WO2017163390A1

WO2017163390A1 - Printed board and printed board manufacturing method

Info

Publication number: WO2017163390A1
Application number: PCT/JP2016/059536
Authority: WO
Inventors: 清隆冨山; 佐々木　康; 宏義宮崎
Original assignee: 株式会社日立産機システム
Priority date: 2016-03-25
Filing date: 2016-03-25
Publication date: 2017-09-28
Also published as: JPWO2017163390A1; JP6640986B2

Abstract

In order to prevent a coating material from adhering to a component terminal via a through-via without requiring, with respect to a printed board, an additional step between a printed board manufacturing step and a step for mounting a component on the printed board, and make it possible to reduce the cost of applying a corrosion preventing coating material, the present invention is characterized by having: a step for forming a through-via penetrating a first surface and a second surface of the printed board; and a silkscreen printing step for displaying component-related information on the first surface or the second surface. The present invention is also characterized by closing the hole of the through-via in the silkscreen printing step.

Description

Printed circuit board and printed circuit board manufacturing method

The present invention relates to a printed circuit board on which connector parts and the like are mounted.

As a background art in this technical field, there is JP 2010-10498 A (Patent Document 1). This publication states that “a component with a slag part is soldered by solder printing and reflowing the slag part, and a footprint 13 for mounting the slag part and a through via provided in the footprint 13 for mounting the slag part. 11 is a component mounting method for mounting on a printed board having an information printing ink or component fixing adhesive 14 or a component mounting step in the step of mounting the slag-attached component on the printed board 10. It is described that the component 14 that closes the hole is subjected to a step of closing the hole of the through via 11 before mounting the component, and then component mounting, solder printing, and reflow are performed ”(see summary).

JP 2010-10498 A

To prevent corrosion due to a poor environment, apply a coating material (such as varnish) to prevent corrosion on the surface of the printed circuit board on which components are mounted. The coating material prevents moisture absorption and dust from adhering to the surface of the printed circuit board and the mounted components, and at the same time has an effect of blocking electrical conduction. The coating material is a low-viscosity liquid to ensure a uniform coating finish.

¡To apply the coating material to the surface of the printed circuit board on which the component is mounted, an application device is used in consideration of work efficiency, and it is applied automatically and manually by spraying and moving the coating material over a wide range from the device nozzle for spraying the coating material. In this operation, it is difficult to control the delicate application of the coating material having low viscosity and high permeability.

On the printed circuit board, there are also components that cause electrical connection failures due to the coating material adhering to the terminals, such as connectors, and these components must be prevented from adhering to the coating material. Don't be. Therefore, the coating material is applied by a coating apparatus while avoiding these components and the component peripheral area of the mounting surface.

On the other hand, coating materials are not normally prohibited on the opposite side of component mounting. In this case, the coating material may adhere to the component terminals through the through vias provided for connecting the wiring (copper foil pattern) between the substrate layers, and there is a possibility that an electrical connection failure may occur. In order to avoid this problem, it is only necessary to avoid application of the coating material to the through via, but in that case, the coating application cost becomes high. Specifically, since there are parts and wiring to which coating material is originally applied in areas where coating material is not applied, the amount of coating is adjusted while considering penetration into the parts where coating material adhesion is to be prevented. However, manual repair using a brush or the like is required.

Here, according to the description of Patent Document 1, “in a line (process) for mounting components on a printed board, a through via is blocked to prevent the solder from protruding to the back surface of the printed board in a simple process. (See paragraph 0013), and Patent Document 1 has a different purpose from the present invention that avoids connection failure due to coating material application after component mounting. Further, “the hole of the through via 11 is formed by the information printing ink or the component fixing adhesive 14 in the step of mounting the component with the slag portion on the printed board 10 or the component 14 which closes the hole in the component mounting step. Through the plugging process before mounting the components, component mounting, solder printing, and reflow are performed (see summary). Is to block.

In view of such circumstances, in the present invention, the coating material adheres to the component terminal via the through via without requiring an additional step to the printed circuit board between the printed circuit board production process and the component mounting process to the printed circuit board. It is an object of the present invention to provide a printed circuit board and a method for manufacturing the same that can prevent the above-described problem and reduce the cost of applying a corrosion-preventing coating material.

Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.

A method of manufacturing a printed circuit board in which a first surface on which a component is disposed and a second surface opposite to the first surface are coated with a coating material, wherein the first surface and the second surface are A step of forming a through via that penetrates, and a silk printing step of displaying information on the component on the first surface or the second surface, and in the silk printing step, It is a printed circuit board manufacturing method characterized by closing a hole.

The first surface on which the component is arranged and the second surface opposite to the first surface are coated with a coating material, and penetrate the first surface and the second surface. A through via that indicates information on the component and silk printed on the first surface or the second surface, wherein the silk closes a hole of the through via. It is a printed circuit board.

According to the present invention, an additional process to the printed circuit board is not required between the printed circuit board production process and the component mounting process to the printed circuit board, and the coating material is prevented from adhering to the component terminals through the through vias and corroded. It is possible to provide a printed circuit board capable of reducing the cost of applying the prevention coating material and a method for manufacturing the same.

Explanatory drawing which shows the 1st Example of the printed circuit board by this invention Explanatory drawing which shows 2nd Example of the printed circuit board by this invention. Explanatory drawing which shows the 3rd Example of the printed circuit board by this invention. Flow from printed circuit board production to mounting board completion by this example Illustration of printed circuit board production according to this example Illustration of mounting board using printed circuit board according to this example Illustration of a conventional printed circuit board Explanatory drawing of mounting board using printed circuit board of conventional example Explanatory drawing of coating material penetration route of mounting board using printed circuit board of conventional example

Hereinafter, examples will be described with reference to the drawings. Each embodiment described below is not limited to the illustrated example.

In the following embodiment, when necessary for the sake of convenience, the description will be divided into a plurality of sections or embodiments. However, unless otherwise specified, they are not irrelevant to each other. Is related to some or all of the other modifications, details, supplementary explanations, and the like.

Further, in the following embodiments, when referring to the number of elements (including the number, numerical value, quantity, range, etc.), particularly when clearly indicated and when clearly limited to a specific number in principle, etc. Except, it is not limited to the specific number, and it may be more or less than the specific number.

Further, in the following embodiments, the constituent elements (including element steps) are not necessarily essential unless explicitly stated or considered to be clearly essential in principle. Needless to say.

Similarly, in the following embodiments, when referring to the shape, positional relationship, etc., of components, etc., the shape of the component is substantially the case unless specifically stated or otherwise considered in principle. And the like are included. The same applies to the numerical values and ranges.

A configuration example of the printed circuit board in the present embodiment will be described with reference to FIGS. 1, 4, 5, and 6.

FIG. 4 is a flowchart showing the flow of the production process of the printed circuit board (bare board) and the component mounting process on the printed circuit board. 1, 5, and 6 shown in the flow are described with a two-layer double-sided substrate, the same description can be applied to a multilayer substrate.

The production process of a printed circuit board (bare board) having a circuit pattern will be described with reference to FIGS. In the substrate loading process, as shown in FIG. 5A, the printed circuit board 1 is initially in a state of a copper clad plate in which copper foil is stretched over the entire front and back surfaces. In the case of a double-sided two-layer substrate, it is also called a base material. . In the case of a multilayer printed board, an inner layer having a wiring pattern formed inside the printed board 1 is combined. In the drilling step, in order to form a through-hole 11 for making interlayer connection to the printed circuit board 1 and an insertion-type component described in the third embodiment, a through-hole for mounting the component is formed as shown in FIG. Drill holes in the same way. In the copper plating process, in order to conduct the circuit with the printed circuit board front and back, or the inner layer of the multilayer board, the inner wall of the hole is subjected to conduction plating as shown in FIG. In the etching process, the circuit pattern on the surface of the printed circuit board, and the component pad 12 for soldering the component terminal and the circuit pattern, remove the unnecessary copper foil by etching the copper foil stretched on the front and back of the printed circuit board 1. By doing so, it is formed as shown in FIG. In the resist coating process, the solder that joins the component pad 12 and the component terminal in soldering (flow, reflow, and manual soldering) in component mounting is supplied to and held accurately on the component pad 12, and other circuit patterns are provided. In order to prevent the solder from adhering to the substrate, a resist 13 is applied to a circuit pattern other than the component pads 12 as shown in FIG. In the silk printing process, in order to be able to confirm the component mounting position at the time of component mounting, inspection after component mounting, debugging, maintenance, etc., information related to components such as component outline and component symbols on the front or back side of the printed circuit board, It is printed on the surface of the printed board as shown by silk 15 in FIG. At this time, in the present embodiment, at the same time, in order to prevent the coating material from penetrating, the silk 14a is provided immediately below the component prohibited from adhering to the coating material, around the component, and on the rear surface of the component mounting portion, thereby closing the through-via hole. A component (connector) 2 is mounted using this printed circuit board 1 and soldered with solder 3 to form a component mounting substrate shown in FIG. For example, 22 is a component terminal connected to a connector (not shown), and 21 is a connection terminal connected to the component pad 12. Furthermore, the state which apply | coated the coating material 4 to this component mounting board | substrate becomes FIG.

Here, the printed circuit board produced without applying the present invention and the problem will be described with reference to FIGS. FIG. 7 shows a printed circuit board produced without applying the present invention. It differs from FIG. 5 (f) described above in that there is no silk 14a. A component mounting board shown in FIG. 8 is configured by mounting the component (connector) 2 using the printed board 1 and soldering with the solder 3. Furthermore, the state which apply | coated the coating material 4 to this component mounting board | substrate becomes FIG.

In FIG. 9, in order to avoid the penetration of the coating material into the component terminals 22 on the component mounting surface (component surface), a coating material application prohibited space is secured and the coating material is applied.

On the other hand, regarding the back surface (solder surface) of the component mounting surface, the coating material 4 may be applied in consideration of the component mounting state of the solder surface, and coating of the coating material on the back surface (solder surface) of the component (connector) 2 is prohibited. do not do. Therefore, the coating material 4 cannot be prevented from penetrating from the through via 11 of the printed circuit board 1 into the component terminal 22 via the substrate surface and further through the external surface of the component 2 as shown in the coating material penetration route b of FIG. . Further, as a method for preventing the coating material penetration route b from being formed, it is only necessary to avoid the application of the coating material to the through via 11 on the back surface (solder surface) of the component (connector) 2. A circuit pattern exists.

Therefore, in this embodiment, in FIG. 5 (f) of the bare board production process, the coating material penetration is performed by printing the silk (coating material penetration preventing member) 14a on the through via 11 around the part to be prevented from penetrating the coating material in advance. Perform route disconnection. In addition, the range of the silk (coating material penetration preventing member) 14a to be printed is determined in the board design, and no difference occurs in the bare board production process.

Next, the details of the printed circuit board having the silk (coating material penetration preventing member) described above will be described.

Application examples of the printed circuit board in the first embodiment will be described with reference to FIGS.

FIG. 1 is an explanatory view showing a first embodiment of a component-mounting printed board to which the present invention is applied.

The component mounting printed circuit board is composed of a combination of a printed circuit board (bare board) 1, a component 2, solder 3, and a coating material 4. The printed board 1 has a copper foil, a through via 11 made of copper plating, a component pad 12 formed by etching the copper foil, and a circuit pattern (not shown). The through via 11 is provided for the purpose of electrically connecting the component pads 12 and circuit patterns formed on the front and back of the printed board 1 and the circuit pattern of the inner layer. Further, a resist 13 is applied to circuit patterns other than the component pads 12 in order to prevent solder adhesion. At this time, the resist 13 cannot completely close the hole of the through via 11 due to restrictions of the substrate manufacturing method.

In the silk printing process, in order to be able to confirm the component mounting position at the time of component mounting, post-component mounting inspection, debugging, maintenance, etc., the component outline or component symbol is printed on the printed circuit board with silk 15 on the front or back surface of the substrate. Print. At the same time, the silk 14a is printed to prevent the coating material from penetrating. The silk (coating material penetration inhibiting member) 14a is intentionally designed to cover the hole of the through via, and the silk (coating material penetration inhibiting member) 14a is printed in accordance with the substrate design. As a result, the holes of the through vias 11 that cannot be completely closed by the resist 13 are closed by complementing the resist 13 with the silk 14a. Alternatively, the hole of the through via 11 is closed with the silk (coating material penetration preventing member) 14a alone.

FIG. 6 shows a state in which the component (connector) 2 is mounted and soldered after the solder 3 is printed on the component pad 12 on the printed circuit board 1 described above. In this embodiment, after the coating material 4 is applied, the state shown in FIG. 1 is reached, and the silk (coating material permeation prevention member) 14a blocks the through via 11 around the component (connector) 2, and therefore the back surface (solder surface). The route through which the applied coating material 4 penetrates into the component (connector) 2 is blocked. As a result, the coating material can be prevented from adhering to the component terminals, and the occurrence of poor electrical connection can be avoided. Furthermore, it is not necessary to avoid applying the coating material 4 to the through via 11 on the back surface of the printed circuit board around the component (connector) 2 mounting, while considering the penetration of the coating material to prevent the coating material from adhering and adjusting the coating amount No need for manual repair using a brush. Therefore, it is possible to provide a component-mounting printed board that can reduce the cost of applying the corrosion-preventing coating material.

An application example of the printed circuit board in the second embodiment will be described with reference to FIG. In this embodiment, an example of adding functions of the printed circuit board 1 in Embodiment 1 will be described. Therefore, the description of the parts common to the first embodiment is omitted.

FIG. 2A is a cross-sectional view of a component mounting board. FIG. 2B is a view of the printed circuit board 1 viewed from the mounting direction of the component (connector) 2.

In the present embodiment, the configuration in which the coating material penetration route is cut off by printing the silk (coating material penetration prevention member) 14a on the through via 11 around the part which the coating material penetration is to be prevented in advance as described in the first embodiment. Prepare. At the same time, it is characterized in that it has a structure for preventing the penetration of the coating material on the mounting surface of the component (connector) 2.

In this embodiment, the silk (coating material permeation preventing member) 14a is provided in advance so as to be under the coating material 4 and to surround the component (connector) 2. Further, a varnish permeating silk (coating material permeation preventing member) 14b is provided in advance so as to surround the component (connector) 2 on the inner side closer to the component (connector) 2 than 14a. In other words, in the silk printing process, the silk 14b is printed between the region where the silk 14a is printed and the component, and so as to surround the component. At this time, the silk (coating material penetration preventing member) 14a performs the same function as that of the first embodiment. Therefore, the silk 14a is also installed directly under the component (connector) 2. Further, the holes of the through vias 11 that cannot be completely blocked by the resist 13 are closed by complementing the resist 13 with the silk 14a. Alternatively, the hole of the through via 11 is closed with the silk (coating material permeation prevention member) 14a alone.

In this embodiment, the silk (coating material permeation prevention member) 14a and the varnish permeation silk (coating material permeation prevention member) 14b described above have a permeation prevention area a having a groove structure in the silk printing thickness and the space between the silks. Constitute. On the other hand, the application of the coating material 4 on the mounting surface of the component (connector) 2 should avoid the application of the surrounding coating material 4 at a certain distance from the component (connector) 2 in consideration of the permeability of the coating material 4. Don't be. At this time, the above-described permeation prevention area a can be used as a boundary for applying the coating material 4. The coating material 4 applied on the silk (coating material permeation preventing member) 14a is in a state of liquid accumulation immediately after application, and tries to spread until the thickness, viscosity, surface tension, etc. of the coating material 4 are balanced. At this time, when the coating material 4 tries to penetrate into the component (connector) 2 around the component (connector) 2, the coating material 4 that has penetrated through the groove in the penetration prevention area a is stopped in place, and then to the component (connector) 2. Can be prevented.

In this embodiment, by forming the permeation prevention area a, it is possible to arbitrarily set a range in which the surrounding coating material 4 applied at a certain distance from the component (connector) 2 is avoided. That is, since the penetration of the coating material 4 can be controlled, the application prohibited range of the coating material 4 can be minimized.

An application example of the printed circuit board in Example 3 will be described with reference to FIG. In the present embodiment, an example in which a component (connector) 2 having a different form is mounted on the printed circuit board 1 in the first embodiment will be described. Therefore, the description of the parts common to the first embodiment is omitted.

FIG. 3 is an explanatory view showing a third embodiment of the component-mounting printed board to which the present invention is applied. The component (connector) 2 in the present embodiment is an insertion type, and the connection terminal 21 and the component terminal 22 of the component (connector) 2 are the same terminal. The component terminal 22 has exactly the same function as the connection terminal 22 in FIGS. The connection terminal 21 is a terminal to be inserted into the substrate, and is inserted into a component through hole having the same form as the through via 11. The component pad 12 in the component through hole is formed of a layer copper foil and a resist of the through hole. By filling the solder 3 between the through hole outer layer copper foil portion and the connection terminal 21 of the component (connector) 2 and the inner wall of the through hole by soldering, the circuit pattern of the printed circuit board and the connection terminal 21 are connected. For this reason, the through-hole for components is always filled with the connection terminal 21 and the solder 3 by soldering. Therefore, it is not necessary to perform the route blocking process for penetration of the component (connector) 2 of the coating material 4 by the silk (coating material permeation preventing member) 14a with respect to the component through hole. This means that the present invention is not restricted by the mounting form of the component (connector) 2 mounted on the printed circuit board 1.

DESCRIPTION OF SYMBOLS 1 ... Printed circuit board, 2 ... Component (connector), 3 ... Solder, 4 ... Coating material (varnish), 11 ... Through-via, 12 ... Component pad, 13 ... Resist, 14a ... Via sealing silk (coating material penetration prevention) Member), 14b ... silk for varnish penetration (coating material penetration prevention member), 15 ... display silk, 21 ... connection terminal, 22 ... component terminal, a ... penetration prevention area, b ... coating material penetration route

Claims

A method of manufacturing a printed circuit board, wherein a first surface on which a component is disposed and a second surface opposite to the first surface are coated with a coating material,
Forming a through via penetrating the first surface and the second surface;
A silk printing process for displaying information on the component on the first surface or the second surface;
In the silk printing step, a method for manufacturing a printed circuit board, wherein a hole of the through via is closed.
It is a manufacturing method of the printed circuit board according to claim 1,
In the silk printing process, a silk substrate is printed on the first region so as to close the hole of the through via and surround the component.
It is a manufacturing method of the printed circuit board according to claim 2,
In the silk printing process, the silk substrate is printed in a second region so as to surround the component between the first region and the component.
It is a manufacturing method of the printed circuit board according to claim 1,
A method of manufacturing a printed circuit board, comprising: forming a component pad on the first surface for electrically connecting the component to a circuit pattern.
It is a manufacturing method of the printed circuit board according to claim 1,
A method of manufacturing a printed circuit board comprising a step of forming a component through-hole for inserting a terminal of the component through the first surface and the second surface.
A printed circuit board on which a first surface on which a component is arranged and a second surface opposite to the first surface are coated with a coating material,
A through via penetrating the first surface and the second surface;
Showing information on the part, and having silk printed on the first side or the second side,
The printed board, wherein the silk closes a hole of the through via.
The printed circuit board according to claim 6,
The printed board according to claim 1, wherein the silk is printed in a first region so as to close the hole of the through via and surround the component.
The printed circuit board according to claim 7,
The printed board according to claim 1, wherein the silk is printed in a second region so as to surround the component between the first region and the component.
The printed circuit board according to claim 6,
A printed circuit board comprising a component pad on the first surface for electrically connecting the component to a circuit pattern.
The printed circuit board according to claim 6,
A printed circuit board having a component through hole for inserting a terminal of the component through the first surface and the second surface.