JP2021012963A - Printed circuit board and manufacturing method thereof, and printed wiring board - Google Patents

Abstract

To provide a printed circuit board having a structure capable of preventing a protective film agent from flowing out to a region where the protective film agent is prohibited from being applied or to an edge of a substrate when the protective film is coated on the printed circuit board.SOLUTION: A printed wiring board includes a conductor wiring pattern formed on a substrate and its insulating surface. The substrate includes a groove that extends along an outer edge of a protective agent application region which is a region on which a protective film covering an electronic component mounted on the printed wiring board is formed on its insulating surface.SELECTED DRAWING: Figure 1

Description

The present invention relates to a printed circuit board, a method for manufacturing the same, and a printed wiring board.

In order to protect the printed circuit board from moisture, for example, after mounting an electronic component on the printed circuit board, a moisture-proof coating as a protective film is applied. When applying a moisture-proof coating to a printed circuit board, it is common to apply a liquid moisture-proof agent using a coating device such as a dispenser.

Electronic components such as ICs, chip components, and connectors are mounted on the printed circuit board, but the adhesion of moisture-proofing agents like connectors affects the connection, which affects the mounting on the board. Since there is a concern that the moisture-proof agent may reach the edge of the board and the moisture-proof agent wraps around to the back to contaminate the production line, it is necessary to set the area where the moisture-proof agent is applied sufficiently away from the connector and the edge of the board. was there.

Further, by restricting the application area of the moisture-proof agent, there is also a problem that the arrangement of electronic components or the like that require application of the moisture-proof agent is restricted in the vicinity of the connector or the edge of the substrate on the printed circuit board.

There are prior arts described in Patent Documents (1) to (3) for these problems.

In the prior art of Patent Documents (1) and (2), a barrier is formed by solder printing or silk screen printing at the boundary between the area where the moisture-proof agent is applied and the area where application is prohibited, so that the moisture-proof agent is dammed by the barrier and application is prohibited. It prevents the moisture barrier from flowing out to the area.

In the prior art of Patent Document (3), the moisture-proofing agent is applied only to the coating area by covering the application area of the moisture-proofing agent with a shield case and providing an opening in the shield case so that the moisture-proofing agent can be applied. I am trying to do it.

Japanese Unexamined Patent Publication No. 10-93228 Japanese Unexamined Patent Publication No. 2013-183079 Japanese Unexamined Patent Publication No. 10-93228

However, the prior art of the above patent document has the following problems. In the prior art of Patent Documents (1) and (2), when the volatile content of the moisture-proofing agent is large, a large amount of liquid is required to obtain a predetermined thickness of the moisture-proofing agent, and the thickness of the moisture-proofing agent immediately after application is a barrier. As a result of the thickening, there was a problem that the moisture-proofing agent exceeded the barrier.

Further, in the prior art of Patent Document (3), there is a problem that the number of steps and the cost increase because a case is required to prevent the progress of the moisture-proof agent in the moisture-proof coating.

The present invention has been made in view of the above problems of the prior art, and when a protective film such as a moisture-proof film is coated on a printed circuit board, the protective film agent is applied to the area where the protective film agent is prohibited from being applied or the edge of the substrate. It is an object of the present invention to provide a printed circuit board having a structure capable of preventing outflow, a method for manufacturing the printed circuit board, and a printed wiring board.

The printed wiring board of the present invention is a printed wiring board having a conductor wiring pattern formed on a substrate and an insulating surface of 1 of the substrate.
The insulating surface of 1 is characterized by having a groove extending along an outer edge portion of a protective agent application region, which is a region where a protective film covering an electronic component mounted on the printed wiring board is formed. ..

The printed circuit board of the present invention is a printed wiring board having a conductor wiring pattern formed on a substrate and one insulating surface of the substrate, and a printed circuit board having electronic components provided on the insulating surface of the first. There,
An electronic component mounted on the printed wiring board and to be covered with a protective film and a protective film covering the periphery of the electronic component are formed on the insulating surface of 1 along the outer edge of the protective agent application region. It is characterized by having a groove.

The method for manufacturing a printed circuit board of the present invention includes a printed wiring board having a conductor wiring pattern formed on a substrate and the insulating surface of 1 of the substrate, and a printed circuit board having electronic components provided on the insulating surface of 1. It is a method of manufacturing circuit boards.
A groove extending along the outer edge of the protective agent coating region, which is a region on which the protective film covering the electronic component is applied, is formed on the insulating surface of 1 by processing the insulating surface of 1. Groove forming step, mounting step of mounting the electronic component on the printed wiring board, and
After the groove forming step and the mounting step, a step of applying the protective agent to the protective agent application region and curing the protective agent.
It is characterized by including.

It is a schematic plan view of the printed circuit board which concerns on 1st Example of this invention. A in FIG. It is a schematic sectional view along line A. It is a schematic cross-sectional view of a main part explaining the manufacturing method of the printed circuit board of FIG. It is a schematic cross-sectional view of a main part explaining the manufacturing method of the printed circuit board of FIG. It is a schematic cross-sectional view of a main part explaining the manufacturing method of the printed circuit board of FIG. It is a schematic cross-sectional view of a main part explaining the manufacturing method of the printed circuit board of FIG. It is a schematic cross-sectional view of a main part explaining the manufacturing method of the printed circuit board of FIG. It is a schematic cross-sectional view of a main part explaining the manufacturing method of the printed circuit board of FIG. It is a schematic cross-sectional view of a main part explaining the manufacturing method of the printed circuit board of FIG. It is a schematic cross-sectional view of a main part explaining the manufacturing method of the printed circuit board of FIG. It is a schematic cross-sectional view of a main part explaining the manufacturing method of the printed circuit board of FIG. It is a schematic plan view of the printed circuit board which concerns on 2nd Example of this invention. A in Fig. 4? It is a schematic sectional view along line A. It is a schematic plan view explaining the modification of the cross-sectional shape of the groove in the substrate of the printed circuit board which concerns on 1st and 2nd Embodiment of this invention. It is a schematic plan view explaining the modification of the cross-sectional shape of the groove in the substrate of the printed circuit board which concerns on 1st and 2nd Embodiment of this invention.

Hereinafter, the printed wiring board, the printed circuit board, and the manufacturing method thereof according to the embodiment of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following examples. Further, in the embodiment, the components having substantially the same function and configuration are designated by the same reference numerals, so that duplicate description will be omitted.

In the following embodiment, a multilayer circuit board (board) in which a plurality of conductor wiring patterns are laminated will be described as an example, but a single-layer printed circuit board (single-sided substrate or double-sided substrate) having a configuration having a single-layer conductor wiring pattern will be described. The present invention can also be applied to. The substrate constituting the printed wiring board is composed of a flat plate having an insulating property, and for the single-layer printed circuit board, for example, a glass composite substrate, a glass epoxy substrate, a glass polyimide substrate, a metal substrate, and a ceramic substrate can be used. Further, as a multilayer circuit board, for example, a build-up substrate is a multilayer printed circuit board in which one or more wiring layers are formed on the front surface and the back surface of a core substrate (core substrate), respectively. Epoxy resin, polyimide, or the like is used as the material of the interlayer insulator. The conductor wiring pattern can be formed of a conductive material, but is generally formed of, for example, copper. The surface of the printed wiring board in the single-layer printed circuit board and the multi-layer printed circuit board is formed as an insulating surface made of an insulating material.

(Printed circuit board)
FIG. 1 is a plan view seen from the upper surface of the printed circuit board of the first embodiment, and FIG. 2 is line A? It is sectional drawing in A. In this embodiment, the printed circuit board has a laminated structure of four wiring layers.

The printed circuit board has a substrate 1 having an insulating surface and a conductor wiring pattern 2 laminated on the surface side thereof. The conductor wiring pattern 2 includes a wiring portion 2a, a land portion 2b which is an electrical connection portion thereof, and a ground plane 2P which surrounds them with a gap.

The printed circuit board has an internal ground plane 2Pi and an internal wiring 2i laminated on the internal side. The contours of the ground plane 2P and the internal ground plane 2Pi are almost the same. Further, the printed circuit board has 24 penetrating vias 2V that are electrically connected to each other along the contours of the ground plane 2P and the internal ground plane 2Pi and penetrate the front and back surfaces of the substrate 1.

In the printed circuit board, the conductor wiring pattern on the front and back surfaces of the substrate 1 except for the land portion 2b, which is the electrical connection portion on the front and back surfaces of the substrate 1, is covered with the solder resist film SRF. The solder resist film SRF, which is an insulating layer, is applied by using a solder resist so as to cover the conductor wiring pattern 2. As the solder resist, for example, one mainly composed of a photosensitive polymer can be used.

Further, on the printed circuit board, an electronic component 4 (a component to be protected) mounted so as to be electrically connected to the land portion 2b of the conductor wiring pattern 2 and a moisture-proof film 7 which is a protective film covering the mounted electronic component 4. (Moisture-proof insulating film) is included. Specifically, the electronic component 4 is a passive component such as an inductor or a capacitor and an active component such as a diode, a transistor or an IC. Examples of the main component of the film-forming material forming the moisture-proof film 7 include polyolefin resin, acrylic resin, polyurethane resin, fluororesin, and silicone resin. Further, it is also preferable to use an ultraviolet curable resin composition as a film forming material for forming the moisture-proof film 7, and in particular, an ultraviolet curable resin containing an acrylate-based resin as a main component and a photocrosslinking agent is used. May be good. By using an ultraviolet curable resin, the moisture-proof film 7 can be cured by ultraviolet irradiation.

The surface of the substrate 1 (solder resist film SRF) of the printed circuit board is bounded by a protective agent coating region 5 on which the moisture-proof film 7 is formed and a coating prohibited region 6 around the protective agent coating region 5 of the printed circuit board (FIG. It is separated by a one-dot chain line of 1.

The printed circuit board further has a groove 8 extending along the outer edge (boundary) of the protective agent application region 5 of the substrate 1. The groove 8 is formed in advance on the insulating surface of the substrate 1 so as to have a rectangular cross-sectional shape by milling or laser processing at the time of manufacturing the printed wiring board. The groove 8 prevents the material for forming the moisture-proof film 7 from spreading on the surface of the solder resist film SRF when the printed circuit board is manufactured. As shown in FIG. 2, the side wall forming the groove 8 is formed at the opening thereof substantially perpendicular to the surface of the substrate 1. As a result, the action of the surface tension of the film-forming material spreading on the solder resist film SRF on the surface of the substrate 1 is greatly exerted.

It is not necessary to form a groove in the portion where it is not necessary to strictly separate the boundary portion between the application area 5 of the moisture-proof agent and the application prohibition area 6.

Further, the printed circuit board also includes an unprotected electronic component (for example, a through-hole component 9) mounted so as to be electrically connected to the land portion 2b of the conductor wiring pattern 2. The through-hole component 9 is a radial component such as an electrolytic capacitor.

In the first embodiment, the printed circuit board has a structure having a groove 8 having a depth that does not penetrate the substrate 1 along the boundary portion between the application region 5 of the moisture-proof agent and the coating prohibition region 6 on the substrate 1. .. As an example of the dimensions of the groove 8, when the thickness of the substrate 1 is 1.6 mm, the width of the groove is 1.0 mm and the depth of the groove is 0.6 mm, but the thickness of the substrate 1 and the specifications of the moisture-proofing agent are used. The width and depth of the groove and the extension range may be adjusted accordingly. If the average width of the groove 8 is too narrow, the peripheral edge of the film-forming material that expands according to the viscosity may get over the opening of the groove 8 and the spread of the film-forming material may not be suppressed. If the average width of the groove 8 is too wide. Since the conductor wiring pattern 2 cannot be arranged in the groove 8, the region where the conductor wiring pattern 2 can be formed may not be sufficiently secured. Therefore, the conductor wiring pattern 2 is appropriately adjusted and set.

A method of manufacturing a printed circuit board will be described. First, a printed wiring board is manufactured.
(Substrate laminating process)
As the multilayer printed wiring board, for example, one or a plurality of core substrates having wirings are sandwiched between a prepreg resin and a copper foil and laminated by a known method to obtain a substrate 1 as shown in FIG. 3A. The internal ground plane 2Pi and the internal wiring 2i shown in FIG. 2 are formed inside the substrate 1.
(Punching process for penetrating vias)
A through via 2V penetrating the front and back surfaces of the substrate 1 for electrically connecting the ground plane 2P, the internal ground plane 2Pi, and the internal wiring 2i shown in FIG. 2 is formed by a known drilling process. As shown in FIG. 3B, a plurality of through holes H arranged on the peripheral edge of the internal ground plane 2Pi are formed.
(Groove formation process)
As shown in FIG. 3C, the groove 8 extending along the outer edge of the protective agent application region 5 (FIG. 1) of the substrate 1 is used as a machine tool for numerical control (NC) for cutting end mills, face milling cutters, and the like. The operation of the cutting edge of a tool (not shown) is defined by coordinate values, and the cutting tool and substrate 1 are moved by a servomotor built into the machine tool based on the coordinate value information to form a tool with a predetermined depth and width. ..
(Conductor layer forming process)
In the conductor layer forming step, as shown in FIG. 3D, after forming a thin conductive seed layer by electroplating, the copper foil 2M of the substrate 1 is thickened by electroplating on the conductive seed layer, and the inner wall of the through hole H is formed. A copper conductor layer, that is, a penetrating via 2V is formed on the surface.
(Conductor wiring pattern process)
In the conductor wiring pattern step, as shown in FIG. 3E, a conductor wiring pattern 2 (ground plane 2P or the like) is formed by patterning a predetermined pattern on one copper conductor layer of the substrate 1. The patterning of the conductor wiring pattern 2 can be performed by a known method, for example, photoetching. In photoetching, a dry film (not shown) having a predetermined pattern is formed on a portion remaining on the surface of the conductor wiring pattern 2, and then the dry film (not shown) is exposed and developed to be exposed from the dry film portion of the predetermined pattern. Is dissolved in an etching solution and the dry film is removed. By performing this step on the front and back surfaces of the substrate 1, the wiring portion 2a shown in FIG. 1, the land portion 2b around the opening of the penetrating via 2V, and the ground plane 2P are formed. The penetrating via 2V is covered with a dry film (tenting method) as if a tent was set up in the hole opening so that the etching solution does not enter the hole, but the metal in the groove is etched without covering the opening of the groove 8. To do.
(Solder resist film forming process)
In the solder resist film forming step, as shown in FIG. 3F, the liquid solder resist SR is applied over the entire one surface of the substrate 1 on which the conductor wiring pattern 2 is formed. That is, the solder resist SR is applied to the entire front and back surfaces of the laminate including the substrate 1 and the conductor wiring pattern 2. Then, ultraviolet rays are irradiated through a photomask (not shown) that shields the planned mounting region of the electronic component 4 (land portion 2b in FIG. 1) and the planned formation region of the groove 8 (not shown), and the solder resist of the portion that is not shaded. Photocure SR. After that, it is treated with a developing solution such as an aqueous sodium carbonate solution to remove the mask, and as shown in FIG. 3G, a solder resist film SRF that exposes the land portion 2b of the conductor wiring pattern 2 and the bottom of the groove 8 is formed. To. Further, the patterned solder resist film SRF is heat-treated to be cured and stabilized. This step is applied to the front and back surfaces of the substrate 1. Then, as a post-processing step, silk screen printing such as a predetermined symbol and outer shape processing are performed to complete the printed wiring board. Next, the electronic component mounting process is executed on the printed wiring board.
(Electronic component mounting process)
In the electronic component mounting process, as shown in FIG. 3H, the electronic component 4 is electrically connected to the conductor wiring pattern 2. Specifically, a solder bump BP is provided on the land portion 2b exposed in the opening of the solder resist film SRF, the terminal of a predetermined electronic component 4 is placed on the solder bump, and the solder bump is melted by reflow. The terminals of the electronic component 4 are soldered to the conductor wiring pattern 2. Further, the through-hole component 9 is also fitted into the predetermined through-hole via 2V and soldered.
(Protective film laminating process)
In the protective film laminating step, as shown in FIG. 3I, the liquid film forming material 7a, which is a precursor of the moisture-proof film, is applied to the surface of the electronic component 4 mounted on the substrate 1 and cured to cure the moisture-proof film 7. (Fig. 2) is formed. As a method of applying the film-forming material, a generally known brush coating method or spray? A method, a line drawing method, a dispense method, an inkjet method, or the like can be used, but a coating method in which a liquid film-forming material is injected with a coating nozzle is preferable.

The liquid film-forming material applied to the surface of the electronic component 4 spreads on the surface of the solder resist film SRF, but the film-forming material spread on the groove 8 side stays in the groove 8 as shown in FIG. 3I. The spread is suppressed, and the moisture-proof film 7 is not laminated on the coating prohibited region 6 of the solder resist film SRF separated by the groove 8. After that, the film-forming material is cured to form the moisture-proof film 7 (FIG. 2), and the printed circuit board is completed. As described above, the moisture-proof film 7 is formed by applying a liquid film-forming material containing an insulating resin along the surface shape of the electronic component 4, drying and curing, and the moisture from the outside to the electronic component 4 is absorbed. Prevents intrusion.

A series of FIGS. 3 shows an example of the manufacturing process of the printed wiring board, and it has been explained that the formation of the groove 8 (groove forming step: FIG. 3C) is performed after the through-via drilling step (FIG. 3B). However, the formation time of the groove 8 is not limited to this. For example, before the electronic component mounting step (FIG. 3H), the groove forming step is, for example, during the substrate lamination step (FIG. 3A), or the conductor wiring pattern step (FIG. 3E) and the solder resist film forming step (FIG. 3F). ), During the solder resist film forming process (FIG. 3F), or during the external shape processing process after forming the solder resist film, etc., according to the specifications of the printed wiring board, etc., at a manufacturing process stage different from the time described in FIG. 3C. You may.

In this embodiment, the moisture-proof film 7 which is a moisture-proof insulating film has been described as the protective film, but the protective film is not limited to this. For example, in this embodiment, as a modification, an insulating film having at least one protective film having heat dissipation property, electromagnetic wave resistance, rust prevention property, and gas barrier property instead of the moisture-proof film 7. May be good.

The moisture-proof film 7 and the heat-dissipating protective film can function as a conformal coating for protecting against moisture, mold, dust, corrosion and other environmental stresses in a printed circuit board on which electronic components are mounted. Examples of general film-forming materials for applying conformal coating include polyolefin resins, acrylic resins, polyurethane resins, fluororesins, and silicone resins.
(Explanation of effect)
As described above, according to the first embodiment, the groove 8 provided at the boundary between the application area 5 of the moisture-proof agent and the application prohibition area 6 causes an excess amount even when the moisture-proof agent exceeds the application area 5. It prevents the moisture-proof agent from flowing into the groove 8 and flowing out to the area 6 where the application of the moisture-proof agent is prohibited. As a result, the application area 5 of the moisture-proof agent can be set to the vicinity of the parts that are affected by the connection due to the adhesion of the moisture-proof agent and the vicinity of the end portion of the substrate 1, and the flexible component arrangement can be realized. The effects of preventing the moisture-proof agent from dripping from the edge of the substrate 1 and wrapping around the back surface of the substrate 1 and preventing contamination by the moisture-proof agent in the production line can be obtained. Further, in the printed circuit board, the area to which the moisture-proof film 7 is applied is set at low cost and easily, so that the application of the protective film to the application prohibited area 6 where the formation of the protective film is unnecessary is suppressed. Will be done.

Further, since the groove 8 for suppressing the spread of the liquid film-forming material forming the moisture-proof film 7 is formed in advance on the substrate (printed wiring board), the printed circuit board can be manufactured by the existing equipment, so that the manufacturing process can be performed. There is no increase. Further, since the groove 8 functions as a marker, it is suitable for visually confirming the position when the moisture-proof film 7 is formed by a plurality of coatings.

FIG. 4 is a plan view seen from the upper surface of the printed circuit board of the second embodiment, and FIG. 5 is line A? Of FIG. It is sectional drawing in A. In the second embodiment, the ground plane 2P and the internal ground plane 2Pi are provided with a ground plane expansion portion 2Pe and an internal ground plane 2Pie extended to the bottom of the groove 8 and below the bottom, respectively, and both expansion portions 2Pe and 2Pie. Is the same as in the first embodiment except that is connected by 13 penetrating vias 2V penetrating the bottom of the groove 8. In the first embodiment, the groove 8 is formed and arranged in the non-existent region of the conductor wiring pattern 2 so as not to interfere with the conductor wiring pattern 2. However, in the present embodiment, the ground plane 2P and the internal ground plane are arranged. For the purpose of maximizing the area of 2Pi, a groove 8 is dug so that the ground plane 2P and the internal ground plane 2Pi can be connected, and together with the copper plating of the penetrating via 2V, the bottom and both walls of the groove 8 are also formed. It is copper-plated. As a result, it is possible to secure continuity between the ground plane 2P and the internal ground plane 2Pi and improve electrical performance such as lower impedance and improvement of shielding performance.

Further, the penetrating via 2V on the groove 8 is filled with a solder resist film SRF, a permanent hole filling material, or the like from the back surface of the substrate 1 on the opposite side of the groove 8. As a result, even when the liquid film-forming material which is the precursor of the moisture-proof film is accumulated in the groove 8, the liquid film-forming material is prevented from spreading or dripping on the back surface of the substrate 1 through the penetrating via 2V. be able to.

Also in this embodiment, the groove 8 provided at the boundary between the application area 5 of the moisture-proof agent and the application prohibition area 6 allows the excess amount to flow into the groove 8 even when the moisture-proof agent exceeds the application area 5, and the moisture-proof agent Prevents the moisture-proof agent from flowing out to the application prohibited area 6 of the above. As a result, the application area 5 of the moisture-proof agent can be set to the vicinity of the parts that are affected by the connection due to the adhesion of the moisture-proof agent or to the vicinity of the end portion of the substrate 1, and the flexible component arrangement can be realized and the substrate can be set. The same effects as those in the first embodiment can be obtained, such as prevention of dripping of the moisture-proofing agent from the end portion of 1 and wraparound to the back surface of the substrate 1, and prevention of contamination by the moisture-proofing agent in the production line.
(Modification example)
In the first and second embodiments, as an example, the cross-sectional shape of the groove 8 is a steep concave shape in which openings on both side walls of the groove 8 are formed substantially perpendicular to the substrate surface, that is, a rectangular cross-sectional shape. As described above, the cross-sectional shape of the groove 8 is not limited to this. For example, the cross-sectional shape of the groove 8 may be an isosceles triangle or a triangular cross-sectional shape having two different taper angles as shown in FIGS. 6A and 6B. The cross-sectional shape of the groove 8 may be a zigzag cross-sectional shape having 1 or 2 peaks at the bottom as shown in FIGS. 6 (c) and 6 (d). As a result, the liquid film forming material, which is the precursor of the moisture-proof film, changes the inflow rate into the groove 8 to prevent the inflow from exceeding, and the creepage distance of the groove becomes longer to prevent the liquid film forming material from flowing out. You can expect it.

Further, the cross-sectional shape of the groove 8 may be a cross-sectional shape including a part of an arc of a circle or an ellipse as shown in FIGS. 7A and 7B. Further, as shown in FIG. 7C, the cross-sectional shape of the groove 8 may be a trapezoidal cross-sectional shape whose bottom is wider than the opening. Furthermore, as shown in FIG. 7D, the cross-sectional shape of the groove 8 is the rectangular cross-sectional shape of the groove 8 when the cross-sectional shape of the first or second embodiment or the groove is changed. A barrier 14 by solder printing or silk screen printing may be formed on either the inside or the outside, or both inside and outside the groove. As a result, by forming a barrier in addition to the groove 8, the barrier 14 causes the liquid film before the moisture-proof liquid film-forming material flows into the groove 8 or when the liquid film-forming material exceeds the groove 8. It is expected that the effect of preventing the outflow of the forming material will be further enhanced.

Further, in the first and second embodiments, the method of forming the groove by the milling process has been described, but the groove may be formed by a known method other than the milling process. For example, the surface of the substrate 1 may be formed by a laser or the like. A groove may be formed by cutting with.

Further, in the first and second embodiments, the case where the ground plane 2P and the internal ground plane 2Pi are for grounding has been described, but these planes can also be configured for power supply.

In the first embodiment, the groove depth was set to 0.6 mm, but the groove depth was adjusted within a range in which the remaining thickness of the substrate after forming the groove did not affect the strength, and the position was the same as the surface side. A groove may be formed on the back surface side as well. For example, the remaining thickness of the substrate is 0.8 mm, and grooves are formed on the front surface side and the back surface side at a depth of 0.4 mm, respectively. Of course, grooves may be formed at different positions on the front surface side and the back surface side.

1 Board 2 Conductor wiring pattern 2a Wiring part 2b Land part 2P Ground plane 2Pi Internal ground plane 2i Internal wiring 2V Penetration via 4 Electronic parts 5 Coating area 6 Application prohibited area 7 Moisture-proof film 8 Groove 9 Through-hole parts SR Photosensitive solder resist SRF Solder resist film 2P ground plane

Claims (12)

A printed wiring board having a conductor wiring pattern formed on a substrate and the insulating surface of 1 of the substrate.
The insulating surface of 1 is characterized by having a groove extending along an outer edge portion of a protective agent application region, which is a region where a protective film covering an electronic component mounted on the printed wiring board is formed. Printed wiring board. The printed wiring board according to claim 1, wherein the groove portion is a recess formed on the insulating surface of 1. The printed wiring board according to claim 1 or 2, wherein the groove is formed in an absent region of the conductor wiring pattern. The printed wiring board according to any one of claims 1 to 3, wherein the conductor wiring connected to the conductor wiring pattern is provided at least at the bottom of the groove. The printed wiring board according to any one of claims 1 to 4, wherein the groove has a rectangular cross-sectional shape. The printed wiring board according to any one of claims 1 to 4, wherein the groove portion has a trapezoidal cross-sectional shape whose bottom portion is wider than the opening portion. The printed wiring board according to any one of claims 1 to 4, wherein the groove has a zigzag cross-sectional shape. The printed wiring board according to any one of claims 1 to 4, wherein the groove has a cross-sectional shape including a partial arc of a circle or an ellipse. The printed wiring board according to any one of claims 1 to 8, wherein the protective film is a moisture-proof insulating film. The print according to any one of claims 1 to 9, wherein the protective film is an insulating film having at least one of heat dissipation, electromagnetic wave resistance, rust prevention, and gas barrier property. Wiring board. A printed wiring board having a substrate and a conductor wiring pattern formed on the insulating surface of 1 of the substrate, and a printed circuit board having electronic components provided on the insulating surface of 1 of the substrate.
An electronic component mounted on the printed wiring board and to be covered with a protective film and a protective film covering the periphery of the electronic component are formed on the insulating surface of 1 along the outer edge of the protective agent application region. A printed circuit board characterized by having a groove. A method for manufacturing a substrate, a printed wiring board having a conductor wiring pattern formed on the insulating surface of the substrate 1, and a printed circuit board having an electronic component provided on the insulating surface of the substrate 1.
A groove extending along the outer edge of the protective agent coating region, which is a region on which the protective film covering the electronic component is applied, is formed on the insulating surface of 1 by processing the insulating surface of 1. Groove forming step, mounting step of mounting the electronic component on the printed wiring board, and
After the groove forming step and the mounting step, a step of applying the protective agent to the protective agent application region and curing the protective agent.
A method for manufacturing a printed circuit board, which comprises.

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