JP3572272B2 - Method for manufacturing multilayer printed wiring board - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a multilayer printed wiring board.
[0002]
[Prior art]
2. Description of the Related Art In recent years, with the rapid development of electronic information technology, electronic components are required to have performance equal to or higher than conventional ones, and to be reduced in size and thickness. Accordingly, there is a similar demand for a printed wiring board for electrically connecting the electronic components.
[0003]
As the printed wiring board, for example, there is a package board used for connecting an LSI to a motherboard. Most of the package substrates have a size of 20 mm square or less, including the same size (CSP) as the LSI. On the other hand, the package substrate is a multilayer printed wiring board having a configuration in which a plurality of pieces on which a wiring pattern is formed are stacked via an insulator, and the wiring patterns of the respective layers are electrically connected to each other. If each of the package substrates having such a configuration is manufactured individually, it is very troublesome and complicated.
[0004]
Therefore, the individual pieces on which the wiring patterns are formed are assembled to form a printed wiring board (hereinafter, abbreviated as a work size board) having a work size large enough to manufacture a normal board, and a plurality of the work sizes are formed. The package substrate is manufactured by laminating the substrates via an insulator. The work size substrate is press-formed after lamination to integrate a plurality of work size substrates, and after being subjected to a drilling process for forming a through hole for conducting between wiring patterns of each layer, an outer shape process, etc. Of the package substrate.
[0005]
According to the work size substrate, the number of times of being incorporated into a processing device in the drilling process, the outer shape processing, and the like, and the number of shots in an exposure process, a printing process, and the like can be significantly reduced to improve manufacturing efficiency.
[0006]
However, in order to form a wiring pattern on the work-size substrate, a photosensitive resin (dry film) is thermocompression-bonded on a copper foil, and is irradiated with ultraviolet light through a negative film or a positive film by an exposure machine to develop, etch, dry, An error occurs in each step of peeling the film. Alternatively, an error occurs when an etching resist or a plating resist is printed on a copper foil to form a wiring pattern.
[0007]
For this reason, when a plurality of the work size substrates are stacked via an insulator, the accuracy of alignment of the individual pieces decreases as the periphery of each stacked work size substrate decreases, and a through hole or the like is formed after the stacking. In addition, there is an inconvenience that a land may be cut into the through hole and a conduction failure may occur between layers.
[0008]
[Problems to be solved by the invention]
An object of the present invention is to provide a method for manufacturing a multilayer printed wiring board that can solve the above-described inconvenience and can match the positions of the wiring patterns of each layer with high accuracy.
[0009]
[Means for Solving the Problems]
In order to achieve this object, a method of manufacturing a multilayer printed wiring board according to the present invention forms a predetermined wiring pattern on a support to obtain a work-sized printed wiring board including a plurality of sheet-sized printed wiring boards. A method of manufacturing a multilayer printed wiring board, comprising the steps of: laminating a plurality of printed wiring boards of the work size via an insulator and pressing and integrating the printed wiring boards with at least one work size; leaving the wiring board, by dividing the printed circuit board other work size for each printed wiring board sheet size, crop the printed circuit board divided the sheet size, undivided work size of the printed wiring board Are laminated and pressed at predetermined positions via an insulator.
[0010]
According to the method of manufacturing a multilayer printed wiring board of the present invention, first, leaving at least one of the work size substrates, another work size substrate is formed of a sheet including 10 to 100 pieces on which the wiring pattern is formed. Divide for each size substrate. Then, after trimming the divided sheet size substrates, they are laminated via insulators at predetermined positions on the undivided work size substrates.
[0011]
As a result, it is possible to perform positioning on a sheet size substrate basis with reference to an undivided work size substrate, thereby improving the positioning accuracy.
[0012]
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 printed wiring board having a work size 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.
[0013]
In the present embodiment, a case of manufacturing a multilayer printed wiring board used as a package board for connecting an LSI to a motherboard will be described as an example.
[0014]
When manufacturing the package substrate, first, as shown in FIG. 1, a wiring pattern (not shown) corresponding to a piece 2 forming the package substrate is formed on an insulating support such as a glass epoxy substrate 1. Form. The individual pieces 2 on which the wiring patterns are formed are formed by assembling 10 to 100 pieces to form a sheet size substrate 3 having a size of 70 to 160 mm × 70 to 160 mm, and further assembling 2 to 12 sheet size substrates 3. Thus, a work size substrate 4 having a size of 305 to 510 mm × 405 to 610 mm is formed.
[0015]
In this embodiment shown in FIG. 1, six sheet size substrates 3 of 160 mm × 160 mm are arranged in three rows and two rows on both sides of a work size substrate 4 having a size of 340 mm × 510 mm. Have been. Each sheet size substrate 3 includes two groups of 35 pieces 2 each having a size of, for example, about 10 mm × 10 mm.
[0016]
In the individual piece 2 of this embodiment, a land having a diameter of 0.3 mm is provided concentrically with a hole having a diameter of 0.1 mm, a wiring having a width of 50 μm is connected to the land, and a distance between the lands is set to 0. A wiring pattern of 1 mm and a wiring interval of 75 μm is formed.
[0017]
For the wiring pattern, for example, a photosensitive resin (dry film) is thermocompression-bonded on copper foil and copper plating provided on both front and back surfaces of the glass epoxy substrate 1, and is irradiated with ultraviolet light through a negative film or a positive film by an exposure machine. , Development, etching and dry film peeling. Alternatively, an etching resist is screen-printed on a copper foil provided on both front and back surfaces of the glass epoxy substrate 1, and the exposed copper foil which is not covered with the etching resist is etched, and then the etching resist is peeled off. Formed by Further alternatively, a plating resist is screen-printed on the copper foil except for a portion to be a wiring pattern, and a metal layer (for example, solder or Ni-Au) to be an etching resist is formed on a portion to be a wiring pattern 2 by plating. ) May be formed by removing the plating resist and performing etching.
[0018]
The work size substrate 4 has a number corresponding to the number of layers forming the package substrate. For example, when the package substrate is a six-layer plate, as shown in FIG. Are provided on both front and back sides, and three work size substrates 4a, 4b and 4c are prepared.
[0019]
Incidentally, in the work size substrates 4a, 4b, and 4c, an error occurs when an etching resist or a plating resist is printed on the copper foil. For this reason, the wiring patterns 2a of the respective work size substrates 4a, 4b, 4c can be laminated with their positions relatively accurately aligned in the central portion, but the alignment accuracy decreases in the peripheral portion, and after lamination, When a through-hole or the like is formed, a land may be cut into the through-hole and conduction failure may occur between layers.
[0020]
Therefore, next, as shown in FIG. 2B, the work size substrate 4a is divided for each sheet size substrate 3. At this time , each sheet size substrate 3 is further trimmed . The trimming is performed by, for example, cutting using a die press machine or extracting using a router machine (outer shape machine).
[0021]
Then, the undivided work size substrates 4b and 4c are laminated via an insulating resin adhesive layer 5 such as a prepreg, and each sheet size substrate 3 of the work size substrate 4a is unmounted via the insulating resin adhesive layer 5. It is laminated on the divided work size substrate 4b. At this time, when the undivided work size substrates 4a are stacked on the work size substrates 4b, the respective sheet size substrates 3 are stacked at positions where they should originally correspond. The lamination is performed by aligning the respective sheet size substrates 3 by a pin lamination lamination method using guide pins or a method using an X-ray camera (see Japanese Patent Application No. 11-332447), and then disposing them at an accurate position by heat welding. It is done by doing. In the pin lamination laminating method, for example, a plurality of guide pins are provided at predetermined positions on a sheet size substrate of the work size substrate 4b on the side to be laminated, and provided at positions corresponding to the guide pins on each sheet size substrate 3. Positioning is performed by inserting the guide pin into the provided through hole. The guide pins are provided, for example, at four corners of the sheet size substrate of the work size substrate 4b on the side to be laminated.
[0022]
Next, as shown in FIG. 2C, the sheet size substrates 3 stacked via the insulating resin adhesive layer 5 and the undivided work size substrates 4b and 4c are pressed and integrated. Then, a multilayer printed wiring board 7 having a work size is formed.
[0023]
Next, the multilayer printed wiring board 7 is completed through processes such as punching, plating, resist printing, outer shape processing, surface treatment, and inspection, and is divided into sheet sizes. It is divided for each package substrate (individual piece 2 shown in FIG. 1).
[0024]
According to the manufacturing method, since the work size substrate 4a is divided for each sheet size substrate 3 and each sheet size substrate 3 is stacked on the work size substrate 4b, the positions of the wiring patterns 2a are matched with each other with high accuracy. Therefore, poor conduction between the layers can be significantly reduced.
[0025]
In this embodiment, only the work size substrate 4a is divided for each sheet size substrate 3. However, in order to improve the alignment accuracy, at least one work size substrate 4 (for example, work size The substrate 4b) is left undivided, and the other work size substrates 4 (for example, the work size substrates 4a and 4c) are divided for each sheet size substrate 3 to be divided into undivided work size substrates 4b for each sheet size substrate 3. They may be stacked.
[Brief description of the drawings]
FIG. 1 is a plan view showing an example of a work-sized printed wiring board used in the 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.

Claims (1)

Forming a predetermined wiring pattern on the support to obtain a work-sized printed wiring board including a plurality of sheet-sized printed wiring boards,
A process of laminating a plurality of printed wiring boards of the work size via an insulator and pressing and integrating the printed wiring boards to form a multilayer printed wiring board,
Leaving at least one printed wiring board of the work size, dividing a printed wiring board of another work size into printed wiring boards of a sheet size,
Manufacturing the multilayer printed wiring board, wherein the divided printed wiring board of the sheet size is trimmed , laminated at a predetermined position on an undivided work-sized printed wiring board via an insulator, and pressed. Method.

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