JPH0563327A - Printed wiring board with land for inspection use and inspecting method thereof - Google Patents

Abstract

PURPOSE:To facilitate the design of a high-density mounting printed wiring board with lands for inspection use as well as to improve the inspecting method of lead lands in after components are mounted on the printed-wiring board to improve the reliability of an inspected result. CONSTITUTION:Two connection wiring conductors 9, through which lead lands 2b-1 and 2b-2 of high-density mounting components of a lead pitch of 1.00mm are respectively connected to lead lands 3a-5 and 3a-6 of the same high-density mounting components as the above high-density mounting components, are respectively provided with a land 11 for inspection use one piece by one piece. The adjacent lands 11 are arranged in such a way that their centers are separated from each other at a distance of 1.27mm or wider. After the components are mounted on a printed-wiring board designed in such a way, contact probes of an inspection machine are respectively abutted on each land 11 and at the same time, contact probes, which are connected to the same inspection circuit as that of the contact probes, are respectively abutted on the lead lands connected to both ends or the end parts on one side of the conductors 9. Thereby, an inspection mistake due to a contact failure of the contact probes is prevented from being generated.

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 suitable for high-density mounting, and more particularly to a printed wiring board having an inspection land for inspecting an electrical connection state of a solder connection portion of a high-density mounting component. It is a thing.

[0002]

2. Description of the Related Art A printed wiring board which has been surface-mounted by soldering is inspected using an inspector such as an in-circuit tester in order to detect defects such as solder bridges in electrode connection portions. Therefore, it is necessary to bring the contact probe of the inspection machine into contact with the wiring pattern of the printed wiring board, which has been conventionally performed by the method described below.

(A) An inspection land for abutting a contact probe is provided adjacent to an electrode connection land for soldering an electrode such as a terminal or a lead of a mounted component.

(B) Without providing an inspection land
The contact probe is brought into contact with the electrode connecting land of the directly mounted component or the electrode itself.

[0005]

The above-mentioned conventional techniques have the following problems, respectively.

In the method (a), when the mounting component is a chip component, the distance between the lead or electrode connecting land and the wiring conductor adjacent thereto is relatively large, so that the diameter is about 1 mm. Providing the inspection land does not hinder the circuit design of the printed wiring board at all, but the inspection land needs to have a diameter of 0.8 mm or more at the minimum. When the distance between the center lines of the lead connection lands adjacent to each other (hereinafter referred to as the "lead pitch") is 1.27 mm or less, the space between adjacent wiring conductors is small, so each lead connection It is difficult to provide one inspection land adjacent to each land.

In the method (b), a poor electrical contact is likely to occur between the contact probe and the land for electrode connection, and when the contact probe is brought into contact with the electrode of the mounted component, the contact pressure causes In many cases, the electrode comes into contact with the land of the printed wiring board to cause a short circuit, and a solder defect cannot be detected.

The present invention has been made in view of the above problems of the prior art, and has a lead pitch of 1.27 m.
An object of the present invention is to provide a method for inspecting a printed wiring board having an inspection land suitable for a high-density mounted component of m or less and a printed wiring board with an inspection land.

[0009]

In order to achieve the above object, a printed wiring board with an inspection land according to the present invention has a plurality of printed wiring boards each having at least one end connected to an electrode connection land of a mounting component of the printed wiring board. Wiring conductors and one inspection land provided on each of the wiring conductors, and the inspection land is arranged such that its center is separated from the centers of other inspection lands by 1.27 mm or more. It is characterized by

When the distance between the plurality of wiring conductors is 1.27 mm or less, the inspection lands may be arranged in a zigzag pattern so that the inspection lands are separated from each other by 1.27 mm or more.

Further, in the method for inspecting a printed wiring board with an inspection land according to the present invention, the contact probe of the mounting printed wiring board inspection machine is brought into contact with the inspection land provided on the wiring conductor of the mounting printed wiring board, and At least one contact probe connected to the same inspection circuit as the contact probe is brought into contact with an electrode connection land of a mounting component of the mounting printed wiring board connected to at least one end of the wiring conductor. To do.

[0012]

In the printed wiring board with the inspection lands of the present invention, one inspection land is provided for each of the plurality of wiring conductors, and the centers of the adjacent inspection lands are 1.2.
The wiring conductors can be easily designed by arranging them so as to be separated by 7 mm or more. When the distance between the wiring conductors adjacent to each other is 1.27 mm or less, the wiring lands can be more easily designed by arranging the inspection lands in a zigzag pattern.

Further, by making a plurality of contact probes of the mounted printed wiring board inspection machine contact the same wiring conductor, inspection errors due to poor contact of the contact probes can be reduced.

[0014]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic partial view showing a part of the present embodiment. A printed wiring board 1 includes a first flat IC package mounting portion IC1, a second flat IC package mounting portion IC2, and a second flat IC package mounting portion IC2, which are indicated by broken lines. 1 mini-package mounting portion CN1, 2nd mini-package mounting portion CN2, 1st
A chip component mounting portion R1, a second chip component mounting portion R2, and a third chip component mounting portion D1. In the first flat IC package mounting portion IC1 and the second flat IC package mounting portion IC2,
Lead lands 2a-1 to 2a-n, 2b-1 to 2b-, which are many electrode connecting lands arranged in two rows, respectively.
n and 3a-1 to 3a-n and 3b-1 to 3b-n are provided (shown in FIG. 2), and the distance L1 (hereinafter, referred to as "lead pitch") between the center lines of the lead lands in each row. 1.
It is 00 mm. Similarly, the first mini-package mounting portion CN1 and the second mini-package mounting portion CN2 are provided with through-hole-equipped lead lands 4a, 4b and 5a, 5b arranged in two rows of three, respectively. (See FIG. 3), the lead pitch of the lead lands in each row is also 1.00 mm.

Two chip component mounting portions R1 and R2
And a pair of lead lands 6a, 6b and 7 respectively.
a, 7b, and further, three lead lands 8a, 8b, 8c are provided on the chip component mounting portion D1.

Lead lands 2a-1 to 2a-n, 2 in each row of the first and second IC flat package mounting portions.
b-1 to 2b-n, 3a-1 to 3a-n, 3b-1 to 3b
b-n are parts thereof (for example, the lead land 2).
b-1 and the lead land 2b-2) are the connection wiring conductors 9
Is connected to the lead lands (lead land 3a-5 and lead land 3a-6 in the above-mentioned example) of the other component by the remaining lead lands (for example, the lead land 3a-5).
a-2) is connected to the non-connection wiring conductor 10 which does not have the counterpart lead land to be connected.

The connection wiring conductors 9 each have one inspection land 11, and similarly, the non-connection wiring conductors 10 each also have one inspection land 12. The distance between the connection wiring conductor 9 and the non-connection wiring conductor 10 adjacent to each other is 1.2.
If it is 7 mm or less, by separating the inspection lands 11 and 12 from each other along the respective wiring conductors,
The centers are arranged so that the distance L2 between them is 1.27 mm or more (shown in FIG. 3).

For example, each of the lead lands 2b-1 to 2b-1
In the case of the five connection wiring conductors 9 connected to 2b-5, the distance L1 between the lead lands 2b-1 to 2b-5 is as described above.
Is 1.00 mm, and the spacing between the connecting wiring conductors 9 is 1.0
Since the inspection lands 11 are set to 0 mm, the intervals (L2) between the inspection lands 11 adjacent to each other are set to 1.27 mm or more by arranging the inspection lands 11 in a zigzag pattern.

Lead lands 4a, 4b and 5a, 5b of mini-package mounting portions CN1 and CN2 and lead lands 6 of chip component mounting portions R1, R2 and D1.
Similarly, for a, 6b, 7a, 7b and 8a, 8b, 8c, the connection wiring conductor 9 having the inspection land 11 or the non-connection wiring conductor 10 having the inspection land 12 is connected.

After mounting a predetermined component on the printed wiring board 1 and soldering it, the solder connection portion is inspected by an in-circuit tester.

In the inspection, the contact probe of the in-circuit tester is brought into contact with the inspection lands 11 and 12 and connected to various measuring instruments, signals are given to the respective mounted parts, and the results are read to obtain the solder. Eliminate defective connections. As mentioned above, the inspection run 11,1
Since Nos. 2 are arranged at intervals of 1.27 mm or more, the contact probes abutting on the adjacent inspection lands do not interfere with each other, and the reliability of the inspection result is extremely high.

In mounting the components on the printed wiring board shown in FIGS. 1, 2 and 3 and performing the inspection by the in-circuit tester, the contact probe of the in-circuit tester is inspected as described above. A contact probe that contacts the inspection lands 11 and 12 and is connected to the same inspection line as the contact probe that contacts the inspection lands 11 and 12 directly contacts the lead land to which each inspection land is connected. By doing so, it is possible to improve the reliability of the inspection result of the in-circuit tester. For example, the contact probe of the in-circuit tester is used as the lead land 2b-1 and the lead land 3a-5.
One or two contact probes that are brought into contact with the inspection land 11 of the connection wiring conductor 9 that connects with and are connected to the same inspection line as the contact probe are directly connected to the lead land 2b-1 and the lead land 3a-5. Abut one or both.

As described above, by bringing a plurality of contact probes into contact with each wiring conductor, the same line is connected even if a contact probe contact failure occurs due to residual flux in the inspection land 11. Since it is possible to send an inspection signal from the contact probe to the mounted component, there is no possibility that a contact failure of the contact probe with respect to the inspection land 11 is erroneously detected as a defect of the solder connection portion.

Further, the contact probe provided on the inspection land is generally a serrated type as shown in FIG. 4A, but a printed wiring mounted by an automatic mounting apparatus without a cleaning step. In the plate, since the contact flux of the contact probe is often hindered by the residual flux of the inspection land, it is shown in (b) to (e) of FIG. It is desirable to use a contact probe having a special shape such as a main needle, and to set the contact pressure of the contact probe to 1.4 to 2 times that in the case of using the general example shown in FIG.

[0026]

Since the present invention is configured as described above, it has the following effects.

It is possible to easily design a wiring conductor having an inspection land in a printed wiring board on which a high-density mounting component having a lead pitch of 1.27 mm or less is mounted, and further mounting using the inspection land. The reliability of the inspection result of the printed wiring board is improved.

[Brief description of drawings]

FIG. 1 is a schematic partial view showing a part of the present embodiment.

FIG. 2 is an enlarged partial view showing an upper half portion of FIG. 1 obtained by dividing FIG. 1 along the line AA ′.

FIG. 3 is an enlarged partial view showing a lower half portion of FIG. 1 obtained by dividing FIG. 1 along the line AA ′.

FIG. 4 is an explanatory diagram showing a modified example of the contact probe.

[Explanation of symbols]

1 Printed wiring board IC1, IC2 Flat IC package mounting part CN1, CN2 Mini package mounting part R1, R2, D1 Chip component mounting part 2a-1, 2a-n, 2b-1, 2b-n Lead land 3a-1, 3a -N, 3b-1, 3b-n Lead land 4a, 4b, 5a, 5b Lead land 6a, 6b, 7a, 7b, 8a, 8b, 8c Lead land 9 Connection wiring conductor 10 Non-connection wiring conductor 11, 12 For inspection Land L1 Lead pitch

Claims (3)

[Claims] 1. A plurality of wiring conductors each having at least one end connected to an electrode connection land of a mounting component of a printed wiring board, and one inspection land provided on each of the wiring conductors. A printed wiring board with an inspection land, wherein the inspection land is arranged such that its center is separated from the center of another inspection land by 1.27 mm or more. 2. The printed wiring board with an inspection land according to claim 1, wherein the distance between the center lines of the wiring conductors adjacent to each other is 1.27 mm or less. 3. At least one contact probe of the mounting printed wiring board inspecting device is brought into contact with an inspection land provided on a wiring conductor of the mounting printed wiring board and connected to the same inspection circuit as the contact probe. A method of inspecting a printed wiring board with an inspection land, comprising contacting a contact probe with an electrode connection land of a mounting component of the mounting printed wiring board connected to at least one end of the wiring conductor.