JP2003008210A - Method of manufacturing multilayer printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a multilayer printed wiring board which is improved in manufacturing yield. SOLUTION: A work-size board 4, which is equipped with sheet-size boards 3 where prescribed wiring patterns 2a are formed on supports 1 is obtained. Work-size printed boards 4a, 4b, and 4c are laminated through the intermediary of an insulator 4 and pressed into one piece. It is inspected as to whether the wiring pattern 2a formed on the work-size board 4 is defective. When it is found that the wiring pattern 2a is defective, the work-size board 4 where the defective wiring pattern 2a is formed is divided into respective sheet-size boards 3, and the defective sheet-size board 3a is removed. A non-defective sheet-size board 3 is replenished and laminated together with the other sheet-size boards 3 on an undivided work-size board 4. A work-size printed wiring board having a wiring density higher than the prescribed value is subjected to this inspection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer printed wiring board.

[0002]

2. Description of the Related Art In recent years, with the rapid development of electronic information technology, electronic parts have the same or higher performance than conventional ones.
It is required to reduce the size and reduce the thickness. Along with this, there is a similar demand for a printed wiring board that electrically connects the electronic components.

As the printed wiring board, for example, L
There are package substrates used to connect the SI to the motherboard. Most of the package substrates, including those having the same size as an LSI (CSP), have a size of 20 mm square or less. On the other hand, the package board is a multilayer printed wiring board having a structure in which a plurality of pieces each having a wiring pattern are laminated via an insulator and the wiring patterns of each layer are electrically connected to each other. It is very time-consuming and complicated to manufacture each of the package substrates having such a configuration.

Therefore, a large number of pieces on which the wiring pattern is formed are assembled to form a work-sized printed wiring board (hereinafter abbreviated as a work-size board) of a size for performing ordinary board manufacturing, and a plurality of pieces are formed. The package substrate is manufactured by stacking the work size substrates via an insulator. The work size substrate is press-molded after stacking to integrate a plurality of work size substrates, and is subjected to perforation processing, outer shape processing, etc. for forming through holes for conducting between the wiring patterns of each layer, and then, individually. Of the package substrate.

According to the work size substrate, the number of times the device is incorporated in the processing device in the punching process, the outer shape process, etc.,
It is possible to significantly reduce the number of shots in the exposure process, the printing process, etc., and improve the manufacturing efficiency.

However, in the package substrate,
With the miniaturization and thinning of the board itself, the wiring width has been reduced, the land for mounting electronic components has been reduced, and the wiring density has been increased. Such a defect is likely to occur, and if even one of the individual pieces included in the work size substrate is defective, there is no choice but to discard the entire work size substrate as a defect, resulting in a significant decrease in yield. .

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a multilayer printed wiring board, which can solve the above disadvantages and improve the yield.

[0008]

In order to achieve such an object, a method for manufacturing a multilayer printed wiring board according to the present invention comprises forming a predetermined wiring pattern on a support to form a printed wiring board having a plurality of sheet sizes. In a method for manufacturing a multilayer printed wiring board, comprising: a step of obtaining a printed wiring board having a work size, and a step of stacking a plurality of printed wiring boards of the work size through an insulator and integrating them by pressing. The presence or absence of abnormality in the wiring pattern formed on the work-size printed wiring board is inspected, and the work-sized printed wiring board in which abnormality is found in the wiring pattern is inspected for each sheet-sized printed wiring board. The printed wiring board of the sheet size having the wiring pattern in which the abnormality is found is divided into In place of the sheet-size printed wiring board, a good-quality sheet-sized printed wiring board prepared in advance is replenished, and together with the divided other sheet-sized printed wiring boards, on an undivided work-sized printed wiring board. It is characterized by laminating and pressing at a predetermined position via an insulator.

According to the method for manufacturing a multilayer printed wiring board of the present invention, when an abnormality is found in the wiring pattern formed on the work size board, the work size board is divided into individual pieces on which the wiring pattern is formed. It is divided into 10 to 100 sheet size substrates. As a result, only the sheet size substrate having the wiring pattern in which the abnormality is found may be removed as a defect, and the other sheet size substrates can be used as they are, so that the yield can be improved.

The wiring pattern formed on the work size board may be inspected for all the work size boards forming the multilayer printed wiring board, but the wiring pattern becomes defective as the wiring density increases. It will be easier. Therefore, the inspection may be performed on the work size substrate whose wiring density is higher than a predetermined value. As described above, the work can be simplified by intensively inspecting the work size substrate in which a defect is likely to occur.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 is a plan view of a work-size printed wiring board used in the manufacturing method of the present embodiment, and FIG. 2 is an explanatory sectional view showing the manufacturing method of the present embodiment.

In this embodiment, a case where a multilayer printed wiring board used as a package board for connecting an LSI to a mother board is manufactured will be described as an example.

When manufacturing the package substrate,
First, as shown in FIG. 1, a wiring pattern (not shown) corresponding to an individual piece 2 forming the package substrate is formed on an insulating support such as a glass epoxy substrate 1. 10 to 100 pieces of the wiring pattern-formed pieces 2 are assembled to form a sheet size substrate 3 having a size of 70 to 160 mm × 70 to 160 mm.
2 to 12 pieces are collected to form 305 to 510 mm x 405 to
A work size substrate 4 having a size of 610 mm is formed.

In the present embodiment shown in FIG. 1, 340 mm ×
On both front and back surfaces of a work size substrate 4 having a size of 510 mm, six sheet size substrates 3 having a size of 160 mm × 160 mm are arranged in three rows and two columns.
Each sheet size substrate 3 includes two groups of 35 pieces 2 each having a size of about 10 mm × 10 mm.

The piece 2 of this embodiment has a diameter of 0.1 mm.
A land having a diameter of 0.3 mm, which is concentric with the hole, is provided around the hole, a wiring having a width of 50 μm is connected to the land, and a wiring pattern having a land interval of 0.1 mm and a wiring interval of 75 μm is formed.

For the wiring pattern, for example, a photosensitive resin (dry film) is thermocompression bonded onto copper foil and copper plating provided on both front and back surfaces of the glass epoxy substrate 1, and a negative film or a positive film is passed through an exposure machine. It is formed through ultraviolet irradiation, development, etching, and dry film peeling steps. Alternatively, an etching resist is screen-printed on the copper foils provided on both front and back surfaces of the glass epoxy substrate 1, the exposed copper foil not covered with the etching resist is etched, and then the etching resist is peeled off. Is formed by. Further alternatively, a plating resist is screen-printed on the copper foil except a portion to be a wiring pattern, and a metal layer to be an etching resist is formed on a portion to be the wiring pattern 2 by plating (for example, solder or Ni-Au). ) May be deposited, the plating resist may be removed, and etching may be performed.

The work size substrates 4 are prepared in a number corresponding to the number of layers forming the package substrate. For example, when the package substrate is a 6-layer plate, FIG.
As shown in (a), three work size substrates 4a, 4b, 4c having wiring patterns 2a on both front and back surfaces are prepared.

Next, the work size boards 4a, 4b, 4c shown in FIG. 2A are inspected for abnormalities in the formed wiring pattern 2a. At this time, in the wiring pattern 2a formed by the above method, the wiring width and the wiring interval are limited to 50 μm, and if the wiring width and the wiring interval are less than 75 μm, defects will occur. Therefore, the inspection of the work size substrates 4a, 4b, 4c may be performed only on the one having the wiring pattern 2a having a wiring width and a wiring interval of less than 75 μm.

Next, when an abnormality of the wiring pattern 2a is detected on the work size substrate 4a, FIG.
As shown in, the work size substrate 4 a is divided into the sheet size substrates 3. Then, the sheet size substrate 3a including the wiring pattern 2a in which the abnormality is detected is removed as a defect. At this time, the sheet size substrate 3a is a cutting or router processing machine (outline processing machine) using a die press machine.
Is removed by a sampling process using.

Next, as shown in FIG. 2 (c), the undivided work size substrates 4b and 4c are laminated via the insulating resin adhesive layer 5 such as prepreg and the sheet size substrate removed as a defect. The remaining sheet size substrates 3 except 3a are laminated on the undivided work size substrate 4b via the insulating resin adhesive layer 5. At this time, each sheet size substrate 3 is stacked at a position corresponding to the size of the work size substrate 4a when the work size substrate 4a is stacked without being divided.

In this way, the portion 6 where the sheet size substrate 3a removed as defective should have been laminated
Therefore, a non-defective sheet size substrate 3b prepared in advance is replenished and laminated in this portion 6. The lamination is performed by aligning the non-defective sheet size substrate 3b by a pin lamination lamination method using a guide pin or a method using an X-ray camera (see Japanese Patent Application No. 11-332447), and then heat-welding to an accurate position. It is done by placing. In the pin lamination stacking method, for example, a plurality of guide pins are provided at predetermined positions on the sheet size substrate 3b on the side to be stacked, and the through holes provided at the positions corresponding to the guide pins of the sheet size substrate 3b are provided. Positioning is performed by inserting the guide pin. The guide pins are provided, for example, at the four corners of the sheet size substrate 3b on the side to be stacked.

Then, the sheet-size substrates 3 and 3b laminated via the insulating resin adhesive layer 5 and the undivided work-size substrates 4b and 4c are pressed to be integrated, as shown in FIG. ), The work-size multilayer printed wiring board 7 is formed.

Next, the multilayer printed wiring board 7 is completed through steps such as punching, plating, resist printing, outer shape processing, surface treatment, and inspection, and is divided into a sheet size, and then further formed into a wiring pattern 2. It is divided into corresponding package substrates (pieces 2 shown in FIG. 1).

According to the manufacturing method of this embodiment, a non-defective sheet size substrate 3b prepared in advance is replenished in place of the sheet size substrate 3a removed as a defect. Therefore, even when an abnormality is detected in the wiring pattern 2a by the inspection, the sheet size substrate 3 including the wiring pattern 2a having no abnormality can be effectively used without discarding the entire work size substrate 4a including the wiring pattern 2a. Can be used.

As a result, the yield of package substrates, which was about 50% per one work-size multilayer printed wiring board 7 in the past, can be increased to 99% or more.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of a work-sized printed wiring board used in a manufacturing method of the present invention.

FIG. 2 is an explanatory sectional view showing an embodiment of the manufacturing method of the present invention.

[Explanation of symbols]

2a ... Wiring pattern, 3 ... Sheet size printed wiring board, 4 ... Work size printed wiring board, 5
... Insulator, 7 ... Multilayer printed wiring board.

Continued front page    (72) Inventor Tsuyoshi Sunada             573-19 Toiso, Eniwa, Hokkaido Clover Den             Child Industry Co., Ltd. (72) Inventor Masaru Ogasawara             573-19 Toiso, Eniwa, Hokkaido Clover Den             Child Industry Co., Ltd. F-term (reference) 5E346 AA02 CC04 CC09 CC32 DD02                       DD22 DD32 DD33 DD44 DD45                       EE03 EE15 FF04 GG14 GG15                       GG17 GG19 GG22 GG24 GG26                       GG28 HH33

Claims (2)

[Claims] 1. A step of forming a predetermined wiring pattern on a support to obtain a work-size printed wiring board including a plurality of sheet-sized printed wiring boards, and an insulating material for the plurality of work-sized printed wiring boards. In the method for manufacturing a multilayer printed wiring board, which comprises a step of stacking and pressing through to integrate the wiring patterns, the wiring pattern formed on the printed wiring board of the work size is inspected for abnormality, and the inspection is performed. A work-size printed wiring board in which an abnormality is found in the wiring pattern is divided for each printed wiring board in the sheet size, and the sheet-sized printed wiring board having the wiring pattern in which the abnormality is found is removed. Then, instead of the removed sheet-sized printed wiring board, a good-quality sheet-sized printer prepared in advance. It is characterized in that the wiring board is replenished, and the printed wiring board of the other divided sheet size is laminated and pressed at a predetermined position on the undivided printed wiring board of the work size via an insulator. Manufacturing method of multilayer printed wiring board. 2. The method for manufacturing a multilayer printed wiring board according to claim 1, wherein the inspection is performed on a printed wiring board having a work size whose wiring density is higher than a predetermined value.