth embodiment is the same as the first embodiment except that a caulking pin 84 for caulking is used instead of the metal pin. Therefore, the same members as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof will be omitted, and only portions different from those of the first embodiment will be described.

  In the sixth embodiment, after fixing the multilayer wiring board 20 with the through holes 62 as shown in FIG. 3B on the resin jig 66, as shown in FIG. The caulking pin 84 is inserted into the through hole 62, and the head portion 84a of the caulking pin 84 is crushed and caulking is performed. Thereafter, the non-through hole 68 is formed using the non-through hole processing machine 10.

  As described above, the pad layer 26 positioned at the opening end of the through-hole 62 is likely to be turned over or missing, and the electrical connectivity between the pad layer 26 and the straight metal pin 64 tends to be unstable. . Therefore, the caulking pin 84 is used and the head 84a of the caulking pin 84 is crushed. As a result, the head portion 84a of the caulking pin 84 is deformed and the peripheral edge thereof is expanded in diameter. As a result, the adhesion between the caulking pin 84 and the pad layer 26 can be improved.

  According to the sixth embodiment, since the contact failure between the pad layer 26 and the caulking pin 84 is suppressed, the accuracy of position detection of the drill blade 12 is further improved as compared with the first embodiment.

  In addition, this invention is not limited to above-described embodiment, It is also possible to combine said each embodiment. For example, the conductive tape 80 may be attached to the heads of the metal pins 64, the taper pins 82, and the caulking pins 84 having a diameter larger than that of the through holes 62 to be electrically connected to the pad layer 26. It is also possible to add a caulking process by crushing the heads of the metal pin 64 and the taper pin 82 having a diameter larger than that of the through hole 62.

  Here, in the present invention, the through hole 62 into which various pins are inserted or filled with the conductive paste may be formed at any position on the work board, but the through hole 62 is better. The formation position will be described below.

  First, as in the third embodiment, the fifth embodiment, and the sixth embodiment described above, the multilayer wiring board 20 is formed by press-fitting the metal pin 64, pushing the taper pin 82, or caulking the caulking pin 84, or the like. When some damage is caused, it is preferable to provide a through hole 62 at a predetermined position of the outer frame portion 4 of the work board 2 as indicated by reference numeral 86 in FIG. In this case, there is a space between the through hole 62 and the product (circuit board 1), and the influence on the product (circuit board 1) can be reduced.

  On the other hand, since the work board 2 is warped, it is preferable to provide a through hole 62 as close to the product (circuit board 1) as possible in order to further improve the accuracy of position detection of the drill blade 12. In this case, as indicated by reference numeral 88 in FIG. 1, it is preferable to provide a through hole 62 at a predetermined position of the discard frame portion 8.

  In order to further improve the accuracy of detecting the position of the drill blade 62, it is preferable to provide a through hole in the product (circuit board 1). In this case, as indicated by reference numeral 90 in FIG. 1, it is preferable to provide a through hole 62 at a predetermined position in the product (circuit board 1). When the through hole 62 is provided in the product (circuit board 1), the accuracy of detecting the position of the drill blade 12 is higher than when the through hole 62 is provided in the throwing frame portion 8. More preferably, the through hole 62 is formed at a position where it can be used as a conductive via so that it can be used effectively in the circuit board 1. In this case, it is preferable to employ the second embodiment using the above-described conductive paste.

<Embodiment of the present invention>
A printed circuit board manufacturing method according to a first embodiment of the present invention includes an insulating substrate, a number of internal conductor layers provided inside the substrate, and an external conductor provided on a surface portion of the substrate. A through hole forming step of preparing a multilayer wiring board having a layer and a pad layer, and forming a through hole penetrating through the target internal conductor layer and the pad layer among the internal conductor layers in the multilayer wiring board; A drill blade drive device for driving the drill blade, a drive control device for controlling the drill blade drive device, a first input terminal to which the drill blade is electrically connected, and a second input to which the detection target is to be connected And detecting the continuity between the first input end and the second input end, and detecting the continuity between the drill blade and the detection target, the detected information to the drive control device Processing with the continuity detection device to send and the drill blade A drilling machine having a jig capable of holding a target to be held, holding the multilayer wiring board on the jig, electrically connecting the pad layer and the second input end, and Inserting a conductive object into the hole and bringing the conductive object into contact with the target internal conductive layer and the pad layer; and using the drilling machine, the external conductive layer of the multilayer wiring board The drill blade is pressed against the portion to advance the drilling process, and the tip of the drill blade contacts the target internal conductor layer, and the conduction between the target internal conductor layer and the drill blade is caused by the conduction detecting device. When detected, the drive control device stops the drill blade drive device based on detection information from the continuity detection device, and forms a non-through hole extending from the external conductor layer to the target internal conductor layer. Non-through hole type It is provided with a step.

  In the method for manufacturing a circuit board according to the first embodiment, by inserting a conductive object into a through-hole provided in the multilayer wiring board, the conductive object is brought into contact with a target internal conductor layer, Through this conductive object, the drill blade is positioned by detecting the conduction between the target internal conductor layer and the drill blade. For this reason, while maintaining the conventional positioning accuracy in the depth direction of the non-through holes, the conventional plating process (formation of plated through holes for electrical connection) as described above is omitted. Can do. Therefore, since the plating process can be performed only once when the blind via hole is formed, the total thickness of the external conductor layer and the plating layer can be made thinner than before. As a result, the surface circuit formation by etching is better than before. For this reason, the circuit width can be narrowed, and the circuit density can be increased. In addition, since variations in circuit width can be suppressed to a small level, the impedance characteristics of the circuit board can be improved, the occurrence rate of defects such as disconnection and short circuit in circuit formation can be reduced, and the yield of products can be improved.

  Moreover, since the frequency | count of a plating process can be reduced compared with the past as mentioned above, the manufacturing cost in manufacture of a circuit board can be reduced compared with the past.

  A circuit board manufacturing method according to a second embodiment of the present invention is a printed circuit board manufacturing method according to the first embodiment, in which the conductive object is a metal pin. According to this configuration, the effect according to the first embodiment can be obtained only by using a simple member such as a metal pin.

  A method for manufacturing a circuit board according to a third embodiment of the present invention is a method for manufacturing a printed circuit board according to the second embodiment, wherein the metal pin is a cylindrical pin having a cylindrical shape, and the outside of the cylindrical pin. The diameter is larger than the inner diameter of the through hole into which the cylindrical pin is inserted, and the cylindrical pin is press-fitted into the through hole in the conductive object inserting step. According to this configuration, the electrical connectivity between the metal pin and the pad layer is increased, and the position detection accuracy of the drill blade is further improved.

  A circuit board manufacturing method according to a fourth embodiment of the present invention is a printed circuit board manufacturing method according to the second embodiment, wherein the metal pin is a tapered pin having a tapered shape. According to this configuration, the electrical connectivity between the metal pin and the pad layer is increased, and the position detection accuracy of the drill is further improved.

  A method for manufacturing a circuit board according to a fifth embodiment of the present invention is a method for manufacturing a printed circuit board according to any of the second to fourth embodiments, wherein the head of the metal pin in the conductive object insertion step. Is crushed and caulked. According to this configuration, the electrical connectivity between the metal pin and the pad layer is further increased, and the position detection accuracy of the drill blade is further improved.

  A circuit board manufacturing method according to a sixth embodiment of the present invention is a printed circuit board manufacturing method according to any of the first to fifth embodiments, wherein the head of the metal pin and the periphery of the head The pad layer located at a position is connected with a conductive tape. According to this configuration, electrical conductivity between the metal pin and the pad layer is complemented by the conductive tape, and the position detection accuracy of the drill blade is further improved.

  A circuit board manufacturing method according to a seventh embodiment of the present invention is a printed circuit board manufacturing method according to the first embodiment, wherein the conductive object is a conductive paste. According to this configuration, the effects according to the first embodiment described above are more remarkably exhibited, and the portion of the through hole into which the conductive paste is inserted can be used as a conductive via.

  A circuit board manufacturing method according to an eighth embodiment of the present invention is a printed circuit board manufacturing method according to any one of the first to seventh embodiments, wherein the multilayer wiring board comprises a work board, The board is an outer frame portion positioned at the periphery, a plurality of sheets positioned inside the outer frame portion, including the discard frame portion, and a circuit board as a product positioned inside the discard frame portion. A plurality of product parts, and the through hole is formed in the outer frame part in the through hole forming step. With this configuration, there is a space between the through hole and the product (circuit board), and damage to the product (circuit board) due to press-fitting of metal pins or the like can be reduced.

  A circuit board manufacturing method according to a ninth embodiment of the present invention is a printed circuit board manufacturing method according to any of the first to seventh embodiments, wherein the multilayer wiring board is formed of a work board, The board is an outer frame portion positioned at the periphery, a plurality of sheets positioned inside the outer frame portion, including the discard frame portion, and a circuit board as a product positioned inside the discard frame portion. A plurality of product parts, and the through holes are formed in the discard frame part in the through hole forming step. With this configuration, it is possible to reduce the influence on the position detection accuracy of the drill blade due to the warping of the work board.

  A circuit board manufacturing method according to a tenth embodiment of the present invention is a printed circuit board manufacturing method according to any one of the first to seventh embodiments, wherein the multilayer wiring board comprises a work board, The board is an outer frame portion positioned at the periphery, a plurality of sheets positioned inside the outer frame portion, including the discard frame portion, and a circuit board as a product positioned inside the discard frame portion. A plurality of product parts, and the through hole is formed in the product part in the through hole forming step. With this configuration, the accuracy of detecting the position of the drill blade is further improved.

DESCRIPTION OF SYMBOLS 1 Circuit board 10 Non-through-hole processing machine 12 Drill blade 14 Drill blade drive device 16 Drive control device 18 Drill position detection device 20 Multilayer wiring board 24 External conductor layer 26 Pad layer 54 Target internal conductor layer (target pad layer)
62 through-hole 68 non-through-hole 72 blind via hole 76 conductive paste 80 conductive tape 82 taper pin 84 caulking pin

Claims (10)

Preparing a multilayer wiring board having an insulating substrate, a number of internal conductor layers provided inside the substrate, and an external conductor layer and a pad layer provided on a surface portion of the substrate; A through hole forming step for forming a through hole penetrating the target internal conductor layer and the pad layer among the internal conductor layers on the plate;
A drill blade driving device for driving a drill blade, a drive control device for controlling the drill blade driving device, a first input end to which the drill blade is electrically connected, and a second input end to which a detection target is to be connected When the continuity between the first input end and the second input end can be detected and the continuity between the drill blade and the detection target is detected, the detection information is sent to the drive control device. A drilling machine having a continuity detecting device and a jig capable of holding an object to be processed by the drill blade is prepared, the multilayer wiring board is held by the jig, the pad layer and the second input end And electrically connecting the conductive object to the through hole, and the conductive object is brought into contact with the target internal conductor layer and the pad layer, and
Using the drilling machine, the drill blade is pushed against the portion of the external conductor layer of the multilayer wiring board to advance the drilling process, and the tip of the drill blade comes into contact with the target internal conductor layer. When the continuity between the target internal conductor layer and the drill blade is detected by the continuity detection device, the drive control device stops the drill blade drive device based on the detection information from the continuity detection device, A non-through hole forming step of forming a non-through hole extending from an external conductor layer to the target internal conductor layer;
A method for manufacturing a circuit board, comprising:   The circuit board manufacturing method according to claim 1, wherein the conductive object is a metal pin.   The metal pin is a cylindrical pin having a cylindrical shape, and an outer diameter of the cylindrical pin is larger than an inner diameter of the through hole into which the cylindrical pin is inserted, and the cylindrical pin is inserted in the conductive object insertion step. The method for manufacturing a circuit board according to claim 2, wherein the circuit board is press-fitted into the through hole.   The circuit board manufacturing method according to claim 2, wherein the metal pin is a tapered pin having a tapered shape.   The method of manufacturing a circuit board according to claim 2, wherein a head portion of the metal pin is crushed and caulking is performed in the conductive object insertion step.   The circuit board manufacturing method according to claim 1, wherein a head of the metal pin and the pad layer located around the head are connected by a conductive tape.   The circuit board manufacturing method according to claim 1, wherein the conductive object is a conductive paste. The multilayer wiring board is formed of a work board, and the work board is located on a peripheral edge, a plurality of sheets positioned inside the outer frame part and including a discard frame part, and the discard frame part. And has a plurality of product parts to be circuit boards as products,
The method for manufacturing a circuit board according to claim 1, wherein the through hole is formed in the outer frame portion in the through hole forming step. The multilayer wiring board is formed of a work board, and the work board is located on a peripheral edge, a plurality of sheets positioned inside the outer frame part and including a discard frame part, and the discard frame part. And has a plurality of product parts to be circuit boards as products,
The method for manufacturing a circuit board according to claim 1, wherein the through hole is formed in the discard frame portion in the through hole forming step. The multilayer wiring board is formed of a work board, and the work board is located on a peripheral edge, a plurality of sheets positioned inside the outer frame part and including a discard frame part, and the discard frame part. And has a plurality of product parts to be circuit boards as products,
The method for manufacturing a circuit board according to claim 1, wherein the through hole is formed in the product portion in the through hole forming step.

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