JP2009124080A - Printed wiring board, and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printed wiring board which can prevent lowering of mounting reliability. <P>SOLUTION: A printed wiring board 1 has an insulating layer, a conductor layer having a component mounting region A, laminated on the insulating layer with an electronic component 60 mounted, a first solder resist 40 applied on the conductor layer, a silk print 80 which is applied to an area near the component mounting region A on the first solder resist 40 and a second solder resist 50 applied to at least a periphery of the silk print 80 on the first solder resist 40. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a printed wiring board, and more particularly to a printed wiring board in which a covering member is applied to a substrate surface.

  A coating member such as a solder resist is applied to the surface of the printed wiring board. The covering member is applied to prevent oxidation of a conductive member such as copper constituting the wiring layer.

In printed wiring boards coated with such a covering member, figures and symbols (identification marks) are attached with character ink from the solder resist to identify the component mounting position and the type of mounted component. There is.

  In recent years, the demand for high-density mounting has further increased, and the thickness of the printed wiring board itself has been reduced. A printed wiring board is not usually used alone, and electronic components are often mounted on the surface. Solder is used for electrical connection between the electronic component and the printed wiring board. That is, solder is applied to the electrodes provided on the printed wiring board to electrically connect the electrodes of the electronic component. In general, for the application of solder, a mask having an opening at a position facing an electrode portion of a printed board is prepared. This masking is mounted on a printed wiring board, solder is applied, and the solder is spread (applied) using a tool such as a squeegee.

  However, in recent high-density mounting, problems occur due to character ink such as figures and symbols attached on the solder resist. That is, depending on the thickness of the character ink, there are portions where the thickness is different even in the same printed wiring board between the portion where the character ink is applied and the portion where it is not attached. Thus, by mounting the masking and applying the solder, there is a problem that the applied height of the solder is different and the mounting reliability of the electronic component to be mounted is lowered.

Patent Document 1 discloses a technique of a printed wiring board that prevents a contact between a lower part of a chip part and the marking ink by printing a soldering resist on a predetermined portion on a substrate and then curing the resist. .
JP-A-5-251855 (page 3, FIG. 1)

  However, in the technique of Patent Document 1, there is a difference in coating height (printing height) between when the outermost surface is a solder resist and when marking ink is printed. When applied, the problem of differing solder applied height remains.

  Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to provide a printed wiring board that can prevent a reduction in mounting reliability even when a marking that exhibits an identification effect is used. To do.

  In order to achieve the above object, a printed wiring board according to the present invention is coated on an insulating layer, a conductor layer having a component mounting region laminated on the insulating layer and mounting an electronic component, and the conductor layer. A first covering member, an identification mark applied on the first covering member in the vicinity of the component mounting area, and on the first covering member, at least around the identification mark. And a second covering member applied to the substrate.

  An electronic device according to the present invention is an electronic device that houses a printed wiring board, and the printed wiring board has an insulating layer and a component mounting region on which the electronic component is mounted. A conductive layer, a first covering member applied on the conductive layer, an identification mark applied on the first covering member in the vicinity of the component mounting region, and the first covering And a second covering member applied at least around the identification mark on the member.

  A reduction in mounting reliability can be prevented.

  Hereinafter, an embodiment of a printed circuit board according to the present invention will be described with reference to the drawings, taking as an example a case where the printed circuit board is applied to a portable computer which is one of electronic devices.

  FIG. 1 is a perspective view of a portable computer according to an embodiment of the present invention. In FIG. 1, a main body 8 of a portable computer 1 is provided with a display unit housing 3 so as to be rotatable via a hinge mechanism. The main body 8 is provided with operation units such as a pointing device 4 and a keyboard 5. The display unit housing 3 is provided with a display device 6 such as an LCD.

  The main body 8 is provided with a printed circuit board (mother board) 2 in which a control circuit for controlling the operation device such as the pointing device 4 and the keyboard 5 and the display device 6 is incorporated.

(Regarding the first embodiment of the printed circuit board)
FIG. 2 is a diagram showing a first embodiment of the printed circuit board according to the present invention. As shown in FIG. 1, a printed circuit board 2 according to this embodiment is obtained by electrically connecting a printed wiring board 1 and an electronic component 60 via a solder 70.

  The printed wiring board 1 according to the present embodiment includes the base material 10, the electrode 20, the wiring 30, the first solder resist 40, the silk printing 80, and the second solder resist 50 as main components. To do. The substrate 10 is made of, for example, a glass epoxy resin and plays a role as an insulating layer.

  The electrode 20 is formed on the substrate 10 and is provided at a position facing the electrode of the electronic component 60 mounted on the printed wiring board 1 according to the number of electrodes of the electronic component. The electrode 20 is composed of a conductive member such as copper. 2 has a component mounting area A in which the electronic component 60 is mounted.

  The wiring 30 is formed on the substrate 10 and plays a role of electrically connecting a plurality of electronic components mounted on the printed wiring board 1. The wiring 30 is made of a conductive member such as copper. In addition, the electrode 20 and the wiring 30 are comprised with the conductor. As shown in FIG. 2, a layer in which the electrode 20 or the wiring 30 or the electrode 20 and the wiring 30 are formed of the same layer is also referred to as a conductor layer.

  The first solder resist 40 is a covering member formed on the conductor layer, and plays a role of preventing oxidation of the electrode 20 and the wiring 30. The solder resist 40 is a member such as resin or ceramics.

  The silk print 80 is attached in the vicinity of the component mounting area A. The silk print 80 serves as a so-called identification mark that indicates, for example, the position where the electronic component 60 is mounted and the type of the electronic component 60.

  The second solder resist 50 is a covering member formed on the first solder resist 40, and the coating height (printing height) of the first solder resist 40 and the silk printing 80 generated by the printing of the silk printing 80. The difference in the above is eliminated, and the surface of the printed wiring board 1 is smoothed. Further, the second solder resist 50 covers the silk print 80. Therefore, in the present embodiment, the thickness (t2) of the second solder resist 50 needs to be thicker than the thickness (t1) of the silk print 80. Here, the 2nd soldering resist 50 is members, such as resin and ceramics, for example.

  The second solder resist 50 has transparency. That is, even if the second solder resist 50 is applied from above the silk print 80, the silk print 80 needs to be recognized when viewed from the second solder resist 50 that is the outermost surface.

  The printed wiring board 1 may be a multilayer printed wiring board. Moreover, it is preferable to apply the first solder resist 40 and the second solder resist 50 on the outermost conductor layer.

  The effects of the above-described printed wiring board 1 will be described with reference to FIGS. FIG. 3 is a top view of the printed wiring board 1. As shown in FIG. 3A, the printed wiring board 1 is formed around the component mounting area A and used as an identification character or an identification symbol.

  For example, as shown in FIG. 3B, the silk print 80a and the silk print 80b formed near the corner of the component mounting area A are printed circuits in which electronic components are mounted on the printed wiring board 1 as shown in FIG. When manufacturing a board, it can be used as a role as an identification mark for determining the mounting position of the electronic component 60.

  Further, as shown in FIG. 3C, the type of electronic component 60 mounted in the component mounting area A can be formed by forming silk print 80c indicating the component type separately with the silk prints 80a and 80b. Can be grasped visually.

(Printed wiring board manufacturing method)
Next, a method for manufacturing a printed wiring board according to the first embodiment of the present invention will be described.

FIG. 4 is a flowchart showing a method for manufacturing a printed wiring board according to an embodiment of the present invention. As shown in FIG. 4, in order to manufacture the printed wiring board of this Embodiment, the copper clad laminated board 11 is prepared first (step S1, copper clad laminated board preparation process). FIG. 5 is a diagram showing a copper clad laminate preparation process. As shown in FIG. 5, a copper clad laminate 11 is prepared in which a conductor layer 21 is laminated on the entire surface of a base material 10 that is an insulating layer. Although the copper clad laminate 11 shown in FIG. 5 shows a conductor layer only on one side for convenience, a copper clad laminate 11 having a conductor layer on both sides is prepared, and an etching process to be described later on both sides May be used to manufacture a multilayer printed wiring board.

  Next, a predetermined etching process is performed on the conductor layer of the copper clad laminate 11 prepared in Step S1 (Step S2, etching process). FIG. 6 is a diagram showing an etching process. As shown in FIG. 6, this etching step is a step of removing a unnecessary portion from the conductor layer by, for example, chemical etching, and forming a predetermined wiring layout or electrode pattern. By performing this step, the printed wiring board 1a in which the electrode 20 and the wiring 30 are formed on the base material 10 as shown in FIG. 6 is obtained.

  Next, the 1st soldering resist 40 is apply | coated (step S3, 1st soldering resist application | coating process). FIG. 7 shows the first solder resist coating process. By performing this process, as shown in FIG. 7, the printed wiring board 1b on which the first solder resist 40 having the electrode 20 opened is formed.

  Next, silk printing which becomes an identification mark is performed (step S4, silk printing execution process). FIG. 8 is a diagram showing a silk printing execution process. As shown in FIG. 8, in this silk printing execution step, for example, a plate in which a mesh is formed with nylon or the like so as to create a portion through which ink passes and a portion through which ink does not pass is prepared. Then, the ink is extruded and printed on the printed wiring board 1b. Printing is performed while pressing with a squeegee as in solder printing. By performing this step, a printed wiring board 1c is obtained in which silk printing 80 is applied at a predetermined position on the first solder resist 40 as shown in FIG.

  Next, the 2nd soldering resist 50 is apply | coated (step S5, 2nd soldering resist application process). FIG. 9 shows the second solder resist coating process. By performing this step, as shown in FIG. 9, the second solder resist 50 is applied on the silk print 80, and the printed wiring board 1 in which the surface of the printed wiring board 1 is smoothed is obtained.

  Through the steps S1 to S5 described above, the silk print 80 can be recognized through the second solder resist 50, and the surface of the printed wiring board 1 is also kept smooth.

  Accordingly, it is possible to eliminate a step due to a printing thickness such as silk printing that has been conventionally used as an identification mark. That is, it is possible to apply the same thickness of solder to the portion where the character ink is applied and the portion where the character ink is not applied depending on the thickness of the character ink. Therefore, it is possible to prevent a reduction in mounting reliability of electronic components to be mounted.

(About the second embodiment of the printed circuit board)
FIG. 10 is a diagram showing a second embodiment of the printed circuit board according to the embodiment of the present invention. 10, the same parts as those of the first embodiment in FIG. 2 are denoted by the same symbols, and the description thereof is omitted.

  As shown in FIG. 10, in the printed circuit board 2b according to the present embodiment, the printed wiring board 1 is changed to a printed wiring board 1B. That is, the printed wiring board 1 </ b> B is common to the printed wiring board 1 in that the second solder resist 50 b is applied on the first solder resist 40. However, the second solder resist 50 b is different from the printed wiring board 1 in that it is not applied on the silk print 80.

  That is, as shown in FIG. 10, the second solder resist 50b is applied to a region excluding the electrode 20 and the silk print 80 which are predetermined electrode portions. The thickness (t2) of the second solder resist 50b and the thickness (t1) of the silk print 80 are applied while maintaining the same thickness. Thereby, the surface of the printed wiring board 1B is smoothed.

  In the present embodiment, since the silk printing 80 is provided on the outermost surface of the printed wiring board 1B, the second solder resist 50 is not only a so-called resist member, but has a different color from the silk printing 80, for example. If it has, this part may also be a silk printing member.

  Also in the second embodiment described above, it is possible to eliminate a step due to a printing thickness such as silk printing that has been conventionally used as an identification mark. That is, it is possible to apply the same thickness of solder to the portion where the character ink is applied and the portion where the character ink is not applied depending on the thickness of the character ink. Therefore, it is possible to prevent a reduction in mounting reliability of electronic components to be mounted.

  The present invention is not limited to the above-described embodiment, and may be another embodiment. For example, the first solder resist 40 and the second solder resist 50 are not limited to liquid solder resists, and may be dry film types. Moreover, it is not restricted to a thermosetting type or an ultraviolet curable type, and may be photosensitive. Also, the solder resist printing method (coating method) may be a screen printing method or a so-called photographic method that reduces exposure / development or the like that removes excess portions after irradiation with ultraviolet rays.

1 is a perspective view of a portable computer according to an embodiment of the present invention. The figure which showed 1st Embodiment of the printed circuit board of this invention. The top view of the printed wiring board 1. FIG. The flowchart which showed the manufacturing method of the printed wiring board which is embodiment of this invention. The figure which showed the copper clad laminated board preparation process. The figure which showed the etching process. The figure which showed the 1st soldering resist application process. The figure which showed the silk printing implementation process. The figure which showed the 2nd soldering resist application process. The figure which showed 2nd Embodiment of the printed circuit board concerning embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printed wiring board 10 Base material 11 Copper clad laminated board 2 Printed circuit board 20 Electrode 21 Conductor layer 30 Wiring 40 1st soldering resist 41 Opening part 50 2nd soldering resist 60 Electronic component 70 Solder 80 Silk printing A Component mounting area α1, α2 Screen version β Squeegee

Claims (5)

An insulating layer;
A conductor layer having a component mounting area on which an electronic component is mounted stacked on the insulating layer;
A first covering member applied on the conductor layer;
An identification mark applied on the first covering member and in the vicinity of the component mounting region; and a second coating applied on the first covering member and at least around the identification mark. Members,
A printed wiring board comprising:   The printed wiring board according to claim 1, wherein the first and second covering members are solder resists.   The printed wiring board according to claim 2, wherein the second covering member is applied on the first covering member so as to cover the identification mark.   The printed wiring board according to claim 1, wherein the first covering member is a solder resist member, and the second covering member is a silk printing member having a color different from that of the identification mark. An electronic device containing a printed wiring board,
The printed wiring board is
An insulating layer;
A conductor layer having a component mounting area on which an electronic component is mounted stacked on the insulating layer;
A first covering member applied on the conductor layer;
An identification mark applied on the first covering member and in the vicinity of the component mounting region; and a second coating applied on the first covering member and at least around the identification mark. Members,
An electronic device comprising:

Images