JP2002373962A - Printed wiring board and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printed wiring board and its manufacturing method; in which 1) the connection reliability of the terminal parts on the upper and lower surfaces of an interposer substrate is enhanced; 2) high density micro size terminals (lands) can be designed in order to provide a fine pitch small area electrode of an electronic component or element thus realizing high density mounting; and 3) at the contact hole of the terminals on the upper and lower surface, the efficiency of boring work is enhanced while reducing the cost by reducing works for boring a micro hole and decreasing the number of contact holes significantly. SOLUTION: As a contact part for electrically conducting the connection terminal part 7 on the upper surface of a printed wiring board and the external connection terminal part on the lower surface, a contact part 16 is formed on the side face or the corner of the printed wiring board by cutting the substantially central part of a non-through contact hole where the upper and lower faces of a filler filling a plated through hole is covered with a metal conductor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed wiring board used for mounting electronic components and elements such as semiconductor chips on an interposer substrate, which is a printed wiring board, and a method of manufacturing the same.

[0002]

2. Description of the Related Art For example, a chip-on-board (hereinafter abbreviated as COB) in which electronic components such as semiconductor chips and bare chip elements are mounted on a mother board which is a parent printed wiring board via an intermediate board called an interposer board. Do)
There is an implementation method. In this COB mounting method, bumps are formed as protruding electrodes on each electrode (hereinafter referred to as a pad) provided on a circuit surface on the lower surface side of a semiconductor chip which is to be mounted on a printed wiring board. However, this is a mounting method in which the semiconductor chip on which the bumps are formed is directly mounted face down on the component mounting surface of the printed wiring board, and there is an advantage that the semiconductor chip and the like can be mounted at a high density.

Conventionally, as shown in FIG. 7A, the interposer substrate 5 is provided with an upper surface connection terminal portion (land) 7 and a non-through connection hole 16, and as shown in FIG. A ring-shaped land 8 is formed all around the upper end edge of the through connection hole 16, and the upper surface connection terminal portion (land) 7 and the ring-shaped land 8 of the non-through connection hole 16 are interposed via the wiring pattern 9. Conducted. The non-through connection hole 16 is electrically connected to the external connection terminal portion 6 on the lower surface formed on the lower surface of the interposer substrate 5 through the through hole plating formed on the inner side wall. Upper and lower terminal portions (lands) 7 and 6 are electrically connected to each other through a connection 16.

As shown in FIG. 6, a non-through connection hole 16 in which the upper and lower surfaces of a filler filled in a plated through hole are covered with a metal conductor, that is, a metal conductor of a flat through hole is connected as the interposer substrate 5. A terminal portion (land) 7 on the upper surface serving as a terminal portion is formed, and the pitch between electrodes is reduced and the wiring pattern 9 shown in FIG. 7 is omitted to reduce the area. For example, since the size of one interposer substrate 5 is 0.8 × 1.0 mm, the land 7 of the terminal part on the upper and lower surfaces, and the flat through hole 3 is formed substantially at the center of the size of 0.2 × 0.3 mm, Micro hole diameter φ0.15
(Laser Drilling) If 10 rows × 10 rows / sheet, laser drilling with a hole diameter φ0.15 must be performed 400 holes / sheet. Furthermore, if the working size of the printed wiring board is 330 × 330 mm / board, about 7
80 sheets / board = 312000 holes / board.

[0005]

In recent years, the trend of electronic devices to become lighter, thinner and smaller has become more and more intense, and high-performance integration and high-speed signal processing have been promoted. Also, the pitch between electrodes has been narrowed and the area has been reduced. Forming a plurality of lands, wiring patterns, and laser holes with a small hole diameter on a printed wiring board by associating each electronic component or element with such a narrow pitch with a connection terminal portion requires only advanced special technology. Instead, the reliability of the connection for electrically connecting the upper terminal portion (upper land) and the lower terminal portion (lower land) is deteriorated, and the cost is further increased.

The present invention has been made in view of the above-mentioned conventional problems, and a first object is to improve the connection reliability of upper and lower surface conductors (terminal portions) of an interposer substrate. A second object is to enable the design of high-density and minute-sized terminal portions (lands), to reduce the pitch and the area between electrodes of electronic components and elements, and to realize high-density mounting. A third object of the present invention is to improve drilling work efficiency and reduce costs by reducing the processing of minute hole diameters and greatly reducing the number of connection holes in the connection holes of the upper and lower terminals.

[0007]

In order to achieve this object, the invention according to claim 1 is directed to an upper surface connection terminal portion of a printed wiring board located on the outer periphery of the printed wiring board or near a dividing line for dividing the printed wiring board into a plurality of parts. Non-through connection hole, in which the upper and lower surfaces of the filler filled in the plated through hole are covered with a metal conductor, that is, approximately the center of the flat through hole Is divided and cut to form a connection portion on a side surface or a corner portion of the printed wiring board. A terminal portion (land) is formed on the upper and lower surfaces of the printed wiring board so as to be overlapped (connected) with a part of the edge of the non-through connection hole. Therefore, since it is not necessary to form a land on the entire surface of the non-through connection hole, it is possible to design a high-density and minute-sized terminal portion (land).

According to a second aspect of the present invention, a single connection hole is provided as a connection portion for electrically connecting a connection terminal portion as an upper surface conductor and an external connection terminal portion as a lower surface conductor of a printed wiring board. A printed wiring board having a connection portion function for 2 to 8 pieces after division and cutting. That is, a substantially central portion of the flat through hole is cut into a plurality of portions as connection holes, and connection portions are formed on side surfaces or corner portions of the printed wiring board. However, as the connection part on the upper surface of the printed wiring board, the connection part and the terminal part (land) may be distinguished from each other and their positions may be changed depending on the size of mounting electronic components and elements.

According to a third aspect of the present invention, there is provided a method of forming a flat through hole, wherein insulating portions are provided on both sides of the dividing line so that the metal conductor does not come into contact with the dividing line crossing substantially the center of the flat through hole. A step of etching to provide (interval), and a step of dividing and cutting each electronic component or element on the connection terminal part after the division line, from the upper connection terminal part in contact with a part of the flat through hole and the outside of the lower surface. This is a method for manufacturing a printed wiring board for forming a connection terminal portion. Therefore, since no land is formed on the entire periphery of the non-through connection hole, a terminal portion (land) having a very small size can be obtained, and the terminal pitch can be reduced as much as possible.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing a case where individual interposer substrates according to the present invention are joined in a sheet shape with 10 rows × 10 steps / sheet. FIG. 2 is a plan view showing an essential part of the interposer substrate according to the present invention in which the individual interposer substrate 5 in FIG. 1 is enlarged, and FIG. 3B is a plan view of FIG. 3A of the interposer substrate according to the present invention. FIG. 4 is an enlarged perspective view showing an individual interposer substrate in FIG. FIG. 5 is a plan view of an individual interposer substrate according to the second embodiment of the present invention. In these drawings, the same or equivalent members described in the prior art shown in FIGS. 6 and 7 described above are denoted by the same reference numerals, and detailed description will be appropriately omitted.

First, the situation of the method for manufacturing an interposer substrate according to the present invention will be described with reference to a plan view in which the interposer substrate 5 of FIG. In FIG. 1, the outer periphery of an insulating substrate 1 such as a glass-based epoxy resin or BT resin is interspersed with a plurality of individual interposer substrates 5 and the dividing lines 12 are formed on a sheet-like substrate 2 by an NC drilling machine. A through hole φ0.5 is drilled at the intersection of the outer periphery and the corner of the outer periphery, and a plating conductor is formed on the inner wall of the through hole and the surface of the insulating substrate by electroless copper plating and electrolytic copper plating to form a through connection hole. Form. Fill the filling connection holes, which are plated through holes, with filling material.
Hardening and polishing to form a non-through connection hole 16;
The second electroless copper plating process forms a plated conductor on the surface of the non-through connection hole 16 in which the upper and lower surfaces of the filler filled in the plated through hole (through connection hole) are covered with a metal conductor and on the surface of the insulating substrate. I do. In other words, flat through hole 3
To form

Next, insulating portions (intervals) are provided on both sides of the dividing line by etching so that the metal conductor does not come into contact with the dividing line crossing substantially the center of the flat through hole 3, and at the same time, the vicinity of the dividing line Then, terminal portions (lands) to be predetermined upper surface connection terminal portions 7 and lower surface external connection terminal portions 6 of the printed wiring board are formed by etching. After that, each electronic component or element is mounted on the connection terminal portion, and then the dividing line 12 is diced and cut with a dicer to divide it into individual interposer substrates. This is a method of manufacturing a printed wiring board in which a terminal portion and an external connection terminal portion on the lower surface are formed.

For example, 1
The size of each interposer substrate 5 is 0.8 × 1.0 m
m, land size of the upper and lower terminals 0.2 x 0.3m
m, 10 rows × 10 steps / sheet, the number of through holes of φ0.5 is 121 holes / sheet (94380 holes / board), which is about 30% of the conventional (400 holes / sheet. 312000 holes / board). Thus, a connection function of electrically connecting the upper and lower terminals can be achieved. Furthermore, the drilling process can be changed from laser processing to NC drilling, and the number of layers can be reduced from one to five to ten. That is, in the plan view of the interposer substrate according to the present invention of FIG. One hole (piece) of the flat through hole located at the intersection of the dividing lines crossing sideways has the function of an efficient connection part that electrically connects four (eight on the top and bottom) terminals on one side.

At this time, as shown in FIG. 2, the upper connection terminal portion 7 of the printed wiring board and the outer surface A terminal portion (land) to be a connection terminal portion is formed.
That is, four terminal portions are formed at substantially the same positions on the upper and lower surfaces of the printed wiring board at the corners of the individual interposer substrate 5 and formed so as not to contact the outer peripheral end surface of the printed wiring board. By directly electrically connecting a terminal portion (land) to a part of the upper end edge of the non-through connection hole 16, a land serving as an electrode is formed on the entire surface of the filler and the upper end edge of the non-through connection hole 16. And the terminal part (land)
A wiring pattern for connecting the non-penetrating connection hole 16 with the wiring pattern becomes unnecessary. The through hole of the connection part electrically connected to the upper connection terminal part 7 and the external connection terminal part 6 on the lower surface has a diameter of φ0.
Since the diameter is as large as 5, drilling, electroless copper plating, and electrolytic copper plating are simple and easy to manage, and a plated conductor with high connection reliability can be formed.

As described above, according to the present invention, as shown in FIG. In order to provide insulating parts (intervals) by etching on both sides of the dividing line so that the metal conductor does not touch the dividing line that crosses sideways,
The upper surface connection terminal portion 7 and the external connection terminal portion 6 on the lower surface do not contact the outer peripheral end surface of the printed wiring board. Furthermore, the terminal portion (land) is formed on the upper and lower surfaces of the printed wiring board so as to overlap with the approximately 1/4 circumferential portion of the edge of the non-through connection hole 16 (1/4 division of the flat through hole). Nevertheless, the shape of the upper and lower terminals is an accurate square. Round. It is possible to design a terminal part (land) having an oval shape and a minute size. Therefore, as a high-density and minute-sized terminal portion, for example, a land size of 0.1 × 0.15 mm (1 size of the conventional size)
/ 4 area), and the terminal pitch from 0.5 mm to 0.5 mm.
A design of 3 mm is possible.

Further, as shown in an enlarged perspective view of the interposer substrate of FIG.
Terminal portions (lands) 7, 6 on the upper and lower surfaces of the printed wiring board so as to overlap with about 1/8 of the circumferential edge of the edge of the 6 or less.
It was confirmed that high connection reliability could be obtained even when forming.
Therefore, high-density mounting is possible by narrowing the terminal pitch between the high-density and minute-sized terminal portions. That is,
One flat through hole (connection hole) can have the function of 2 to 8 connection portions.

FIG. 5 shows a second embodiment of the present invention.
It is a top view which expands and shows the principal part of an interposer board | substrate. In the second embodiment, the non-penetrating connection holes 16 are vertically connected to the interposer substrate 5 in a sheet shape. It is formed so that the center of the non-penetrating connection hole 16b is located at the non-penetrating connection hole 16a at the intersection of the dividing lines that intersect horizontally and at a straight line portion other than the intersection. In this case also, the non-through connection hole 1
Since the connection portion obtained by dividing and cutting 6b can be installed on the outer peripheral side surface of the printed wiring board, high-density mounting of electronic components and elements having a large number of terminals becomes possible. Further, in the present embodiment, the double-sided printed wiring board has been described, but the present invention can also be applied to a multilayer printed wiring board.

However, as the connection portion on the upper surface of the printed wiring board, the connection portion and the terminal portion (land) may be distinguished from each other and their positions may be changed depending on the size of mounting electronic components and elements. For example, when the bare chip element is small and the pitch between the external connection terminals and the electrodes on the lower surface of the interposer substrate needs to be changed, a terminal portion (land) for wire bonding is formed inside the connection portion on the upper surface.

[0019]

As described above, according to the present invention, not only connection reliability can be improved, but also high-density design and high-density mounting can be performed, and work efficiency can be improved and cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view when individual interposer substrates according to the present invention are joined in a sheet shape.

FIG. 2 is a plan view showing an enlarged main part of one interposer substrate in FIG. 1;

FIG. 3 is a plan view and a cross-sectional view of an interposer substrate.

FIG. 4 is an enlarged perspective view showing an individual interposer substrate in FIG. 2;

FIG. 5 is an enlarged plan view showing a second embodiment of the present invention.

FIG. 6 is a plan view showing a conventional flat through-hole interposer substrate.

FIG. 7 is a plan view showing a conventional interposer substrate.

[Explanation of symbols]

2 ... sheet-like substrate, 3 ... flat through hole, 5 ... interposer substrate, 6, 7 ... terminal (land), 16 ...
Non-through connection hole.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5E317 AA24 GG20 5E338 BB31 EE60

Claims (3)

[Claims] A flat through-hole (plating through) is provided as a connecting portion for electrically connecting an upper surface terminal portion and a lower surface terminal portion of the printed wiring board located on the outer periphery of the printed wiring board or in the vicinity of a dividing line to be divided into a plurality of parts. A printed wiring board characterized in that a connection portion is formed on a side surface or a corner of the printed wiring board by dividing and cutting a non-through connection hole in which the upper and lower surfaces of a filler filled in a hole are covered with a metal conductor. 2. A connection portion for electrically connecting an upper surface conductor and a lower surface conductor of a printed wiring board has a function of two to eight connection portions after dividing and cutting with one connection hole. Printed wiring board. 3. A flat through hole comprising: a step of forming a flat through hole; a step of etching both sides of a dividing line crossing a substantially central portion of the flat through hole; and a step of dividing and cutting by the dividing line. A method for manufacturing a printed wiring board, comprising: forming an upper surface connection terminal portion in contact with a portion and a lower surface external connection terminal portion.