JP4817009B2 - Method for manufacturing printed wiring board - Google Patents

Description

  The present invention relates to a method for manufacturing a printed wiring board, and more particularly to a method for manufacturing a multilayer printed wiring board for positioning a non-through hole IVH and a circuit conductor, and a positioning mark for positioning a non-through hole IVH and a circuit conductor. It is.

  In a conventional multilayer printed wiring board, positioning the circuit conductors of each inner layer and via holes of non-through holes is achieved by using the through through hole as a reference mark and receiving the transmitted light from below the through through hole with a CCD camera. Therefore, the positioning of the through-hole and the circuit conductor pattern is important, and the via hole of the non-through hole is positioned as an alternative to the through-hole, and the via hole of the non-through hole and the circuit conductor pattern are positioned with high accuracy. It was difficult to do.

As a conventional example, there is a method for manufacturing a multilayer printed wiring board disclosed in Japanese Patent Application Laid-Open No. 2004-146427.
This is a method of manufacturing a multilayer printed wiring board by a build-up method that forms via holes stacked in layers while laminating resin-coated copper foil, and can recognize transmitted light from below the multilayer printed wiring board The reference mark (φ1.0 mm) from which the copper foil has been removed is provided on the bottom land for the first via hole of the double-sided printed wiring board as the core material, and the area (φ2.0 mm) is such that the reference mark can be recognized on the upper surface. The first via-hole positioning part (11) and via-hole position adjusting hole part (11) by detecting the transmitted light from below the multilayer printed wiring board are laminated. 12) A method for producing a multilayer printed wiring board in which a first via hole forming portion (13) is provided.

  However, in the above manufacturing method, the positioning part (11) of the first via hole that detects the transmitted light from below the multilayer printed wiring board that positions the via hole is a reference mark and the reference mark can be recognized. Since a circular opening with an area (φ2.0 mm) is provided in the outer layer on the top surface of the core material, the resin of the core material is limited to a material with good transmittance, and the space of this reference mark allows the wiring circuit conductor to be arranged. It becomes an invalid area. Furthermore, the space of the via hole position adjusting hole (12) is also an invalid area.

In addition, when forming a stacked via hole in which via holes formed in each layer of the printed wiring board are stacked in multiple stages, the first bottom land made of a conductor provided in the core material is used as the first reference, and the first via is formed. The hole positioning is performed by laser drilling, and then the second via hole is positioned by laser drilling with reference to the first top land of the first via hole, and the second top of the second via hole is processed. Form a land.
However, since the laser drilling process changes the positioning reference, the center position of the first via hole and the center position of the second via hole are misaligned, and it is difficult to make the positioning highly accurate.

  As the printed circuit board becomes more dense, lasers can be used to connect the inner circuit of each stage and between the outer layer and the inner circuit of each stage. The application of non-penetrating via holes with small hole diameters due to drilling has increased, and the requirement for positioning accuracy between IVH and surface circuit conductors in which conductor plating is applied in non-penetrating via holes has increased.

Moreover, in a printed wiring board in which through-holes and non-through IVHs are mixed, the NC drill drilling process (device) for through-through holes and the laser drilling process (device) for non-through via holes are: Therefore, a positional deviation occurs between the through-hole and the non-through-hole IVH.
In particular, the positioning of the non-penetrating IVH and the surface circuit conductor (land, line) was required to be highly accurate.
JP 2004-146427 A

Conventionally, in a printed wiring board in which through through holes and non-through IVHs are mixed, the NC drilling device that forms through holes and the laser drilling device that forms non-through via holes have different device functions. Of course, the processing steps are different from each other, and there are problems of positioning guides, expansion and contraction of the printed wiring board, and positional misalignment between the through-hole and the non-through-hole IVH.
In this application, IVH is a generic term for blind vias reaching from the outer layer circuit conductor to the inner layer circuit conductor, and buried vias connecting the inner layer circuit conductors, and are referred to as IVH (interstitial via hole).
In the first and second stages of laser drilling, the laser drilling positioning reference changes, so the center position of the first via hole and the center position of the second via hole are misaligned and not penetrated. The positioning accuracy of IVH and surface circuit conductors (land and wiring lines) was poor.

In the present invention, a via hole for IVH reaching from the outer layer of the printed wiring board to the circuit conductor of the inner layer of each step is formed by laser drilling, and drilling is performed at a depth from the outer layer to the inner layer of each step. A number of IVHs with conductor plating are set in the non-through holes of the via holes.
In order to position the IVH top land circuit conductors (lands and wiring lines) with high accuracy, a plurality of IVHs (M stages × N columns) are supported in a specific area. It aims at providing the manufacturing method of the multilayer printed wiring board which provides a positioning mark.

In order to solve the above-mentioned problems, the invention of claim 1 is a method for manufacturing a multilayer printed wiring board, wherein a (multi-stage) × (multi-row) IVH block in which non-through holes of via holes are subjected to conductor plating is IVH. Of the positioning mark (M), and the reflected light from the IVH of the positioning mark (M) is received by the CCD camera, and the printed wiring board for positioning the IVH and the surface circuit conductor formed on the upper surface side of the IVH is manufactured. Is the method.
In other words, in the method of manufacturing a multilayer printed wiring board, a top formed on the upper surface side of the IVH is obtained by using the IVH reflected by the IVH as a positioning reference, with the IVH having conductor plating in the non-through hole of the via hole. This is a method of manufacturing a printed wiring board in which the positions of circuit conductors that are lands are matched to perform accurate positioning. In addition, (multiple stages) × (multiple columns) IVH blocks are used as IVH positioning marks (M).

The invention of claim 2 is a method of manufacturing a printed wiring board in which the positioning mark (M) is not arranged at the center position consisting of blocks of (odd number stages) × (odd number columns).

According to a third aspect of the present invention, there is provided a printed wiring board manufacturing method in which the positioning mark and the block of the IVH hole are arranged in a specific area outside the effective area where a plurality of individual printed wiring boards are provided.

In the printed wiring board according to claims 1 to 3 , the circuit conductors of each stage (lands and wiring lines as wiring patterns) are aligned with the IVH positions after conductor plating is performed in the non-through holes of the via holes. A method of manufacturing a printed wiring board that performs accurate positioning can be provided.

In particular, in the method of manufacturing a multilayer printed wiring board, IVH obtained by plating a conductor in a non-through hole of a via hole is used as a positioning reference, and reflected light from the IVH is received by a CCD camera and formed on the upper surface side of the IVH. This is a method of manufacturing a printed wiring board capable of positioning a topland circuit conductor with high accuracy.
That is, it is possible to provide the positioning mark (M) for positioning the IVH and the surface circuit conductor which is a top land in which (multiple stages) × (multiple columns) IVH blocks are formed on the upper surface side of the IVH.

  In the laser drilling method of the via hole for IVH connecting the layers of the multilayer printed wiring board, the non-penetrating via hole reaching the inner layer circuit conductor (metal conductor) from the insulating resin layer between each layer and the top land of IVH A method for manufacturing a printed wiring board for highly accurate positioning of wiring patterns (lands and wiring lines) that are circuit conductors will be described.

  In the present application, a via hole having a diameter of 0.10 mm was formed by irradiating a carbon dioxide laser and burning and removing the resin on the bottom land at a predetermined position of the inner layer circuit conductor. IVH is a generic term for blind vias that reach from the outer layer circuit conductor to the inner layer circuit conductor and buried vias that connect the inner layer circuit conductors together, and are referred to as IVH (interstitial via hole).

Hereinafter, a method for manufacturing a printed wiring board will be described with reference to FIG. First, first bottom lands 3 (four in this figure) are provided at predetermined positions of the inner layer circuit conductor 2 provided on both surfaces of the double-sided printed wiring board serving as the core material 5, and the first step via hole on the upper surface is provided. 1st IVH8 (4 places in this figure) to which conductor plating was applied is set.
A wiring pattern (land or wiring line) that is a circuit conductor is formed on the surface (upper surface side) of the non-penetrating first IVH 8. This is a method for manufacturing a printed wiring board, in which the positioning of the non-penetrating first IVH 8 and the first top land 4 of IVH is made highly accurate.

The non-penetrating IVH and the positioning marks M (M1 to M4) for accurately positioning the top land of the IVH will be described with reference to FIGS.
In FIG. 4, in the printed wiring board in which the through-through hole 17 and the non-through IVH 7 are mixed, the position of the positioning mark M of the printed wiring board is an effective area of the large printed wiring board 10 in which a plurality of individual printed wiring boards are attached. Non-penetrating IVHs 7 are arranged as a plurality of positioning marks M (M1 to M4) in a specific area outside E (within one positioning mark M = 5 mm × 5 mm) (in this figure, four positions are provided in the corner portion) However, the positioning mark M can be made smaller (for example, 1 mm × 1 mm size) and placed in the effective area E of the large printed wiring board 10 in order to improve the board cutting efficiency.

In addition, the position of the positioning mark M on the printed wiring board is usually a printed wiring board on a large board in order to correct and confirm the size of the alignment position of the printed wiring board base and the photomask film due to humidity, temperature, polishing load, etc. during the manufacturing process. Two or more places (for example, M1 and M2, M3 and M4) are provided on the plate 10.
This positioning mark M is based on IVH7 with conductor plating in the non-through hole of the via hole, and makes positioning of the non-through IVH7 and IVH7 top land circuit conductors (lands and wiring lines) highly accurate. It is.

FIG. 5 shows a specific example of the positioning mark M.
In FIG. 5A, non-penetrating IVH7 (φ0.10 mm) of the printed wiring board is arranged in 5 rows × 5 rows at a pitch P = 0.5 mm, and the center position (3 steps × 3 rows) is the center. The non-penetrating IVH7 is not arranged so that it can be clearly detected that it is a part. That is, the positioning mark M can be made as small as (about 2 mm × 2 mm size).

In FIG. 5B, in order to reduce the size of the positioning mark M on the printed wiring board, non-penetrating IVH7 (φ0.10 mm) of the printed wiring board is arranged in 3 rows × 3 rows at a pitch P = 0.5 mm. The non-penetrating IVH 7 is not arranged at the position (2 steps × 2 rows) so that the center can be clearly detected. In this case, the positioning mark M can be further reduced to (about 1 mm × 1 mm size).
In addition, when the hole diameter of IVH7 is φ0.20 mm or more, the reflected light of IVH7 becomes strong (a lot), and may be arranged as one non-penetrating IVH7.

  Note that only one non-penetrating IVH 7 can be arranged as the positioning mark M, but it is difficult to identify the positioning mark M because the hole diameter is small. Further, it is desirable not to arrange the non-penetrating IVH 7 so that the positioning mark M can be clearly detected to be the central portion at the center position composed of (odd number of stages) × (odd number of rows) blocks. However, the hole diameter, pitch P, arrangement (M stages × N rows), etc. of IVH7 can be selected as appropriate, but should be standardized.

  As a positioning reference for multilayer printed wiring boards, a block of IVH (odd number) x (odd number) with conductor plating in the non-through hole of the via hole is used as a positioning mark, and the reflected light of IVH is received by a CCD camera. These are IVH block positioning marks for positioning the top-land circuit conductor formed on the upper surface side of the IVH arranged in the effective area of the large printed wiring board.

  Next, as shown in FIG. 2, the first IVH 8 (four places in this figure) in which the first via hole provided on both surfaces of the core material 5 is plated and the non-penetrating first IVH 8 is formed on the upper surface side. The second IVH9 (four locations in this figure) in which the upper surface of the first topland 4 is subjected to conductor plating in the second via hole via an insulating resin, and the high-definition second IVH9 on the upper surface side of the non-penetrating second IVH9. Two top lands 6 were formed to form a multilayer printed wiring board 1 having six layers. This is a printed wiring board manufacturing method in which positioning of the non-penetrating second IVH 9 and IVH first top land 6 is performed with high accuracy using the positioning mark M.

Next, as shown in FIG. 3, in positioning of the non-penetrating second IVH 9 and IVH second top land 6 (shown only on the upper surface side in FIG. 2), the diffused light from the printed wiring board is positioned. A circuit including the high-definition second IVH 9 and the high-definition second top land 6 on the upper surface side with high accuracy, by irradiating the mark M portion and receiving reflected light from the non-penetrating IVH 7 of the positioning mark M portion with the CCD camera 20 The conductor is formed with high positioning.
That is, it is a method for manufacturing a printed wiring board in which a small-diameter, high-precision IVH is used as a positioning guide and a circuit conductor including a top land on a high-definition IVH surface is highly positioned.

  The first through-hole first IVH 8 and the second through-hole second IVH 9 can be stacked via holes in the same place in two stages (multi-stages), and the non-penetrating positioning mark M can be obtained.

In addition, a method of manufacturing a printed wiring board that forms a high-definition, high-positioning surface circuit conductor by directly exposing a multilayer printed wiring board using a direct drawing exposure system called direct drawing exposure will be described.
The direct drawing exposure described above is a high-resolution direct drawing exposure system with high drawing speed because it uses UV light or laser light from a mercury lamp.

  In the direct drawing exposure system, laser direct imaging (LDI) is used after vacuum-pressing a photosensitive laminate film on the upper surface of a multilayer printed wiring board without using an exposure forming tool (such as a photo film mask or a glass dry plate). The circuit conductor including the high-definition IVH and the top land on the upper surface side of the high-definition surface is formed by high-positioning by direct drawing exposure using direct drawing data called.

  As a positioning reference for the multilayer printed wiring board, the IVH positioning mark (M) with conductor plating in the non-through hole of the via hole is used as a positioning reference. Positioning with high accuracy

  Since the above-mentioned LDI system does not use a conventional tool (such as a photo film mask or a glass dry plate) for exposing the surface circuit conductor, the pre-exposure setup for positioning the multilayer printed wiring board and the tool to be exposed is performed. Work becomes unnecessary.

  In addition, the direct drawing exposure system enables high-definition IVH and high-definition because it can be drawn and exposed directly with stretchable LDI data tailored to individual positions due to temperature and humidity expansion, dimensional variation, and manufacturing process variation of multilayer printed wiring boards. The surface circuit conductor can be positioned highly.

It is sectional drawing of the multilayer printed wiring board of 4 layers explaining the manufacturing method of the printed wiring board of this invention. It is sectional drawing of the multilayer printed wiring board of 6 layers explaining the manufacturing method of the printed wiring board of this invention. It is an expanded sectional view explaining positioning of 2nd IVH9 of this invention, and 2nd top land 6 of this 2nd IVH. It is a top view explaining the specific area | region of the positioning mark M of this invention. It is a top view which shows the specific example of the positioning mark M of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Printed wiring board, 2 ... Inner-layer circuit conductor, 3 ... 1st bottom land,
4 ... 1st top land, 5 ... Core material, 6 ... 2nd top land,
7 ... IVH, 17 ... through hole, 8 ... first IVH, 9 ... second IVH,
20: CCD camera, M: positioning mark.

Claims (3)

In the method of manufacturing a multilayer printed wiring board, an IVH block (multiple rows) × (multiple rows) in which conductor plating is performed in a non-through hole of a via hole is used as an IVH positioning mark (M), and the positioning mark (M) A method of manufacturing a printed wiring board, comprising: receiving reflected light from IVH with a CCD camera; and positioning IVH and a circuit conductor formed on an upper surface side of the IVH. 2. The method of manufacturing a printed wiring board according to claim 1, wherein the IVH is not arranged at a center position where the positioning mark (M) is composed of blocks of (odd number) × (odd number). 3. The method of manufacturing a printed wiring board according to claim 1, wherein the plurality of positioning marks (M) are arranged in a specific area outside the effective area of the multilayer printed wiring board.

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