JP2013041963A - Method of manufacturing printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reinforce sprocket holes by covering the surroundings of the sprocket holes with a metal film without reducing positioning accuracy during exposure by the sprocket holes.SOLUTION: A method of manufacturing a printed wiring board includes the steps of: bonding a dry film resist 14 on a first main surface 10a of an insulated substrate 10 while covering a metal film 11 and sprocket holes 13; processing the dry film resist 14 exposed from the sprocket holes 13 to a second main surface 10b side of the insulated substrate 10 by developer through the sprocket holes 13 and removing resist materials 14r of portions exposed form the sprocket holes 13 of the dry film resist 14; and etching the metal film 11 by using a resist pattern 14p obtained by exposing and developing the dry film resist 14 from the first main surface 10a side of the insulated substrate 10 on the basis of the sprocket holes 13 as a mask to form wiring 11w, and forming a reinforcement part covering the surroundings of the sprocket holes 13 with the metal film 11.

Description

  The present invention relates to a method of manufacturing a printed wiring board having a sprocket hole whose periphery is covered with a metal film.

  In the printed wiring board manufacturing process, for example, wiring is formed on at least one surface of a flexible insulating substrate. In some cases, both ends of the insulating substrate are provided with sprocket holes for carrying and positioning. However, when such a sprocket hole is formed, the strength of the printed wiring board is lowered, and there are cases where, for example, the conveyance in the manufacturing process of the printed wiring board is hindered. In recent years, the thickness of a printed wiring board has increased, such as the use of an ultra-thin board of 50 μm or less, and such a decrease in strength has become more serious.

  Therefore, for example, in Patent Document 1, when a dry film is laminated including a transport hole (sprocket hole) of a tape base material to form a wiring pattern on the conductive layer, a reinforcing conductive layer is formed around the transport hole. A method is disclosed in which the mechanical strength of the transport hole is increased while leaving

JP 2007-250695 A

  However, if the dry film resist is pasted over the sprocket hole, the resist material of the dry film resist contacts the edge of the sprocket hole, causing abnormal flow, and bubbles are formed in the dry film resist portion stretched over the sprocket hole. (Void) may occur. If such bubbles are generated, it may become a source of dust generation in the subsequent process, and when using the sprocket hole for positioning during exposure, the visibility of the sprocket hole will be reduced and positioning will be difficult. was there.

  An object of the present invention is to provide a method of manufacturing a printed wiring board that can cover and reinforce the periphery of a sprocket hole with a metal film without reducing the positioning accuracy during exposure by the sprocket hole.

  According to the first aspect of the present invention, a step of forming a sprocket hole in an insulating substrate having at least a metal film formed on the first main surface, and the metal film and the first main surface of the insulating substrate, A step of covering the sprocket hole with a dry film resist, and the dry film resist exposed from the sprocket hole to the second main surface side of the insulating substrate is processed with a developer through the sprocket hole; Removing the resist material in a portion of the resist exposed from the sprocket hole; and exposing and developing the dry film resist from the first main surface side of the insulating substrate based on the sprocket hole; The wiring formation pattern and the sprocket hole are arranged in a predetermined manner with respect to the hole. Forming a resist pattern having a reinforcing part forming pattern; etching the metal film using the resist pattern as a mask to form a wiring; and a reinforcing part having a periphery of the sprocket hole covered with the metal film And a method of manufacturing a printed wiring board.

  According to a second aspect of the present invention, the wiring is a wiring to which an electronic component is connected, and in the step of forming the sprocket hole, a through-hole for aligning the electronic component with respect to the wiring is provided. In the step of processing the dry film resist formed in the product region of the insulating substrate in a predetermined arrangement with respect to the sprocket hole and exposed to the second main surface side, the dry film resist is also removed from the through hole. The printed wiring board according to the first aspect, wherein in the step of forming the resist pattern by processing with a developing solution, the wiring forming pattern is formed in a predetermined arrangement with respect to the through hole with respect to the sprocket hole. A manufacturing method is provided.

  According to the present invention, the periphery of the sprocket hole can be covered with the metal film and reinforced without lowering the positioning accuracy during exposure by the sprocket hole.

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 a top view. It is a figure which shows the manufacturing method of the printed wiring board which concerns on one Embodiment of this invention, Comprising: It is sectional drawing corresponding to the process of FIG.1 (d), (e). It is sectional drawing which shows a mode that electronic components are aligned with the printed wiring board which concerns on one Embodiment of this invention.

<One Embodiment of the Present Invention>
Below, the manufacturing method of the printed wiring board which concerns on one Embodiment of this invention is demonstrated using FIG.1 and FIG.2. FIG. 1 is a process diagram showing each process of the method for manufacturing the printed wiring board 1 according to the present embodiment in a plan view. FIG. 2 is a view showing a method of manufacturing the printed wiring board 1 according to the present embodiment, and is a cross-sectional view corresponding to the steps of FIGS. 1 (d) and 1 (e).

  The printed wiring board 1 is formed by arranging a plurality of insulating substrates 10, near both ends of the insulating substrate 10, sprocket holes 13 used for positioning during conveyance and exposure, and in the product area of the insulating substrate 10. And a wiring 11w formed on the insulating substrate 10 in a predetermined arrangement with respect to the jig hole 12 to which an electronic component or the like is connected. At least a part of the sprocket hole 13 is configured as a positioning hole 13 a for forming the wiring 11 w in a predetermined arrangement with respect to the jig hole 12. The jig hole 12 is configured as a component hole for aligning an electronic component with respect to the wiring 11w. Around the sprocket hole 13 and the jig hole 12, a belt-like part 11s as a reinforcing part for reinforcing the periphery and a jig hole covering part 11h as a through hole covering part are formed.

(Insulating substrate preparation process)
First, a substrate in which the metal film 11 shown in FIG. 1B is formed on at least the first main surface 10a of the insulating substrate 10 shown in FIG. The insulating substrate 10 is configured as a flexible substrate having a thickness of 3 μm to 25 μm, for example, and is made of a resin such as polyimide (PI). The metal film 11 is made of, for example, stainless steel (SUS), copper (Cu), or the like, and is formed, for example, by bonding a stainless foil or copper foil having a thickness of 8 μm or more and 15 μm or less to the insulating substrate 10 with an adhesive (not shown). In addition, it may be formed by vapor deposition or sputtering.

(Sprocket hole formation process)
Next, as shown in FIG. 1 (c), the sprocket hole 13 used for transporting the insulating substrate 10, positioning at the time of exposure, etc. is penetrated through the insulating substrate 10 on which the metal film 11 is formed by punching or the like. And a jig hole 12 as a through hole for aligning electronic components and the like. For example, a plurality of jig holes 12 can be formed so as to surround a region where the wiring 11w is to be formed later, so that the electronic components can be easily aligned. Both the jig hole 12 and the wiring 11w are formed in the product region when the printed wiring board 1 is separated into a product later.

  In order to form the sprocket hole 13 and the jig hole 12, a punching method using a die as in the above punching can be used, a laser cutting method by laser irradiation, a Thomson blade or a pinnacle blade. It is possible to use a push-cut method using a sculpture sword.

  Further, although the jig hole 12 is shown in a circular shape in the drawing, it can be formed in various shapes such as an ellipse, a polygon such as a triangle or a quadrangle, and a cross.

(Dry film resist bonding process)
Subsequently, as shown in FIG. 1 (d), the dry film covers the metal film 11, the sprocket hole 13, and the jig hole 12 over substantially the entire surface of the first main surface 10 a of the insulating substrate 10 having the metal film 11. Resist 14 is bonded.

  2D corresponding to FIG. 1D, the dry film resist 14 is made of polyethylene terephthalate on the front and back surfaces of a negative resist material 14r having a thickness of 10 μm to 20 μm, for example. A protective film 14g having a thickness of about 16 μm made of (PET) or the like and a base film (not shown) made of PI or the like are provided. The dry film resist 14 may be a positive dry film resist using a positive resist material.

  When the dry film resist 14 is bonded, the resist material 14r having the protective film 14g is directly bonded by pressing the insulating film 10 with a roller or the like while peeling off the base film, for example. At this time, if the sprocket hole 13 is provided in the insulating substrate 10, the resist material 14 r in contact with the edge of the sprocket hole 13 causes abnormal flow in the dry film resist 14 portion stretched over the sprocket hole 13. In some cases, bubbles 14v may be generated in the resist material 14r. Such bubbles 14v are also generated in the dry film resist 14 portion stretched over the jig hole 12, and the resist material 14r includes the bubbles 14v in almost all the sprocket holes 13 and the jig hole 12 portions. Become.

  In the past, such bubbles sometimes hindered subsequent processes. That is, for example, the surrounding resist material in which bubbles are generated may remain as a residue even after the dry film resist is peeled off, resulting in a dust generation source. In addition, for example, when using sprocket holes for positioning during exposure, the visibility of the sprocket holes is reduced due to air bubbles, which makes positioning difficult, wastes time, and causes misalignment of the exposure pattern. was there.

  Therefore, in the present embodiment, by performing the steps described below, bubbles 14v generated in the portion of the dry film resist 14 stretched over the sprocket holes 13 and the jig holes 12 are reduced.

(Dry film resist processing process)
In this step shown in FIG. 1E, the dry film resist 14 stretched over the sprocket holes 13 and the jig holes 12 is processed with a developer from the lower surface side. That is, FIG. 1 (e)
2E corresponding to FIG. 2E, the dry film resist 14 exposed from the sprocket hole 13 and the jig hole 12 to the second main surface side 10b of the insulating substrate 10 is replaced with the sprocket hole 13 and the jig. Each is processed with a developer through the holes 12.

  The resist material 14r included in the dry film resist 14 is not exposed, and the resist material 14r exposed from the sprocket hole 13 and the jig hole 12 is removed by the developer. In this way, the resist material 14r in which the bubbles 14v are generated is removed, and only the protective film 14g is stretched over the sprocket holes 13 and the jig holes 12. Since the bubbles 14v are thus reduced, dust generation from the sprocket holes 13 and the jig holes 12 is suppressed in a later process. Moreover, the visibility of the sprocket hole 13 in which at least a part is used for positioning is improved in a later process.

(Resist pattern formation process)
Next, as shown in FIG. 1F, the dry film resist 14 is exposed from the first main surface 10a side of the insulating substrate 10 and developed to form a resist pattern 14p. That is, for example, in the case of a negative type dry film resist 14, first, the portion to be left as the resist pattern 14p is exposed. At this time, a part of the sprocket hole 13, for example, an arbitrary set of both ends of the insulating substrate 10 is used as the positioning hole 13a. By exposing and developing a wiring formation pattern 14w, which will be described later, with reference to the positioning hole 13a, the exposure position is determined so that the wiring 11w to be formed later has a predetermined arrangement with respect to the jig hole 12 and the positioning hole 13a. can do.

  Subsequently, after the protective film 14g is peeled off, the dry film resist 14 is developed, and a wiring formation pattern 14w, a jig hole covering pattern 14h as a through hole covering pattern, and a strip portion forming pattern 14s as a reinforcing portion forming pattern are formed. A resist pattern 14p is formed.

  As described above, the wiring formation pattern 14w can be set at a predetermined position in a region surrounded by the plurality of jig holes 12, for example. Further, the jig hole covering pattern 14h is sufficiently larger than the jig hole 12 and has a similar shape to the jig hole 12 so that the jig hole 12 can be completely covered. It is desirable. Further, the strip-shaped portion forming pattern 14 s is formed in a strip shape at both ends of the insulating substrate 10 so as to cover the individual sprocket holes 13.

(Wiring formation process)
Next, the metal film 11 is etched using the resist pattern 14p as a mask, and the wiring 11w shown in FIG. 1G is formed in a predetermined arrangement with respect to the positioning hole 13a and the jig hole 12. On the other hand, around the jig hole 12 masked by the jig hole covering pattern 14h, a jig hole covering portion 11h as a through hole covering portion covered with the metal film 11 so as to border the periphery of the jig hole 12 is provided. Is formed. Further, at both ends of the insulating substrate 10 masked with the band-shaped part forming pattern 14s, band-shaped parts 11s as reinforcing parts in which the periphery of each sprocket hole 13 is covered with the metal film 11 in a band shape are formed. After the etching of the metal film 11, the resist pattern 14p is peeled off.

  1G, the insulating substrate 10, the sprocket holes 13 formed in the vicinity of both ends of the insulating substrate 10, the jig hole 12 formed in the product region of the insulating substrate 10, The metal film 11 formed on the insulating substrate 10 is patterned to be formed in a predetermined arrangement with respect to the jig hole 12, and includes a wiring 11w to which an electronic component is connected. The sprocket hole 13 and the jig hole 12 are provided. The printed wiring board 1 in which the insulating substrate 10 around the substrate is covered with the metal film 11 is manufactured.

After the printed wiring board 1 is shipped in a long form or after the above process, the electronic component is connected to the wiring 11w, and a product region including the wiring 11w and the jig hole 12 is punched out. Separated into products. The electronic components may be connected after being separated. FIG. 3 is a cross-sectional view showing how electronic components are aligned with the printed wiring board 1.

  As described above, in this embodiment, the wiring 11w is formed so as to have a predetermined arrangement with respect to the jig hole 12. Thereby, as shown in FIG. 3, for example, when a jig pin 40p as a fixing member provided on the electronic component side is inserted into the jig hole 12 provided in the printed wiring board 1, the electrons are placed in a predetermined position with respect to the wiring 11w. Parts can be placed. As described above, in the present embodiment, the wiring 11w and the electronic component can be easily aligned, and thus the wiring 11w and the electronic component can be easily connected with high positional accuracy.

  The requirement of positional accuracy between the wiring 11w and the electronic component may be on the order of several μm, and the printed wiring board 1 tends to be thin and easily bent. Therefore, the wiring with high positional accuracy as in this embodiment. It is more important to form 11w and the jig hole 12.

  The electronic component connected to the wiring 11w includes the semiconductor device described above. When the electronic component is a probe card provided in an inspection device such as a prober, for example, an inspection signal is supplied from a probe pin provided in the probe card to a test pad or the like of the wiring 11w of the printed wiring board 1 with high positional accuracy. It is possible to determine whether the product is good or bad.

  In addition, the through hole formed in the product area is provided for the purpose of adjusting the through hole used as a vent hole in a printed wiring board used in an environment where a pressure difference or pressure change occurs, and the flexibility of the printed wiring board. It may be a through hole or the like.

  As described above, in this embodiment, when the metal film 11 is etched, the periphery of the sprocket hole 13 and the jig hole 12 is covered with the metal film 11 to form the belt-shaped portion 11s and the jig hole covering portion 11h. As a result, the sprocket hole 13 and the jig hole 12 are reinforced by the belt-like portion 11s and the jig hole covering portion 11h, respectively, and the sprocket hole 13 and the jig hole 12 are bent or deformed. Can be suppressed. Therefore, the strength of the printed wiring board 1 can be improved and the conveyance error during the manufacturing process can be suppressed. Moreover, the bending of the printed wiring board 1 is reduced, and the positional accuracy between the wiring 11w and the electronic component can be further improved. Such a configuration becomes more and more useful as the printed wiring board 1 becomes thinner.

  Further, by providing the jig hole covering portion 11h, that is, the jig hole 12 is edged by the metal film 11, the visibility of the jig hole 12 is improved, and the positioning of the electronic component is further facilitated. . However, with respect to the jig hole covering portion 11h, when the strength of the periphery of the jig hole 12 or the printed wiring board 1 is sufficiently obtained or when there is no problem in the visibility of the jig hole 12, this is used. It is also possible to adopt a configuration in which no provision is made.

  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.

DESCRIPTION OF SYMBOLS 1 Printed wiring board 10 Insulating board 11 Metal film 11h Jig hole covering part 11s Band-shaped part (reinforcement part)
11w Wiring 12 Jig hole (through hole)
13 Sprocket hole 13a Positioning hole 14 Dry film resist 14h Jig hole covering pattern 14p Resist pattern 14s Band-shaped part forming pattern (reinforcing part forming pattern)
14v bubble 14w wiring pattern

Claims (2)

Forming a sprocket hole in an insulating substrate having a metal film formed on at least the first main surface;
A step of bonding a dry film resist on the first main surface of the insulating substrate so as to cover the metal film and the sprocket hole;
The dry film resist exposed to the second main surface side of the insulating substrate from the sprocket hole is treated with a developing solution through the sprocket hole, and the resist material in a portion exposed from the sprocket hole of the dry film resist is removed. Process,
Using the sprocket hole as a reference, the dry film resist is exposed and developed from the first main surface side of the insulating substrate to cover the wiring formation pattern and the sprocket hole which are arranged in a predetermined manner with respect to the sprocket hole. Forming a resist pattern having a reinforcing portion forming pattern;
Etching the metal film using the resist pattern as a mask to form a wiring, and forming a reinforcing portion in which the periphery of the sprocket hole is covered with the metal film. Manufacturing method. The wiring is a wiring to which an electronic component is connected,
In the step of forming the sprocket hole,
A through hole for aligning the electronic component with respect to the wiring is formed in a product region of the insulating substrate in a predetermined arrangement with respect to the sprocket hole,
In the step of processing the dry film resist exposed to the second main surface side,
The dry film resist is treated with the developer from the through hole,
In the step of forming the resist pattern,
The method for manufacturing a printed wiring board according to claim 1, wherein the wiring formation pattern is formed in a predetermined arrangement with respect to the through hole with respect to the sprocket hole.

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