JPH08262094A - Electrode for electric test - Google Patents

Abstract

PURPOSE: To specify the generating site of a migration in a short time by forming a protrusion protruding to an adjacent conductor, and providing a predetermined air gap between the opposite protrusions. CONSTITUTION: An electrode 1 is a comb type electrode, and the comb type electrode 10 made of a cathode side electrode 4 and an anode side electrode 6 is provided on a glass fiber-reinforced epoxy resin board 2 having a thickness of 0.1 to 2mm. The electrodes 4 form cathode side conductors 41 each having predetermined width and length, a coupling conductor 4J and leads 4K, and the electrodes 6 form anode side conductors 6A to 6G, a coupling conductor 6H and leads 6I. Protrusions 20 protruding to the adjacent opposed conductor is formed on the superposed allowance (W) of each conductor. The protrusion 20 is provided at the opposed position. The protrusion 20 has a triangular shape, in which a bottom side H1 is 0.1 to 5mm, the height H2 is 2 to 20mm, and the distance G between the protrusions 20 is 0.1 to 1.5mm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrical test electrode used when performing an electrical test such as an insulation test or a migration test of a printed circuit board, and further to a solder flux. It can also be used effectively for insulation tests such as.

[0002]

2. Description of the Related Art In recent years, along with the miniaturization of electric and electronic parts, multilayering and high density of printed circuit boards have been advanced.

Such a printed circuit board is made of, for example, a copper clad laminated board. However, as shown in FIG. 9, due to water, dust, dirt, etc. attached to the printed circuit board in the manufacturing process of the printed circuit board. It is known that migration 100 occurs between the cathode side conductor (−) and the anode side conductor (+), and the quality of the printed circuit board is significantly deteriorated.

Therefore, conventionally, various methods have been devised for cleaning and handling the printed circuit board in the manufacturing process to prevent the printed circuit board from being contaminated, prevent migration, and improve quality.

Currently, a migration test is carried out as a means for controlling the manufacturing process of printed circuit boards.
FIG. 10 shows a comb-type electrode for migration test used at that time.

Conventionally used migration test comb-shaped electrodes include a comb-shaped electrode of type 1 shown in FIG. 10 (A) and a comb-shaped electrode of type 2 shown in FIG. 10 (B). In the comb-shaped electrode, the cathode-side conductor (−) and the anode-side conductor (+) are alternately arranged on the laminated substrate with a predetermined conductor interval (L) and a predetermined length of overlap (W). It was done. Table 1 shows the dimensional relationship of these comb electrodes for migration test.

[0007]

[Table 1]

This comb-shaped electrode is dipped in a cleaning solution for a printed circuit board used in the manufacturing process of the printed circuit board and dried, and then a predetermined voltage is applied between the cathode side conductor (-) and the anode side conductor (+). In addition, the insulation between the cathode side conductor (−) and the anode side conductor (+) of this comb-shaped electrode was measured by an ammeter or the like. The insulation characteristics changed depending on the degree of contamination of the cleaning liquid, and the degree of contamination of the cleaning liquid was judged from this.

[0009]

However, even if migration occurs, it may not be measured by an ammeter or the like, and in order to confirm the occurrence of migration, it is necessary to directly inspect the comb electrode. Was needed.

According to the experiments conducted by the present inventors, in the conventional comb-shaped electrode, the occurrence of migration is overlooked even when the occurrence of migration is monitored, and the site where migration occurs is visually identified in a short time. It turned out to be extremely difficult.

Therefore, an object of the present invention is to easily identify a migration generation site in a short time, to perform an electrical test such as an insulation test or a migration test of a printed circuit board, or a solder flux. An object of the present invention is to provide an electrical test electrode that can be effectively used for an insulation test and the like.

[0012]

The above objects are achieved by the electrical test electrode according to the present invention. In summary, the present invention provides an electrical test electrode in which a cathode-side conductor and an anode-side conductor are arranged on a substrate with a predetermined conductor-to-conductor distance, and the conductor has a protrusion protruding toward an adjacent conductor. Is formed, and a predetermined gap is provided between the opposing projections. According to the present invention, the cathode-side conductor and the anode-side conductor are alternately arranged with a predetermined inter-conductor distance and a predetermined length of overlap margin, and the protrusion is formed in this overlap margin portion. Or the cathode-side conductor and the anode-side conductor are arranged in parallel with a predetermined inter-conductor distance, and the cathode-side conductor and the anode-side conductor are opposed to each other and abutted against each other. The butt-shaped electrodes are arranged in a state, and projections are formed on the ends of the conductors facing each other.

Preferably, the protrusions have a triangular shape, a circular arc shape, or a square shape, and a gap distance between the adjacent protrusions is 0.1 μm to 1.5 mm.

According to another aspect of the invention, the electrical test electrode comprises a plurality of sets of comb-shaped or butt-shaped electrodes, the conductor of each electrode being adjacent to the conductor as described above. Protrusions are formed so as to project to the conductor, and a predetermined gap is provided between the opposing protrusions. At this time, the plurality of sets of electrodes may have different gap distances between the adjacent protrusions.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The electrical test electrode according to the present invention will be described in more detail below with reference to the drawings.

FIG. 1 shows an embodiment of the electrical test electrode of the present invention. According to this embodiment, the electrical test electrode 1
Is a comb-shaped electrode similar to the conventional one, and has a thickness of 0.1
A comb-shaped electrode 10 composed of a cathode side electrode 4 and an anode side electrode 6 is provided on a substrate 2 such as a glass fiber reinforced epoxy resin laminated substrate of about 2 mm.

Explaining further, the cathode side electrode 4 includes cathode side conductors 4A to 4I having a predetermined width and length.
A connecting conductor 4J connecting these cathode-side conductors, and a lead 4K connecting this connecting conductor 4J and the cathode terminal 5
It is formed by and. In addition, the anode-side electrode 6 has anode-side conductors 6A to 6G having a predetermined width and length, a connecting conductor 6H that connects these anode-side conductors, and a lead that connects the connecting conductor 6H and the anode terminal 7. It is formed with 6I. The cathode-side electrode 4 and the anode-side electrode 6 are positioned in a state in which the cathode-side conductor and the anode-side conductor are alternately combined with a predetermined conductor spacing L and a predetermined overlapping length W. Arranged to do so.

In this embodiment, the comb-shaped electrode 10 has a structure in which the three cathode side conductors 4A, 4B and 4C of the cathode side electrode 4 are combined with the two anode side conductors 6A and 6B of the anode side electrode 6. 1. Comb-shaped electrode 11 and second comb-shaped electrode 12 in which six cathode-side conductors 4D to 4I of the cathode-side electrode 4 are combined with five anode-side conductors 6C to 6G of the anode-side electrode 6. And the first comb electrode 1
In the connection region between the first and second comb-shaped electrodes 12, the cathode side conductors 4C and 4D are adjacent to each other. However, the comb electrode 10 of the present invention is not limited to such a configuration.

Further, in the present embodiment, the cathode side conductors 4A ...
4I and the anode side conductors 6A to 6G have a width w of 0.01 to
2 mm, conductor spacing L is 0.01 to 2 mm, stacking margin W is 1
It is set to 0 to 30 mm. As an example, the width w of the cathode-side conductors 4A to 4I and the anode-side conductors 6A to 6G is 0.5 mm, the conductor interval L is 0.5 mm, and the overlapping margin W is 20.
Good results could be obtained by setting to mm.

According to the present invention, the protrusions 20 are formed on the conductors at the overlapping portions (W) overlapping each other so as to project to the adjacent conductors facing each other. Adjacent conductor protrusion 2
0s are provided at opposite positions. In this embodiment, the protrusions 20 are arranged in alignment along the center line of the comb-shaped electrode 10 (that is, the center position of the overlapping conductors).

In the embodiment shown in FIG. 1, the protrusion 20 has a triangular shape, and its size is not limited, but
The base H ₁ will be 0.1-5 mm and the height H ₂ will be 2-20 mm. Also, the distance G between the adjacent protrusions 20
Is usually 0.1 μm to 1.5 mm. When the distance G is out of this range, that is, when it is smaller than 0.1 μm, the problem in manufacturing the substrate is large, while when the distance G is 1.5 m.
If it is larger than m, migration is unlikely to occur, so there is no point in setting the distance G larger than 1.5 mm.

The shape of the protrusion 20 can be various shapes other than the triangular shape. For example, as shown in FIG. 2A, the protrusion 20 is an arcuate protrusion having a radius R of 0.1 to 1 mm. Alternatively, as shown in FIG. 2B, the width H ₁ is 0.01
~ ₂ mm, height H ₂ is 1-20 mm square protrusions,
The tip may be arcuate as shown, or triangular. Also in these cases, the distance G between the adjacent protrusions is 0.1 μm to 1.5 μm as described above.
mm.

The electrical test comb-shaped electrode 1 of the present invention as described above uses a copper-clad laminated substrate or a plating-deposited substrate used for producing a printed circuit board, etc. Can be easily manufactured.

According to the results of the research and experiment conducted by the present inventors, when the electric test comb electrode 1 of the present invention having the above-described configuration is used, migration occurs between the protrusions 20,
Further, it has been found that the generated migration can be clearly identified by visual observation as compared with the case where the conventional comb-shaped electrode is used, where the generated migration can be specified.

Further, the comb electrode 1 for electrical test of the present invention
As described above, since the migration occurs between the protrusions 20, it is possible to automate the monitoring of the migration by moving the camera or the like back and forth or left and right and observing between the protrusions 20. It is convenient.

Further, according to the present invention, as shown in FIG.
The comb-shaped electrode 1 for electrical test includes three sets of comb-shaped electrodes 10.
It can also be composed of A, 10B, and 10C. Each of the comb electrodes 10A, 10B, 10C has the same configuration as the comb electrode 10 shown in FIG. That is, in this embodiment, 3
The comb-shaped electrodes 10A, 10B, and 10C of the set have the same conductor width, conductor interval, and overlapping margin, but are configured so that the distance between the protrusions formed on each conductor is different. In the embodiment of FIG. 3, the distance between the protrusions of the upper comb-shaped electrode 10A is 0.1 mm, the distance between the protrusions of the intermediate comb-shaped electrode 10B is 0.2 mm, and the lower comb-shaped electrode 10C. The distance between the protrusions is 0.3 mm. In this embodiment, three sets of comb-shaped electrodes 10A, 10B and 10C are provided.
A set may be used, and further, a configuration having four or more sets may be adopted.

When the comb-shaped electrode 1 for electrical testing provided with a plurality of sets of comb-shaped electrodes 10 having different distances between the projections is used, the reliability of migration of the material to be evaluated, for example, cleaning liquid, flux, etc. You can know the level of sex.

For example, it is assumed that the test results when four evaluation materials A, B, C and D are tested with the comb electrodes shown in FIG. 3 are as shown in Table 2, for example. In the evaluation of the materials A, B, C, and D in this case, it can be determined that the material A has the highest reliability and the material D has the lowest reliability, as in A>B>C> D.

[0029]

[Table 2]

Further, in the conventional comb-shaped electrode shown in FIG.
There are no comb-shaped electrodes with different conductor-to-conductor distances formed on the same substrate. Therefore, when conducting tests with different conductor-to-conductor distances, it is essential to use multiple comb-shaped electrodes. Was done. If a plurality of electrodes are used in this way, a test error due to variations among the test comb electrodes cannot be avoided, and there is a problem in terms of reliability.

On the other hand, when the electric test comb electrode 1 of the present invention having a plurality of sets of comb electrodes 10 as shown in FIG. 3 is used, the test is conducted on the same substrate. It is possible to eliminate variations between solids, and it is possible to correctly evaluate the difference in the distance between the protrusions (for example, 0.1 mm, 0.2 mm, 0.3 mm).

Furthermore, according to the present invention, as shown in FIG. 4, a plurality of comb-shaped electrodes for electrical test, each of which has a plurality of pairs as shown in FIG. It is also possible to have a configuration in which they are arranged. By using the comb-shaped electrode having such a structure, it becomes possible to test different materials A, B and C on the same comb-shaped electrode, that is, on the same substrate,
This eliminates the variation between the solids, and the materials A, B,
There is a benefit that C can be evaluated under the same conditions.

In each of the above embodiments, the electrical test electrode of the present invention is described as a comb-type electrode, but it is also possible to have a butt-type electrode structure as shown in FIG.

Referring to FIG. 5, according to this embodiment, the electrical test electrode 1 is similar to the above-mentioned comb-shaped electrode, for example, a glass fiber reinforced epoxy resin laminated substrate having a thickness of about 0.3 to 2 mm. An electrode 10 composed of a cathode side electrode 4 and an anode side electrode 6 is provided on such a substrate 2.

Explaining further, the cathode side electrode 4 is constructed by arranging a plurality of, in this embodiment, six cathode side conductors 4A to 4F having a predetermined width and length, in parallel.
One end of each of these cathode side conductors is connected by a connecting conductor 4J. The connecting conductor 4J is connected to the cathode terminal 5 by the lead 4K. The anode-side electrode 6 is formed by arranging a plurality of, in the present embodiment, six anode-side conductors 6A to 6F having a predetermined width and length, and these anode-side conductors have one end thereof. Are connected by a connecting conductor 6H. The connecting conductor 6H is connected to the anode terminal 7 by the lead 6I.

According to this embodiment, the cathode side conductors 4A ...
4F and the anode-side conductors 6A to 6F are arranged in a butted state so as to face each other, and a protrusion 20 is formed at an end portion of the conductor that faces each other. That is, the electrode of this example is a butt-type electrode.

Also in the butt electrode of the present embodiment, the width w of the cathode side conductors 4A to 4F and the anode side conductors 6A to 6F is w.
Is 0.01 to 2 mm, and the conductor interval L is 0.01 to 2 mm. As an example, good results could be obtained by setting the width w of the cathode-side conductor and the anode-side conductor to 0.5 mm and the conductor interval L to 0.5 mm.

According to the present embodiment, the protrusions 20 are formed at the facing tips of the conductors so as to project toward the facing conductors. In the embodiment shown in FIG. 5, the protrusion 20 has a triangular shape, and the dimensions thereof are not limited, but the bottom side H ₁ is the conductor width w and the height H ₂ is ₂ to 20 mm. . The distance G between the adjacent protrusions 20 is usually 0.1 μm to 1.5 mm, as in the previous embodiment.

The shape of the protrusion 20 can be various shapes other than the triangular shape. For example, as shown in FIG. 6 (A), the protrusion 20 is an arcuate protrusion having a radius R of 0.1 to 1 mm. Alternatively, as shown in FIG. 6 (B), it may have a rectangular shape. In these cases, the distance G between adjacent protrusions is usually 0.1 μm to 1.5 mm. At this time, if the butt electrode 1 of the present invention is manufactured by etching, the tips or corners of the triangular or quadrangular projections are over-etched to be rounded as shown in FIG. However, it will be apparent to those skilled in the art that even with such a shape, the same operational effects as described above can be exhibited.

Further, the electrical test butt-type electrode 1 of the present embodiment also has three sets of butt-type electrodes 10A, 10B, as shown in FIG. 8, similarly to the comb-type electrode shown in FIG. 10
It can also be constructed from C. Each butt type electrode 10
A, 10B and 10C are the butt type electrodes 1 shown in FIG.
It has the same structure as 0, but only three sets of butt-type electrodes 10
A, 10B, and 10C have different distances between the protrusions formed on the conductors, for example, 0.1, 0.2, and 0.3 mm.
It is said. In this embodiment, three sets of butt type electrodes 10 are used.
Although A, 10B, and 10C are included, two pairs may be provided, and further four or more pairs may be included.

Further, in this embodiment, although not shown, a plurality of sets of electrical comb electrodes for electrical testing as shown in FIG. 8 are provided as in the comb electrodes shown in FIG. It is also possible to adopt a configuration in which a plurality of sets, for example, three sets, are arranged in parallel, and the same operational effect as that of the previous embodiment can be obtained.

As described above, in any of the examples, the electrical test electrode 1 of the present invention is immersed in a cleaning solution for the printed circuit board and dried in the printed circuit board manufacturing process, and then the terminals 5, 7 are formed. By applying a predetermined voltage to the cathode, the presence or absence of migration between the protrusions 20 between the cathode-side conductor (-) and the anode-side conductor (+) is visually inspected.
Alternatively, it can be observed through an automatic monitoring device equipped with a camera. Of course, it is also possible to measure the insulation between the cathode-side conductor (−) and the anode-side conductor (+) with an ammeter or the like.

As described above, the electric test electrode 1 of the present invention can not only inspect the degree of contamination of the cleaning liquid and thus inspect the migration, but it can also be immersed in a molten solder flux to clean the cleaning liquid. It is also possible to inspect the insulation resistance of the solder flux in the same manner as in the case of 1.

[0044]

As described above, in the electrical test electrode of the present invention, the cathode-side conductor and the anode-side conductor, which are arranged on the substrate, have the projections protruding toward the adjacent conductors and are opposed to each other. Since there is a predetermined gap between the protrusions, the migration occurs between the protrusions, and therefore the site where the migration occurs can be easily identified in a short time, and the insulation test of the printed circuit board or Can be effectively used for an electrical test such as a migration test or an insulation test such as a solder flux, and is useful for manufacturing a high quality printed circuit board.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of an electrical test electrode of the present invention.

FIG. 2 is a plan view showing an embodiment of protrusions of the electrical test electrode of the present invention.

FIG. 3 is a plan view showing another embodiment of the electrical test electrode of the present invention.

FIG. 4 is a plan view showing another embodiment of the electrical test electrode of the present invention.

FIG. 5 is a plan view showing still another embodiment of the electrical test electrode of the present invention.

FIG. 6 is a plan view showing an embodiment of protrusions of the electrical test electrode of the present invention.

FIG. 7 is a plan view showing another embodiment of the protrusion of the electrical test electrode of the present invention.

FIG. 8 is a plan view showing still another embodiment of the electrical test electrode of the present invention.

FIG. 9 is a diagram illustrating migration.

FIG. 10 is a plan view showing a conventional comb-shaped electrode for electrical test.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrode for electrical test 2 Substrate 4 Cathode side electrode 4A-4I Cathode side conductor 6 Anode side electrode 6A-6G Anode side conductor 10 Comb type (butting type) electrode 20 Protrusion

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masayuki Hasegawa 2-1224 Moto-Hachioji-cho, Hachioji-shi, Tokyo Inside Terisa Research Co., Ltd. In BTS

Claims (11)

[Claims] 1. An electrical test electrode in which a cathode-side conductor and an anode-side conductor are arranged with a predetermined conductor-to-conductor distance on a substrate, wherein the conductor is formed with a protrusion protruding to an adjacent conductor. An electrode for electrical testing, characterized in that a predetermined gap is provided between the opposing projections. 2. The cathode-side conductor and the anode-side conductor are alternately arranged with a predetermined inter-conductor distance and a predetermined length of overlap margin, and the protrusion is formed in the overlap margin portion. The electrical test electrode according to claim 1, wherein the electrical test electrode is a comb-shaped electrode. 3. The electrode for electrical test according to claim 2, wherein a plurality of sets of the comb-shaped electrodes are provided. 4. The electrical test electrode according to claim 3, wherein the plurality of sets of comb-shaped electrodes have different gap distances between protrusions. 5. The electrical test electrode according to claim 2, wherein the protrusion has a triangular shape, a circular arc shape, or a square shape. 6. The gap distance between adjacent protrusions is
The electrical test electrode according to claim 2, 3, 4 or 5, having a thickness of 0.1 μm to 1.5 mm. 7. The cathode-side conductor and the anode-side conductor are arranged in parallel with a predetermined inter-conductor distance, and the cathode-side conductor and the anode-side conductor are arranged to face each other in a butted state. The electrical test electrode according to claim 1, which is a butt-type electrode in which protrusions are formed on the ends of the conductors facing each other. 8. The electrical test electrode according to claim 7, wherein a plurality of sets of the butted electrodes are provided. 9. The electrical test electrode according to claim 8, wherein a plurality of sets of comb-shaped electrodes have different gap distances between the protrusions. 10. The electrode for electrical test according to claim 7, 8 or 9, wherein the projections of the cathode-side conductor and the anode-side conductor have a triangular shape, an arc shape, or a square shape. 11. The gap distance between adjacent protrusions is
The electrical test electrode according to claim 7, 8, 9 or 10, which has a thickness of 0.1 µm to 1.5 mm.