JP2012248805A - Manufacturing method of print circuit board mounted with components - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a print circuit board mounted with components capable of reducing the thickness and simplifying the manufacturing steps thereof.SOLUTION: The manufacturing method of a print circuit board mounted components which are electrically connected to each other includes the steps of: a through-hole forming step to form through-holes corresponding to the size of the components and the positions of the terminals on the print circuit board; a through-hole connecting step to form component insertion parts to connect through-holes 17 to each other by removing a part of the print circuit board between at least two through-holes formed in the through-hole forming step; and a component inserting step to insert the components so that each of the terminals of the components are brought into contact with the inner wall surface of at least two through-holes which is left after the through-hole connecting step.

Description

  The present invention relates to a method for manufacturing a component-mounted printed wiring board.

Examples of conventional component mounting methods on a printed wiring board include the following.
As shown in FIG. 4A, first, a land 14 and a circuit pattern 15 continuous to the land 14 are formed on the surface of the substrate 11 to form a printed wiring board. Next, the component 12 provided with connection terminals 13 at both ends is arranged so that the terminal 13 is placed on the land 14, and the components are mounted by electrical and physical connection with solder 16. Do. When component mounting is performed on an actual printed wiring board, component mounting is performed through a solder paste printing process on the land 14, a component placing process, a solder paste melting and fixing process by reflow heating, and the like. .

Mounting components on such a printed wiring board has been conventionally performed, and a technique of further stacking on a printed wiring board on which components are mounted has been proposed. Such a thing is mentioned.
The object described in Patent Document 1 is to provide a component-embedded multilayer printed wiring board that prevents warping of the substrate, has a high wiring density, and can be thinned. The purpose of the present invention is to provide a printed wiring board with built-in components with high reliability and excellent flatness of the built-in electronic circuit components, and a method for manufacturing the printed wiring board with built-in components with high productivity. These patent documents 1 and 2 are common in that they are technologies for mounting components on the inner layer of a multilayer printed wiring board.
JP 2008-078573 A JP 2009-289790 A

  In the conventional component mounting method shown in FIG. 4, it is necessary to go through a number of processes such as a solder paste printing process on the land 14, a process of placing the parts, and a process of melting and fixing the solder paste by reflow heating. Therefore, the manufacturing process is complicated and the manufacturing cost becomes high.

Further, as shown in FIG. 4C, when the component 12 is mounted on the printed wiring board, the height of the entire product is obtained by adding the mounting height of the component 12 to the height of the substrate 11. Therefore, there is a problem that it is difficult to reduce the thickness of the printed wiring board.
This is also the case in Patent Documents 1 and 2 in which multi-layering is performed after component mounting. When the component to be mounted is large, the layer on which the component is mounted and the layer stacked thereon Therefore, there is a problem in that the thickness of the multilayer printed wiring board as a whole increases and the printed wiring board cannot be thinned.

  The present invention has been made in view of the above problems, and provides a method for manufacturing a component-mounted printed wiring board that can simplify the manufacturing process and realize a thinner printed wiring board. It is the purpose.

  According to a first aspect of the present invention, when a component that needs to be electrically connected is mounted on a printed wiring board, through holes are formed in the printed wiring board at locations corresponding to the size and terminal position of the component. Through-hole forming step, and a through-hole connecting step of removing a printed wiring board portion between at least two through-holes formed in the through-hole forming step and connecting the through-hole 17 to form a component insertion portion And mounting the component by mounting the component so that the terminal of the component comes into contact with the inner wall surfaces of at least two through holes remaining after the through-hole connecting step. It is a manufacturing method of a printed wiring board.

  According to a second aspect of the present invention, in addition to the first aspect, in the through-hole forming step, two through-holes having straight portions in a plan view are formed in parallel, and the two through-holes are formed. The through hole formation position is determined so that the distance between the inner wall surfaces located outside each other matches the length between the terminals of the flat terminal formed on both ends. It is the manufacturing method of the component mounting printed wiring board to do.

  According to a third aspect of the present invention, in addition to the second aspect, in the through-hole connecting step, the printed wiring board portion is removed so that the inner wall surfaces of the two through-holes located outside each other remain. This is a method for manufacturing a component-mounted printed wiring board, characterized by forming a portion.

  According to a fourth aspect of the present invention, in addition to the first to third aspects, in the component fitting step, a conductive adhesive is applied between the terminal of the component and the inner wall surface of the through hole to insert the component. This is a method of manufacturing a component-mounted printed wiring board characterized by being configured as described above.

According to the first aspect of the present invention, a through hole is formed at a position where a printed wiring board is to be mounted on a component and at a position where a terminal of the component will come into contact, and a space between the plurality of through holes is formed. The printed wiring board part is removed to form the component insertion part, and the component is fitted without the soldering process by fitting the component so that the terminal of the component is in contact with the inner wall surface of the through hole. It becomes possible to do.
In addition, because it is possible to mount components by fitting them in the thickness direction of the printed wiring board, the printed wiring board is significantly thinner than when mounting components on a conventional printed wiring board. Is possible.

  According to a second aspect of the present invention, in the through hole forming step, two long hole through holes having straight portions are formed in parallel in a plan view, and the two through holes are positioned outside each other. The positions where the through holes are formed are determined so that the distance between the inner wall surfaces matches the length between the terminals of the parts having planar terminals formed at both ends. When a part having a terminal is fitted into the terminal, the terminal accurately contacts the inner wall surface of the through hole, and electrical conduction is reliably performed.

  According to a third aspect of the present invention, in the through hole connecting step, the printed wiring board portion is removed so as to form the component insertion portion so that the inner wall surfaces located outside the two through holes remain. As a result, an optimal component insertion portion can be formed by appropriately removing the printed wiring board portion according to the size of the component, while leaving the inner wall surface of the through hole with which the component terminal contacts.

  According to the invention of claim 4, since the component fitting step is performed by applying a conductive adhesive between the terminal of the component and the inner wall surface of the through hole, the component fitting is performed. Even if the distance between the inner wall surfaces is designed with a slight margin, electrical conduction can be ensured by applying a conductive adhesive between the terminal 13 and the inner wall surface of the through hole. Therefore, an electrically stable connection can be achieved while absorbing dimensional errors of parts, errors in the formation positions of through holes, and the like.

(A)-(c) is a perspective view showing each process of the manufacturing method of the component mounting printed wiring board of this invention. (A)-(c) is the top view and sectional drawing showing each process of the manufacturing method of the component mounting printed wiring board of this invention. (A), (b) is the top view showing the other Example which connects two through-holes by router processing, (c) represented the example which forms two through-holes in a rectangular shape. It is a top view and (d) is a top view showing the example which connected two through holes in the case of the above-mentioned (c) by router processing. (A), (b) is a perspective view showing each process of the manufacturing method of the conventional component mounting printed wiring board, (c) is AA of the printed wiring board after component mounting of (b). It is line sectional drawing.

  In the method of manufacturing a component-mounted printed wiring board according to the present invention, when a component that needs to be electrically connected is mounted on a printed wiring board, the printed wiring board is placed at a location corresponding to the size and terminal position of the component. A through hole forming step for forming each through hole, and a printed wiring board portion between at least two through holes formed in the through hole forming step is removed and the through hole 17 is connected to form a component insertion portion. Component mounting by performing a through-hole connecting step and a component fitting step of fitting the component so that the terminal of the component comes into contact with the inner wall surfaces of at least two through holes remaining after the through-hole connecting step. It is a feature. Details will be described below.

  The manufacturing method of the component mounting printed wiring board of this invention is demonstrated. The method for manufacturing a component-mounted printed wiring board according to the present invention mainly includes a through-hole forming step, a through-hole connecting step, and a component fitting step. Hereinafter, each step will be described.

[Through hole formation process]
First, the through hole forming process will be described. As shown in FIGS. 1 (a) and 2 (a), the present invention is characterized in that a long through hole 17 is formed in parallel and close to a place where a component is mounted. As a through hole forming step, after laminating a copper foil on the substrate 11, a long through hole is formed in a portion where a through hole is to be formed, for example, drilling or router processing, and then desmearing is performed. Thereafter, through-holes 17 are formed by plating the through-holes. Finally, the copper foil is removed by etching, leaving a portion adjacent to the through hole 17 and a portion where the circuit pattern 15 is to be formed, whereby the through hole 17 and the circuit pattern 15 are formed. The through hole 17 formed here is formed as a long hole so as to have a portion that becomes a straight line in plan view, that is, a portion that becomes a plane on the inner wall surface. In addition, the formation position of the through hole 17 is determined so that the distance between the inner wall surfaces located on the outer sides of the two through holes 17 formed in close proximity to each other matches the size of the component 12 to be mounted.

[Through hole connection process]
After the long through holes 17 are formed in close proximity to each other, the process proceeds to the through hole connecting step. In this step, the substrate portion between the two through holes 17 is removed and the two through holes 17 are connected. Specifically, by cutting the inner side of the broken line shown in the plan view of FIG. 2A by router processing, the two through holes 17 are connected as shown in FIGS. 1B and 2B. Thus, the component insertion portion 18 is formed. The component insertion part 18 needs to be formed so as to have a width that allows at least the component 12 to be fitted. The inner wall surfaces of the two through holes 17 remaining after this step function as contact portions of the terminals 13.
Note that the method of removing the substrate portion between the two through holes 17 is not limited to the router processing, and may be another method capable of laser processing or the like.

[Part fitting process]
After the through-hole connection process is completed, the process shifts to a part fitting process. In this step, the component 12 is fitted and electrically connected to the component insertion portion 18. As shown in FIG. 2B, the component 12 is provided with connection terminals 13 at both ends, and these terminals 13 come into contact with the inner wall surfaces of the two through holes 17 and are electrically connected. The part 12 is fitted so that it may do. Since the distance between the inner wall surfaces of the two through-holes 17 is designed and formed in advance in the through-hole forming step so as to be the same as the length of the component 12, the component 12 is fitted to the component insertion portion 18 without a gap. Are connected without any electrical problems. The state after component fitting is shown in FIG.1 (c) and FIG.2 (c).

  As described above, through the through-hole forming step, the through-hole connecting step, and the component fitting step, the component mounting print as shown in FIG. 1 (c) and FIG. 2 (c) without passing through the soldering step. The wiring board 10 can be manufactured. When mounting a component 12 having substantially the same thickness as the substrate 11 as shown in the cross-sectional view of FIG. 2C, the thickness of the printed wiring board as compared with the conventional mounting method as shown in FIG. Can be halved, and a significant space saving can be realized.

Further, when the component 12 having the same thickness as that of the substrate 11 as shown in the cross-sectional view of FIG. 2 (c) is mounted, even when the circuit pattern is laminated on the outer side, the extra prepreg of the component portion is cut out Since it is not necessary to carry out a complicated process, the cost can be reduced by omitting the process.
Even when a component having a thickness larger than that of the substrate 11 is mounted and a circuit pattern is further laminated on the outer side, a part protruding from the substrate 11 is inserted by fitting the component 12 to the substrate 11 by the thickness of the substrate 11. As a result, the distance between the layers can be shortened as compared with the case where the component is mounted on the substrate 11 as it is, and the printed wiring board can be thinned as a whole.

  In the above embodiment, in the through-hole connecting step, the part insertion portion as shown in the plan view of FIG. 2B is obtained by connecting the two through-holes 17 by removing the part 12 by the width of the parts. 18 was formed. However, the shape is not limited to the shape of the component insertion portion 18 as shown in the plan view of FIG. 2B. For example, the component insertion portion 18 has a shape as shown in FIG. 3A or 3B. You may make it connect a through hole so that it may become. In both of these, since the plated portion of the inner wall surface of the straight portion of the through hole 17 is left as it is, it is in a state in which electrical connection with the component 12 can be satisfactorily performed. .

  Moreover, in the said Example, since it demonstrated as what forms a through-hole of a long hole by drilling or a router process in the process of through-hole formation, the through-hole 17 after a plating process also has a cylindrical part at the end Met. However, the present invention is not limited to this. For example, when a method capable of high-precision processing such as laser processing is employed, the end portion is also precisely as shown in FIG. It is also possible to form a rectangular through hole 17 having a right angle. In this case, by connecting the two through holes 17, as shown in FIG. 3 (d), a rectangular component insertion portion 18 can be formed in plan view, and the rectangular parallelepiped component 12 can be fitted without a gap. It is also possible to make it.

  In the embodiment, in the through hole forming step, the distance between the inner wall surfaces of the two through holes 17 is designed and formed in advance so as to be the same as the length of the component 12. Electrical connection was made by fitting without gaps. In this case, formation of the through hole 17 having a certain degree of dimensional accuracy and manufacture of the component 12 are required. If the dimensional error is large, there is a risk that the part will not fit or the electrical connection will become unstable due to the loose fit of the part. Therefore, the distance between the inner wall surfaces of the two through holes 17 is designed with a slight clearance, and a conductive adhesive is applied between the terminal 13 and the inner wall surface of the through hole 17 when the component 12 is fitted. By attaching the connection, it is possible to realize an electrically stable connection while lowering the required level of dimensional accuracy.

  In the above-described embodiment, the description has been given as the drawing in which the through hole is formed when the number of the substrates 11 is one. However, the present invention is not limited to this, and all layers are penetrated through the multilayered printed wiring board. The present invention can also be realized by forming the two through holes 17 and performing the through hole connecting step and the component fitting step in the same manner. Thereby, even if it is a case where the component 12 with a large volume is inserted, the component 12 can be mounted within the thickness range of the printed wiring board, and the printed wiring board can be thinned.

  In the above-described embodiment, in order to correspond to the component 12 having the two terminals 13, the two insertion holes 18 are formed by connecting the two through holes 17 to each other. For example, in order to deal with a three-terminal component, three through holes 17 are formed and connected to each other to electrically connect the three terminals. The part 18 can also be used. These are matters that can be appropriately set according to the number of terminals of the component.

  In the above embodiment, as shown in FIG. 1B, the description has been made using the component 12 in which the terminals 13 are formed on the two opposing faces of the rectangular parallelepiped. In the plan view, the long through hole 17 has a straight line portion. However, the present invention is not limited to this. For example, when the terminal 13 is a part formed in a semi-cylindrical shape, the through-hole 17 to be formed may be a circular through-hole. possible. That is, the shape of the through hole 17 can be appropriately changed according to the shape of the terminal 13 portion of the component 12.

DESCRIPTION OF SYMBOLS 10 ... Component mounting printed wiring board, 11 ... Board | substrate, 12 ... Component, 13 ... Terminal, 14 ... Land, 15 ... Circuit pattern, 16 ... Solder, 17 ... Through hole, 18 ... Component insertion part.

Claims (4)

  When mounting a component that needs to be electrically connected to a printed wiring board, a through hole forming step for forming a through hole at a location corresponding to the size and terminal position of the component on the printed wiring board, and A through hole connecting step of removing a printed wiring board portion between at least two through holes formed in the through hole forming step and connecting the through holes 17 to form a component insertion portion; and after the through hole connecting step A component mounting printed wiring board manufacturing method comprising: mounting a component by a component fitting step of fitting the component so that the terminal of the component comes into contact with the inner wall surfaces of at least two remaining through holes.   In the through hole forming step, through holes of two long holes having straight portions in a plan view are formed in parallel, and the distance between the inner wall surfaces of the two through holes located outside each other is at both ends. 2. The method of manufacturing a component-mounting printed wiring board according to claim 1, wherein the through-hole formation position is determined so as to match the length between the terminals of the component on which the planar terminals are formed.   3. The through-hole connecting step is formed by removing a printed wiring board portion to form a component insertion portion so that inner wall surfaces located outside each other of two through holes remain. Manufacturing method of component mounting printed wiring board.   4. The component mounting according to claim 1, wherein in the component fitting step, the component is fitted by applying a conductive adhesive between a terminal of the component and an inner wall surface of the through hole. Manufacturing method of printed wiring board.

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