JPH06260799A - Circuit board inspecting method, and circuit board - Google Patents

Abstract

PURPOSE:To inspect a mounted circuit board with a good accuracy through a simple process, by contacting twin probes respectively with the sections of test pads provided on the mounted circuit board exposed to the second principal surface of the mounting circuit board, and by inspecting whether a surface mount type part or the section to be connected therewith electrically is good or bad. CONSTITUTION:A test pad 15 is so provided on a circuit board main body 12 that it is connected electrically with the section of a wiring pattern 13 which is provided only on a first principal surface 12a and which serves only as the interconnecting section between plural surface mount circuit parts 22 and that its certain section is exposed to a second principal surface 12b. Then, twin probes 6a, 6b are contacted respectively with sections 15e of the test pads 15 provided on a mounted circuit board 20 which are exposed to the second principal surface 12b, or are contacted respectively with the sections of the circuit part 22 provided on the mounted circuit board 20 which are exposed to the second principal surface 12b. Thereby, it is inspected whether the surface mount type circuit part 22 provided on the mounted circuit board 20 is good or bad, or whether the section to be connected electrically with the part 22 is good or bad.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit board inspection method for inspecting a mounted circuit board on which surface mount type circuit components are mounted, and a circuit board suitable for carrying out this inspection method.

[0002]

2. Description of the Related Art In a mounted circuit board on which circuit components are mounted, an inspection of the mounted circuit board for inspecting the circuit components, wiring patterns, and connections between them is performed by an in-circuit tester (inspection device). This is conventionally done by pressing a pin (probe) against the terminal part of the circuit component. FIG. 5 is an explanatory diagram for explaining this conventional inspection method. The mounting circuit board 10 includes a circuit board 1 formed by disposing a predetermined wiring pattern 3 on a main surface of a circuit board body 2.
It has circuit components 4 and 5 mounted on this circuit board 1. The pins 4b and 5b provided on the circuit components 4 and 5 are soldered to predetermined portions of the wiring pattern 3 so that the circuit components 4 and 5 are mounted at predetermined positions on the circuit board 1. The circuit components 4 and 5 are mounted such that the respective main body portions 4a and 5a are located on the surface of the circuit board main body 2, that is, on the component surface (first main surface) 2a side.

The discrete component 4 among the circuit components 4 and 5 is the back surface of the circuit board body 2, that is, the solder surface (second
Is a circuit component in which the tip portion of the pin 4b is exposed on the main surface 2b. In the mounted circuit board 10 on which only the discrete component 4 is mounted, the inspection is performed by pressing the pair of inspection pins 6a and 6b into contact with the exposed portions of the pins 4b on the solder surface 2b. Was there. On the other hand, in the mounting circuit board 10 on which the surface mounting component (surface mounting type circuit component) 5 in which the pin 5b is not exposed to the solder surface 2b is mounted, the inspection pins 6a and 6b are pressed against the pin 5b of the surface mounting component 5. Thus, the quality inspection of the surface mount component 5 has been executed.

[0004]

Since the mounting circuit board 10 on which the surface mounting component 5 is mounted has been inspected by the method as described above, firstly, the inspection pins 6a and 6b are
There is a problem in that it is necessary to press not only the solder surface 2b but also the component surface 2a, which complicates the inspection process. In addition, since it is necessary to configure a jig of the inspection device to inspect both sides, there is a problem that the cost of the inspection device becomes high.

Secondly, as the fine pitch of the surface mount component 5 has progressed in recent years, the inspection pins 6a, 6
There is a problem that it is difficult to perform the inspection using b with high accuracy. For this reason, there has been a situation in which it is unavoidable to ship products while leaving parts that cannot be inspected.
There is a problem that poor contact between the surface mount component and the wiring pattern is frequently occurring.

Thirdly, as shown schematically in FIG. 6, even in the case of so-called "lead floating", in which the pin 5b and the wiring pattern 3 are not well connected due to defective soldering, the inspection pin 6a. , 6b, the pin 5b and the wiring pattern 3 may be temporarily connected at the time of the inspection. Therefore, there is a problem that a circuit portion that should be originally determined to be defective is erroneously determined to be acceptable.

The present invention has been made in order to solve the above problems, and provides a circuit board inspection method capable of inspecting a mounted circuit board with high accuracy in a simple process, and an inspection method therefor. An object is to provide a circuit board suitable for implementation.

[0008]

A circuit board inspection method according to the present invention is a circuit board inspection method for inspecting a mounted circuit board formed by mounting a plurality of circuit components including a plurality of surface mount type circuit components on a circuit board. And (a) the first and second
A step of preparing a circuit board body of an electrical insulator having a main surface of (1), and (b) including a pair of probes, and detecting electrical characteristics between the pair of probes in contact with an inspection object. Accordingly, a step of preparing an inspection device for inspecting the quality of the inspection object is provided, and (c) a wiring pattern for electrically connecting the plurality of circuit components is arranged on at least the first main surface. And (d) a portion in which a test pad of a substantially electric conductor is disposed only on the first main surface of the wiring pattern, and the plurality of surface mount circuit components are provided. A step of electrically connecting to only a portion connecting between the two, and installing the portion on the circuit board body so that a part of the plurality of circuit components is exposed to the second main surface; Each of the main body parts is located on the first main surface side of the circuit board main body, A step of forming a mounting circuit board by mounting a number of circuit components at predetermined positions on the circuit board body; and (f) replacing one of the pair of probes 1 with the test pad of the mounting circuit board. The other 1 is brought into contact with a portion exposed on the second main surface, and the other 1 is exposed on the second main surface of the other test pad of the mounting circuit board, or of the circuit component of the mounting circuit board. A step of inspecting the quality of the surface mount type circuit component of the mount circuit board or a part to be electrically connected to the surface mount type circuit component by contacting the part exposed on the second main surface, Equipped with.

A circuit board according to the present invention is a circuit board on which a plurality of circuit components including a plurality of surface mount type circuit components are to be mounted, and (a) each one main body portion of the plurality of circuit components is positioned. The electrically insulating circuit board body having the first main surface and the second main surface, which are the sides to be formed, and (b) the plurality of circuit components should be electrically connected in a predetermined manner. A plurality of wiring patterns, at least a wiring pattern arranged on the first main surface, and (c) a portion of the wiring pattern arranged only on the first main surface, A test pad which is electrically connected to a portion connecting only the surface mount type circuit components, and which is installed on the circuit board body, and a part of which is exposed on the second main surface. And an electrical conductor test pad.

[0010]

According to the circuit board inspection method of the present invention, in the mounting circuit board on which the surface mounting type circuit component is mounted, in the wiring pattern arranged on the mounting circuit board, the main body of the circuit component is located. A test pad that is electrically connected to a portion that is provided only on the main surface and that is connected only to the surface mount type component is provided. The test pad is substantially conductive, and a portion of the test pad is on the second side of the mounting circuit board.
Exposed on the main surface of. The inspection of the mounted circuit board is performed by exposing the portion exposed on the second main surface of the circuit component and the second portion of the test pad.
The probe of the inspection device is brought into contact with any of the portions exposed on the main surface of the. For this reason, since the probe need only contact the second main surface side at all times, the inspection process is simplified. Further, since it is not necessary to bring the probe into contact with the surface mount component, it is possible to perform a highly accurate inspection even in the inspection of the mounted circuit board on which the surface mount component having a fine pitch is mounted. Furthermore, since no pressure is applied to the surface-mounted component by the probe, a defective connection portion between the surface-mounted component and the wiring pattern can be detected without overlooking.

In the circuit board according to the present invention, the portion of the wiring pattern provided only on the first main surface on which the main body of the circuit component is to be located, and electrically connected to the portion to be connected only to the surface mount type component. It has a test pad to connect to. The test pad is substantially conductive, and a part thereof is exposed on the second main surface of the mounting circuit board. Therefore, the inspection of the mounted circuit board formed by mounting the circuit component including the surface mount component on this circuit board is performed by exposing the portion exposed on the second main surface of the circuit component and the same second main surface of the test pad. This can be performed by bringing the probe of the inspection device into contact with any of the parts to be covered. Therefore, the mounting circuit board can be inspected in a simple process with high accuracy.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS <Structure of Mounted Circuit Board> FIG. 2 is a front sectional view showing the structure of a mounted circuit board in which surface mount type circuit components are mounted on the circuit board according to an embodiment of the present invention (FIG. 2).
(A)) and a top view (FIG.2 (b)). The mounted circuit board 20 includes a circuit board 11 in which a predetermined wiring pattern 13 is arranged on the main surface of the circuit board body 12, and circuit components mounted on the circuit board 11. In FIG. 2, two surface mount components (surface mount type circuit components) 21 and 22 mounted on the circuit board 11 are illustrated. Pins 21b and 22b provided on the surface mount components 21 and 22 respectively
However, the surface mount components 21 and 22 are mounted at predetermined positions on the circuit board 11 by being soldered to predetermined portions of the wiring pattern 13. In addition, surface mount component 2
1 and 22, the main body portions 21a and 22a are the surface of the circuit board main body 12, that is, the component surface (first main surface) 12
It is mounted so as to be located on the a side. Surface mount component 2
Reference numeral 1 is, for example, a surface mount type capacitive element, and surface mount component 22 is, for example, a surface mount type integrated circuit element. The wiring pattern 13 is made of, for example, a copper material and is formed by using, for example, a well-known printed wiring technique.

A test pad is provided in the partial wiring pattern that connects only surface mount components and is arranged only on the component surface 12a in the continuous partial wiring pattern that constitutes the wiring pattern 13. There is. In the example of FIG. 2, the test pad 15 is provided on the partial wiring pattern 13a connected only between the surface mount components 21 and 22.

FIG. 3 is a partial sectional perspective view (FIGS. 3A and 3C) and a side sectional view (FIG. 3B) showing the structure of the test pad 15. The circuit board 11 is provided with a through hole 15a penetrating the partial wiring pattern 13a and the circuit board body 12. Inner surface 15 of through hole 15a
Plating 15c of the same material as the wiring pattern 13 is applied to b. The component surface 12a and the back surface of the circuit board body 2,
That is, the through hole 15 to the solder surface (second main surface) 12b
Circular patterns 15d and 15e made of the same material as the wiring pattern 13 and having a predetermined diameter are provided in the opening a. The plating 15c and the circular patterns 15d and 15e are conductors and are electrically connected to the partial wiring pattern 13a.

When the wiring pattern 13 is formed by using the printed wiring technique, the circuit board body 12 is preceded by it.
Copper plating is applied in advance over the entire main surface of the.
The through hole 15 is previously provided at a predetermined position of the circuit board body 12.
By providing a, the plating 15c,
The circular patterns 15d and 15e can be simultaneously formed.

That is, the test pad 15 itself is
It has the same structure as a conventionally known through hole or via hole and can be formed by a similar method. However, the through holes are provided for the purpose of connecting discrete components, and the via holes are provided for the purpose of electrically connecting between the wiring patterns 13 arranged on the two main surfaces of the circuit board body 12. It is what is done. The test pad 15 in the present invention is characterized in that it is provided on a partial wiring pattern 13a of the wiring pattern 13, which is connected to only the surface mount components and is arranged only on the component surface 12a, not any of them. At this position where the test pad 15 is provided, neither a through hole nor a via hole is provided. That is, it should be noted that the test pad 15 cannot be substituted by the through hole or the via hole. With the test pad 15, as will be described later,
It is possible to perform the inspection of the mounted circuit board 20 with high efficiency and accuracy.

Table 1 shows two representative examples of the dimensions of the test pad 15, that is, the outer diameters A and C and the inner diameter B of the circular patterns 15d and 15e. The one with a relatively small diameter is tentatively called a mini-via, and the one with a larger diameter is called a middle bayer.

[0018]

[Table 1]

Needless to say, the mounting circuit board 20 may be mounted with not only surface mounting components but also discrete components.

<Inspection Method> A method of inspecting the mounting circuit board 20 performed after the mounting circuit board 20 is formed will be described. 1 and 4 are explanatory views showing this inspection method. The in-circuit tester (inspection device) 6 including the inspection pins 6a and 6b detects electrical characteristics such as resistance, capacitance, induction, impedance, and voltage between the inspection pins (probes) 6a and 6b in the device body 6c. I do.

In FIG. 1, each of the partial wiring patterns 13a connected to the pair of pins 22b of the surface mount component 22 is connected only to another surface mount component and is arranged only on the component surface 12a. An example is shown. Therefore, the test pads 15 are provided on these partial wiring patterns 13a. The quality of the characteristics of the surface mount component 22 on the mount circuit board 20 or the surface mount component 2
2 is an inspection of the quality of the connection between the partial wiring pattern 13a and
It is performed by pressing the inspection pins 6a and 6b against the two test pads 15 from the solder surface 12b side. If the predetermined electrical characteristics originally possessed by the surface mount component 22 are detected in this inspection, then both the surface mount component 22 itself and the connection between the surface mount component 22 and the partial wiring pattern 13a are good. You can judge.
On the contrary, if the predetermined electrical characteristics are not obtained, it can be determined that any one of them is defective. In this case, the cause of the defect is further sought by visual inspection, and the disposal,
Predetermined measures such as replacement and repair are planned.

FIG. 4 shows a method for inspecting the quality of the characteristics of the discrete component 23 on the mounting circuit board 20. The pin 23b is penetrated through the through hole of the through hole 16 connected to the wiring pattern 13, and the pin 23b
The discrete component 23 is mounted at a predetermined position on the circuit board 11 by soldering the to the through hole 16. When inspecting the discrete component 23, the inspection pins 6a and 6b are attached to the solder surface 1 from the side of the solder surface 12b.
It is executed by pressing the tip of the pin 23b exposed to 2b.

FIG. 4 also shows a method of inspecting the surface mount component 22 mounted on the mount circuit board 20 at the same time. In the surface mount component 22, one of the wiring patterns 13 connected to the pair of pins 22b is the other surface mount component 21.
And the other one is connected to the discrete component 23. Discrete component 23 in which inspection pins 6a and 6b are connected to one pin 22b of surface mount component 22 and the other pin 22b by wiring pattern 13.
Each of the pins 23b is pressed against the solder surface 12b from the side of the solder surface 12b, so that the quality of the characteristics of the surface mount component 22 and the quality of the connection between the surface mount component 22 and the wiring pattern 13 are inspected. It

As shown in the above example, in the inspection method of this embodiment, the inspection pins 6a and 6b are connected to the test pad 1
5, or the surface mount component 21 on the mounting circuit board 20 by pressing against the pins exposed on the solder face 12b of the discrete component from the solder face 12b side,
22 and the like, and the connection state between them and the wiring pattern 13 are inspected. It is not necessary to press the inspection pins 6a and 6b against the component surface 12a side.
Since it is necessary to press only on the side of b, the inspection process is simpler and more efficient than the conventional method. Further, unlike the conventional method, the inspection pin 6a is attached to the pin 21b of the surface mount component 21 or the like.
Since it is not necessary to press with the 6b, the surface mount component 21 having a fine pitch and the like can be easily inspected, and the connection between the pin 21b and the wiring pattern 13 can be prevented due to the pressure of the inspection pins 6a and 6b. There is no fear of overlooking.

[0025]

According to the circuit board inspection method of the present invention, a test pad is provided in advance on the circuit board, and the probe of the inspection device is brought into contact with the second main surface side of the circuit board using this test pad. , The inspection of the mounting circuit board on which the surface mounting type circuit component is mounted is executed. For this reason, it is not necessary to bring the probe into contact with both the first and second principal surface sides, so that there is an effect that the inspection can be executed in a simple process. Also,
Since it is not necessary to bring the probe into contact with the surface mount type circuit component, there is an effect that an accurate test can be executed even in the inspection of the mounted circuit board on which the surface mount component having a fine pitch is mounted. Further, since the probe does not apply pressure to the surface mount component, there is an effect that an accurate inspection can be performed without failing to detect a defective connection portion between the surface mount component and the wiring pattern.

In the circuit board according to the present invention, the test pad is provided in the portion of the wiring pattern which is connected only to the surface mount type component and is arranged only on the first main surface. Therefore, there is an effect that an inspection of a mounted circuit board formed by mounting a circuit component including a surface mount component on this circuit substrate can be performed with high accuracy in a simple process.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an inspection method according to an embodiment of the present invention.

FIG. 2 is a structural diagram showing a structure of a mounting circuit board according to an embodiment of the present invention.

FIG. 3 is a structural diagram showing a structure of a test pad according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram showing an inspection method according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram illustrating a conventional inspection method.

FIG. 6 is an explanatory diagram illustrating a conventional inspection method.

[Explanation of symbols]

 6 in-circuit tester 6a, 6b inspection pin (probe) 11 circuit board 12 circuit board body 12a component surface (first main surface) 12b solder surface (second main surface) 13 wiring pattern 15 test pad 20 mounting circuit board 21, 22 Surface-Mounted Components (Surface-Mounted Circuit Components) 23 Discrete Components 21a, 22a, 23a Main Body

Claims (2)

[Claims] 1. A circuit board inspection method for inspecting a mounted circuit board in which a plurality of circuit components including a plurality of surface mount type circuit components are mounted on a circuit board, comprising: (a) first and second main components. A step of preparing a circuit board body of an electric insulator having a surface, and (b) a step of providing a pair of probes and contacting an inspection object.
A step of preparing an inspection device for inspecting the quality of the inspection object by detecting an electrical characteristic between the pair of probes; and (c) electrically connecting the plurality of circuit components. Arranging a wiring pattern on at least the first main surface, and (d) arranging a substantially electrically conductive test pad only on the first main surface in the wiring pattern. The part is electrically connected to a part that connects only the plurality of surface mount type circuit components, and is installed on the circuit board body so that a part of the part is exposed to the second main surface. And (e) the plurality of circuit components are arranged in a predetermined manner on the circuit board body so that each one of the plurality of circuit components is located on the first main surface side of the circuit board body. A step of creating a mounting circuit board by mounting at a position, and (f) before One of the pair of probes is brought into contact with a portion of the mounting circuit board exposed to the second main surface of the test pad, and the other one is connected to the other portion of the test pad of the mounting circuit board. The surface mounting type circuit component or the surface mounting on the mounting circuit board is brought into contact with the portion exposed on the main surface of No. 2 or the portion exposing on the second main surface of the circuit component on the mounting circuit board. A method of inspecting a circuit board, comprising the step of inspecting the quality of a portion to be electrically connected to the mold circuit component. 2. A circuit board on which a plurality of circuit components including a plurality of surface mount type circuit components are to be mounted, wherein: (a) a side on which a main body of each one of the plurality of circuit components is to be located; A circuit board body of an electrical insulator having one main surface and a second main surface, and (b) a wiring pattern for electrically connecting the plurality of circuit components in a predetermined manner, At least the first
And (c) a portion of the wiring pattern, which is provided only on the first main surface, between the plurality of surface mount type circuit components. A test pad which is electrically connected to a connecting portion and which is installed on the circuit board body, and which is a substantially electrically conductive test pad, a part of which is exposed on the second main surface; Circuit board equipped.