JP2006121005A - Printed circuit board and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printed circuit board that improves the reliability of electrical connections between the built-in electric devices and conductive patterns, and to provide a method for manufacturing the printed circuit board. <P>SOLUTION: This printed circuit board 100 is manufactured by positioning an electric device 30 in a thermoplastic resin 10 and electrically connecting the electrodes 31 and 32 of the electric device 30 to the conductive pattern 20b via connection via holes 40a and 40d with an infill of connection materials. In this printed circuit board, the thermoplastic resin 10 is fabricated by laminating multiple resin films and bonding the films mutually through pressure and heating from the upper and lower sides; and multiple via holes 40a to 40d with an infill of connection materials including at least connection via holes 40a and 40d are mounted on the upper and lower surfaces of the electric device 30, at any positions where inclination in the lamination direction of the electric device 30 during pressure or heating, buckling in the connection via holes 40a and 40d with an infill of connection materials and inclination in the lamination direction of the conductive pattern 20b are all regulated. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a printed circuit board in which an electric element is incorporated in a thermoplastic resin in which a conductor pattern is arranged, and a method for manufacturing the same.

  As a printed circuit board in which an electric element is built in a thermoplastic resin in which a conductor pattern is arranged and a method for manufacturing the same, the present applicant discloses, for example, Patent Document 1.

According to the method for manufacturing a printed circuit board disclosed in Patent Document 1, first, a through-hole having substantially the same dimensions as the outer shape of an electric element is formed in a resin film made of a thermoplastic resin corresponding to the position where the electric element is arranged. While laminating a plurality of resin films including a film, an electric element is disposed in the through hole to form a laminate. The laminate is heated while being pressed from above and below by a hot press plate (that is, batch pressing), whereby the electrical element is sealed by the resin film adhered to each other, and the electrical element is connected via the connection material in the via hole. A printed circuit board in which the electrode and the conductor pattern are electrically connected is formed.
JP 2003-86949 A

  Some electric elements have electrodes on the upper surface and the lower surface (including both ends) in the stacking direction, such as passive elements such as resistors, capacitors, filters, and coils. In such an electric element, via holes can be arranged on both the upper surface and the lower surface of the electric element. Therefore, depending on the circuit pattern, for example, a configuration in which a via hole filled with a connection material is disposed on the upper surface of the left electrode and the lower surface of the right electrode can be considered.

  Here, in the method for manufacturing a printed circuit board shown in Patent Document 1, the pressure applied to each part of the upper surface and the lower surface of the electric element from the hot press plate by the conductor pattern arranged in the thermoplastic resin and the via hole filled with the connection material. There will be a difference. In the case of the arrangement of the via holes described above, the via holes that transmit the pressure from the hot press plate to the electric elements are in positions that do not overlap each other in the stacking direction on the upper and lower surfaces of the electric elements. Accordingly, at the time of pressurization / heating, stress in the rotational direction is generated around the electric element, and at least one of the inclination of the electric element in the stacking direction, the buckling of the connection via hole filled with the connection material, and the inclination of the conductor pattern in the stacking direction. There is a risk that it will occur. That is, depending on the arrangement of the via holes facing the upper and lower surfaces of the electric element, there is a possibility that the reliability of electrical connection between the built-in electric element and the conductor pattern is lowered.

  In view of the above problems, an object of the present invention is to provide a printed circuit board capable of improving the electrical connection reliability between a built-in electric element and a conductor pattern, and a method for manufacturing the same.

  In order to achieve the above object, the invention according to any one of claims 1 to 11 is characterized in that an electrical element is disposed in a thermoplastic resin, and an electrode of the electrical element is thermoplastic through a connection via hole filled with a connection material. The present invention relates to a printed circuit board that is electrically connected to a conductor pattern disposed on a resin.

  First, as described in claim 1, a thermoplastic resin is formed by laminating a plurality of resin films made of a thermoplastic resin and bonding them to each other by applying pressure and heating from both upper and lower surfaces. On the upper and lower surfaces of the element, at the time of pressing and heating, at least at a position that regulates the inclination in the stacking direction of the electric element, the buckling of the connection via hole filled with the connection material, and the tilt in the stacking direction of the conductor pattern. A plurality of via holes filled with a connection material including connection via holes face.

  As described above, according to the present invention, during pressurization and heating (batch pressing), the stress in the rotation direction around the electric element, which is caused by the pressure difference between the upper and lower surfaces of the electric element, is reduced or eliminated. In addition, via holes facing the upper and lower surfaces of the electric element are arranged at positions that regulate the inclination of the electric element in the stacking direction, the buckling of the connection via hole filled with the connection material, and the inclination of the conductive pattern in the stacking direction. Yes. In such a configuration, since a connection failure is unlikely to occur between the electrical element and the connection material and / or the connection material and the conductor pattern, the printed circuit board having a configuration in which the via hole faces the upper surface and the lower surface of the electrical element. The reliability of electrical connection between the built-in electric element and the conductor pattern can be improved.

  The position of the via hole facing the upper surface and the lower surface of the electric element may be the electrode forming part of the electric element, or may be another part.

  As described in claim 2, when the electric element is housed in a space provided inside the thermoplastic resin, deformation of the printed circuit board due to the incorporation of the electric element, breakage of the conductor pattern associated therewith, etc. Can be prevented.

  According to a third aspect of the present invention, it is preferable that the filled connection material is connected to the conductor pattern in all of the plurality of via holes. At the time of pressurization and heating, in the state where the thermoplastic resin is softened, the electrical element or the like is displaced (inclined or the like) due to the stress in the rotation direction around the electrical element. However, if the other end of the via hole whose one end faces the electrical element faces the conductor pattern (the connection material in the via hole is connected to the conductor pattern), the resistance in the thermoplastic resin in which the conductor pattern is softened Become. Therefore, if the connection material filled in the via hole other than the connection via hole is also connected to the conductor pattern, the resistance against misalignment increases, so the electrical element between the electric element incorporated in the thermoplastic resin and the conductor pattern is increased. Connection reliability can be further improved.

  Specifically, as described in claim 4, at least one via pair that at least partially overlaps in the stacking direction is configured by a via hole facing the upper surface of the electric element and a via hole facing the lower surface of the electric element. It is preferable. If comprised in this way, the pressure transmitted via the via hole which faces the upper surface of an electric element, and the pressure transmitted via the via hole which faces the lower surface of an electric element will not counter each other across the electric element. Therefore, it is possible to reduce or eliminate the stress in the rotation direction around the electric element, which is caused by the pressure difference received by each part of the upper and lower surfaces of the electric element.

  As described in claim 5, a plurality of via pairs may be arranged for one electric element. In this case, if a plurality of via pairs are arranged so as to be evenly distributed in the plane direction of the electric element, for example, as described in claim 6, stress in the rotational direction around the electric element can be further reduced or eliminated. it can. Further, as described in claim 7, even if the electric elements are arranged at symmetrical positions in the plane direction, the same effect can be obtained.

  In the configuration in which the electrode of the electric element is formed from the upper surface to the lower surface, the connection material filled in both via holes constituting the via pair is respectively connected to the electrode as described in claim 8. Thus, the stress in the rotation direction around the electric element can be further reduced or eliminated. In this case, since at least one of the via pairs is a connection via hole, the configuration of the via hole can be simplified. At that time, as described in claim 9, when the via pair is arranged for all the electrodes, the stress in the rotation direction around the electric element can be further reduced or eliminated, and the configuration of the via hole Can be further simplified.

  In addition, in the structure of Claim 8 or Claim 9, only the connection material with which one via hole (namely, connection via hole) which comprises the via | veer pair connected with the electrode was connected with the conductor pattern In addition, as described in claim 10, both via holes constituting the via pair can be connected to the conductor pattern. In the configuration in which both via holes are connected to the conductor pattern, the conductor pattern in which the connection material filled in one via hole is connected is not electrically connected to the other conductor pattern. It can also be configured as a dummy conductor pattern. Thus, the effect of Claim 3 can be acquired by intentionally arrange | positioning a dummy conductor pattern.

  The invention according to any one of claims 12 to 21 is a plurality of sheets made of a thermoplastic resin, including a thermoplastic resin film having a conductive via pattern formed on at least one surface as a bottom surface and a connection via hole filled with a connection material. Preparing a resin film, positioning and laminating a plurality of resin films, placing an electric element between the resin films to form a laminate, and laminating the laminate with a hot press plate It is equipped with a pressurizing and heating process that pressurizes and heats from both sides and bonds each resin film to each other, and electrically connects the electrodes of the electric element and the conductor pattern through the connection material filled in the connection via holes. It is related with the manufacturing method of the printed circuit board formed by connection, It is an example for manufacturing the printed circuit board of Claims 1-11.

  Since the operational effect of the invention described in claim 12 is the same as the operational effect of the invention described in claim 1 and claim 2, the description is omitted.

  Since the operational effects of the inventions according to claims 13 to 21 are the same as the operational effects of the inventions according to claims 3 to 11, the description thereof is omitted.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, about the multilayer board | substrate shown in the following embodiment, and its manufacturing method, the present applicant manufactured the printed circuit board which consists of a thermoplastic resin previously shown by Unexamined-Japanese-Patent No. 2003-86949, etc. and / or printed circuit board. Since there are many parts in common with the method, the detailed description of the common parts will be omitted below, and the characteristic parts will be explained mainly.
(First embodiment)
1A and 1B are diagrams showing a schematic configuration of a printed circuit board 100 according to the present embodiment, where FIG. 1A is a cross-sectional view, and FIG. 1B is a schematic diagram showing a positional relationship between via holes facing an upper surface and a lower surface of an electric element. is there.

  As shown in FIG. 1, the printed circuit board 100 in this embodiment includes a thermoplastic resin 10, a conductor pattern 20, an electric element 30, and a via hole 40 filled with a connection material.

  The thermoplastic resin 10 is formed by laminating a plurality of resin films made of a thermoplastic resin and bonding them to each other. The constituent material of the thermoplastic resin 10 is not particularly limited as long as it is a thermoplastic resin. Further, a surface protective layer made of a non-thermoplastic resin such as thermosetting can be provided on at least one of the upper surface and the lower surface of the thermoplastic resin 10. In this embodiment, the upper surface and the lower surface of the thermoplastic resin 10 are not provided with a surface protective layer, and the thermoplastic resin 10 includes, for example, a plurality of resin films made of a liquid crystal polymer (LCP) having a thickness of 50 μm (this example). 6 are laminated and bonded (welded) to each other.

  In this thermoplastic resin 10, a plurality of conductor patterns 20 are arranged in multiple layers. Some of the plurality of conductor patterns 20 provide surface electrodes that are exposed on the upper or lower surface or both upper and lower surfaces of the thermoplastic resin 10. The plurality of conductor patterns 20 are electrically connected by a connecting material filled in the via hole 40 at a predetermined portion in order to provide a part of an electrical circuit designed in advance. Accordingly, a plurality of via holes 40 are formed in the thermoplastic resin 10 as connection pillars filled with a connection material. In FIG. 1A and the subsequent cross-sectional views of the printed circuit board 100, the reference numerals of the connection material filled in the via holes 40 are omitted for convenience.

  The conductor pattern 20 in the present embodiment is disposed between the land 20a as an electrode disposed on both surfaces of the thermoplastic resin 10, and between the electrode of the electric element 30 and the land 20a, and is electrically connected to both. The wiring pattern 20b and the dummy wiring pattern 20c that is not electrically connected to the other conductor pattern 20 are configured. The wiring pattern 20b corresponds to a conductor pattern in which the inclination described in the claims is restricted, and the dummy wiring pattern 20c corresponds to the dummy conductor pattern described in the claims.

  The constituent material of the conductor pattern 20 is not particularly limited as long as it is a low resistance metal material. In the present embodiment, it is formed by processing a Cu foil to which a resin film constituting the thermoplastic resin 10 is attached. Further, the printed circuit board 100 in the present embodiment has lands 20a on both surfaces of the thermoplastic resin 10, and between the lands 20a, the connection material filled in the wiring pattern 20b and the via hole 40, and the electric element 30 are provided. It has the structure electrically connected via.

  Further, at least one electric element 30 is embedded in the thermoplastic resin 10. The electric element 30 has a plurality of electrodes, and in this embodiment, has electrodes on both upper and lower surfaces in the stacking direction. Examples of such an electric element 30 include passive elements such as a resistor, a capacitor, a coil, and a filter. As shown in FIG. 1A, the electric element 30 in the present embodiment is a resistor in which electrodes 31 and 32 are formed on both ends including the upper surface and the lower surface (that is, from the upper surface to the lower surface). (Not shown) is applied.

  A plurality of via holes 40 are arranged on the upper and lower surfaces of the electric element 30 as connecting columns filled with a connecting material. At least some of the plurality of via holes 40 face the electrodes 31 and 32 of the electric element 30, and the filled connection material is electrically and mechanically connected to the electrodes 31 and 32. In the present embodiment, via holes 40 a and 40 d as connection columns for electrical connection with the wiring pattern 20 b are disposed on the upper surface of the electrode 31 and the lower surface of the electrode 32, and on the lower surface of the electrode 31 and the upper surface of the electrode 32. Via holes 40b and 40c as connecting pillars for anchors and stress distribution are arranged.

  As shown in FIG. 1B, the via holes 40a and 40d serving as connection columns for electrical connection are located substantially in the center in the short direction of the electric element 30 (the plane direction of the printed circuit board 100). Further, the electrical elements 30 are arranged symmetrically with respect to the central axis in the longitudinal direction. In the present embodiment, via holes 40a and 40d as connection pillars connecting the electrodes 31 and 32 and the wiring pattern 20b, and via holes 40e and 40f as connection pillars connecting the wiring pattern 20b and the land 20a, Are arranged apart from each other in the plane direction of the printed circuit board 100 so as not to overlap with each other in the stacking direction of the printed circuit board 100.

  The via holes 40b and 40c as connection pillars for anchor and stress distribution face the electrodes 31 and 32 on the back side of the via holes 40a and 40d as connection pillars for electrical connection, and the filled connection material is a dummy. The wiring pattern 20c is electrically and mechanically connected. The dummy wiring pattern 20c is not electrically connected to the other conductor pattern 20, and does not constitute a part of the electric circuit. It acts as an anchor for the lamination direction of the thermoplastic resin 10. Thus, among the via holes 40a to 40f, the upper surface via hole 40a and the lower surface via hole 40d correspond to connection via holes filled with a connection material for electrically connecting the electrodes 31 and 32 of the electric element 30 and the wiring pattern 20b. . The upper surface via holes 40a and 40c and the lower surface via holes 40b and 40d correspond to a plurality of via holes facing the upper surface and the lower surface of the electric element 30 described in the claims.

  Here, for example, in the electric element 30 having electrodes on the upper surface and the lower surface, the via holes 40 can be disposed on both the upper surface and the lower surface of the electric element 30. Therefore, depending on the configuration of the electric circuit, as shown in FIG. 2, via holes 40a and 40d as connection pillars that are electrically connected to the wiring pattern 20b on the upper surface of the electrode 31 and the lower surface of the electrode 32 to provide the electric circuit. A configuration in which is arranged is also conceivable.

  However, in the case of the configuration shown in FIG. 2, via holes 40 a and 40 d facing the upper surface and the lower surface of the electric element 30 (transmitting pressure from the hot press plate to the electric element 30) are stacked on the upper and lower surfaces of the electric element 30. They are in positions that do not overlap each other in any direction. Further, via holes 40a and 40d filled with a connection material for connecting the electrodes 31 and 32 and the wiring pattern 20b, and via holes 40e and 40f filled with a connection material for connecting the wiring pattern 20b and the land 20a, The printed circuit boards 100 are arranged apart from each other with respect to the plane direction of the printed circuit board 100 so as not to overlap with each other in the stacking direction of the printed circuit boards 100. FIG. 2 is a schematic sectional view for explaining the conventional problems.

  Further, when a printed circuit board 100 is formed by laminating a plurality of resin films made of thermoplastic resin and pressurizing and heating (collective pressing), the conductive patterns 20a and 20b arranged on the thermoplastic resin 10 and connection columns are used. The via holes 40a, 40d, 40e, and 40f cause a difference in the pressure received by the respective portions of the upper surface and the lower surface of the electric element 30 from the hot press plate.

  In the configuration shown in FIG. 2, the pressure (open arrow in FIG. 2) transmitted through the via hole 40 a serving as a connection column facing the upper surface of the electric element 30 and the connection column facing the lower surface of the electric element 30. The pressure (the white arrow in FIG. 2) transmitted through the via hole 40 d acts in a reverse direction at different positions in the plane direction of the electric element 30. Accordingly, a stress in the rotational direction around the electric element 30 is generated, and this stress may cause asymmetric deformation around the electric element 30. This asymmetric deformation is, for example, at least one of the inclination of the electric element 30 in the stacking direction, the buckling of the via holes 40a and 40d facing the upper and lower surfaces of the electric element 30, and the inclination of the wiring pattern 20b in the stacking direction. . FIG. 2 shows an example in which the via holes 40a and 40d are buckled and the wiring pattern 20b is inclined due to the stress in the rotational direction.

  On the other hand, in the printed circuit board 100 according to the present embodiment, via holes 40b and 40c as connection pillars for anchoring and stress dispersion are respectively connected to via holes 40a and 40d as connection pillars for electrical connection and the stacking direction of the printed circuit board 100. In FIG. 4, a via pair at least partially overlaps. That is, the upper surface via holes 40a and 40c and the lower surface via holes 40b are located at predetermined positions with respect to the upper surface and the lower surface of the electric element 30 so as to reduce or eliminate stress in the rotation direction around the electric element 30 during pressurization and heating. , 40d are arranged.

  As described above, the printed circuit board 100 according to this embodiment includes the electrical material 30 and the connection material filled in the via holes 40a and 40d and / or the connection material filled in the via holes 40a and 40d and the conductor pattern 30b. Connection failure is unlikely to occur between them. Therefore, in the printed circuit board 100 configured such that the via holes 40a and 40d face the upper and lower surfaces of the electric element 30, the electrical connection between the built-in electric element 30 and the conductor pattern 20 (the wiring pattern 20b and the land 20a). Reliability can be improved.

  In this embodiment, as shown in FIGS. 1A and 1B, the upper surface via hole 40a and the lower surface via hole 40b, and the upper surface via hole 40c and the lower surface via hole 40d constituting the via pair are completely formed in the stacking direction. It is comprised so that it may overlap. Therefore, the electrical connection reliability between the built-in electric element 30 and the conductor pattern 20 (the wiring pattern 20b and the land 20a) can be further improved.

  In the present embodiment, as shown in FIG. 1B, a plurality (two) of via pairs are arranged at symmetrical positions with respect to the electric element 30. Therefore, the stress in the rotation direction around the electric element 30 can be further reduced or eliminated during pressurization and heating.

  Next, an example of a method for manufacturing the printed circuit board 100 having the above-described configuration will be described with reference to cross-sectional views according to processes shown in FIGS. In FIG. 3, (a) shows the preparation step, (b) shows the lamination step, and (c) shows the state after the pressurizing / heating step.

First, the preparation process is performed. A resin film made of a thermoplastic resin and provided with a conductive foil on one side is prepared (in this example, two resin films 11 and 12 are prepared). Then, the conductor pattern 20 (land 20a, wiring pattern 20b, dummy wiring pattern 20c) is formed by etching the conductor foil into a desired pattern. In the present embodiment, a type 1 LCP (melting point: 320 ° C.) having a thickness of 50 μm is used as a constituent material of the resin films 11 and 12, and a Cu foil is used as a conductor foil. In addition, the conductor pattern 20 can also be formed using a printing method or a plating method other than the etching of the conductor foil. further,
After the conductor pattern 20 is formed, as shown in FIG. 3A, the resin films 11 and 12 are irradiated with, for example, a carbon dioxide laser from the back side of the conductor pattern 20 (20a to 20c) to thereby form the conductor pattern 20 (20a to 20c). The bottomed via hole 40 (40a to 40f) is formed. For forming the via hole 40 (40a to 40f), it is possible to use a UV-YAG laser, an excimer laser, or the like in addition to the carbon dioxide laser. In addition, via holes can be formed mechanically by drilling or the like, but since it is necessary to process the conductor pattern 20 (20a to 20c) without damaging it, a laser processing method is selected. It is preferable to do.

  In addition, when the via holes 40 (40a to 40f) are formed in the resin film 13, the dimensions of the electrical elements 30 are approximately the same as the outer dimensions of the electrical elements 30 by laser processing corresponding to the arrangement positions of the electrical elements 30 incorporated in the process described later. A through hole 13a is formed. Thus, if the through hole 13a is formed in the same process as the formation of the via hole 40 (40a to 40f), the manufacturing process can be simplified. However, the through-hole 13a only needs to be formed before the later-described lamination process, and the through-hole 13a can be formed by punching, router processing, or the like separately from the formation of the via holes 40 (40a to 40f).

When the formation of the via holes 40 (40a to 40f) is completed, each via hole 40 (40a to 40f) is filled with a conductive paste as a connection material. This conductive paste is a paste obtained by mixing tin particles and silver particles so that the tin particles occupy approximately 35 wt% and adding an organic solvent (for example, terpineol). A screen printer, a dispenser, or the like can be used for filling the conductive paste. In addition, when a thing with an average particle diameter of 0.5-20 micrometers and a specific surface area in the range of 0.1-1.5 m < ² > / g is used as a tin particle and silver particle, interlayer connection reliability can be improved. The conductive paste is filled in the via holes 40 (40a to 40f) and then heated for a predetermined time to dry the organic solvent. The above is the preparation process.

  When the preparation process is completed, the resin film 11 to 13 are stacked together with the electric element 30 in the stacked configuration shown in FIG. At this time, the electric element 30 is accommodated in the space part 50 which consists of the resin film 13 in which the through-hole 13a was formed, and the back surface of the conductor pattern formation surface of the resin film 12. In the stacked state, upper surface via holes 40a and 40c and lower surface via holes 40b and 40d constituting via pairs are disposed on the upper and lower surfaces of the electrodes 31 and 32 with respect to the electrodes 31 and 32 of the electric element 30, respectively. In addition, in FIG.3 (b), the electrical element 30 and each resin film 11-13 are spaced apart and shown for convenience.

  And after a lamination process, the pressurization and the heating process of heating while pressing with a hot press machine which is not illustrated from the upper and lower sides of a layered product are carried out. At this time, heating temperature shall be more than the temperature (glass transition point thru | or melting | fusing point) at which the elasticity modulus of each resin film 11-13 falls. In this embodiment, heating was performed at a temperature of 320 ° C. for several tens of seconds while applying a pressure of 1 to 10 MPa.

  As a result, the resin films 11 to 13 are softened and bonded to each other to be an integrated thermoplastic resin 10. Further, the connection material in the via hole 40 (40a to 40f) becomes an integrated conductive composition by sintering, and the adjacent conductor pattern 20 (20a to 20c) and the electrodes 31 and 32 of the electric element 30 Diffusion bonding is performed. That is, the lands 20a are electrically connected to the electric element 30 via the connection material filled in the via holes 40 (40a, 40d, 40e, 40f) and the conductor pattern 20 (wiring pattern 20b).

  At this time, in this embodiment, the upper surface via hole 40a facing the upper surface portion of the electrode 31 of the electric element 30, the lower surface via hole 40b facing the lower surface portion, and the upper surface via hole facing the upper surface portion of the electrode 32 of the electric element 30. 40c and the lower surface via hole 40d facing the lower surface portion form a via pair at least partially overlapping in the stacking direction. Therefore, the upper surface via holes 40a and 40c and the lower surface via holes 40b are located at predetermined positions with respect to the upper surface and the lower surface of the electric element 30 so as to reduce or eliminate stress in the rotation direction around the electric element 30 during pressurization and heating. , 40d are arranged. Therefore, the electrical connection reliability between the built-in electric element 30 and the conductor pattern 20 (the wiring pattern 20b and the land 20a) can be improved.

  Then, through a cooling step after hot pressing, as shown in FIG. 3C, a printed circuit board 100 incorporating the electric element 30 is formed. Thereafter, an electronic component (not shown) is mounted on the land 20 a of the printed circuit board 100.

  Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be implemented with various modifications.

  In the present embodiment, an example in which the thermoplastic resin 10 constituting the printed circuit board 100 is configured by stacking six resin films 11, 12, and 13 is shown. However, the number of electrical elements 30 is not particularly limited as long as the electrical elements 30 can be arranged in the thermoplastic resin 10.

  Moreover, in this Embodiment, the example which uses the liquid crystal polymer (LCP) which is a thermoplastic resin as each film 11, 12, 13 which comprises the printed circuit board 100 was shown. However, other than that, a thermoplastic resin film composed of 65 to 35% of polyetheretherketone (PEEK) and 35 to 65% of polyetherimide (PEI) may be used, or PEEK and PEI are used alone. May be. Furthermore, polyethersulfone (PES), polyphenylene ether (PPE), polyethylene naphthalate (PEN), a styrenic resin having a syndiotactic structure, etc. may be used alone, or each of them including PEEK and PEI. Any one of them may be mixed and used. In short, in the heating / pressurizing step, the resin films can be bonded to each other, and any resin film having heat resistance necessary for soldering or the like, which is a subsequent step, can be suitably used.

  Further, in the present embodiment, all the via holes 40a to 40d facing the upper surface and the lower surface of the electric element 30 are formed on the conductor pattern 20 (the wiring pattern 20b and the dummy wiring pattern 20c) at the other end facing the electric element 30. An example of facing (filled connecting material is connected to the conductor pattern 20) is shown. However, a configuration without the conductor pattern 20 may be used in a portion where the circuit pattern is not particularly necessary. An example is shown in FIG. FIG. 4 is a schematic cross-sectional view showing a modification of the present embodiment, which is a configuration without the dummy wiring pattern 20c as compared with the first embodiment. However, the conductor pattern 20 (20b, 20c) facing the via holes 40a to 40d becomes a load on the softened thermoplastic resin 10 when a stress in the rotational direction occurs during pressurization and heating, and the inclination of the electric element 30 Suppress etc. Therefore, it is preferable to provide the dummy wiring pattern 20c for all the via holes 40a to 40d facing the upper surface and the lower surface of the electric element 30, even if the via holes 40b and 40c are not necessary on the circuit pattern.

  Moreover, in this embodiment, the example of a structure by which a via pair is arrange | positioned to all the electrodes 31 and 32 of the electric element 30 was shown. However, if the stress in the rotational direction can be regulated, there is no need to arrange via pairs at 31 and 32 for all electrodes. For example, as shown in FIG. 5, the pressure from the upper surface via hole 40a side shown in FIG. 2 is applied even in the configuration in which the via pair consisting of the upper surface via hole 40a and the lower surface via hole 40b is arranged only on one electrode 31 of the electric element 30. Since the stress can be relaxed, the stress in the rotational direction can be reduced. However, as shown in the present embodiment, the configuration in which via pairs are arranged in all the electrodes 31 and 32 of the electric element 30 is more effective because there are a plurality of via pairs. FIG. 5 is a schematic cross-sectional view showing a modification of the present embodiment, which is a configuration without the upper surface via hole 40c and the dummy wiring pattern 20c as compared with the first embodiment.

  Further, in the present embodiment, an example in which the upper surface via holes 40a and 40c and the lower surface via holes 40b and 40d constituting the via pair are provided so as to completely coincide with each other in the stacking direction has been described. However, as shown in FIGS. 6A and 6B, for example, the via pair may be provided so that at least a part thereof overlaps in the stacking direction. 6A and 6B are diagrams showing a modification of the present embodiment, where FIG. 6A is a cross-sectional view, and FIG. 6B is a via hole 40a to 40d facing the upper and lower surfaces of the electric element 30. It is a schematic diagram which shows these positional relationships.

  Moreover, in this embodiment, the example which regulates the inclination of the lamination direction of the electrical element 30, etc. by arrange | positioning a via pair to each electrode 31 and 32 of the electrical element 30 was shown. However, the position where the inclination of the electric element 30 in the stacking direction and the like is restricted may be the upper surface and the lower surface of the electric element 30 and is not limited to the electrodes 31 and 32. For example, as shown in FIGS. 7A and 7B, a via pair composed of the upper surface via hole 40g and the lower surface via hole 40h filled with the connection material may be disposed in a region other than the electrode formation region (for example, the protective ceramic region). good. The upper surface via hole 40g and the lower surface via hole 40h are provided at substantially the center position in the planar direction of the electric element 30, and thereby, the inclination in the stacking direction of the electric element 30 with respect to the stress in the rotation direction can be regulated. . 7A and 7B are views showing a modification of the present embodiment, in which FIG. 7A is a cross-sectional view, and FIG. 7B is a via hole 40a to 40d facing the upper and lower surfaces of the electric element 30. , 40g, 40h is a schematic diagram showing the positional relationship.

  Further, the configuration for reducing or eliminating the stress in the rotation direction around the electric element 30 is not limited to the via pair by the via hole facing the upper surface and the lower surface of the electric element 30. For example, with respect to the electric element 30 shown in the present embodiment, the lower surface via holes 40b and 40d are disposed on the lower surfaces of the electrodes 31 and 32, and the upper surface via hole is disposed on the upper surface portion at the intermediate position between the lower surface via holes 40b and 40d. good.

  In the present embodiment, an example in which an element in which the electrodes 31 and 32 are formed on both end portions including the upper surface and the lower surface (that is, from the upper surface to the lower surface) is applied as the electric element 30 has been described. However, for example, the present invention can also be applied to the electric element 30 in which electrodes are formed only on one side.

  Moreover, in this embodiment, the example which arrange | positions two via pairs in a symmetrical position in the planar direction of the electric element 30 was shown. However, in the case of a configuration in which three or more via pairs are arranged with respect to the electric element 30, if the via pairs are evenly distributed in the plane direction of the electric element 30, the stress in the rotation direction around the electric element 30 is increased. It can be reduced or eliminated. An example is shown in FIG. In FIG. 8, reference numerals 40j, 40m, 40p, 40r, and 40t are upper surface via holes, and reference numerals 40k, 40n, 40q, 40s, and 40u indicate lower surface via holes.

  The printed circuit board 100 has a configuration in which a resin other than the thermoplastic resin (for example, a thermosetting resin or a glass cloth-containing resin) is disposed on at least one of the upper surface and the lower surface of the above-described printed circuit board 100 made of the thermoplastic resin 10. Also good.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows schematic structure of the printed circuit board in the 1st Embodiment of this invention, (a) is sectional drawing. FIG. 2 is a schematic cross-sectional view illustrating a conventional problem. It is sectional drawing according to process which shows an example of the manufacturing method of a printed circuit board, (a) is a preparatory process, (b) is a lamination process, (c) has shown the pressurization and heating process. It is a schematic sectional drawing which shows the modification of this embodiment. It is a schematic sectional drawing which shows the modification of this embodiment. It is a figure which shows the modification of this embodiment, (a) is sectional drawing, (b) is a schematic diagram which shows the positional relationship of the via hole which faces the upper surface and lower surface of an electric element. It is a figure which shows the modification of this embodiment, (a) is sectional drawing, (b) is a schematic diagram which shows the positional relationship of the via hole which faces the upper surface and lower surface of an electric element. It is the schematic diagram which showed the positional relationship of the via hole which faces the upper surface and lower surface of the electric element which shows the modification of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Thermoplastic resin 11-13 ... Resin film 20 ... Conductor pattern 20a ... Land 20b ... Wiring pattern 20c ... Dummy wiring pattern 30 ... Electric element 31, 32 ... Electrode 40: Via holes 40a, 40c filled with connection material Upper surface via holes 40b, 40d ... Lower surface via hole 100 ... Printed circuit board

Claims (21)

A printed circuit board in which an electrical element is disposed in a thermoplastic resin, and an electrode of the electrical element is electrically connected to a conductor pattern disposed in the thermoplastic resin through a connection via hole filled with a connection material Because
The thermoplastic resin is constituted by laminating a plurality of resin films made of a thermoplastic resin and adhering to each other by pressing and heating from both the upper and lower sides,
The upper surface and the lower surface of the electric element in the stacking direction are inclined in the stacking direction of the electric element, buckling of the connection via hole filled with the connection material, and the stacking direction of the conductor pattern during the pressing and heating. A printed circuit board, wherein a plurality of via holes filled with the connection material including at least the connection via holes face a position that regulates the inclination of the printed circuit board.   The printed circuit board according to claim 1, wherein the electrical element is housed in a space provided inside the thermoplastic resin.   The printed circuit board according to claim 1, wherein the connection material filled is connected to the conductor pattern in all of the plurality of via holes.   2. The via hole facing the upper surface of the electric element and the via hole facing the lower surface of the electric element constitute at least one via pair at least partially overlapping in the stacking direction. The printed circuit board according to any one of? 3.   The printed circuit board according to claim 4, wherein a plurality of the via pairs are provided.   The printed circuit board according to claim 5, wherein the plurality of via pairs are evenly distributed in a planar direction of the electric element.   The printed circuit board according to claim 5, wherein the plurality of via pairs are arranged at symmetrical positions in a planar direction of the electric element. The electrode of the electric element is formed from the upper surface to the lower surface,
8. The printed circuit board according to claim 4, wherein in each of the via holes constituting the via pair, the filled connection material is connected to the electrode. 9.   The printed circuit board according to claim 8, wherein the via pairs are arranged for all the electrodes.   10. The printed circuit board according to claim 8, wherein the filled connection material is connected to the conductor pattern in both via holes constituting the via pair. 11.   11. The conductor pattern to which the filled connection material is connected in one via hole constituting the via pair is a dummy conductor pattern that is not electrically connected to the other conductor pattern. Printed circuit board as described in 1. A preparation step of preparing a plurality of resin films made of a thermoplastic resin, including a thermoplastic resin resin film in which a connection via hole filled with a connection material is formed with a conductive pattern formed on at least one surface as a bottom surface;
Laminating step of positioning and laminating a plurality of the resin films, placing an electric element between the resin films, and forming a laminate,
Pressurizing and heating the laminate from above and below both sides with a hot press plate, and a pressurizing and heating process for bonding the resin films to each other,
Through a connection material filled in the connection via hole, a method for producing a printed circuit board in which the electrode of the electric element and the conductor pattern are electrically connected,
In the preparation step, corresponding to the position where the electric element is arranged at the time of lamination, a through hole having a dimension substantially the same as the outer shape of the electric element or a groove is formed in the resin film,
A plurality of via holes filled with the connection material including at least the connection via holes are formed in the resin film so as to face predetermined positions on the upper surface and the lower surface of the electric element in the stacking direction during stacking,
In the pressurizing / heating step, the inclination of the electric element in the stacking direction, the buckling of the connection via hole filled with the connection material, and the inclination of the conductive pattern in the stacking direction are suppressed. Production method.   13. The method of manufacturing a printed circuit board according to claim 12, wherein in the preparing step, all of the plurality of via holes are formed with the conductor pattern as a bottom surface.   In the stacking step, the preparation is performed so that at least one via pair at least partially overlaps in the stacking direction is formed by the via hole facing the upper surface of the electric element and the via hole facing the lower surface of the electric element. The method for manufacturing a printed circuit board according to claim 12 or 13, wherein in the step, the via hole is formed in the resin film.   The method for manufacturing a printed circuit board according to claim 14, wherein a plurality of the via pairs are configured.   The method of manufacturing a printed circuit board according to claim 15, wherein the via hole is formed in the resin film in the preparation step so that a plurality of the via pairs are evenly distributed in a planar direction of the electric element. .   The via hole is formed in the resin film in the preparation step so that a plurality of the via pairs are arranged at symmetrical positions in the planar direction of the electric element. Manufacturing method for printed circuit boards. The electrode of the electric element is formed from the upper surface to the lower surface,
The via hole is formed in the resin film in the preparation step so that the filled connection material is connected to the electrode in both via holes constituting the via pair. 17. The method for producing a printed circuit board according to any one of 17 above.   The method of manufacturing a printed circuit board according to claim 18, wherein the via pairs are arranged for all the electrodes.   The via hole is formed in the resin film in the preparation step so that the filled connection material is connected to the conductive pattern in both via holes constituting the via pair. Or the manufacturing method of the printed circuit board of Claim 19.   21. The conductor pattern to which the filled connection material is connected in one via hole constituting the via pair is a dummy conductor pattern that is not electrically connected to the other conductor pattern. The manufacturing method of the printed circuit board of description.

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