JP4893688B2 - Method and apparatus for filling connecting conductor into bottomed hole formed in sheet material - Google Patents

Description

  The present invention relates to a method and an apparatus for filling a connecting conductor into a bottomed hole formed in a sheet material for forming a multilayer circuit board.

  In order to form a multilayer circuit board, a filling method for filling a conductive paste in a hole provided in a sheet material is disclosed in, for example, Japanese Patent Laid-Open No. 56-147499 (Patent Document 1) and Japanese Patent Laid-Open No. 2003-182023 ( It is disclosed in Patent Document 2).

  FIG. 3 is a view showing a typical example of a method of filling the conductive paste into the holes formed in the sheet material, and FIG. 3A is a cross-sectional view showing how the holes H are formed on the surface of the sheet material 10. FIG. 3B is a cross-sectional view showing a state in which the conductive paste P is filled into the hole H. FIG.

  In the sheet material 10 shown to Fig.3 (a), the copper (Cu) foil 2 is affixed on the one side of the resin film 1 which consists of thermoplastic resins, and the protective film 3 is affixed on the other side. . As the protective film 3, for example, an adhesive film made of polyethylene terephthalate (PET) is used. Although illustration is simplified, the copper foil 2 is patterned into a predetermined circuit pattern.

  As shown in FIG. 3 (a), in the hole forming step on the surface of the sheet material 10, the laser beam from the laser processing apparatus Z is scanned and irradiated from the top of the resin film 1 to which the protective film 3 is attached. A bottomed hole H with the foil 2 as a bottom is formed. Next, as shown in FIG. 3B, in the paste filling step, the conductive paste P supplied to the surface of the sheet material 10 is pushed into the bottomed hole H by using the squeegee S and filled. Thus, the conductive paste P supplied to the surface of the sheet material 10 is squeezed and filled on the surface of the protective film 3 using the squeegee S. Next, the protective film 3 is peeled off from the sheet material 10 filled with the conductive paste P in the bottomed hole H of FIG. 3B, and a plurality of these are laminated, and the laminated body is heated and pressurized to be collectively. And paste them together. At this time, the conductive paste P filled in the bottomed hole H is simultaneously sintered to form a connection conductor that connects circuit patterns in different layers. Thereby, a multilayer circuit board is manufactured.

In the paste filling step shown in FIG. 3B, a conductive paste made of, for example, silver (Ag) and tin (Sn) is used as the conductive paste P. Since the size of the bottomed hole H is as fine as, for example, a diameter of 100 μm and a depth of 50 μm, the conductive paste P needs to keep the ratio of silver and tin always stable. For this reason, fine powders of silver and tin of several μm are used, and these are dispersed in a volatile solvent such as terpineol and used as a paste. The conductive paste P thus adjusted has been filled in a vacuum vessel by mechanically pushing it into the bottomed hole H using a squeegee S such as a spatula as shown in the figure.
JP-A-56-147499 JP 2003-182023 A

  In the filling method of the conductive paste P for manufacturing the multilayer circuit board, the protective film 3 is attached to the resin film 1 in order to prevent the conductive paste P from adhering to the surface of the resin film 1 other than the bottomed hole H in a later step. As shown in FIG. 3A, a method of simultaneously processing the protective film 3 and the resin film 1 when the bottomed hole H is laser processed is employed. However, if processing waste is generated during laser processing in the step of FIG. 3A, the processing waste enters the conductive paste P in the next step of FIG. 3B, and the processing waste is present together with the conductive paste P. The bottom hole H may be filled and cause connection failure later. Further, the adhesive applied to the protective film 3 is taken into the conductive paste P, the quality of the conductive paste P is lowered, the life is shortened, and the cost is increased.

  The present invention solves the problems associated with the method of filling a conductive paste for manufacturing a multilayer circuit board as described above, and does not require a protective film, and is formed on a sheet material for forming a multilayer circuit board. It is an object of the present invention to provide a novel method for filling a connection conductor into a hole and a filling apparatus.

  The invention according to claim 1 is a method of filling a connection conductor, in which a bottomed hole formed in a sheet material for forming a multilayer circuit board is filled with a connection conductor having substantially the same diameter as the bottomed hole. In the elastic body having a concave diaphragm portion formed in the central portion and a lip portion formed in a V shape on the outer peripheral portion, the connection conductor is held in the concave portion of the diaphragm portion, and the bottomed hole With respect to the sheet material that holds the opening portion facing vertically downward, the lip portion of the elastic body is brought into contact from the vertically downward direction, and the diaphragm portion holding the connection conductor is pressurized from the outside, The diaphragm portion is deformed, and the connecting conductor is pushed and filled into the bottomed hole.

  In the above filling method, a conductive conductor that has been conventionally used in the manufacture of multilayer circuit boards is not used, and a connection conductor having substantially the same diameter as the bottomed hole formed in the sheet material is used to connect circuit patterns to each other. To do. In the conventional filling method using the conductive paste, the metal powder constituting the conductive paste is finer than the surface roughness of the resin film serving as the insulating material of the multilayer circuit board. It was necessary to protect the surface by sticking to the surface. However, in the above filling method, since the connection conductor having the same diameter as the bottomed hole is used, the protective film used in the conventional filling method using the conductive paste is not particularly necessary.

  In addition, in the above filling method, the bottomed hole opening portion is directed vertically downward in order to suppress the mixing of laser processing debris and the like when forming the bottomed hole, which has been a problem in the conventional multilayer circuit board manufacturing method. The sheet material is held. As a result, fine foreign matters such as laser processing scraps that obstruct the filling of the connection conductor having the same diameter as the bottomed hole are selectively removed by gravity sedimentation, and the foreign matter together with the connection conductor enters the bottomed hole. Mixing can be suppressed. As described above, the filling method has a function of separating and selecting fine foreign matters that hinder filling of the connection conductor.

  In the above filling method, the connecting conductor is filled into the bottomed hole by an elastic body having a deformable diaphragm portion and a lip portion. Since the opening of the bottomed hole is directed vertically downward, the lip portion of the elastic body is brought into contact with the sheet material from below, and is deformed so as to press the diaphragm portion holding the connection conductor, The connecting conductor located at the opening of the bottomed hole is pushed and filled into the bottomed hole.

  As described above, the connection conductor filling method is a method of filling the connection conductor into the bottomed hole formed in the sheet material, and is an alternative to the conventional conductive paste filling method for manufacturing a multilayer circuit board. It is a new filling method that does not require a protective film.

  In the filling method, as described in claim 2, the connection conductor may be a sintered body of metal powder. For example, as described in claim 3, the sintered body is preliminarily sintered using silver (Ag) powder and tin (Sn) powder, which are constituent materials of the conductive paste.

  In the method for filling the connection conductor, as described above, the sheet material is held with the opening of the bottomed hole directed vertically downward. Therefore, for example, even when the sintered body that is the connection conductor collapses to become metal powder waste during filling, the metal powder waste is allowed to settle by gravity without filling the bottomed hole with the metal powder waste. It can be stored in the concave portion of the diaphragm portion.

  The connection conductor may have a spherical shape, for example, but preferably has the same cylindrical shape as the bottomed hole as described in claim 4.

  The elastic body can be made of fluororubber as described in claim 5, for example.

  In the method for filling the connection conductor, as described in claim 6, it is preferable that the liquid is held in the concave portion of the diaphragm portion together with the connection conductor. For example, as in claim 7, the liquid is terpineol.

  The liquid held in the concave portion of the diaphragm portion together with the connection conductor has a lubricating function for reducing friction and wear due to contact between the connection conductors held in the diaphragm portion and the sheet material, and has a surface tension. It can be used for holding the connection conductor filled in the bottom hole. Therefore, when the liquid is used, the connection conductor filled in the bottomed hole can be held even if the connection conductor has a smaller diameter than the opening of the bottomed hole.

  In the method for filling the connection conductor, as described in claim 8, it is preferable that the connection conductor is pushed and filled into the bottomed hole while the elastic body is swung along the surface of the sheet material. . Thereby, since the position and direction of the connection conductor can be changed little by little, the filling probability of the connection conductor in the bottomed hole can be remarkably increased, and the filling time can be shortened.

  Further, in the method for filling the connection conductor, as described in claim 9, the elastic body is moved along the surface of the sheet material, and the connection conductor is pushed and filled into the bottomed hole. preferable. In this way, the elastic body is scanned along the surface of the sheet material, so that the connecting conductor whose tip is approaching the bottomed hole is connected to the bottomed hole by the V-shaped lip portion of the outer peripheral portion of the elastic body. It can be surely pushed and filled in. Further, since scanning is performed along the surface of the sheet material, even a small-capacity elastic body can cope with a large-area sheet material.

  In the method for filling the connection conductor, as described in claim 10, after filling the connection conductor, the pressure applied to the diaphragm portion during the filling is released so that the bottomed hole is not filled. It is preferable that the remaining connection conductor is recovered by dropping from the surface of the sheet material into the concave portion of the diaphragm portion. Furthermore, as described in claim 11, it is more preferable that the outside of the diaphragm portion is decompressed after the connection conductor is filled.

  According to this, the connection conductor remaining without being filled in the bottomed hole can be reliably collected in the diaphragm portion, and the elastic body holding the filled connection conductor is transferred to the next sheet material. It can be used as it is for filling.

  In this case, as described in claim 12, the recovery angle, which is the contact angle between the surface of the sheet material at the time of recovery and the inner peripheral surface of the lip portion, is the surface of the sheet material at the time of filling and the lip portion. It is preferable to set a larger value than the filling angle, which is the contact angle of the inner peripheral surface. As a result, at the time of filling, as described above, the lip portion is pushed into the connecting conductor whose tip has entered the bottomed hole, and at the time of recovery, the lip portion is recovered to the connecting conductor attached to the sheet material surface. It can be used efficiently.

  According to a preliminary experiment, it is preferable that the filling angle is 50 ° or more and 70 ° or less and the recovery angle is 80 ° or more and 100 ° or less.

  In the method for filling the connection conductor, as described in claim 14, the sheet material is a resin film in which a conductor pattern is formed on a surface of a thermoplastic resin film, and the bottomed hole has the conductor pattern formed thereon. It is suitable when the hole is the bottom. In particular, as described in claim 15, it is suitable when the bottomed hole is formed by laser processing.

  Moreover, as for the filling method of the said connection conductor, as described in Claim 16, it is preferable to fill the said connection conductor in the said bottomed hole in a vacuum state. According to this, it is possible to prevent air from getting into the bottomed hole and fill it with the liquid, and it is possible to cope with filling of the connection conductor into a fine bottomed hole or a deep bottomed hole.

  The invention described in claims 17 to 22 relates to a filling device used in the method for filling the connection conductor.

  According to a seventeenth aspect of the present invention, there is provided a connecting conductor filling apparatus for filling a bottomed hole formed in a sheet material for forming a multilayer circuit board with a connecting conductor having substantially the same diameter as the bottomed hole. A base portion for holding the sheet material with the opening of the bottomed hole directed vertically downward, a diaphragm portion formed in a concave shape in the central portion, and a lip portion formed in a V shape in the outer peripheral portion; A filling head comprising: an elastic body that holds the connection conductor in a recess of the diaphragm portion; and a pressure chamber that includes the elastic body and a support portion of the elastic body. And a vertical movement mechanism of the filling head for bringing the lip portion of the elastic body into contact with the sheet material from a vertically downward direction, and the diaphragm portion where the connection conductor is held via the pressure chamber The diaphragm is deformed by applying pressure from the outside. It is characterized by comprising a pressure mechanism for filling pushing the connecting conductors to the bottomed hole. Thereby, the filling method according to claim 1 can be carried out.

  As described above, the elastic body can be, for example, a fluororubber according to claim 18.

  The filling device according to claim 19, in addition to the configuration of the filling device, for pushing and filling the connection conductor into the bottomed hole while swinging the elastic body along the surface of the sheet material. It has a swaying mechanism of the filling head. Thus, the filling method according to the eighth aspect can be carried out.

  The filling device according to claim 20, wherein, in addition to the configuration of the filling device, the elastic body is moved along the surface of the sheet material to push the connection conductor into the bottomed hole for filling. It has a moving mechanism for the filling head. Thus, the filling method according to the ninth aspect can be carried out.

  According to a twenty-first aspect of the present invention, in addition to the configuration of the above-described filling device, the filling device has a pressure-reducing mechanism for depressurizing the outside of the diaphragm portion through the pressure chamber. As a result, the filling method according to claim 11 can be carried out.

  The filling device according to claim 22, comprising a vacuum chamber head surrounding the filling head, a vertical movement mechanism of the vacuum chamber head, and a decompression mechanism for decompressing the inside of the vacuum chamber head. Yes. As a result, the filling method according to claim 16 can be carried out.

  The effects obtained by using the filling device are the same as those described in the method for filling the connection conductors, and the description thereof is omitted.

  The present invention relates to a connection conductor filling method for filling a bottomed hole formed in a sheet material for forming a multilayer circuit board with a connection conductor having substantially the same diameter as the bottomed hole, and a filling apparatus used therefor. . The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a partial sectional view schematically showing a filling device 100 as an example of a filling device for carrying out the method for filling a connection conductor of the present invention.

  A filling device 100 shown in FIG. 1 has a base portion 20 for holding a sheet material 11 as a workpiece with the opening of the bottomed hole H directed vertically downward. The sheet material 11 in FIG. 1 is a resin film in which a conductor pattern 2 is formed on the surface of a thermoplastic resin film 1 similar to the sheet material 10 shown in FIG. 3, but the protective film 3 in FIG. It is not affixed on the resin film 1 of one sheet material 11. The bottomed hole H formed in the sheet material 11 in FIG. 1 is a hole having the bottom of the conductor pattern 2 similar to that in FIG. 3 and is formed by laser processing. The sheet material 11 is vacuum-sucked through the groove 21 and is held by the base portion 20 that is a work chuck base.

  A filling device 100 shown in FIG. 1 includes a filling head 30 having a pressure chamber 33 constituted by an elastic body 31 and a support portion 32 of the elastic body 31. The elastic body 31 is made of fluoro rubber and has a diaphragm portion 31a formed in a concave shape at the center portion and a lip portion 31b formed in a V shape at the outer peripheral portion. As will be described later, the lip portion 31 b has a role of sliding on the surface of the sheet material 11 with the V-shaped tip pressed against the sheet material 11. A spherical connection conductor D1 is held in the concave portion of the diaphragm portion 31a. In addition to the connection conductor D1, the liquid L made of terpineol is held in the concave portion of the diaphragm portion 31a. The diaphragm portion 31a has a role of holding the connection conductor D1 and the liquid L as described above and a role of filling the connection conductor D1 in the bottomed hole H of the sheet material 11 as described later. In addition, the diaphragm part 31a and the lip part 31b are not limited to those integrally formed like the elastic body 31 made of fluororubber in FIG. 1, and the diaphragm part 31a and the lip part can be used as long as the same form and function can be realized. You may make it comprise 31b with the combination of a dissimilar material. For example, the lip portion 31b is made of fluoro rubber, and the diaphragm portion 31a is made of a fluororesin thin film.

  The pressure port 33p connected to the pressure chamber 33 in FIG. 1 is a gas port for increasing / decreasing the pressure chamber 33. As will be described later, the pressure port 33p pressurizes the diaphragm portion 31a holding the connection conductor D1 from the outside via the pressure chamber 33, thereby deforming the diaphragm portion 31a, and connecting the connection conductor D1 with a bottom. A pressurizing mechanism (not shown) for pushing into and filling the hole H is connected. In addition, the pressure port 33p is filled with the diaphragm 11a through the pressure chamber 33 in order to reliably recover the connection conductor D1 adhering to the surface of the sheet 11 without being filled. A decompression mechanism (not shown) for decompressing the outside is also connected.

  The filling device 100 in FIG. 1 has a vertical movement mechanism of the filling head 30 including a pressure cylinder 41 and the like, thereby bringing the lip portion 31b of the elastic body 31 into contact with the sheet material 11 from the vertically downward direction. . Further, the filling device 100 has a swaying mechanism of the filling head 30 including a motor 51 and a swaying shaft 52, etc., thereby connecting the elastic body 31 while swaying along the surface of the sheet material 11. The conductor D1 is pushed into the bottomed hole H and filled. Further, the filling device 100 has a moving mechanism for the filling head 30 including a slide guide 61, a slide rail 62, and the like. By this, the elastic body 31 is moved along the surface of the sheet material 11, thereby connecting conductors D1. Is pushed into the bottomed hole H and filled.

  Further, the filling apparatus 100 shown in FIG. 1 includes a vacuum chamber head 70 that surrounds the filling head 30, a vertical movement mechanism of the vacuum chamber head 70 including a pressurizing cylinder 71 and the like, and a decompression mechanism for decompressing the inside of the vacuum chamber head 70. (Not shown). As a result, the lip packing 70a disposed at the tip of the vacuum chamber head 71 is brought into contact with the sheet material 11 from below in the vertical direction, and the inside of the space where the connection conductor D1 of the filling head 30 is held is depressurized. Thus, the connecting conductor D1 can be filled in the bottomed hole H of the sheet material 11.

  FIG. 2 is a view for explaining the connection conductor filling method of the present invention using the filling device 100 of FIG. In FIG. 2, a series of steps of (1) preparation step, (2) filling step, and (3) recovery step are illustrated on one sheet material 11.

  In the preparation step shown in FIG. 2A, the gas pressure in the pressure chamber 33 provided in the filling head 30 is released, and the diaphragm portion 31a and the lip portion 31b of the elastic body 31 are in a free-form state during rubber molding. It keeps in. Although the spherical connection conductor D1 is shown in FIG. 1 as the connection conductor filling the bottomed hole H, the connection conductor D2 in FIG. The connection conductor D2 is a sintered body obtained by pre-sintering silver (Ag) powder and tin (Sn) powder, which are constituent materials of the conductive paste. However, the connection conductor D2 is not limited to this, and may be a sintered body of any metal powder. Needless to say, it may be a solid connection conductor having higher strength.

  Since the bottomed hole H provided in the sheet material 11 has a diameter of Φ100 × depth of 50 μm, the connecting conductor D2 made of a sintered metal powder has a diameter of Φ100 × height of 60 μm, which is a little higher than the diameter. It is molded into a cylindrical pellet, and is stored in the concave portion of the diaphragm portion 31a of the filling head 30 in a state of being dispersed in the liquid L made of terpineol. The amount of storage is set to a depth of several mm (in the embodiment, about 2 mm). The movable range of the diaphragm portion 31a is set to ± 5 mm, and the opening diameter of the lip portion 31b is set to 30 mm ± 2 mm. The filling head 30 having the above configuration is pressed against the filling surface of the sheet material 11 by 0.3 to 0.5 mm so that the lip portion 31b seals the surface of the sheet material 11 to prepare for filling.

  In the filling step shown in (2) of FIG. 2, gas (air in the embodiment) is introduced into the pressure chamber 33 provided in the filling head 30 as indicated by the white arrow, and a gas pressure of 0.01 Mpa is applied to the diaphragm. Add part 31a. Thus, the diaphragm portion 31a is deformed so as to be pressed against the surface of the sheet material 11, and the connection conductor D2 made of a pellet-shaped sintered body is supplied to the surface of the sheet material 11. The connection conductor D <b> 2 pressed against the surface of the sheet material 11 by the diaphragm portion 31 a is filled in the bottomed hole H in order from the position and posture suitable for the bottomed hole H.

  As described above, the filling efficiency of the connecting conductor D2 into the bottomed hole H is governed by the matching probability of the position and orientation (direction) with the bottomed hole H. Therefore, in order to increase the matching probability, the connecting conductor D2 is pushed into the bottomed hole H and filled while the filling head 30 (elastic body 31) is swung along the surface of the sheet material 11. Thereby, since the position and direction of the connection conductor D2 can be changed little by little, the filling probability into the bottomed hole H of the connection conductor D2 can be remarkably increased, and the filling time can be shortened. The displacement of the swing is about 2 mm in the front / rear and left / right directions along the surface of the sheet material 11.

  Further, in FIG. 2B, since the filling range of the sheet material 11 is wider than the width of the filling head 30, the filling head 30 (elastic body 31) is moved along the surface of the sheet material 11 to connect conductors. D2 is pushed into the bottomed hole H and filled. By scanning the elastic body 31 along the surface of the sheet material 11 in this way, even a small-capacity elastic body 31 can correspond to the large-area sheet material 11. In addition, the lip portion 31b of the elastic body 31 is opened outside the free shape at the time of rubber molding during the above movement, and the surface of the sheet material 11 and the inner peripheral surface of the lip portion 31b shown in the figure at the time of filling are filled. The angle K1 is set to be a predetermined contact angle. According to preliminary experiments, it is preferable that the filling angle K1 is not less than 50 ° and not more than 70 °. In this way, by setting the predetermined filling angle K1, the connecting conductor D2 whose tip is approaching the bottomed hole H is surely and firmly fixed in the bottomed hole H by the lip portion 31b formed in a V shape. Can be pushed into and filled. Further, as the lip portion 31b moves, the connection conductor D2 that is not filled in the bottomed hole H and overlaps the surface of the sheet material 11 and the other connection conductor D2 is replaced while being displaced, and is filled again. used.

  By repeating the above operation several times, all the bottomed holes H are filled with the connection conductor D2, and the filling process is completed.

  At the time of filling, the liquid L made of terpineol held in the diaphragm portion 31a together with the connection conductor D2 is lubricated to reduce friction and wear due to contact between the connection conductors D2 held in the diaphragm portion 31a and the sheet material 11. Demonstrate the function. The liquid L also has a function of holding the connection conductor D2 filled in the bottomed hole H by its surface tension. Therefore, when the liquid L is used, the connection conductor D2 filled in the bottomed hole H can be held even if the connection conductor D2 has a smaller diameter than the opening of the bottomed hole H. Become.

  In the above filling method, the opening of the bottomed hole H is directed vertically downward in order to suppress the mixing of laser processing debris and the like during the formation of the bottomed hole H, which was a problem in the conventional multilayer circuit board manufacturing method. The sheet material 11 is held. As a result, fine foreign matters such as laser-processed debris that obstruct the filling of the connection conductor D2 having the same diameter as the bottomed hole H are selectively removed by gravity sedimentation, and the foreign matter is removed together with the connection conductor D2. Mixing into the holes H can be suppressed. As described above, the filling method has a function of separating and selecting fine foreign matters that hinder the filling of the connection conductor D2.

  Similar effects can be obtained in the filling step shown in FIG. In the method for filling the connection conductor, since the sheet material 11 is held with the opening of the bottomed hole H directed vertically downward, for example, the sintered body of the connection conductor D2 collapses at the time of filling and the metal powder waste Even in this case, the metal powder waste can be gravity settled. Therefore, the metal powder waste can be stored in the concave portion of the diaphragm portion 31a without filling the bottomed hole H.

  In the recovery step shown in (3) of FIG. 2, after filling the connection conductor D2, the pressure applied to the diaphragm portion 31a at the time of filling is released, and the connection conductor D2 remaining in the bottomed hole H without being filled is removed. Then, the sheet material 11 is dropped from the surface of the sheet material 11 into the concave portion of the diaphragm portion 31a and collected.

  Preferably, the filling head 30 after filling is moved to a position where the bottomed hole H of the sheet material 11 is not present or a position dedicated to collection along the sheet material 11 (hereinafter referred to as a collection surface), and outside the diaphragm portion 31a. The pressure chamber 33 is depressurized by a depressurization mechanism including a vacuum device (not shown). As a result, the space formed by the collection surface and the diaphragm portion 31a is expanded, and the lip portion 31b is closed to the inner side from the free shape at the time of rubber molding. The collection angle K2 of the inner peripheral surface of 31b is set to be a predetermined contact angle. According to preliminary experiments, the recovery angle K2 is preferably 80 ° or more and 100 ° or less. With the above space shape maintained, the filling head 30 is moved along the sheet material 11, and the connection conductor D2 and the liquid L adhering to the recovery surface are recovered in the recess of the diaphragm portion 31a. As described above, by setting the recovery angle K2 to be larger than the filling angle K1, during the filling, the lip portion 31b is pushed into the connecting conductor D2 whose tip approaches the bottomed hole H as described above. At the time of collection, the lip portion 31b can be efficiently used for collecting the connection conductor D2 attached to the surface of the sheet material 11.

  Further, by the operation of the filling head 30, fine foreign matters generated by friction between the surface of the sheet material 11 and the connecting conductors D2 made of a sintered body sink in the recesses of the diaphragm portion 31a, and the large connecting conductors D2 are formed in the upper layer of the diaphragm portion 31a. It is a so-called sorting mechanism that gathers together.

  After the connection conductor D2 is recovered, the recovery process is completed by pulling the filling head 30 away from the sheet material 11. If there is a dedicated collecting surface in a region other than the sheet material 11, the filling head 30 may be shifted to filling the next sheet material without being separated from the collecting surface. Through the above recovery process, the connection conductor D2 remaining without being filled in the bottomed hole H can be reliably recovered to the diaphragm portion 31a, and the elastic body 31 holding the connection conductor D2 after filling is obtained. It can be used as it is for filling the next sheet material. In addition, since the fine foreign material of the sintered compact damaged during filling gathers in the bottom part of the diaphragm part 31a as mentioned above, it is removed by regular cleaning.

  2 is filled with the connection conductor D2 having the same diameter as the bottomed hole H in the bottomed hole H formed in the sheet material 11 for forming the multilayer circuit board. In the elastic body 31 having a diaphragm portion 31a formed in a concave shape in the central portion and a lip portion 31b formed in a V shape in the outer peripheral portion, the connecting conductor filling method is performed in the concave portion of the diaphragm portion 31a. The lip portion 31b of the elastic body 31 is brought into contact with the sheet material 11 holding the connecting conductor D2 and holding the opening of the bottomed hole H facing vertically downward, so that the connecting conductor D2 The held diaphragm portion 31a is pressurized from the outside, the diaphragm portion 31a is deformed, and the connection conductor D2 is pushed into the bottomed hole H and filled.

  In the above filling method, the bottomed hole H formed in the sheet material 11 is used to connect the circuit patterns 2 to each other without using the conductive paste P shown in FIG. A connection conductor D2 having substantially the same diameter is used. In the conventional filling method of FIG. 3 using the conductive paste P, since the metal powder constituting the conductive paste P is finer than the surface roughness of the resin film 1 serving as the insulating material of the multilayer circuit board, protection is provided during filling. It was necessary to affix the film 3 on the surface of the resin film 1 to protect the surface. However, in the filling method shown in FIG. 2, since the connection conductor D2 having the same diameter as the bottomed hole H is used, the protective film 3 used in the filling method using the conventional conductive paste P of FIG. It is not particularly necessary.

  As described above, the connection conductor filling method described above is a method of filling a connection conductor into a bottomed hole formed in a sheet material, and is a conventional method of filling a conductive paste for manufacturing a multilayer circuit board. Instead of this, it is a new filling method that does not require a protective film.

  In the above filling method, the connecting conductor D2 is not filled in vacuum in the filling step shown in FIG. However, when air in the bottomed hole obstructs filling when filling the finer bottomed hole or deep bottomed hole with the connection conductor D2, using the vacuum chamber head 70 or the like of the filling device 100 described above, The inside of the holding portion of the connection conductor D2 (the space formed by the sheet material 11 and the diaphragm portion 31a) may be evacuated and filled. In that case, the pressure balance of each chamber is adjusted as appropriate, such as the pressure applied to the pressure chamber 33 and the inside of the holding portion of the connection conductor D2 being opened to the atmosphere during recovery. Although specific numerical values such as the size of the holding portion of the connection conductor D2 and the holding amount of the connection conductor D2 are described, these are the configuration sizes of the machine confirmed by the inventor as examples, and according to the size of the object It is possible to change appropriately.

It is an example of the filling apparatus for enforcing the filling method of the connection conductor of this invention, and is partial sectional drawing which showed the filling apparatus 100 typically. FIG. 2 is a diagram for explaining a filling method of a connection conductor according to the present invention using the filling device 100 of FIG. It is a figure which shows the typical example of the method of filling the electrically conductive paste in the hole formed in the sheet | seat material, (a) is sectional drawing which showed a mode that the hole H was formed in the sheet | seat material 10 surface, (b) These are sectional views showing how the conductive paste P is filled into the holes H. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,11 Sheet material 1 Resin film 2 Conductor pattern H Bottomed hole D1, D2 Connection conductor L Liquid 31 Elastic body 31a Diaphragm part 31b Lip part 33 Pressure chamber 100 Filling device

Claims (22)

A connection conductor filling method for filling a bottomed hole formed in a sheet material for forming a multilayer circuit board with a connection conductor having substantially the same diameter as the bottomed hole,
In an elastic body having a diaphragm portion formed in a concave shape in the central portion and a lip portion formed in a V shape in the outer peripheral portion, the connection conductor is held in the concave portion of the diaphragm portion,
With respect to the sheet material that holds the opening of the bottomed hole facing vertically downward, the lip portion of the elastic body is contacted from vertically downward,
A method of filling a connection conductor, wherein the diaphragm portion holding the connection conductor is pressurized from the outside, the diaphragm portion is deformed, and the connection conductor is pushed into the bottomed hole for filling.   The method for filling a connection conductor according to claim 1, wherein the connection conductor is a sintered body of metal powder.   The method for filling a connection conductor according to claim 2, wherein the sintered body is a sintered body of silver (Ag) powder and tin (Sn) powder.   The method for filling a connection conductor according to any one of claims 1 to 3, wherein the connection conductor has a cylindrical shape.   The method for filling a connection conductor according to any one of claims 1 to 4, wherein the elastic body is made of fluororubber.   The method for filling a connection conductor according to any one of claims 1 to 5, wherein the liquid is held in the concave portion of the diaphragm portion together with the connection conductor.   The method for filling a connection conductor according to claim 6, wherein the liquid is terpineol.   The connection conductor according to any one of claims 1 to 7, wherein the connection conductor is pushed and filled into the bottomed hole while the elastic body is swung along the surface of the sheet material. Filling method.   The filling of the connection conductor according to any one of claims 1 to 8, wherein the elastic body is moved along the surface of the sheet material, and the connection conductor is pushed and filled into the bottomed hole. Method.   After filling the connection conductor, the pressure applied to the diaphragm portion during filling is released, and the connection conductor remaining without being filled in the bottomed hole is transferred from the surface of the sheet material to the concave portion of the diaphragm portion. The method for filling a connection conductor according to claim 1, wherein the connection conductor is dropped and collected.   The method for filling a connection conductor according to claim 10, wherein the outside of the diaphragm portion is decompressed after the connection conductor is filled.   The collection angle, which is the contact angle between the surface of the sheet material and the inner peripheral surface of the lip portion at the time of recovery, is the filling angle that is the contact angle of the surface of the sheet material and the inner peripheral surface of the lip portion at the time of filling. The filling method of the connection conductor according to claim 10, wherein the connection conductor is set to be larger than the connection conductor. The filling angle is 50 ° or more and 70 ° or less,
The method of filling a connection conductor according to claim 12, wherein the recovery angle is 80 ° or more and 100 ° or less. The sheet material is a resin film in which a conductor pattern is formed on the surface of a thermoplastic resin film,
The method for filling a connection conductor according to any one of claims 1 to 13, wherein the bottomed hole is a hole having the conductor pattern as a bottom.   The method for filling a connection conductor according to claim 14, wherein the bottomed hole is formed by laser processing.   The method for filling a connection conductor according to any one of claims 1 to 15, wherein the connection conductor is filled in the bottomed hole in a vacuum state. A connection conductor filling device that fills a bottomed hole formed in a sheet material for forming a multilayer circuit board with a connection conductor having substantially the same diameter as the bottomed hole,
A base portion for holding the sheet material with the opening of the bottomed hole directed vertically downward;
An elastic body having a diaphragm portion formed in a concave shape in the central portion and a lip portion formed in a V shape in the outer peripheral portion, the elastic body holding the connection conductor in the concave portion of the diaphragm portion; ,
A filling head having a pressure chamber composed of the elastic body and a support portion of the elastic body;
A vertical movement mechanism of the filling head for bringing the lip portion of the elastic body into contact with the sheet material from a vertically downward direction;
A pressurizing mechanism for pressurizing the diaphragm portion holding the connection conductor from the outside through the pressure chamber, deforming the diaphragm portion, and pushing and filling the connection conductor into the bottomed hole; A connecting conductor filling device comprising:   18. The connecting conductor filling device according to claim 17, wherein the elastic body is made of fluoro rubber.   The oscillating mechanism of the filling head for pushing and filling the connecting conductor into the bottomed hole while oscillating the elastic body along the surface of the sheet material. The filling device for a connection conductor according to 17 or 18.   18. A moving mechanism of the filling head for moving the elastic body along the surface of the sheet material to push the connecting conductor into the bottomed hole for filling. 20. The connecting conductor filling device according to any one of items 19.   21. The connecting conductor filling device according to claim 17, further comprising a pressure reducing mechanism for reducing the pressure outside the diaphragm through the pressure chamber.   The vacuum chamber head surrounding the filling head, a vertical movement mechanism of the vacuum chamber head, and a decompression mechanism for decompressing the inside of the vacuum chamber head. The connecting conductor filling device according to Item.

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