JPH02260689A - Printed wiring board - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a printed wiring board, and particularly to a printed wiring board on which semiconductor chip elements and the like are mounted.

(Prior art) For the purpose of downsizing circuits for electronic devices, high-density mounting circuit components (equipment )It has been known. Incidentally, in the construction of this type of high-density mounting circuit components, a printed wiring board, a part of which is shown in plan in FIG. 2, has usually been used. That is, a printed wiring board having a basic configuration in which a chip pad 2 is formed on at least one principal surface of an insulating substrate 1 and a conductive pattern 3 electrically connected to the chip pad 2 is used. However, in the case of a printed wiring board with the above configuration, in order to perform a predetermined electrical inspection on the printed wiring board, contacting the chip pad 2 with a terminal pin may cause damage, or the conductor pattern 3 may be damaged due to an inconvenience in the circuit. Even if an attempt is made to cut the jumper wire and solder the jumper wire to the chip pad 2, the size of the chip pad 2 is determined according to the chip element to be mounted and mounted, so the soldering cannot be performed as desired. There are often cases.

In response to the above problem, a printed wiring board having a structure partially shown in plan view in FIG. 3 has been developed. That is, a small-diameter land 4 with a diameter of about 0.5 nua is provided at a position close to the chip pad 2 of the conductor pattern 3 that is electrically connected to the chip pad 2 provided on one main surface of the insulating substrate 1, and the jumper Attempts have been made to make it easier to solder wires. A through hole 5 having a diameter of about 0.31 mm is formed in the center of the small diameter land 4, and the two surfaces of the substrate 1 may be connected via this through hole 5 with a jumper wire.

(Problems to be Solved by the Invention) By providing the small-diameter land 4 in the middle of the conductor pattern 3 electrically connected to the chip pad 2 as described above, it is possible to easily solder the jumper wire. There's a problem. That is, the small-diameter land 4 on the printed wiring board has a small diameter of about 0.5 IIm, and the connection between the conductor patterns 3 is insufficient, resulting in poor reliability. Furthermore, the through hole 5 formed in the center of the small diameter land 4 is also small, with a diameter of about 0.3 m11, so when connecting the jumper wires between both sides of the board 1 through the through holes 5, it is difficult to insert the jumper wires. It has the disadvantage of being difficult.

[Structure of the Invention] (Means for Solving the Problems) The present invention has been made in response to the above-mentioned circumstances, and includes a chip pad formed on one main surface of an insulating substrate, and a chip pad formed on one main surface of the insulating substrate. A printed wiring board comprising a conductor pattern formed on a main surface and electrically connected to a chip pad, and a small-diameter land provided in a position close to the chip pad of the conductor pattern. It is characterized by having a diameter of, for example, approximately 1 m11, which is relatively large (semi-small diameter) compared to the conventional case.

(Function) As described above, by making the land provided in the vicinity of the chip pad of the conductive pattern electrically connected to the chip pad formed on one main surface of the insulating substrate have a semi-small diameter, Electrical connection with the extending conductor pattern can be made sufficiently and reliably, and terminal pins can be easily brought into contact with each other during electrical inspection. Moreover, as the land becomes semi-small in diameter, the diameter of the coaxially formed through hole can also be set large, so that it is easy to insert and connect jumper wires, for example.

(Example) Hereinafter, an example will be described with reference to FIG. 1, which shows a main part of a printed wiring board according to the present invention in a plan view.

FIG. 1 shows a region where a chip pad 2 of a printed wiring board and a conductor pattern 3 electrically connected to the chip pad 2 are formed.

That is, a chip pad 2 for mounting and mounting a required chip element, such as a semiconductor chip element, is formed in a predetermined area of the printed wiring board, and this chip pad 2 is connected to a required conductor pattern 3. It has a composition. On the other hand, in the middle of the conductor pattern 3, there is a semi-small diameter land 4a with a diameter of 1 wg+ at a position close to the chip pad 2, and a semi-small diameter land 4a with a diameter of 0.5 a+w coaxially with this semi-small diameter land 4a.
A through hole 5a is provided.

In the above, the diameter of the semi-small diameter land 4a is l■.

Although an example is shown in which the diameter of the through hole 5a is set to 0.5+aml, it may be appropriately selected and set within a range of, for example, about ±0.1 m1Il, taking into consideration the wiring pattern density, the width or pitch of the wiring pattern, etc. . Furthermore, the printed wiring board structure may be any one of a single-sided type, a single-sided type, or a multilayer type.

[Effects of the Invention] According to the present invention, a conductive pattern electrically connected to a chip pad has a semi-small diameter land whose diameter is larger than that of the conventional case. In other words, the conductor pattern connected to the chip pad is connected by a semi-small diameter land in a region close to the chip pad. Here, since the diameter of the land interposed in the middle of the conductive pattern is relatively large, the electrical connection of the conductive pattern is reliably maintained, and the terminal pin is used for electrical inspection of printed wiring boards. Since mounting and soldering of jumper wires can be easily and reliably performed, the quality of the printed wiring board can also be improved. Furthermore, since the diameter of the through hole formed in the semi-small diameter land portion can be set to be relatively large due to thermal necessity, it is possible to easily insert, for example, a jumper wire for connection.

Thus, it can be said that the printed wiring board according to the present invention is suitable for high-density packaging.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the configuration of main parts of a printed wiring board according to the present invention, and FIGS. 2 and 3 are plan views showing different examples of the structure of main parts of a conventional printed wiring board. 1...Insulating substrate 2...Chip pad 3...Conductor pattern 4a...Semi-small diameter land 5a...Through Hole Applicant Co., Ltd. Toshiba

Claims (1)

[Scope of Claims] A chip pad formed on one main surface of an insulating substrate, a conductor pattern formed on one main surface of the insulating substrate and electrically connected to the chip pad, and the conductor A printed wiring board characterized by comprising a semi-small diameter land provided in a position close to a chip pad of a pattern.