JP2013041958A - Printed wiring board and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily suppress quality deterioration due to dust generated from an end surface of a substrate without increasing cost.SOLUTION: A printed wiring board includes a substrate 10, metal wiring 20p formed on both surfaces or one surface of the substrate 10, and a film type solder resist 50 which covers and protects at least part of both surfaces or one surface of the substrate 10, on which the metal wiring 20p is formed. The film type solder resist 50 covers at least part of an end surface E of the substrate 10.

Description

  The present invention relates to a printed wiring board including a metal wiring formed on both surfaces or one surface of a base material, and a solder resist that covers and protects both surfaces or one surface of the base material on which the metal wiring is formed. Regarding the method.

  Examples of the printed wiring board include a TAB (Tape Automated Bonding) method and a TCP (Tape Carrier Package) method in which metal wiring is formed on both surfaces or one surface of a flexible substrate. FIG. 3 shows a method of manufacturing the printed wiring board 2 having the metal wiring 220p on both surfaces of the base 210 as a conventional example. First, the metal wiring 220p is formed on both surfaces of the substrate 210 (FIG. 3A). Next, an outer shape process is performed to cut a part of the base material 210 so as to represent a product after singulation (FIG. 3B), and both surfaces of the base material 210 are, for example, liquid (ink type) solder. Cover with a resist 250 (FIG. 3C). A part of the metal wiring 220p covered with the solder resist 250 is exposed (FIG. 3D). In addition, the process of FIG.3 (b) and the process of FIG.3 (c) and (d) may be mixed.

  In the above, for example, dust may be generated from the end surface 2E of the base material 210 that has been subjected to external processing, and the quality of the printed wiring board 2 may be deteriorated. Therefore, for example, a covering layer 255 made of a resin or the like is formed so as to cover the end face 2E (FIG. 3E). For example, Patent Document 1 discloses a technique for applying and forming an insulating resin layer on an end portion of a polyimide tape.

Japanese Patent Laid-Open No. 2001-093944

  However, as described above, if the coating layer 255 is formed in order to suppress dust generation, the number of steps increases and the cost increases. Moreover, since the contact area of the base material 210 or the solder resist 250 and the coating layer 255 is small, sufficient adhesion cannot be obtained, and the coating layer 255 may fall off.

  An object of the present invention is to provide a printed wiring board and a printed wiring board manufacturing method capable of easily suppressing deterioration in quality due to dust generation from the end face of a base material without increasing costs.

  According to the first aspect of the present invention, the base material, the metal wiring formed on both sides or one side of the base material, and at least a part on both sides or one side of the base material on which the metal wiring is formed. A printed wiring board that covers at least a part of the end surface of the base material.

  According to a second aspect of the present invention, there is provided the printed wiring board according to the first aspect, wherein the base material includes a polymer resin whose main component is at least one of polyimide, bismaleimide triazine, and epoxy. The

According to a third aspect of the present invention, there is provided the printed wiring board according to the first or second aspect, wherein the film type solder resist is a photo solder resist.

  According to a fourth aspect of the present invention, there is provided the printed wiring board according to the third aspect, wherein the photo solder resist is mainly composed of at least one of epoxy, acrylic, urethane, or polyimide.

  According to the fifth aspect of the present invention, the step of forming the metal wiring on both surfaces or one surface of the base material, and at least a part on both surfaces or one surface of the base material on which the metal wiring is formed are film-type solder. A method of manufacturing a printed wiring board in which at least a part of an end surface of the base material is covered with the film type solder resist in the step of covering and protecting with the film type solder resist. Provided.

  According to the sixth aspect of the present invention, in the step of covering and protecting with the film type solder resist, the film type solder resist is affixed on both sides or one side of the substrate using a vacuum roll laminating method or a vacuum pressing method. A printed wiring board manufacturing method according to the fifth aspect is provided.

  According to the present invention, it is possible to easily suppress deterioration in quality due to dust generation from the end face of the base material without increasing the cost.

It is sectional drawing which shows a part of printed wiring board which concerns on one Embodiment of this invention. It is process drawing which shows each process of the manufacturing method of the printed wiring board which concerns on one Embodiment of this invention with sectional drawing of the same direction side as FIG. It is process drawing which shows each process of the manufacturing method of the printed wiring board which concerns on a prior art example.

<One Embodiment of the Present Invention>

(1) Structure of Printed Wiring Board First, the structure of the printed wiring board according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view showing a part of a printed wiring board 1 according to the present embodiment. The cross section in the figure is a horizontal cross section with respect to the width direction of the printed wiring board 1 configured in a long shape, for example.

  As shown in FIG. 1, the printed wiring board 1 includes a base material 10 and metal wirings 20 p formed on both surfaces of the base material 10. The base material 10 is made of, for example, a flexible resin, and the printed wiring board 1 is configured as, for example, a flexible flexible substrate. The resin constituting the substrate 10 can be, for example, a polymer resin containing at least one of polyimide, bismaleimide triazine, and epoxy as a main component. The base material 10 has an end surface E including a cut surface and the like subjected to outer shape processing for cutting a part of an outer shape line when being separated into individual products. The end surface E is, for example, a machined surface by a rotary blade or a Thomson blade, a cut surface by etching, laser processing, or the like. For example, as shown in FIG. May be included.

The metal wiring 20p formed on both surfaces of the substrate 10 includes, for example, a first metal wiring 21p formed by patterning a copper foil or the like formed on one surface of the substrate 10, and the other surface of the substrate 10 And the second metal wiring 22p formed by patterning the copper foil or the like formed on the substrate. Further, the metal wiring 20p has a pad, a land, etc. (not shown) to which a semiconductor device and other electronic components are connected.

  Note that the surface of the metal wiring 20p exposed from the openings 51h and 52h, which will be described later, or the entire surface of the metal wiring 20p may have a plating (not shown) such as gold (Au) or tin (Sn). Thereby, it is possible to improve the bonding property between the semiconductor device and other electronic components and the metal wiring 20p.

  Further, the printed wiring board 1 includes a film-type solder resist 50 that covers and protects at least a part of both surfaces of the base material 10 on which the metal wiring 20p is formed. The film-type solder resist 50 covers at least a part of the end surface E of the substrate 10, for example, a side surface obtained by cutting off both ends of the substrate 10 in the width direction.

  The film type solder resist 50 is, for example, a photo solder resist (photosensitive solder resist) formed into a film shape. The photo solder resist can contain, for example, at least one of epoxy, acrylic, urethane, or polyimide as a main component. As the film-type solder resist 50, for example, a photo-curing type, that is, a negative type resist, is used, and openings 51h and 52h are provided by exposure and development as described later, and in the vicinity of the end face E of the substrate 10 Is formed to have a predetermined outer dimension. A semiconductor device (not shown) and other electronic components are connected to the first and second metal wirings 21p and 22p exposed from the openings 51h and 52h, respectively.

  As described above, dust may be generated from the end face E of the base material 10 that is a cut surface or the like during the outer shape processing due to resin cutting waste or the like constituting the base material 10. However, as described above, in this embodiment, the film-type solder resist 50 that covers and protects both surfaces of the base material 10 on which the metal wiring 20p is formed covers at least a part of the end surface E of the base material 10. It is configured. Thereby, the dust generation from the end surface E of the base material 10 can be suppressed, and the quality of the printed wiring board 1 can be improved.

  In the present embodiment, the film-type solder resist 50 that covers both surfaces of the base material 10 is configured to integrally cover the end surface E of the base material 10. Thus, unlike the coating layer 255 provided independently of the solder resist 250 as in the above-described conventional printed wiring board 2 of FIG. 3, the film type solder resist 50 from the end surface E of the base material 10 is different. Dropping can be suppressed.

  In the present embodiment, for example, a photo-curing resist is used for the film-type solder resist 50. Thereby, the shape of the vicinity of the end surface E of the base material 10 can be adjusted by exposure and development, and the printed wiring board 1 having a predetermined outer dimension can be obtained.

(2) Manufacturing method of printed wiring board Next, the manufacturing method of the printed wiring board 1 which concerns on one Embodiment of this invention is demonstrated using FIG. FIG. 2 is a process diagram showing each process of the method for manufacturing the printed wiring board 1 according to the present embodiment in a sectional view on the same direction side as FIG. That is, the cross section in the figure is a horizontal cross section with respect to the width direction of the printed wiring board 1 configured in a long shape, for example.

(Metal wiring formation process)
First, as shown in FIG. 2A, a base material 10 having a first metal layer 21 on one surface and a second metal layer 22 on the other surface is prepared. The first and second metal layers 21 and 22 can be formed by attaching a copper foil or the like to the base material 10 with an adhesive (not shown), for example, or may be formed by vapor deposition or sputtering. In addition, sprocket holes (not shown) used for transporting or positioning the base material 10 may be formed near both ends of the base material 10 in the width direction.

  In the metal wiring forming step, the first and second metal layers 21 and 22 are subjected to patterning or the like to form the metal wiring 20p on both surfaces of the base material 10. That is, first, as shown in FIG. 2 (b), for example, a photoresist 30 is applied on the first metal layer 21 formed on one surface of the base material 10, and is exposed and developed. As shown in FIG. 3, a resist pattern 30p is formed. At this time, a dry film or the like may be used instead of the photoresist 30.

  Subsequently, as shown in FIG. 2D, the first metal layer 21 is etched using the resist pattern 30p as a mask to form a first metal wiring 21p. At that time, for example, a masking tape (not shown) is attached on the second metal layer 22 formed on the other surface of the substrate 10 to mask the second metal layer 22 so that it is not etched. After the etching of the first metal layer 21, the resist pattern 30p and the masking tape are peeled off.

  Next, as shown in FIG. 2 (e), for example, a photoresist 40 is applied on the second metal layer 22 formed on the other surface of the base material 10, and is exposed and developed. As shown, a resist pattern 40p is formed. At this time, a dry film or the like may be used instead of the photoresist 40.

  Subsequently, as shown in FIG. 2G, the second metal layer 22 is etched using the resist pattern 40p as a mask to form a second metal wiring 22p. At that time, for example, a masking tape (not shown) is attached on the first metal wiring 21p formed on one surface of the base material 10, and masking is performed so that the first metal wiring 21p is not etched. After the etching of the second metal layer 22, the resist pattern 40p and the masking tape are peeled off.

  Thus, the metal wiring 20p is formed on both surfaces of the base material 10. In addition, you may implement the process of FIG.2 (b)-(d), and the process of FIG.2 (e)-(g), changing order.

(Outline processing process)
Next, as shown in FIG. 2 (h), an outer shape process is performed in which a part of the base material 10 is cut so as to represent a product after being singulated. Specifically, a part of the outer shape line is cut off with a rotary blade or the like so that the product portion is not completely separated from the base material 10 along the outer shape line when the base material 10 is separated as a product. Cutting is performed by machining with a Thomson blade or the like, etching, or laser processing. As a result, as shown in a predetermined position of the base material 10, for example, as shown in FIG.

(Film type solder resist coating process)
Next, at least a part of both surfaces of the base material 10 on which the metal wiring 20p is formed is covered with the film type solder resist 50. Thereby, both surfaces of the metal wiring 20p and the base material 10 are protected.

Specifically, as shown in FIG. 2 (j), a first film-type solder resist 51 is pasted on one surface of the substrate 10 on which the first metal wiring 21p is formed, thereby forming the second metal wiring 22p. A second film type solder resist 52 is affixed to the other surface of the base material 10 thus prepared. As the first and second film type solder resists 51 and 52, for example, a photo solder resist formed into a film shape, more specifically, a photo-curing resist is used, and a vacuum roll laminating method, a vacuum pressing method, or the like is used. It can be used while applying heat. Moreover, it is preferable that the widths of the first and second film-type solder resists 51 and 52 are wider than the width of the substrate 10. Thereby, both ends of the first and second film-type solder resists 51 and 52 that protrude from the base material 10 are bonded to each other, and at least a part of the end surface E of the base material 10, for example, a side surface obtained by cutting off both ends in the width direction, Substantially the entire substrate 10 is covered with the first and second film-type solder resists 51 and 52.

  Subsequently, openings 51 h and 52 h are formed in the film-type solder resist 50 and the shape in the vicinity of the end surface E of the substrate 10 is adjusted. Specifically, as shown in FIG. 2 (k), the first film type solder resist 51 is exposed using a photomask 60. Next, as shown in FIG. 2L, the second film type solder resist 52 is exposed using a photomask 70.

  Accordingly, for example, the first and second film type solder resists 51 and 52 constituted by, for example, a photo-curing resist or the like are cured at a portion exposed to the exposure light, and developed, thereby FIG. As shown in FIG. 5, the unexposed portion is removed, and an opening 51h where the first metal wiring 21p is exposed and 52h where the second metal wiring 22p is exposed are formed. Further, the shape in the vicinity of the end surface E of the base material 10 is adjusted, and the width direction of the base material 10 is formed into a predetermined outer dimension. Thus, in this embodiment, the film type solder resist 50 acts as a negative resist.

  Thus, the film type solder resist coating step is completed. In addition, you may implement the process of FIG.2 (k), and the process of FIG.2 (l), changing order.

  After forming the openings 51h and 52h in the film-type solder resist 50, the surface of the metal wiring 20p exposed from the openings 51h and 52h is subjected to plating (not shown) such as gold (Au) or tin (Sn). Also good. Alternatively, the plating may be performed at any timing after the metal wiring forming process and before the film-type solder resist coating process.

  With the above, the printed wiring board 1 according to the present embodiment is manufactured.

  Thus, in this embodiment, the film type solder resist 50 covers and protects both surfaces of the base material 10 on which the metal wiring 20p is formed, and also covers the end surface E of the base material 10 integrally. Thereby, dust generation from the end surface E of the substrate 10 can be suppressed, and the solder resist 50 can be prevented from dropping off from the end surface E. Therefore, the quality of the printed wiring board 1 can be improved.

  In the present embodiment, the end surface E of the substrate 10 is covered with the film-type solder resist 50 in the film-type solder resist coating step for covering and protecting both surfaces of the substrate 10 on which the metal wiring 20p is formed. Thereby, a film type solder resist coating process will also serve as a measure against dust generation from the end face E of the substrate 10, and dust generation can be suppressed without increasing the number of processes. Therefore, the quality of the printed circuit board 1 can be easily improved without causing an increase in cost due to an increase in the number of steps.

  In the present embodiment, the film type solder resist 50 is formed by exposure and development. Thereby, the printed wiring board 1 which has a predetermined external dimension can be manufactured accurately. Therefore, the quality of the printed wiring board 1 can be further improved.

<Other Embodiments of the Present Invention>
As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to the above-mentioned embodiment, It can change variously in the range which does not deviate from the summary.

For example, in the above-described embodiment, the printed wiring board 1 is configured as a flexible flexible board, but may be a rigid rigid board. The base material in this case may be a sheet-like base material composed of, for example, a glass cloth containing a polymer resin whose main component is at least one of polyimide, bismaleimide triazine, and epoxy.

  In the above-described embodiment, the first and second metal wirings 21p and 22p are formed on both surfaces of the base material 10, respectively. However, the metal wiring may be formed only on one surface of the base material. Good. In this case, it is good also as covering only the single side | surface in which the metal wiring was formed with the film type solder resist. In order to cover the end face of the base material with the film type solder resist only on one side, for example, a film type solder resist wider than the width of the outer shape processing of the base material is applied to one side of the base material while applying heat. The film-type solder resist is melted by heat at the time of application, and the end surface of the base material can be covered with a portion protruding from the width of the outer shape processing. The method of melting the film type solder resist and covering the end face of the substrate can also be used when the film type solder resist is applied to both sides.

  Moreover, in the above-mentioned embodiment, although the end surface E of the base material 10 was said to be the cut surface of the base material 10 by which a part of the outline line of the product was cut | disconnected by external shape processing, an end surface is not restricted to this. . For example, the end surface of the outer periphery of the base material when cut into a strip shape, or each end surface when the base material is configured in a sheet shape as described above, whether the end surface is generated by external processing, The present invention can be applied to end faces that are likely to generate dust regardless of whether or not they exist.

  In the above-described embodiment, the film type solder resist 50 is composed of a negative type resist, but it may be a positive type. Moreover, it is good also as apply | coating an ink type resist not only when sticking the resist shape | molded by the film form.

  Next, examples according to the present invention will be described.

  First, the printed wiring board which has the film type solder resist which covers the end surface of a base material with the method similar to the above-mentioned embodiment was manufactured. As the base material, Upicel (registered trademark) made by Ube Industries with a thickness of 20 μm was used, and as the metal layer, electrolytic copper foil F2-WS made by Furukawa Electric with a thickness of 12 μm was used. For the film type solder resist, DM325 manufactured by Nichigo Morton Co., Ltd. was used as a photo-curing resist. The film type solder resist was coated by a vacuum roll laminating method.

  In the printed wiring board produced as described above, dust generation from the end face of the base material was reduced. Further, the film type solder resist was not removed in the vicinity of the end face of the substrate. Further, the external dimensions of the printed wiring board can be within ± 10 μm with respect to the design value, and the processing accuracy of the printed wiring board can be improved.

DESCRIPTION OF SYMBOLS 1 Printed wiring board 10 Base material 20p Metal wiring 21p 1st metal wiring 22p 2nd metal wiring 50 Film type solder resist 51 1st film type solder resist 52 2nd film type solder resist 51h, 52h Opening part

Claims (6)

A substrate;
Metal wiring formed on both sides or one side of the substrate;
A film type solder resist that covers and protects at least a part of both sides or one side of the base material on which the metal wiring is formed, and
The printed wiring board, wherein the film-type solder resist covers at least a part of an end surface of the base material. The printed wiring board according to claim 1, wherein the base material includes a polymer resin mainly containing at least one of polyimide, bismaleimide triazine, and epoxy. The printed wiring board according to claim 1, wherein the film type solder resist is a photo solder resist. The printed wiring board according to claim 3, wherein the photo solder resist contains at least one of epoxy, acrylic, urethane, and polyimide as a main component. Forming metal wiring on both sides or one side of the substrate;
Covering and protecting at least a part of both sides or one side of the base material on which the metal wiring is formed with a film-type solder resist,
In the process of covering and protecting with the film type solder resist,
A printed wiring board manufacturing method, wherein at least a part of an end surface of the base material is covered with the film type solder resist. In the process of covering and protecting with the film type solder resist,
6. The method for producing a printed wiring board according to claim 5, wherein the film type solder resist is attached to both sides or one side of the base material using a vacuum roll laminating method or a vacuum pressing method.

Images