JP2001230543A - Printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printed wiring board, capable of readily inspecting a solder jointed state of a plurality of leads of electronic components to pads of the printed wiring board. SOLUTION: This printed wiring board 10 comprises a part lead connecting pad 2, provided with a pair of base pad 2a and end pad 2b formed, by bisecting in a direction perpendicular to the axial line of a lead 22, so as to connect the lead 22 of a connector 20 to a surface of a substrate body 1, and a lead-out pad 4 provided on the reverse surface of the substrate body 1, so as to interlock by use of a through-hole 3 with the base pad 2a connected to the base of the lead 22. The inspection of a jointed state of the lead 22 in the printed wiring board 10, to which the connector 20 is mounted is conducted by confirming presence or absence of a conduction by bringing a pair of probes 45, 46 into contact with the lead-out pad 4 interlocked with the end pad 2d and the base pad 2a.

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 structure of a component lead connection pad for connecting leads of an electronic component in the printed wiring board.

[0002]

2. Description of the Related Art When electronic parts having leads such as ICs, resistors, connectors, etc. are surface-mounted on a printed wiring board,
Solder paste (cream solder) is applied to the lead connection pads provided on the surface of the printed wiring board, and the electronic components are mounted so that the lead ends of these electronic components are placed on the lead connection pads. The paste is melted and solidified, and the lead and the lead connection pad are collectively solder-bonded. After that, using an in-circuit tester or the like, various functional tests of electrical characteristics including the suitability of the solder joint are performed.

Conventionally, a printed wiring board of this type has been used as shown in FIG. In FIG.
The printed wiring board denoted by reference numeral 0 is a board body 41 made of an insulating base material such as phenol resin or epoxy resin containing glass fiber.
Has a component lead connection pad 44 for connecting the lead 43 of the electronic component 42, and an electronic circuit, that is, a pattern (not shown) connected to the component lead connection pad 44 is formed. . On the printed wiring board 40 thus configured, the leads 4 of the electronic component 42 are provided.
3 is mounted on the component lead connection pad 44 of the board main body 41 by solder 45.

[0004] As described above, the open or short of the connection of the soldered portion on the printed wiring board 40 on which the electronic component 42 is mounted is confirmed by using an in-circuit tester or the like with the lead 43 of the electronic component 42 or the printed wiring board 40. The probe is brought into contact with a test pad 46 provided by extending the component lead connection pad 44 to check continuity.

[0005]

However, FIG.
Even if the lead 43 is open from the pad 44 as shown in (1), the lead 4 is opened as shown in FIG.
When the probes 45 and 46 are brought into contact with the pad 3 and the pad 44, the open lead 43 is pressed by the probe 46 to contact the pad 44, and the probe 45 contacted with the pad 44 and the probe contacted with the lead 43 There is a problem that conduction is made between 46.

For this reason, among the electronic components, when a surface mount type connector used for input / output of various signals and the like is mounted on a printed wiring board, a female connector mounted on the printed wiring board 40 as shown in FIG. A method is adopted in which the male connector 47 is fitted into the connector 42 to check the continuity between the probe 45 contacting the pad 44 and the male connector 47. However, this method requires a long time for the test and has a problem of low productivity. was there.

The present invention has been made in view of such a conventional problem, and it is possible to easily inspect the solder bonding state of a large number of leads of an electronic component mounted on a printed wiring board. Workability, and
It is an object of the present invention to provide a printed wiring board capable of improving reliability in inspection.

[0008]

In order to achieve the above object, a printed wiring board according to claim 1 of the present invention is provided as a component lead connection pad for connecting a lead of an electronic component to a surface of the printed wiring board. 2 perpendicular to the axis of the lead
A base pad and an end pad which are divided and separated from each other, and a lead-out pad provided on the back surface of the printed wiring board so as to be connected to a base pad to which the base of the lead is connected. And Therefore,
The connection of the leads of the electronic component to the printed wiring board is performed using the component lead connection pads, and the probing is performed using the drawing pads on the front and back of the printed wiring board.

According to a second aspect of the present invention, in the printed wiring board according to the first aspect of the present invention, the component lead connection pad divided into two parts is connected to an end pad to which the lead tip is connected. It has a drawer pad provided on the surface of the printed wiring board. Therefore, probing on the front surface side of the printed wiring board is performed using the drawing pad connected to the end pad.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings. FIG. 1 is a plan view showing a main part of a printed wiring board according to an embodiment of the present invention in which a surface mount type connector is mounted, and FIG. 2 is a longitudinal sectional view of the printed wiring board of FIG. In these figures, reference numeral 10 denotes a printed wiring board, and reference numeral 20 denotes a connector as an electronic component having leads 22. The connector 20 includes a housing 21 made of synthetic resin and a plurality of copper alloy leads 22, 22.
...

The printed wiring board 10 includes a board body 1 and a pair of bases formed by dividing the board body 1 into two parts in a direction perpendicular to the axis of the lead 22 so as to connect the leads 22 of the connector 20 to the surface of the board body 1. A large number of component lead connection pads 2 each including a pad 2a and an end pad 2b;
A lead pad 4 is provided on the back surface of the substrate body 1 by being connected to a base pad 2a to which the base of the lead 22 of the connector 20 is connected using a conduction hole 3 such as a through hole. The base pad 2a, the end pad 2b
An electronic circuit (pattern) (not shown) connected to the base pad 2a or the end pad 2b is formed on one of the two.

The connector 20 is collectively soldered to other electronic components as in the case of surface mounting, and the base pad 2a and the end pad 2a constituting the component lead connection pads 2 on the surface of the printed wiring board 10. A solder paste is applied to the pad 2b by screen printing or the like, the lead 22 of the connector 20 is placed on the pad 2a, 2b, and the solder paste is melted and solidified, so that the lead 22 and the pad 2a, 2b are connected. Are joined.

In order to confirm the open connection of the soldered portion on the printed wiring board 10 on which the connector 20 is mounted as described above, as shown by a chain line in FIG. 2, a pair of probes 45 such as an in-circuit tester, One of the probes 46 (the probe 46 in FIG. 2) is brought into contact with the end pad 2b to which the distal end of the lead 22 is joined, and the other probe (the probe 45 in FIG. 2) is connected to the base pad 2a. The presence or absence of conduction is confirmed by contacting the pad 4.

Accordingly, if the lead 22 is not joined to either or both of the base pad 2a and the end pad 2b and the lead 22 is lifted, the base pad 2a and the lead-out pad 4 are not connected. It can be confirmed that the continuity is not established and the lead 22 is in the open state. As described above, the probe 46 is connected to the lead 2 as in the related art.
2 is not contacted with the base pad 2,
The open state of the lead 22 can be reliably detected without forcibly contacting the a or the end pad 2b.

FIG. 3 is a plan view of a printed wiring board showing another embodiment of the present invention. In this embodiment, the contact with the end pads 2b is facilitated, and high-density mounting is supported. In the printed wiring board 10a according to the present embodiment, an end pad 2b for soldering the tip of the lead 22 of the connector 20 and an extraction pad 2c connected to the pad 2b are provided on the surface of the substrate body 1. . The area of the draw-out pad 2c is
The tip of FIG. 2 is set as small as possible in order to easily touch the tip and prevent contact with other patterns.

In the present embodiment, since the contact area of the probe 46 can be sufficiently secured by the pull-out pad 2c, the lead 22 does not become an obstacle during probing. Further, since the contact area of the probe 46 can be sufficiently secured by the pull-out pad 2c, it is possible to prevent the occurrence of connection or contact failure. ,

In the above embodiment, the case where the electronic component is a connector has been described. However, the electronic component is not limited to the connector but may be any component having a lead.

[0018]

As described above, in the present invention, a component lead connecting pad for connecting a lead of an electronic component is provided on a surface of a printed wiring board and is divided into two parts in a direction perpendicular to the axis of the lead and separated from each other. By providing a base pad and an end pad, and a lead-out pad provided on the back surface of the printed wiring board in connection with the base pad to which the base of the lead is connected, the lead of the mounted electronic component is provided. When the probe is lifted up from the lead connection pad and becomes open, inspection can be performed without contacting the probe on the lead as before, so that the lead does not come into contact with the pad forcibly,
The open state of the lead can be reliably detected.

Further, of the two divided lead connection pads, there is a lead pad provided on the surface of the printed wiring board in connection with the end pad to which the lead end of the electronic component is connected. Since the contact area of the probe can be sufficiently secured by the pad, the lead does not become an obstacle during probing. Also,
Since the contact area of the probe can be sufficiently secured by the pull-out pad, it is possible to prevent the occurrence of connection or contact failure.

Furthermore, even when a connector used for inputting and outputting various signals and the like among electronic components is mounted on a printed wiring board, the female connector mounted on the printed wiring board is fitted with the male connector. This eliminates the need to check the continuity between the probe in contact with the pad and the male connector, so that the test can be performed quickly and productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a plan view showing a main part of a state in which a surface mount type connector is mounted on a printed wiring board according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the printed wiring board of FIG.

FIG. 3 is a plan view showing a main part of a printed wiring board according to another embodiment of the present invention.

FIG. 4 is a plan view showing a main part in a state where electronic components are mounted on a conventional printed wiring board.

FIG. 5 is a view for explaining a conventional inspection method of a bonding state between a lead of an electronic component and a lead connection pad of a printed wiring board.

FIG. 6 is a view for explaining a conventional inspection method of a bonding state between a lead of a surface mount type connector and a lead connection pad of a printed wiring board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Board main body 2 Component lead connection pad Lead connection land 2a Base pad 2b End pad 2c Lead-out pad 3 Conducting hole 4 Lead-out pad 20 Connector 21 Housing 22 Lead

Claims (2)

[Claims] 1. A base pad and an end pad provided as component lead connection pads for connecting leads of an electronic component to a surface of a printed wiring board and divided into two parts in a direction orthogonal to the axis of the leads and separated from each other. And a lead-out pad provided on the back surface of the printed wiring board in connection with a base pad to which the base of the lead is connected. 2. A lead pad provided on the surface of the printed wiring board in connection with an end pad to which the lead end of the component lead connection pad provided in two parts is connected. The printed wiring board according to claim 1, wherein