JP2001251062A - Multilayer printed wiring board and inspection method of multilayer printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately and quickly inspect deviation of a wiring pattern. SOLUTION: This inspection method is provided with a step wherein probes 31, 32 are brought into contact with land parts 23a, 23b of both end portions of a first outer layer inspecting pattern 23, respectively, to inspect whether an electric continuity between the land parts 23a, 23b of the first outer layer inspecting pattern 23 exists, and probes 33, 34 are brought into contact with land parts 24a, 24b of both end portions of a second outer layer inspecting pattern 24, respectively, to inspect whether an electric continuity between the land parts 24a, 24b of the second outer layer inspecting pattern 23 exists, and a step wherein the probes 33, 34 are brought into contact with the land part 23b of the first outer layer inspecting pattern 23 and the land part 24b of the second outer layer inspecting pattern 24, respectively, to inspect whether an electric continuity between the first outer layer inspecting pattern 23 and the second outer layer inspecting pattern 24 exists.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer printed wiring board provided with an inspection pattern for detecting a shift of each layer, and a method for inspecting the multilayer printed wiring board.

[0002]

2. Description of the Related Art Heretofore, a multilayer printed wiring board has been inspected for laminating misalignment and through-hole misalignment by visually confirming an image projected on a monitor using an X-ray inspection apparatus.

[0003]

However, the inspection for the stacking deviation and the positional deviation of the through-hole using the X-ray inspection apparatus has been described.
It is time-consuming because it is a visual inspection, and it is difficult to inspect all the parts because it takes time. In addition, since this inspection was a visual inspection, it could not be performed accurately.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a multilayer printed wiring board having an inspection pattern capable of accurately and quickly shifting a wiring pattern, and an inspection method for the multilayer printed wiring board.

[0005]

In order to solve the above-mentioned problems, a multilayer printed wiring board according to the present invention is electrically connected to both surfaces constituting an outer layer through a first through hole,
A first outer layer inspection pattern provided with lands where probes are contacted at both ends, and second through holes are electrically disconnected from the first outer layer inspection pattern and are formed on both surfaces constituting the outer layer. A second outer layer inspection pattern electrically connected to the probe through the second outer layer inspection pattern and provided at both ends with lands that contact the probe, and a second outer layer inspection pattern provided on the inner layer and through the second through hole An inner layer inspection pattern is provided electrically connected to the pattern and is electrically disconnected from the first outer layer inspection pattern via a clearance around the first through hole.

In the inspection method for inspecting a multilayer printed wiring board as described above, a probe is brought into contact with the lands at both ends of the first outer layer inspection pattern, and the distance between the lands of the first outer layer inspection pattern is reduced. Inspecting whether there is continuity and contacting the probes with the lands at both ends of the second outer layer inspection pattern to inspect whether there is continuity between the lands of the second outer layer inspection pattern; A probe is brought into contact with at least one land portion of the first outer layer inspection pattern and at least one land portion of the second outer layer inspection pattern, so that the first outer layer inspection pattern and the second inspection pattern become conductive. Checking whether or not there is Note that these steps may be performed in separate steps, or may be performed simultaneously to improve inspection efficiency.

According to the present invention, when the first outer layer inspection pattern is electrically connected to the second outer layer inspection pattern, it can be seen that each probe is surely in contact with each land. Then, the probe is brought into contact with at least one of the lands of the first outer layer inspection pattern and at least one of the lands of the second outer layer inspection pattern, and when these are conducted, the first outer layer inspection pattern and the second outer layer inspection pattern are connected. It can be seen that there is a short circuit with the outer layer inspection pattern, and when these are not conducting, it can be seen that the inner layer is not short circuited without shifting.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A multilayer printed wiring board to which the present invention is applied and a method for inspecting the multilayer printed wiring board will be described below with reference to the drawings. The multilayer printed wiring board 1 to which the present invention is applied is a multilayer printed wiring board provided with four conductive layers.

As shown in FIG. 1, the multilayer printed wiring board 1 has an inner substrate 2 and circuit patterns 3 and 4 constituting an inner layer are formed on both surfaces of the inner substrate 2. The circuit patterns 3 and 4 are formed by exposing and developing a conductive layer made of copper foil provided on both surfaces of the inner layer substrate 2 and then performing etching. On the circuit patterns 3 and 4, prepregs 5 and 6 constituting an insulating layer formed by impregnating glass fiber with an epoxy resin or the like.
Are formed on the prepregs 5, 6, and circuit patterns 7, 8 constituting an outer layer are formed. Inner layer substrate 2 provided with circuit patterns 3 and 4 and prepregs 5 and 6
And the copper foil forming the circuit patterns 7 and 8 as outer layers
The substrate 11 is formed by press working so as to form one substrate and integrated. Then, the integrated substrate 1
1, a through hole 9 is formed, and copper plating 10 is applied to the entire surface including the inner surface of the through hole 9, so that the circuit patterns 7 and 8 serving as outer layers are electrically connected. Thereafter, the circuit patterns 7 and 8 as outer layers are formed by exposing and developing a conductive layer made of a copper foil provided on the prepregs 5 and 6 and then performing etching. Although not shown, a solder resist layer is formed on the circuit patterns 7 and 8 serving as outer layers in a region other than a land portion where soldering is performed for mounting electronic components. Such multilayer printed wiring board 1
Is formed such that the circuit pattern 7 of the conductive layer becomes the first layer, the circuit pattern 3 becomes the second layer, the circuit pattern 4 becomes the third layer, and the circuit pattern 8 becomes the fourth layer.

The multilayer printed wiring board 1 as described above is formed by laminating the inner layer board 2, the prepregs 5, 6 and the copper foils constituting the circuit patterns 7, 8, so that the circuit of each layer is formed. The patterns 3, 4, 7, and 8 may be shifted from each other. Therefore, as shown in FIG. 2, the multilayer printed wiring board 1 is provided with inspection patterns 21 and 22 for inspecting deviations of the circuit patterns 3, 4, 7, and 8 of each layer. These inspection patterns 2
The reference numerals 1 and 22 are provided at the farthest position of the multilayer printed wiring board 1 so that the displacement of the inner layer can be accurately inspected with a minimum number. For example, when the board is substantially rectangular, , At the two most distant points on the diagonal. Since the inspection patterns 21 and 22 have the same configuration, the inspection pattern 21 will be described below as an example.

[0011] As shown in FIG.
Is the same as the first outer layer inspection pattern 23 formed when the first layer circuit pattern 7 serving as the outer layer is formed.
A second outer layer inspection pattern 24 formed when forming the first layer circuit pattern 7; and a first inner layer inspection pattern 25 formed when forming the second layer circuit pattern 3 to be an inner layer. , A second inner-layer inspection pattern 26 formed when forming the third-layer circuit pattern 4 serving as an inner layer
Similarly, the third outer layer inspection pattern 27 formed when forming the fourth layer circuit pattern 8 serving as the outer layer,
And a fourth outer layer inspection pattern 28 formed when the fourth layer circuit pattern 8 is formed. In addition, first and second through holes 29 and 30 are formed in the substrate 11 at the same time when the through hole 9 is formed.
The copper plating 10 is applied to the peripheral surfaces of the through holes 29 and 30 at the same time as the copper plating 10 is applied to the peripheral surface of the through holes 9. As a result, the first through hole 29 electrically connects the first outer layer inspection pattern 23 and the third outer layer inspection pattern 27, and the second through hole 30 connects the second outer layer inspection pattern 24.
And the fourth outer layer inspection pattern 28 are electrically connected.

As shown in FIGS. 3, 4A and 4D, the first and third outer layer inspection patterns 23 and 27 of the first layer and the fourth layer, respectively, Measuring land portions 23a and 27a provided at positions away from the holes 29;
And connection lands 23b and 27b for establishing electrical connection with other layers, measurement lands 23a and 27a, and connection lands 23b and 27b.
And connecting portions 23c and 27c for connecting.
The measurement land 23a of the first outer layer inspection pattern 23 of the first layer is connected to the first probe 3 of the inspection device 35.
1 is contacted, and the connection land portion 23b is
Of the second probe 32 is contacted.

The second and fourth outer layer inspection patterns 24 and 28 of the first and fourth layers have substantially the same configuration as the first and third outer layer inspection patterns 23 and 27. 30
Measuring land portions 24a, 2 provided at positions away from
8a and connection lands 24b and 28b provided around the second through-hole 30 for electrical connection with other layers.
And the measurement land portions 24a and 28a and the connection land portion 2
4b and 28b. The measurement land portion 24b of the second outer layer inspection pattern 24 of the first layer is
Probe 33 is contacted, and the connection land portion 24b is
The fourth probe 34 of the inspection device 35 is brought into contact. The first and third outer layer inspection patterns 23 and 27 and the second
And the third outer layer inspection patterns 24 and 28 include connection lands 23b and 27b and connection lands 24b and 28b.
Are formed apart from each other, and are electrically disconnected by forming different patterns.

As shown in FIGS. 3, 4B and 4C, the first and second inner layer inspection patterns 25 and 26 of the second and third layers are formed through the first through holes. First pattern portions 25a and 26a provided around hole 29 and second pattern portions 25b and 2 provided around second through hole 30 are provided.
6b, connecting portions 25c and 26 connecting the first pattern portions 25a and 26a and the second pattern portions 25b and 26b.
c.

The first pattern portions 25a and 26a are
Are formed around the through hole 29 through the copper plating 10 formed on the peripheral wall of the first through hole 29 and clearances 25d and 26d. The clearances 25d and 26d are
The circuit patterns 3 and 4 provided closest to each other in the second layer and the third layer are formed to be narrower than the pattern interval at the position where the circuit patterns 3 and 4 are provided. That is, the clearance 25d,
26d is the first pattern portion 2 due to factors such as aging.
The dimensions are such that they do not come into contact with the copper plating 10 in the first through-hole 29 even when 5a and 26a are displaced. In addition, the second pattern portions 25b and 26b are formed around the second through-hole 30 in contact with the copper plating 10 formed on the peripheral wall of the second through-hole 30 so as to achieve electrical connection. ing.
That is, the first and second inner layer inspection patterns 25 and 26 of the second and third layers are electrically connected to the second outer layer inspection pattern 24 and the fourth outer layer inspection pattern 28 of the outer layer, The first outer layer inspection pattern 23 and the third outer layer inspection pattern 27 are electrically disconnected.

An inspection device 35 for inspecting the displacement of the inner layer pattern of the multilayer printed wiring board 1 as described above.
Are the measurement land portions 23 of the first outer layer inspection pattern 23
a, a second probe 32 that contacts the connection land 23b, and a third probe 33 that contacts the measurement land 24b of the second outer layer inspection pattern 24. And a fourth probe 34 that comes into contact with the connection land 24b. The first probe 31 and the second probe 32 are connected to the measurement land portions 23 provided at both ends of the first outer layer inspection pattern 23.
A continuity test is performed between a and the connection land 23b. In addition, the third probe 33 and the fourth probe 34 conduct a continuity test between the measurement land portion 24b and the connection land portion 24b provided at both ends of the second outer layer test pattern 24. Further, the second probe 32 and the fourth probe 34 are electrically connected to the second connection land 23b of the first outer layer inspection pattern 23 and the connection land 24b of the second outer layer inspection pattern 24. Inspect.

That is, the inspection device 35 uses the second probe 32 and the fourth probe 34 to perform a continuity test between the connection land 23b and the connection land 24b, and thereby the first device is caused by a pattern shift. And the second pattern portions 25b, 26b of the second inner layer inspection patterns 25, 26 are the first
Contact with the copper plating 10 in the through hole 29, and inspect whether the circuit is short-circuited. At the same time, the inspection device 35
Are the measurement land portions 23 of the first outer layer inspection pattern 23
By conducting a continuity test between a and the connection land 23b,
The second probe 32 contacts the connection land 23b,
It is detected whether or not a continuity test between the connection land 23b and the connection land 24b can be performed. In addition, the inspection device 35 performs continuity inspection between the measurement land portion 24a and the connection land portion 24b of the second outer layer inspection pattern 24, so that the fourth probe 34 contacts the connection land portion 24b, It is detected whether or not a continuity test between the connection land 23b and the connection land 24b can be performed.

Here, Table 1 shows that between the land portions 23a and 23b of the first outer layer inspection pattern 23, between the land portions 24a and 24b of the second outer layer inspection pattern 24, and between the connection land portion 23b and the connection land portion 23b. A list of inspection results between the land portions 24b is shown. In Table 1, “0” indicates “with conduction” and “1” indicates “without conduction”.

[0019]

[Table 1]

In case 3, the first outer layer inspection pattern 2
3 and the lands 24a and 24b of the second outer layer inspection pattern 24 are electrically connected, and the connection lands 23b and the connection lands 24b are not electrically connected. Therefore, the case 3 is such that the first to fourth probes 31 to 34 have the predetermined land portions 23a,
23b, 24a, and 24b, the inspection land 23b and the inspection land 24
Since there is no electrical connection between the test patterns 23-2
It can be seen that 8 is within the deviation amount within the standard value.

In case 1, the first outer layer inspection pattern 2
3 and the land portions 24a and 24b of the second outer layer inspection pattern 24 are electrically connected to each other.
Although the inspection can be performed accurately, the inspection patterns 23 to 28 are shifted beyond the standard value and short-circuited because the connection between the connection land 23b and the connection land 24b is in a conductive state. You can see that.

Case 2, Case 5 and Case 6 are the first
Between the land portions 23a and 23b of the outer layer inspection pattern 23 and the land portions 24a and 24b of the second outer layer inspection pattern 24.
Although either or both of them are not conducting, the inspection cannot be performed accurately.
b and the connection land portion 24b are electrically connected.
It can be seen that the inspection patterns 23 to 28 are shifted by more than the standard value. That is, as in the case 2, the case 5, and the case 6, the connection land 23b and the connection land 24b
If there is electrical continuity between the first outer layer inspection patterns 23
The inspection patterns 23 to 28 can be determined to have a deviation of a specified value or more or short-circuited, prioritizing the results between the land portions 23a and 23b of the second outer layer inspection pattern 24 and the land portions 24a and 24b of the second outer layer inspection pattern 24. .

In the case 4, the case 7 and the case 8, since the connection between the connection land 23b and the connection land 24b is not conducted, the first to fourth probes 31 to 34 are connected to the predetermined land 23a, It is necessary to confirm contact with 23b, 24a and 24b. In case 4, case 7, and case 8, the land portion 23 of the first outer layer inspection pattern 23
a or 23b and either or both of the lands 24a and 24b of the second outer layer inspection pattern 24 are not conducting,
Inspection cannot be performed accurately. For this reason, in these cases, they are subject to re-measurement.

The first outer layer inspection pattern 23
Although the continuity test between the land portions 23a and 23b and between the land portions 24a and 24b of the second outer layer test pattern 24 and the continuity test between the connection land portions 23b and the connection land portions 24b are performed at the same time. The present invention relates to the first
Between the land portions 23a and 23b of the outer layer inspection pattern 23 and the land portions 24a and 24 of the second outer layer inspection pattern 24.
After the continuity test between b and b, the continuity test between the connection land 23b and the connection land 24b may be performed. This inspection may be performed using the third and fourth outer layer inspection patterns 27 and 28 of the fourth layer.

In the multilayer printed wiring board 1 as described above, the first and second outer layer inspection patterns 23 and 24 are provided on the same layer as the first layer circuit pattern 7 as the outer layer, and the second layer as the inner layer. A first inner layer inspection pattern 25 is provided on the same layer as the circuit pattern 3 of the first embodiment, a second inner layer inspection pattern 26 is provided on the same layer as the third layer circuit pattern 4 as the inner layer, and a fourth layer circuit as the outer layer is provided. By providing the third and fourth outer layer inspection patterns 27 and 28 on the same layer as the pattern 8, the deviation of each of the inspection patterns 23 to 28 is regarded as the deviation of the corresponding circuit pattern 3, 4, 7 and 8 of each layer. Can be considered and inspected.

The multilayer printed wiring board 1
As shown in FIGS. 3 and 4, the second probe 32 is brought into contact with the connection land 23b of the first outer layer inspection pattern 23, and the second probe 32 is brought into contact with the connection land 24b of the second outer layer inspection pattern 24. By contacting the fourth probe 34 and detecting the conduction state, it is possible to detect the displacement of the inner layer inspection patterns 25 and 26 of the second and third layers. Also, the first
The second outer layer inspection patterns 23 and 24 are provided with measurement lands 23a and 24a, respectively.
By confirming the continuity with b and 23b, it is possible to inspect whether the first to fourth probes 31 to 34 are in contact with the predetermined lands and can perform an accurate inspection. In addition, the first and second inner layer inspection patterns 25, 2
6 of the first pattern portions 25a and 26a and the first through hole 2
9 are formed so as to be narrower than the clearances between the circuit patterns 3 and 4 at positions closest to the second layer and the third layer. The multilayer printed wiring board 1 which clears the above conditions can prevent each layer from shifting due to aging and short-circuiting after the fact.

Although the multilayer printed wiring board 1 provided with four wiring layers to which the present invention is applied has been described with reference to the drawings, the present invention relates to a printed wiring board having more wiring layers. It can also be applied to substrates. For example, in the case of a printed wiring board having six layers,
An insulating layer such as a prepreg may be further provided on the outer layer of the multilayer printed wiring board 1 and the further wiring layer may be formed thereon. In this case, the inspection patterns 21 and 22 are used for inspection of a deviation of a circuit pattern of the multilayer printed wiring board 1 serving as an inner layer substrate, and are hidden when completed.

Further, the above-mentioned multilayer printed wiring board 1
In the example described above, the case where two inner layers are provided has been described,
The inner layer may be one layer or three or more layers.

[0029]

According to the present invention, when the lands of the first outer layer inspection pattern and the lands of the second outer layer inspection pattern are electrically connected, each probe reliably contacts each land. And that an accurate inspection can be performed. Then, a probe is brought into contact with at least one of the lands of the first outer layer inspection pattern and at least one of the lands of the second outer layer inspection pattern to check the conduction state, and thus whether the pattern is short-circuited, It is possible to accurately and quickly inspect whether the pattern is shifted.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a multilayer printed wiring board.

FIG. 2 is a plan view of the multilayer printed wiring board.

FIG. 3 is a sectional view of an inspection pattern of the multilayer printed wiring board.

FIG. 4 is a plan view showing an inspection pattern of each layer.

[Explanation of symbols]

1 multilayer printed wiring board, 2 inner layer board, 3rd
Circuit pattern of the fourth layer, circuit pattern of the third layer, 5, 6
Prepreg, 7 first layer circuit pattern, 8 fourth layer circuit pattern, 21, 22 inspection pattern, 23 first outer layer inspection pattern, 24 second outer layer inspection pattern, 2
5 First inner layer inspection pattern, 26 second inner layer inspection pattern, 27 third outer layer inspection pattern, 28 fourth outer layer inspection pattern, 29 first through hole, 30 second through hole, 31 to 34 1st to 4th probes

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shoji Horie No. 86 Akaimachi, Negami-cho, Nomi-gun, Ishikawa F-term (reference) in Sony Negami Co., Ltd. 2G014 AA02 AA03 AA08 AA13 AB59 AC09 5E346 AA15 BB01 GG32 HH08 HH32

Claims (3)

[Claims] A first outer layer inspection pattern electrically connected to both surfaces constituting an outer layer through a first through hole, and a land portion provided at both ends with a probe contacting each other; 1 is electrically disconnected from the outer layer inspection pattern,
A second outer layer inspection pattern electrically connected to both surfaces constituting the outer layer via a second through hole, and a land portion provided at both ends with a probe to be contacted with each other; The first outer layer inspection pattern is electrically connected to the second outer layer inspection pattern via the second through hole, and is electrically connected to the first outer layer inspection pattern via a clearance around the first through hole. A multilayer printed wiring board comprising an unconnected inner layer inspection pattern. 2. The multilayer printed wiring board according to claim 1, wherein the clearance is smaller than an interval between wiring patterns provided on the same layer as the inner layer inspection pattern. 3. A first outer layer inspection pattern electrically connected to both surfaces constituting an outer layer through a first through hole, and provided with land portions at both end portions to which probes are respectively contacted, Land portions that are electrically disconnected from the first outer layer test pattern, are electrically connected to both surfaces constituting the outer layer through second through holes, and are provided at both end portions with which probes are respectively in contact. A second outer layer inspection pattern, provided in the inner layer, electrically connected to the second outer layer inspection pattern through the second through hole, and provided with a clearance around the first through hole; A method for inspecting a multilayer printed wiring board, comprising a first outer layer inspection pattern and an inner layer inspection pattern electrically disconnected via the first outer layer inspection pattern, wherein the first outer layer inspection pattern has land portions at both ends of the first outer layer inspection pattern. Yes A probe is contacted to check whether the lands of the first outer layer test pattern are electrically connected, and the probes are respectively contacted with lands at both end portions of the second outer layer test pattern. Inspecting whether or not the lands of the second outer layer inspection pattern are electrically connected; and at least one land of the first outer layer inspection pattern and at least one land of the second outer layer inspection pattern. Inspecting whether the first outer layer inspection pattern and the second inspection pattern are electrically connected to each other by contacting a probe to the printed circuit board.