JP2001053452A - Pattern registration system for printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the relative misregistration between patterns by providing a low-layer pattern recognition mark on the pattern which is one layer below a layer on which a pattern is to be formed and reading the mark with a camera for position detection through the insulating resin of the layer on which the pattern is to be formed, and then, registering the mark with an exposure recognition mark. SOLUTION: In the formation of a build layer pattern, a lower-layer pattern recognition mark 7 is formed simultaneously with the pattern in the lower-layer recognition mark and exposure recognition mark indicating area 5 of a mask film for exposing the surface-layer pattern of a core layer. Then the mark 7 is recognized with a camera for position detection incorporated in an exposing device through the resin of a build layer and registered with the exposure recognition mark 8 of a mask film for forming the pattern of the build layer. When the mark 7 is formed in the above-mentioned way, the sticking deviation between a base material and a film can be controlled with high accuracy, because the mark 7 can be registered directly with a pattern or hole to be registered instead of a visually deformed reference hole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for manufacturing a multilayer printed wiring board, and more particularly to a pattern alignment method. Here, the pattern alignment is a general term for pattern alignment of each layer, through holes for patterns, and alignment of patterns for through holes.

[0002]

2. Description of the Related Art In order to manufacture a multilayer printed wiring board, it is necessary to keep the relative displacement between the pattern position and the through hole position of each layer within an allowable error range at the time of design. 2. Description of the Related Art Conventionally, a reference hole alignment method is generally used for alignment. In other words, all manufacturing jigs are created based on the reference hole positions, and the inner layer material reference holes drilled in the inner layer base material are used as all the alignment references during the manufacturing process, so that the pattern and through hole positions can be determined. This is a method in which the amount of deviation is kept within an allowable range.

Hereinafter, a specific example of the reference hole alignment method in the conventional method will be described with reference to process drawings. FIG. 4 shows an example of main steps of a semi-additive method build-up printed wiring board which is advantageous for forming a fine pattern. The process name related to the reference hole alignment is provided with a circled number at the beginning. In manufacturing the inner layer of the core layer, a pattern is formed on the inner layer base material by aligning an inner layer material reference hole preliminarily formed in the inner layer base material with an alignment mark provided on the inner layer pattern film. In laminating the core layers, the positions of the conductor patterns of each layer are adjusted by laminating the inner layer material reference holes of the respective inner layers with the reference pins of the bonding plate. In drilling holes for the core layer IVH, the holes are fixed to the bed of the NC drill machine with reference holes. The origin of the drill data and the origin of the drill machine are aligned by matching the positional relationship with the reference hole. Mask film alignment at the time of pattern exposure in the core layer resist processing step is performed by a camera alignment mechanism built into the exposure machine using the reference holes and alignment marks provided on the mask film. In drilling a via hole for a build layer, the reference hole and the via hole are aligned by positioning with the reference hole and drilling with a laser. The mask film alignment in the build layer resist processing step is performed by a camera alignment mechanism built in the exposure machine using the reference holes and the alignment marks of the mask film. FIG. 5 shows a specific example of a conventional method of a reference hole and a mask film alignment mark used for mask film alignment in the build layer resist processing step. 12 is a reference hole of the base material 10,
Reference numeral 13 denotes an alignment mark of the mask film 11.

As described above, the conventional reference hole alignment method is seemingly rational because all alignment references are used as reference holes, but the reference holes have the following problems. The inner layer material reference hole is close to a perfect circle, and is suitable for use as an alignment reference when forming the inner layer pattern of the item, and for inserting and fixing the bonding plate, which is a jig for lamination, to the stack pins when preparing the item for lamination. . However,
There is a slight expansion and contraction of each inner layer base material and the flow of the resin of the prepreg as an adhesive due to the heating and pressing at the time of lamination, and a reference hole is formed at the stack pin position of the bonding plate in a shape where the stack pin is pulled out. You. Therefore, although it is called a reference hole, it has already included an error in the forming stage as described above, and the shape of the reference hole which has come off in a cylindrical shape is not a perfect cylindrical shape but a slightly deformed shape. is there. This fine deformation is not a problem when fixed to the drill machine with a pin, but appears as a center position detection error when viewed with a position detection camera. Further, the distortion of the inner peripheral shape of the reference hole that is slightly deformed in the subsequent panel copper plating is emphasized, particularly visually, that is, when viewed with the position detection camera.

On the other hand, errors in manufacturing a printed wiring board include expansion and contraction of a substrate and expansion and contraction of a mask film in addition to alignment errors, and the processing accuracy of equipment and tools cannot be ignored. With respect to the expansion and contraction of the base material and the expansion and contraction of the mask film, the relative position accuracy is improved by taking measures to suppress expansion and contraction and making corrections to the perforation data and the mask film. Equipment and tools have also been devised, and processing accuracy has been dramatically improved.

[0006]

However, with the miniaturization and high integration of the components mounted on the printed wiring board, the wiring density and the number of layers of the printed wiring board are increased, and the manufacturing tolerance in designing the printed wiring board is increased. There is a growing need to further reduce. Therefore, the yield has been reduced or manufacturing has become impossible unless improvements are made to reduce various error factors.
An object of the present technology is to provide a pattern alignment method that completely reviews the conventional reference hole alignment method and reduces a relative displacement of a pattern similar to an alignment error as a measure for solving the above-described problem. And

[0007]

According to a first aspect of the present invention, there is provided a printed wiring board pattern alignment method, comprising:
A lower-layer pattern recognition mark is provided in advance on the pattern of the lower layer of the layer on which the pattern is to be formed, and the lower-layer pattern recognition mark is read by a position detection camera through the insulating resin of the layer on which the pattern is to be formed, and the layer on which the pattern is formed And the exposure recognition mark of the pattern exposure mask film.

According to the pattern alignment system of the first aspect of the present invention, unlike the conventional system in which the lower layer pattern and the upper layer pattern are indirectly aligned via the respective reference holes, the lower layer pattern and the upper layer pattern are directly positioned. There are few opportunities for error intervention because they are combined. Further, since the reference hole is not used, there is no influence of the reference hole center point reading error due to the deformation of the reference hole.

According to a second aspect of the present invention, there is provided a method of aligning a pattern of a printed wiring board, the method comprising the steps of: A new second reference hole is formed in the vicinity based on the original reference hole, and the position of the pattern exposure mask film is aligned with the second reference hole.

According to the second aspect of the present invention, the original reference hole is deformed by stress at the time of lamination, and copper is abnormally deposited on a deformed portion around the reference hole in a subsequent copper plating process. Thus, while it is difficult to read the center point of the reference hole by the position detection camera, the accuracy of reading the center point of the reference hole is increased because the new second reference hole has a substantially perfect circle.

According to a third aspect of the present invention, there is provided a pattern alignment method for a printed wiring board, wherein a special mark for laser drilling is provided in advance in a pattern of one layer below in forming a via hole for a build layer of a build-up printed wiring board. After laminating the insulating resin, the mark dedicated to laser drilling is read by a position detection camera through the resin and aligned.

According to the printed wiring board pattern alignment method of the present invention, the reference hole does not intervene in the alignment, and the lower layer pattern is directly aligned with the via hole hole data in the build layer. Few. Further, since the reference hole is not used, there is no influence of the reference hole center point reading error due to the deformation of the reference hole.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described step by step. Table 1 lists the steps related to pattern alignment in the build-up printed wiring board manufacturing process, and lists the objects to be aligned, the alignment means, and the relationships with the claims.

[Table 1] In Table 1, the item is a step related to the embodiment of the present invention, and the item is a step of performing matching by the same method as in the related art.

A description will be given below with reference to various matching criteria shown in FIGS. 1, 2 and 3. FIG. 1 shows an example of setting various reference marks, 1 indicates a work board area, and 2 indicates a product area. 3,
Reference numerals 4, 5, and 6 are provided at each of the four corners of the work board area 1 outside the product area 2, 3 is a reference hole, and 4 is a second hole.
Reference holes 5, 5 are lower layer recognition marks and exposure recognition mark display areas, and 6 is a laser drilling dedicated mark display area. FIG. 2 shows an embodiment of the lower layer recognition mark and the exposure recognition mark in the lower layer recognition mark and the exposure recognition mark display area 5, and FIG. 3 shows an embodiment of the laser drilling exclusive mark in the laser hole only mark display area 6. Show. First, since the reference hole 3 in FIG. 1 is visually deformed as described above, in the drilling process, the hole for the IVH is fixed by fixing the reference hole 3 to the bed of the drill machine with a pin. Along with
A second reference hole 4 is newly formed by a drill. At the time of exposing the surface layer pattern of the core layer, the second reference hole 4 is aligned with the mask film alignment mark. (The method according to claim 2) In this alignment method, since the positional relationship between the IVH hole and the second reference hole is formed under the same condition, the alignment method is performed for the purpose of aligning the IVH hole and the core layer surface layer pattern. Optimal.

Next, in the drilling of the via hole for the build layer, a dedicated mark for laser drilling 9 is provided in advance in the laser drilling mark display area 6 of the mask film for exposing the core layer surface pattern, and is formed simultaneously with the pattern. Is recognized by a camera for detecting the position of the laser drilling machine through the build layer resin, and is aligned. (Method according to claim 3)
In this alignment method, the core layer surface layer pattern and the laser drilling dedicated mark are drawn on the same film,
It is most suitable for the purpose of aligning the core layer surface pattern and the build layer via.

Finally, in the formation of the build layer pattern, the lower layer recognition mark 7 which is provided in advance in the lower layer recognition mark and the exposure recognition mark display area 5 of the mask film for exposing the core layer surface pattern and is formed simultaneously with the pattern is built. Through the layer resin, it is recognized by a position detection camera built in the exposure machine, and is aligned with the exposure recognition mark 8 of the build layer pattern forming mask film. (Method of Claim 1) Similarly, the second build layer pattern can be formed by aligning the exposure recognition mark 8 'of the second build layer with the lower layer pattern recognition mark 7' of the first build layer. In addition, since the surface of the build layer resin is roughened due to a smear removing step after laser drilling, and the resin surface is subjected to copper plating in a panel copper plating step, the lower layer pattern recognition mark portion is removed. After laser drilling and before smear removal, protect by applying masking tape. After laminating the photosensitive dry film in the resist processing step, the masking tape portion is pierced so that the lower layer pattern recognition mark 7 can be clearly read through the build layer resin. This alignment method is most suitable for the purpose of aligning the lower layer pattern of one layer and the build layer pattern immediately above.

[0017]

According to the present invention, instead of a visually deformed reference hole, direct alignment with the pattern or hole position to be aligned can be performed. Can be controlled with high precision. In the actual value according to the present embodiment, the deviation amount from the center of the conventional 10 μm order is 2.1 μm at the maximum.
m.

[Brief description of the drawings]

FIG. 1 shows an example of setting various reference marks according to an embodiment of the present invention.

FIG. 2 shows a state where the lower layer pattern recognition mark and the exposure recognition mark are aligned with the embodiment.

FIG. 3 shows an embodiment of a mark dedicated to laser drilling.

FIG. 4 shows main manufacturing steps of a semi-additive build-up printed wiring board.

FIG. 5 shows a combination of a substrate and a film according to a conventional method.

[Explanation of symbols]

 1 Work Board Area 2 Product Area 3 Reference Hole 4 Second Reference Hole 5 Lower Layer Recognition Mark and Exposure Recognition Mark Display Area 6 Laser Hole Dedicated Mark Display Area 7 Lower Layer Pattern Recognition Mark 8 Exposure Recognition Mark 9 Laser Hole Dedicated Mark 10 Material 11 Mask film 12 Reference hole 13 Alignment mark

Claims (3)

[Claims] In positioning a mask film for pattern exposure on a multilayer printed wiring board, a lower layer pattern recognition mark is provided in advance on a pattern of one layer below a layer to be patterned, and the insulating resin of the layer to be patterned is transparent. And reading the lower layer pattern recognition mark with a position detection camera and aligning the lower layer pattern recognition mark with an exposure recognition mark of a pattern exposure mask film of a layer on which a pattern is to be formed. 2. A method for positioning a position of each layer pattern and a position of a through hole in a multilayer printed wiring board, the method including the steps of: A pattern positioning method for a printed wiring board, wherein a pattern exposure mask film is positioned in accordance with the second reference hole. 3. A method of forming a via hole for a build layer of a build-up printed wiring board, in which a mark dedicated to laser drilling is provided in advance in a pattern of a lower layer, and after laminating an insulating resin of the build layer, the resin is passed through the resin. A pattern alignment method for a printed wiring board, wherein a mark dedicated to laser drilling is read by a position detection camera and aligned.