JP2000004069A - Printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance adhesion to adhesive by providing a concave or tubular recessed hole having one recessed enclosed end face thereby eliminating extrusion of adhesive in bonding an electronic part to a specified position through adhesive. SOLUTION: A printed wiring board 1 is provided with a concave recessed hole 6 where a non-through hole 5 has recessed enclosed end face in a lower range for fixing a surface mounting electronic part. In order to enhance adhesion of adhesive for bonding the surface mounting electronic part, a solder resist 7 serving as a dam for ensuring an adhesive reserving part is provided on a through-hole land 2 closely to the periphery of the concave recessed hole 6. Since the adhesive for bonding a surface mounting electronic part is reserved in the recessed hole 6, the adhesive is prevented from extruding and adhesion between the printed wiring board 1 and the adhesive strength can be enhanced.

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, and more particularly to a printed wiring board for mounting with a surface having a non-through hole in which a through hole is filled with a filler.

[0002]

2. Description of the Related Art In recent years, as electronic devices have become smaller and higher in density, when electronic components are mounted on a printed wiring board by surface mounting, resist ink, solder, and the like are formed through conventional through holes and through holes for positioning components. Filling and drying the above-mentioned through-holes to form non-through-holes so that the applied flux, paste solder, flow solder, adhesive, mold resin, and other processing liquids do not flow out through the through-holes. More.

[0003] Further, as electronic components are further miniaturized and densified, the surface-mounted components are stably fixed when the surface-mounted electronic components are surface-mounted above the non-through holes. As described above, the filling material having a convex shape with the extra filling material protruding from the hole end face of the non-through hole is polished and removed to make it flat.

[0004]

When an electronic component is mounted on a printed wiring board with a surface, a through hole is filled with a filler to form a non-through hole, and a soldering flux, paste solder,
It is necessary to prevent flow solder, adhesive, mold resin, various processing liquids, etc. from flowing out of the through holes.

When a conventional electronic component with a surface is mounted on a surface, in order to stably mount the electronic component, an extra filler protruding from the end face of the non-through hole is polished and removed to flatten. Polishing process is required. Furthermore, after forming a solder resist film on the upper surface of the flattened non-through hole, when positioning and fixing the electronic component at a predetermined position with an adhesive, the adhesive protrudes from a lower area of the electronic component, and May have an adverse effect on the solder connection portion, or the surface of the solder resist film may have poor adhesion to the adhesive, resulting in insufficient adhesive strength in a small area.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a printed wiring board having a non-through hole in which a filler is filled in a through hole, wherein one end of the non-through hole has a concave surface and is closed. It is a printed wiring board provided with a concave or cylindrical depression.

In the printed wiring board having the non-through hole, the end face of the non-through hole is dented and hermetically closed in order to eliminate the protrusion of the adhesive for fixing the electronic component for attaching to the surface and the insufficient adhesive force. A dike in which a concave or cylindrical depression is formed and an insulating film such as a solder resist film or a stamping film is not formed on the surface thereof, and an adhesive is stored around the depression using an insulating material such as a solder resist. Is formed.

In the printed wiring board for mounting on a surface, when the electronic component for mounting on a surface is mounted on a flat surface of the printed wiring board, the electronic component for mounting on the surface of the printed wiring board in a lower range of the electronic component for mounting on the surface is mounted. This is a printed wiring board provided with a concave or cylindrical concave hole surrounded by a bank made of an insulating material.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. In the sectional view of the main part of the printed wiring board of FIG. 1A, a non-through hole 5 is formed by filling and hardening the filler 3 in a through hole such as a through hole and a non-through hole for positioning components. In order to stably mount the surface-mounting electronic component, a non-through hole 5 in the lower area for mounting the surface-mounting electronic component was provided with a concave recessed hole 6 in which the hole end face was dented and sealed. It is a printed wiring board 1.

Further, in order to protrude the adhesive for fixing the electronic component for surface mounting and increase the adhesive strength of the adhesive of the printed wiring board 1, a solder resist 7 serving as a dike for securing a portion where the adhesive is accumulated is provided. It is provided on the through hole land 2, approaching the periphery of the concave depression 6. On the opposite side of the concave recessed hole 6 in this figure, the filling 3 is raised and convex, but the filling 3 can be polished and removed to make it flat and flat.

FIG. 1B shows a main part of the printed wiring board 1 in which a non-through hole 5 serving as a cylindrical recessed hole 8 which is closed and has a hole end surface provided in a lower area where a surface-mounted component is mounted. It is sectional drawing. In order to increase the capacity of the liquid pool portion of the adhesive for fixing the electronic component for attaching the surface, the filling 3 of the non-through hole 5
The bottomed cylindrical recessed hole 8 is provided by drilling or laser processing to completely prevent the adhesive from protruding, and it is possible to increase the connection surface area between the filler 3 and the adhesive.

FIG. 1 (c) shows an upper portion of a surface circuit conductor such as a concave recessed hole 6 or a through hole which is closed by sealing the hole end surface of the non-through hole 5 filled with the filling material 3. The solder resist 7 is formed as flat as possible, and the non-through hole 5 is formed.
Printed wiring board 1 by covering the upper surface of the
This ensures the insulation between the surface circuit conductors of the printed wiring board 1 other than the solder connection portion and the electronic component for surface mounting. In the case of FIG. 1 (c), it is convenient to perform surface mounting in which the bonding area of a multi-legged lead component such as an integrated circuit component such as an LSI or a component with a large surface is slightly large. Further, according to the present invention, a concave recessed hole 6 or a cylindrical recessed hole 8 can be provided in the case where surface-mounted components are mounted not only on one side of the printed wiring board 1 but also on both sides.

FIG. 1D is a cross-sectional view of a main portion of the printed wiring board in a lower area of the electronic component for mounting a surface on a flat surface of the printed wiring board 1. is there. On the surface of the printed wiring board in the lower area of the electronic component for attaching a surface, there is provided a concave surface 4 surrounded by a bank made of an insulating material such as a solder resist 7 or a printing ink, or a concave hole 4 concaved in a cylindrical shape. It is a printed wiring board.

[0014]

As described above, according to the present invention, an adhesive for fixing an electronic component for attaching a surface to a surface is provided by providing a concave or cylindrical recessed hole in which one end of the hole is dented and hermetically closed. By storing the adhesive in the recessed hole, it is possible to protrude the adhesive and increase the adhesive strength between the printed wiring board and the adhesive. In addition, a polishing step for polishing and removing the extra filler protruding from the hole end face of the conventional non-through hole becomes unnecessary.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part for describing an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Printed wiring board 2 ... Through-hole land 3 ... Filler 4 ... Depression hole 5 ... Non-through hole 6 ... Concave depression hole 7 ... Solder resist 8 ... Cylindrical depression hole.

Claims (3)

[Claims] 1. A printed wiring board having a non-through hole in which a filling material is filled in a through hole, wherein a depressed hole is provided in which one end face of the non-through hole is dented. . 2. The printed wiring board according to claim 1, wherein an embankment is formed around the depression by an insulating material. 3. A printed wiring board for mounting on a surface, wherein a recessed hole surrounded by an embankment made of an insulating material is provided on a surface of the printed wiring board in a lower area of the electronic component for mounting on a surface. Printed wiring board.