JP4268266B2 - Inspection method for conductor layer forming process of wiring board - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inspection method for inspecting a conductor layer forming process for forming a conductor layer of a wiring board, and in particular, to easily predict an electrical failure occurring in a conductor layer or to easily confirm the effect of process improvement. The present invention relates to an inspection method for a conductor layer forming step of a wiring board that can be formed.
[0002]
[Prior art]
Conventionally, a continuity test of a wiring board is generally performed as follows. That is, the probe pins are brought into contact with connection pads and solder bumps formed on the wiring board, or pins serving as input / output terminals standing on the wiring board. Then, by measuring the wiring resistance or measuring the insulation resistance between the probe pins, an electrical defect such as a disconnection or a short circuit generated in the wiring layer of the wiring board is inspected. That is, after the wiring board is manufactured, electrical inspections such as disconnection of the wiring layers and short circuit between the wiring layers are performed using the formed input / output terminals and the like.
[0003]
[Problems to be solved by the invention]
However, with such an inspection method, inspection cannot be performed until an input / output terminal that can be contacted with a probe pin is formed, and thus generally, until the wiring board is completed or almost completed. In parts other than the input / output terminals, it is difficult to contact the probe pins due to the small dimensions (thin width), etc., and the wiring layer may be damaged by the probe pins, which may cause problems. is there. Further, in the production of a wiring board, the conductor layer produced in the conductor layer forming step usually includes a large number of wiring layers, and the wiring layers are often electrically connected in a complicated manner. It is difficult to inspect. In particular, in a wiring board in which a plurality of wiring layers and insulating layers are sequentially laminated, a continuity test is performed for each conductor layer every time each conductor layer is manufactured, which is difficult.
[0004]
Therefore, even if a failure occurs in the process of forming the conductor layer during the production of the wiring board and an electrical failure occurs in the wiring layer, the electrical failure must occur if the wiring substrate is not manufactured to a nearly completed state. Can't find out. In other words, even though a defect has occurred during manufacturing, it must be manufactured to the end, so it is discarded in a value-added state, increasing wasteful work, and thus increasing the cost of the wiring board. It has become.
[0005]
Furthermore, the above inspection method predicts the frequency of occurrence of electrical failures in the process of forming the conductor layer, predicts the yield due to electrical failure of the wiring board, or takes measures against the occurrence of electrical failures. Even when the effects are compared and examined, it is necessary to inspect the wiring board after it is manufactured to a nearly complete state, and thus a great deal of labor is required. In particular, the lower the occurrence rate of electrical failures, the greater the need to inspect the produced wiring board, making it more difficult to evaluate the effects of measures against electrical failures.
[0006]
Also, in the above inspection method, even if it is found that the inspected wiring board has an electrical failure such as disconnection or short circuit, what is the cause of such an electrical failure or wiring It is extremely difficult to specify in which process during the manufacture of the substrate the electrical failure has occurred.
Therefore, even if an electrical defective product can be found from the conventional continuity inspection of the wiring board, it is difficult to identify the cause, so that the yield at the time of manufacturing the wiring board can be improved. difficult.
[0007]
The present invention has been made in view of the present situation, and it is possible to easily predict the occurrence of an electrical failure in the conductor layer forming process, and to investigate the cause of the electrical failure, and to take measures against it. It is an object of the present invention to provide an inspection method for a conductor layer forming process of a wiring board, which can easily compare and examine the effects.
[0008]
[Means, actions and effects for solving the problems]
The solution is to form an etching resist layer having a predetermined pattern on the metal layer formed on the insulating layer, etching away the exposed metal layer, and removing the etching resist layer to form a conductor layer having a predetermined pattern. A method of inspecting a conductor layer forming step of a wiring board for inspecting a conductor layer forming step, wherein a test etching resist layer having a predetermined test pattern is formed on a test metal layer formed on a test insulating layer, and the exposed test Etching away the metal layer, While leaving the test etching resist layer, A test conductor layer forming step of forming a test conductor layer including a test wiring layer having a thin and long disconnection test portion; With the test etching resist layer left, Check the continuity of the disconnection test section and detect the presence or absence of disconnection failure at the disconnection test section. When the disconnection failure occurs, it is checked whether or not the test etching resist layer remains at the disconnection site. A disconnection detecting step, and a method for inspecting a wiring layer conductor layer forming step.
[0009]
In the present invention, a test conductor layer is formed by the same method as the conductor layer forming step of forming the conductor layer of the wiring board by etching the metal layer, and the presence or absence of disconnection failure is detected in the disconnection test portion of the test conductor layer. And inspect.
In this test method, in the test conductor layer forming step, a test conductor layer including a test wiring layer having a thin disconnection test portion is formed on the test insulating layer so as to be thin and to increase the possibility of disconnection. . For this reason, in this disconnection test part, disconnection easily occurs due to various problems, so by detecting the presence or absence of disconnection defect in this disconnection test part, it is easy to find a disconnection defective product, and to easily identify the disconnection part. Can be found.
[0010]
In particular, since the conductor width of the test conductor layer is narrowed and lengthened in the disconnection test part, disconnection defects are likely to occur in the disconnection test part. That is, a defective disconnection can be found efficiently by detecting the presence or absence of disconnection in the disconnection test section.
Accordingly, the cause of the disconnection failure can be investigated by observing and analyzing the disconnection failure product. Alternatively, when measures against disconnection are taken, the effect of the measures can be easily evaluated when checking the degree of decrease in defective disconnection.
In particular, if a disconnection test part longer than the longest conductor length of the conductor layers is formed with the same or narrower conductor width than the narrowest conductor width among the conductor layers formed in the conductor formation process of the wiring board, The disconnection failure can be generated with a higher probability than the occurrence rate of the disconnection failure in the conductor forming process of the wiring board. For this reason, a defective disconnection product appears only by forming a small number of test conductor layers. Therefore, this can be easily found or a large number of disconnection defective products can be obtained. Therefore, it becomes easy to investigate the cause of the disconnection failure. In addition, the effect of measures against disconnection failure can be easily evaluated.
This is particularly useful when the occurrence rate of disconnection failure in the conductor forming process of the wiring board is low.
Note that the disconnection test section is not limited to one place in one test wiring layer, and may be formed at a plurality of places.
[0011]
Further, in the test conductor layer forming step of the present invention, a test etching resist layer that is usually removed after etching is left. The If the test etching resist layer is left, when the disconnection occurs, the cause of the disconnection can be estimated by visually checking whether or not the test etching resist layer remains also at the disconnection site. . That is, if the test etching resist layer is continuous even though the test conductor layer is cut at the disconnection site, it is estimated that the test etching resist layer may have floated. On the other hand, when the test etching resist layer is also cut, it is estimated that the test etching resist layer may have been caused by an exposure failure due to foreign matter or a pattern failure of the test etching resist layer due to a defect in the test etching resist layer due to contact during handling.
[0012]
Furthermore, in the inspection method of the conductor layer forming step of the wiring board, the disconnection test portion is an elongated area, but the area occupied by the entire wiring pattern by a meandering, zigzag, spiral, etc. wiring pattern It is preferable to provide a method for inspecting a conductor layer forming step of a wiring board, characterized by comprising a miniaturized long portion.
[0013]
In the present invention, since the disconnection test part includes the downsized long part, the length of the disconnection test part can be increased while the area occupied by the test wiring layer (disconnection test part) is reduced. For this reason, even in a small area, there is a high probability that a disconnection failure will appear in the test wiring, and the cause of the disconnection failure can be investigated and the effect of countermeasures can be easily evaluated.
Furthermore, since the disconnection test part can occupy a small area with respect to its length by the miniaturized long part, it is possible to form a number of test conductor layers side by side on the test insulating layer. In this way, it is possible to easily measure the difference in the disconnection failure rate due to the difference in the positions of the four corners and the center of the test insulation layer, which can be useful for investigating the cause of disconnection and predicting the product yield. it can.
Note that a plurality of miniaturized long portions may be formed in one disconnection test portion.
[0014]
In another solution, an etching resist layer having a predetermined pattern is formed on a metal layer formed on an insulating layer, the exposed metal layer is removed by etching, and the etching resist layer is removed to remove a conductor having a predetermined pattern. A method for inspecting a conductor layer forming step of a wiring board for inspecting a conductor layer forming step for forming a layer, wherein a test etching resist layer having a predetermined test pattern is formed on a test metal layer formed on a test insulating layer and exposed. Etch away the above test metal layer, While leaving the test etching resist layer, A test conductor layer forming step of forming a test conductor layer including a plurality of test wiring layers having a short-circuit test portion that keeps a small distance from each other over a long distance; and With the test etching resist layer left, Investigate the continuity or insulation resistance between the short-circuit test parts and detect the presence or absence of short-circuit or insulation failure between the short-circuit test parts. When the short circuit failure or insulation failure occurs, it is checked whether or not the test etching resist layer remains at the generation site. A method of inspecting a conductor layer forming step of a wiring board, comprising: a detecting step of short circuit or the like.
[0015]
In the present invention, a test conductor layer is formed by a method similar to the conductor layer forming step of forming a conductor layer by etching a metal layer, and short-circuit failure or insulation failure between short-circuit test portions of the test conductor layer (hereinafter, collectively) It is detected by detecting the presence or absence of defects such as short circuits.
In this test method, in the test conductor layer forming step, a test conductor layer including a plurality of test wiring layers having a short-circuit test portion that maintains a small distance from each other over a long distance is formed on the test insulating layer in order to easily cause a short circuit or the like. To do. For this reason, defects such as short-circuits easily occur due to various problems between the short-circuit test units, and therefore, defective products such as short-circuits and the occurrence sites thereof are detected by detecting defects such as short-circuits in the short-circuit test units. Can do.
[0016]
Particularly, since the interval between the short-circuit test portions is reduced and the short-circuit test portion is formed long, short-circuit failure and insulation failure are likely to occur in this short-circuit test portion. That is, by detecting the presence or absence of a short circuit or the like in the short circuit test unit, a defective product such as a short circuit can be found efficiently.
In particular, the distance between the conductor layers formed in the conductor forming process of the wiring board is equal to or smaller than the smallest conductor distance, and is longer than the longest distance among the parallel portions of the conductor layers. By forming the short-circuit test portion at a distance, it is possible to generate a defect such as a short circuit with a higher probability than the occurrence rate of defects such as a short circuit in the conductor forming process of the wiring board. For this reason, since a defective product such as a short circuit appears only by forming a small number of test conductor layers, this can be easily found or a large number of defective products such as a short circuit can be obtained. Therefore, it becomes easy to investigate the cause of a defect such as a short circuit. Moreover, the effect of countermeasures against defects such as short circuits can be easily evaluated.
This is particularly useful when the incidence of defects such as short circuits in the conductor formation process of the wiring board is low.
Note that a plurality of short-circuit test portions may be formed in one test wiring layer.
[0017]
Further, in the test conductor layer forming step of the present invention, a test etching resist layer that is usually removed after etching is left. The If the test etching resist layer is left, when a short circuit failure or insulation failure occurs, it is possible to visually check whether the test etching resist layer remains also at the occurrence site of the short circuit, etc. It may be possible to estimate the cause that occurred. That is, if the test etching resist layers are not bridged or close to each other even though the test conductor layers are connected (bridged) or close to each other at the occurrence site of a short circuit or the like, Possible inhibition is estimated. On the other hand, when the test etching resist layers are also bridged or close to each other, it may be possible to estimate the possibility that the test etching resist layers are caused by a pattern defect of the test etching resist layer due to an exposure defect due to foreign matter. .
[0018]
Furthermore, in the inspection method of the conductor layer forming step of the wiring board, the short-circuit test unit, the test wiring layer to be a pair extends in parallel with each other, and is long, meandering, zigzag, It is preferable to provide a method for inspecting a conductor layer forming step of a wiring board, characterized by including a parallel miniaturized long portion whose area occupied by the entire wiring pattern is reduced by a spiral wiring pattern or the like.
[0019]
In the present invention, since the short circuit test unit includes the parallel miniaturized long unit, the length of the short circuit test unit can be increased while the area occupied by the test wiring layer is miniaturized. For this reason, even in a small area, there is a high probability that a short circuit failure or insulation failure will appear in the test wiring layer, and it is possible to easily investigate the cause and evaluate the effect of the countermeasure.
Furthermore, since the area of the short-circuit test portion can be reduced by the miniaturized long portion, it is possible to form a number of test conductor layers side by side on the test insulating layer. In this way, it is possible to easily measure the difference in the occurrence rate of defects such as short circuits due to differences in the positions of the four corners and the center of the test insulation layer, etc., for investigating the cause of short circuits and predicting product yield. Can be useful.
Note that a plurality of parallel miniaturized long portions may be formed in one short-circuit test portion.
[0020]
Furthermore, it is an inspection method of the conductor layer forming step of the wiring board, With the test etching resist layer left, Investigate the continuity of the short-circuit test part and detect the presence of disconnection failure in the short-circuit test part. When the disconnection failure occurs, it is checked whether or not the test etching resist layer remains at the disconnection site. It is preferable to provide an inspection method for a conductor layer forming step of a wiring board characterized by including a disconnection detecting step.
[0021]
In the present invention, the continuity of the short-circuit test unit is also checked, and the presence or absence of disconnection failure in the short-circuit test unit is also detected. In other words, by detecting the presence or absence of short-circuit failure or insulation failure between short-circuit test parts, and also detecting the presence or absence of disconnection defects at these short-circuit test parts, electrical defects for both disconnection defects and short-circuit defects Can be found.
In addition, typically leave a test etch resist layer to be removed. The When an electrical failure occurs, the cause of the failure can be estimated by observing the site where the failure (disconnection, short circuit, insulation failure) has occurred.
[0022]
Alternatively, in the inspection method of the conductor layer forming step of the wiring board, the short-circuit test part of the pair of the test wiring layers each includes a comb-like part of a comb-like wiring pattern that meshes with each other. It is preferable to use an inspection method in the conductor layer forming step of the wiring board.
[0023]
In the present invention, since the short-circuit test portion of the pair of test wiring layers includes the comb-like portion, the length of the small interval between the two test wiring layers is long while the area occupied by the test wiring layer is reduced. I can take it. For this reason, even in a small area, there is a high probability that a short circuit failure or insulation failure will appear between the test wiring layers, and it is possible to easily investigate the cause and evaluate the effect of the countermeasure.
Furthermore, since the area occupied by the short-circuit test portion can be reduced by the comb-like portion, it is possible to form a number of test conductor layers side by side on the test insulating layer. In this way, it is possible to easily measure the occurrence rate of defects such as short circuits due to differences in the positions of the four corners and the center of the test insulation layer, which is useful for investigating the cause of short circuits and predicting product yield. be able to.
In addition, the comb-tooth shaped part may be formed in multiple places in one short circuit test part.
[0024]
Further, in any of the above wiring board conductor layer forming step inspection method, the etching resist layer is formed by exposing the photosensitive resin to the predetermined pattern by exposure and development, the test etching resist layer, It is preferable to use an inspection method for a conductor layer forming step of a wiring board, wherein a photosensitive resin of the same photosensitive type as the etching resist layer is formed in the predetermined test pattern by exposure and development.
[0025]
According to the present invention, the test etching resist layer uses the same photosensitive type photosensitive resin as the etching resist layer, that is, the same negative type or positive type photosensitive resin as the photosensitive resin used for the etching resist layer. For this reason, in the conductor layer forming process of the wiring board, disconnection or short-circuiting, etc. caused by exposure failure of the photosensitive resin due to foreign matters etc. can be caused even in the test conductor layer forming process. Becomes easier.
[0026]
Also , Absolutely A plating resist layer having a predetermined pattern is formed on the metal layer formed on the edge layer, electrolytic plating is performed on the exposed metal layer, the plating resist layer is removed, and the exposed metal layer is etched away. A method of inspecting a conductor layer forming step of a wiring board for inspecting a conductor layer forming step of forming a conductor layer of a predetermined pattern, wherein a test plating resist layer having a predetermined pattern is formed on a test metal layer formed on a test insulating layer Then, electrolytic plating is performed on the exposed test metal layer, the test plating resist layer is removed, the exposed test metal layer is etched away, and a test wiring layer having a thin and long disconnection test portion is included. A test conductor layer forming step for forming a test conductor layer and the continuity of the disconnection test part are checked, and a disconnection test is performed to detect the presence or absence of a disconnection defect in the disconnection test part Inspection method of the conductive layer forming process of the wiring board, characterized in that it comprises a step, Preferably .
[0027]
In this inspection method The test conductor layer is formed by the same method as the conductor layer forming step of forming the conductor layer of the wiring board by performing electroplating and etching the metal layer, and whether there is a disconnection failure in the disconnection test portion of this test conductor layer Detect and inspect.
In this test method, in the test conductor layer forming step, a test conductor layer including a test wiring layer having a thin disconnection test portion is formed on the test insulating layer so as to be thin and to increase the possibility of disconnection. . For this reason, in this disconnection test part, since disconnection is easily caused by various problems, it is possible to easily find a defective disconnection and its disconnection part.
[0028]
In particular, since the test conductor layer is made thinner and longer in the disconnection test portion, disconnection defects are likely to occur in the disconnection test portion. That is, a defective disconnection can be found efficiently by detecting the presence or absence of disconnection in the disconnection test section.
Accordingly, the cause of the disconnection failure can be investigated by observing and analyzing the disconnection failure product. Alternatively, when measures against disconnection are taken, the effect of the measures can be easily evaluated when checking the degree of decrease in defective disconnection.
In particular, if a disconnection test part longer than the longest conductor length of the conductor layers is formed with the same or narrower conductor width than the narrowest conductor width among the conductor layers formed in the conductor formation process of the wiring board, The disconnection failure can be generated with a higher probability than the occurrence rate of the disconnection failure in the conductor forming process of the wiring board. For this reason, a defective disconnection product appears only by forming a small number of test conductor layers. Therefore, this can be easily found or a large number of disconnection defective products can be obtained. Therefore, it becomes easy to investigate the cause of the disconnection failure. In addition, the effect of measures against disconnection failure can be easily evaluated.
This is particularly useful when the occurrence rate of disconnection failure in the conductor forming process of the wiring board is low.
Note that the disconnection test section is not limited to one place in one test wiring layer, and may be formed at a plurality of places.
[0029]
Furthermore, in the inspection method of the conductor layer forming step of the wiring board, the disconnection test portion is an elongated area, but the area occupied by the entire wiring pattern by a meandering, zigzag, spiral, etc. wiring pattern It is preferable to provide a method for inspecting a conductor layer forming step of a wiring board, characterized by comprising a miniaturized long portion.
[0030]
This inspection method Then, since the disconnection test part is provided with a downsized long part, the length of the disconnection test part can be increased while the area occupied by the test wiring layer (disconnection test part) is reduced. For this reason, even in a small area, there is a high probability that a disconnection failure will appear in the test wiring, and the cause of the disconnection failure can be investigated and the effect of countermeasures can be easily evaluated.
Furthermore, since the disconnection test part can occupy a small area with respect to its length by the miniaturized long part, it is possible to form a number of test conductor layers side by side on the test insulating layer. In this way, it is possible to easily measure the difference in the defect occurrence rate due to the difference in the positions of the four corners and the central portion on the test insulating layer, which can be used for investigating the cause of the disconnection and predicting the product yield.
Note that a plurality of miniaturized long portions may be formed in one disconnection test portion.
[0031]
Also , Absolutely A plating resist layer having a predetermined pattern is formed on the metal layer formed on the edge layer, electrolytic plating is performed on the exposed metal layer, the plating resist layer is removed, and the exposed metal layer is etched away. A method of inspecting a conductor layer forming step of a wiring board for inspecting a conductor layer forming step of forming a conductor layer of a predetermined pattern, wherein a test plating resist layer having a predetermined pattern is formed on a test metal layer formed on a test insulating layer Thereafter, electrolytic plating is performed on the exposed test metal layer, the test plating resist layer is removed, the exposed test metal layer is etched away, and a short-circuit test portion that maintains a small distance from each other over a long distance is formed. A test conductor layer forming step for forming a test conductor layer including a plurality of test wiring layers, and adjusting the continuity or insulation resistance between the short-circuit test portions. The inspection method of the conductive layer forming process of the wiring board, characterized in that it comprises a short circuit detection process for detecting the presence or absence of short circuit or insufficient insulation between the short-circuit test section It is also preferable to .
[0032]
This inspection method Then, the test conductor layer is formed by the same method as the conductor layer forming step of forming the conductor layer of the wiring board by performing electroplating and etching the metal layer. Detect and inspect for poor insulation.
In this test method, in the test conductor layer forming step, a test conductor layer including a plurality of test wiring layers having a short-circuit test portion that maintains a small distance from each other over a long distance is formed on the test insulating layer in order to easily cause a short circuit or the like. To do. For this reason, a defect such as a short circuit easily occurs between the short circuit test units due to various problems, and therefore, a defective product such as an electric short circuit and its occurrence site can be found.
[0033]
Particularly, since the interval between the short-circuit test portions is reduced and the short-circuit test portion is formed long, short-circuit failure and insulation failure are likely to occur in this short-circuit test portion. That is, by detecting the presence or absence of a short circuit or the like in the short circuit test unit, a defective product such as a short circuit can be found efficiently.
In particular, of the distances between the conductor layers formed in the conductor formation process of the wiring board, the short-circuit is longer than the longest distance among the parallel portions of the conductor layers, with a narrowness that is the same as or smaller than the smallest conductor distance. If the test part is formed, a defect such as a short circuit can be generated with a higher probability than the occurrence rate of a defect such as a short circuit in the conductor forming process of the wiring board. For this reason, since a defective product such as a short circuit appears only by forming a small number of test conductor layers, this can be easily found or a large number of defective products such as a short circuit can be obtained. Therefore, it becomes easy to investigate the cause of a defect such as a short circuit. Moreover, the effect of countermeasures against defects such as short circuits can be easily evaluated.
This is particularly useful when the incidence of defects such as short circuits in the conductor formation process of the wiring board is low.
Note that a plurality of short-circuit test portions may be formed in one test wiring layer.
[0034]
Furthermore, in the inspection method of the conductor layer forming step of the wiring board, the short-circuit test unit, the test wiring layer to be a pair extends in parallel with each other, and is long, meandering, zigzag, It is preferable to provide a method for inspecting a conductor layer forming step of a wiring board, characterized by including a parallel miniaturized long portion whose area occupied by the entire wiring pattern is reduced by a spiral wiring pattern or the like.
[0035]
This inspection method Then, since the short circuit test unit includes the parallel miniaturized long unit, the length of the short circuit test unit can be increased while the area occupied by the test wiring layer is reduced. For this reason, even in a small area, there is a high probability that a short circuit failure or insulation failure will appear in the test wiring layer, and it is possible to easily investigate the cause and evaluate the effect of the countermeasure.
Furthermore, since the area of the short-circuit test portion can be reduced by the miniaturized long portion, it is possible to form a number of test conductor layers side by side on the test insulating layer. In this way, it is possible to easily measure the difference in the occurrence rate of defects such as short circuits due to differences in the positions of the four corners and the center of the test insulation layer, etc., for investigating the cause of short circuits and predicting product yield. Can be useful.
Note that a plurality of parallel miniaturized long portions may be formed in one short-circuit test portion.
[0036]
Furthermore, it is an inspection method of the conductor layer forming step of the wiring board, comprising a disconnection detecting step of checking the continuity of the short-circuit test portion and detecting the presence or absence of disconnection failure in the short-circuit test portion. A method for inspecting the conductor layer forming step of the wiring board is preferable.
[0037]
This inspection method Then, the continuity of the short-circuit test unit is also checked, and the presence or absence of disconnection failure in the short-circuit test unit is also detected. In other words, by detecting the presence or absence of short-circuit failure or insulation failure between the short-circuit test parts, and also detecting the presence or absence of disconnection defects at these short-circuit test parts, it is an electrical defect product for both disconnection defects and short-circuit defects. Can be found.
[0038]
Alternatively, in the inspection method of the conductor layer forming step of the wiring board, the short-circuit test part of the pair of the test wiring layers each includes a comb-like part of a comb-like wiring pattern that meshes with each other. It is preferable to use an inspection method in the conductor layer forming step of the wiring board.
[0039]
This inspection method Then, since the short-circuit test portion of the pair of test wiring layers includes a comb-like portion, the length of the small interval between the two test wiring layers can be increased while the area occupied by the test wiring layer is reduced. For this reason, even in a small area, there is a high probability that a short circuit failure or insulation failure will appear in the test wiring, and it is possible to easily investigate the cause and evaluate the effect of the countermeasure.
Furthermore, since the area occupied by the short-circuit test portion can be reduced by the comb-like portion, it is possible to form a number of test conductor layers side by side on the test insulating layer. In this way, it is possible to easily measure the occurrence rate of defects such as short circuits due to differences in the positions of the four corners and the center of the test insulation layer, which is useful for investigating the cause of short circuits and predicting product yield. be able to.
In addition, the comb-tooth shaped part may be formed in multiple places in one short circuit test part.
[0040]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
Hereinafter, a first embodiment according to the present invention will be described with reference to the drawings.
As shown in FIG. 1, the wiring board 100 according to the conductor layer forming process to be inspected by the inspection method of the present embodiment is a substantially square plate having a size of 330 mm × 330 mm, and is a large-sized wiring board for taking multiple pieces. That is, the large-sized wiring board 100 is roughly divided into a large number of product parts 101 (40 mm × 40 mm) that are finally separated into individual products by cutting, and the product parts 101 are connected to each other. Specifically, the connection unit 102 is discarded. In the present embodiment, the product parts 101 are arranged three by three in the vertical and horizontal directions (total nine) via the connection part 102, and further, the nine groups are arranged in two vertical and horizontal groups via the connection part 102 (four groups in total). Since they are arranged, 36 (= 9 × 4) product parts 101 belong to one wiring board 100.
The wiring substrate 100 is subjected to various processes including a conductor layer forming process inspected by the inspection method of the present embodiment, and circuit wiring and the like are built in the product part 101. After being subjected to further necessary processing such as solder reflow, the separated wiring substrate 110 shown in FIG. 3 is obtained. The wiring board 110 has a large number of solder bumps 111 that can be connected to the IC chip CH indicated by broken lines on the upper surface 110A, and the lower surface 110B can be mounted on the upper surface MBA of the motherboard MB indicated by broken lines. A large number of solder bumps 112 are formed.
[0041]
The conductor layer 103 formed in the conductor layer forming process inspected by the inspection method of this embodiment is mainly formed in the product portion 101. The pattern of the conductor layer 103 formed in each product part 101 is a pattern including a large number of wiring layers 104 extending substantially radially from the vicinity of the center toward the periphery as shown in FIG. In FIG. 1, these descriptions are omitted.
As can be easily understood, when the wiring layer 104 is disconnected in the middle, the adjacent wiring layers 104 are short-circuited, or the insulation resistance between the wiring layers 104 decreases due to proximity, such as The wiring board 110 including a malfunction does not operate normally. Accordingly, in order to eliminate the wiring board 110 having a defect such as disconnection or short circuit, the inspection is performed after or just before the completion of the wiring board 110. However, it is not easy to inspect many complicated wirings, and the inspection cost is also high. The loss associated with the disposal of defective products is also large.
[0042]
For this reason, although inspection and the cause of a defect are pursued in each process, for example, it is not easy to inspect each wiring layer 103 shown in FIG. Therefore, in the present invention, as shown below, the test conductor layer is formed on the test wiring board by the same test conductor layer forming process as that for forming the conductor layer 103, and the test conductor layer is inspected. From the result, it is evaluated whether or not each device and material in the conductor layer forming process is properly operated and operated according to the intended characteristics, or the yield of products (wiring board 100, wiring board 110, etc.) after the next process. Is predictable. For this reason, for example, before and after the start of the day's work, during the middle, or before, after, or during the insertion of the wiring board 100 in the conductor layer forming process, periodically insert the test wiring board, It is good to do an inspection.
In addition, since it is possible to evaluate the suitability of countermeasures against defects, the magnitude of effects, etc., it is preferable to perform an inspection when various improvements are made.
[0043]
The conductor layer 103 (wiring layer 104) shown in FIG. 2 is formed as follows. That is, a resin insulation layer made of an epoxy resin is formed on the surface of the wiring substrate 100 in advance, and a negative photosensitive resin is formed on the metal layer, specifically, a copper layer, formed in advance on the resin insulation layer. A dry film made of resin is attached, exposed and developed to form an etching resist layer having a predetermined pattern. Thereafter, the exposed copper layer is dissolved and removed by etching to form the conductor layer 103, and the etching resist layer that is no longer needed is further removed and formed.
[0044]
Next, a plan view of the test wiring board 1 manufactured in the present embodiment is shown in FIG.
This test wiring board 1 is composed of a test board 10 (see FIG. 6A) in which epoxy resin-based test resin insulation layers 12 and 13 are respectively formed above and below a test core board 11 made of a glass-epoxy resin composite material. Like the large-sized wiring board 100 described above, it has a substantially square plate shape in a plan view of 330 × 330 mm. The test wiring board 1 includes 36 (= 4 × 9) connection test areas 3 corresponding to the product part 101 (40 × 40 mm) described above. In this connection area 3, four approximately square test areas 2 each having a size of 20 × 20 mm are included in a connected state. The connection test areas 3 are connected to each other by an unnecessary part 5 corresponding to the connection part 102. Therefore, this test wiring board 1 is composed of 144 (= 4 × 9 × 4) test areas 2 and unnecessary portions 5. Further, as will be described later, a test conductor layer 23 having a pattern shown in FIG. 5 is formed in each test region 2 (illustration is omitted in FIG. 4).
In the present embodiment, a test area and an unnecessary portion are similarly formed on the lower surface side (not shown) of the test wiring board 1.
[0045]
Next, a plan view of the test area 2 of the test wiring board 1 is shown in FIG.
In each test region 2, a test conductor layer 23 is formed on a test insulating layer 12 made of the same epoxy resin material as the surface of the wiring substrate 100 described above. The test conductor layer 23 includes two test wiring layers (first test wiring layer 21 and second test wiring layer 22).
Further, the first test wiring layer 21 and the second test wiring layer 22 are formed at both ends of the thin and long disconnection test portions 21A and 22A having substantially the same line width (45 μm) as the wiring layer 104 (see FIG. 2). And a pair of check pads 21B1 and 21B2, 22B1 and 22B2 (each 1 × 1 mm) capable of contacting a probe for measuring electrical characteristics such as conduction. Furthermore, in the region 24 surrounded by the alternate long and short dash line in the figure, the disconnection test portions 21A and 22A are formed in a zigzag wiring pattern, and the disconnection test portions 21A and 22A are both long in this region 24. Although it is a scale, it is set as the miniaturized elongate part 21C, 22C reduced in size so that the area occupied by the zigzag wiring pattern may be accommodated in the region 24.
[0046]
In addition, the first test wiring layer 21 and the second test wiring layer 22 also constitute short-circuit test portions 21D and 22D that maintain a distance of 35 μm from each other in the region 24 so that a short circuit can be easily caused by a malfunction. . Further, the short-circuit test portions 21D and 22D have two test wiring layers 21 and 22 as a pair and extend in a zigzag in parallel with each other, and the area occupied by the entire pattern by the zigzag wiring pattern is long. Is reduced in size and is also referred to as a parallel reduced size long portion 21E, 22E.
Thus, in this embodiment, the miniaturized long parts 21C and 22C are the short circuit test parts 21D and 22D, and also the parallel miniaturized long parts 21E and 22E.
[0047]
Next, the inspection method of the conductor layer formation process of a wiring board is demonstrated, referring FIGS.
In the present embodiment, as described above, the conductor layer forming step of the wiring board 100 to be inspected forms an etching resist layer having a predetermined pattern on the metal layer formed on the resin insulating layer, and the exposed metal layer is formed. Etching is removed, and the etching resist layer is removed to form a conductor layer 103 having a predetermined pattern. Therefore, the test conductor layer 23 of the test wiring board 1 is also formed by etching the metal layer as described below.
[0048]
First, as shown in a partially enlarged cross-sectional view in FIG. 6A, a test substrate 10 is prepared in which test insulating layers 12 and 13 are formed above and below a test core substrate 11 made of a glass-epoxy resin composite material. Test metal layers 14 and 15 made of copper having a thickness of 15 μm are formed on both surfaces 10A and 10B in advance. The test metal layers 14 and 15 are formed by a known method such as laminating a copper foil on the test insulating layers 12 and 13 or performing electroless plating and electrolytic plating on the test insulating layers 12 and 13. It is preferable to form the test metal layers 14 and 15 by the same method as that for manufacturing the wiring board 110 of an actual product.
[0049]
Next, in the test conductor layer forming step, as shown in FIG. 6B, a negative photosensitive dry film made of an acrylic resin (water-soluble acrylic) is formed on substantially the entire surface of each of the test metal layers 14 and 15. Are attached to form test etching resist layers 16 and 17, respectively. The material of the dry film (test etching resist layers 16 and 17) is the same as that used in the conductor layer forming step of the wiring substrate 100 to be inspected, and the manufacturing conditions such as the application conditions and the exposure and development conditions described later are also used. Same as when manufacturing the product.
[0050]
Next, as shown in FIG. 7A, the attached test etching resist layers 16 and 17 are exposed to a predetermined pattern (see FIG. 5), and then developed to develop the first test wiring layer 21 and the second test wiring layer 21. Test etching resist layers 18 and 19 having a predetermined pattern corresponding to the test wiring layer 22 and the like are formed. Since the dry film used in this embodiment is a negative type in which the exposed portion is cured, the exposed portion becomes the test etching resist layers 18 and 19 having a predetermined pattern after development.
[0051]
Next, as shown in FIG. 7B, an etching solution is sprayed onto the test metal layers 14 and 15 exposed from the test etching resist layers 18 and 19 having a predetermined pattern, and the exposed test metal layers 14 and 15 are formed. Etch away. As a result, the test conductor layer 23 including the first test wiring layer 21 and the second test wiring layer 22 is formed on the upper surface 10A, and the test conductor layer 27 is also formed on the lower surface 10B.
In the conductor layer forming step of the wiring substrate to be inspected, after forming the conductor layer 103, the etching resist layer is peeled off to expose the conductor layer 103. In the inspection method of this embodiment, as described later, In order to easily find the cause of the defect, the test etching resist layers 18 and 19 having a predetermined pattern are left as they are even after the etching.
[0052]
Next, in the disconnection detection step, all or part of the test etching resist layer 18 on each check pad 21B1, 21B2 of the first test wiring layer 21 is removed, and then a probe pin is brought into contact with the check pad 21B1 or the like. Then, the continuity between the check pads 21B1 and 21B2 is checked, and the presence or absence of a disconnection failure in the disconnection test part 21A and the miniaturized long part 21C is detected. Similarly, for the second test wiring layer 22, the presence or absence of a disconnection failure in the disconnection test part 22A and the downsized long part 22C is detected.
Further, in the detection process such as a short circuit, a probe is connected to either the check pad 21B1, 21B2 of the first test wiring layer 21 or the check pad 22B1, 22B2 of the second test wiring layer 22 (for example, 21B1 and 22B1). The pins are brought into contact with each other, and the conduction and insulation resistance between them are examined, and the presence or absence of short circuit failure or insulation failure between the short circuit test parts 21C and 22C (between the parallel miniaturized long parts 21D and 22D) is detected.
The probe pins may be brought into contact with the check pads 21B1, 21B2 (22B1, 22B2) so as to penetrate the test etching resist layer 18.
[0053]
As described above, the first test wiring layer 21 and the second test wiring layer 22 are formed with the check pads 21B1, 21B2, 22B1, and 22B2, respectively, so that the probe pins can be easily brought into contact with each other. Electrical inspection can be done.
After inspecting one test area 2 for the above-described disconnection or short-circuit, such inspection is also performed for the other test areas 2, and all 144 test areas 2 in the test wiring board 1 are tested. Inspection is performed to detect the presence of disconnection failure, short circuit failure, or insulation failure. Further, the test conductor layer 27 formed on the lower surface 10B is similarly inspected.
[0054]
In this way, the yield of the test wiring layers 21 and 22 by the similar conductor layer forming process can be understood, not the yield of the conductor layer forming process itself of the wiring board to be inspected. Therefore, unlike the prior art, it is not necessary to inspect the wiring substrate after it is manufactured to a nearly completed state, and the yield level can be easily estimated and evaluated for each conductor layer forming process.
In the present embodiment, since the shape of the test conductor layer 23 is small enough to fit in the test area 2 shown in FIGS. 4 and 5, depending on the data aggregation method, For example, it is possible to calculate the difference in defect occurrence rate near the four corners and near the center, the difference in defect occurrence rate between the test conductor layer 23 on the upper surface 10A and the test conductor layer 27 on the lower surface 10B, and the like. It is also possible to search for the cause of the failure.
Furthermore, since the test wiring board 1 is used, problems associated with the inspection such as a part of the wiring layer in the wiring board 100 to be a product are damaged by the probe pins.
[0055]
Furthermore, in the test method of the present embodiment, in the test conductor layer forming step, the first test wiring layer 21 having the test conductor layer 23, specifically, the thin and long disconnection test portions 21A and 22A, on the test insulating layer 12. The second test wiring layer 22 is formed. In particular, the disconnection test sections 21A and 22A are provided with miniaturized long sections 21C and 22C that are as thin as the wiring layer 104 (see FIG. 2) of the product section 101 and longer than either length. For this reason, if there are various problems, disconnection occurs at a much higher probability than in the case of the conductor layer forming step of the wiring board 100 to be inspected, so only a small amount of the test conductor layer 23 is formed. A defective product appears. Therefore, for example, in the step of forming a conductor layer of the wiring substrate 100 to be inspected, even when the yield is sufficiently high and the possibility of occurrence of disconnection failure is low, the disconnection can be achieved by inspecting a small number of test wiring layers 21 and 22. Since defects appear, it is not necessary to inspect a large number of wiring boards 110 (or product parts 101), and the yield of the conductor layer forming process can be estimated and evaluated.
[0056]
In the test method according to the present embodiment, in the test conductor layer forming step, the gap is equal to the parallel portion of the wiring layer 104 that extends in parallel (40 μm), and a small distance is maintained over a distance longer than any of the lengths. The first test wiring layer 21 and the second test wiring layer 22 having the short-circuit test parts 21D and 22D (parallel miniaturized long parts 21E and 22E) were formed. For this reason, between the short-circuit test portions 21D and 22D, if there are various problems, a short-circuit failure or insulation failure occurs with a much higher probability than in the case of the conductor layer forming step of the wiring board 100. A defective disconnection appears only by forming a small amount of the test conductor layer 23.
Therefore, for example, in the conductor layer forming process of the wiring substrate 100 to be inspected, even when the yield is sufficiently high and the possibility of occurrence of short circuit failure is low, a short circuit can be achieved by inspecting a small number of test wiring layers 21 and 22. Since defects and insulation defects appear, it is not necessary to inspect a large number of wiring boards 101 (or product parts 101), and the yield of the conductor layer forming process can be estimated and evaluated.
[0057]
In addition, when a disconnection failure, a short-circuit failure, or an insulation failure is found by the above-described inspection, it is possible to obtain a clue to search for the cause of the failure by identifying and observing the failure location. First, the state of the test etching resist layers 18 and 19 and the test wiring layers 21 and 22 is examined by visual inspection or using a normal optical microscope or polarizing microscope, and a portion where a disconnection failure, a short-circuit failure, or an insulation failure occurs is found. Observe the condition.
[0058]
In the downsized long portions 21C and 22C, the first and second test wiring layers 21 and 22 are in a dense pattern, so that it is possible to easily find the disconnection portion by simply observing the narrow region 24. This is also convenient. Similarly, in the parallel miniaturized long portions 21E and 22E, the first and second test wiring layers 21 and 22 are formed in a dense pattern. This is also convenient in this respect.
[0059]
When a disconnection failure occurs in the test wiring layer 21A (22A), it is observed whether or not the test etching resist layer 18 is present on the disconnection site 21R.
First, as shown in FIG. 8A, when the test etching resist layer 18 is normally present also on the disconnected portion 21R, that is, although the test etching resist layer 18 has a predetermined shape, In the test wiring layer 21A below the test wiring layer 21A, the test wiring layer 21A does not exist at the disconnection site 21R, and disconnection may occur. In this case, as shown in FIGS. 8B and 8C, when the test etching resist layer 16 (dry film) is attached on the test metal layer 14, the test etching resist layer 18 and the test metal layer 14 are adhered. Since the void V due to the foreign matter FM or the air enters between the test etching resist layer 18 and the floating portion 18R. Thus, it is considered that the etching solution has soaked between the test etching resist layer 18 and the test metal layer 14 and the disconnected portion 21R of the test wiring layer 21A has been removed by etching.
[0060]
On the other hand, as shown in FIG. 9A, the test etching resist layer 18 may also be missing at the disconnected portion 21R. In this case, when the test etching resist layer 16 is exposed in a predetermined pattern, the foreign matter FM2 adheres to the test etching resist layer 16 and an unnecessary shadow is formed. It is considered that the pattern defect was caused by the removal. Alternatively, in handling from development to etching, a part of the test etching resist layer 18 is lost due to contact with a jig or another substrate, and a defective part (disconnected part 21R) is also generated in the test wiring layer 21A. Conceivable.
As described above, since the test etching resist layer 18 is left without being removed, the cause of the disconnection failure can be estimated. Therefore, it is easy to examine countermeasures for the failure and easily measure the effect. .
[0061]
On the other hand, in the case of a short circuit failure or insulation failure, that is, as shown in FIG. 10A, a part of the test metal layer 14 remains undissolved between the test wiring layers 21A and 22A to form a short circuit metal layer 14S. When the two are short-circuited, specifically, the following causes are listed.
First, as shown in FIG. 10B, after the test etching resist layer 18 is formed, the foreign matter FM3 is placed so as to straddle between adjacent test etching resist layers 18 before etching. In this case, the foreign substance FM3 serves as an etching guard, and inhibits the etching removal of the test metal layer 13 below, so that it is considered that the foreign metal FM3 remains as a short-circuit metal layer 14S.
Second, as shown in FIG. 10 (c), two foreign substances FM4 enter between the test etching resist layer 16 and the test metal layer 14 and develop to form two test etching resist layers 18. This is a case where the foreign matter FM4 is located between the etching resist layers 18. Also in this case, it is considered that the foreign material FM4 serves as an etching guard, and the short-circuit metal layer 14S remains.
In these cases, when the foreign matter FM3 or FM4 remains, as well as when the foreign matter FM3 or FM4 remains, the rise of the test etching resist layer 18 in the vicinity of the short-circuit metal layer 14S is checked to identify whether it is due to the foreign matter FM3 or FM4. It may be possible.
[0062]
In this way, when an electrical failure occurs in the test conductor layer, the cause can be easily investigated, and therefore, measures against electrical failure can be facilitated. Furthermore, after taking countermeasures against electrical defects, if the inspection is performed again by the inspection method of the conductor layer forming step, the effect of the countermeasures can be easily evaluated.
[0063]
(Modification 1)
Next, a modification of the first embodiment will be described.
In Embodiment 1 described above, a negative dry film was used as the test etching resist layer. However, when a positive dry film is used in the conductor layer forming step of the wiring substrate 100 to be inspected, it is preferable to form the test conductor layer using the same type of dry film. This is because the test conductor layer is formed under the same conditions as the wiring board 100 as much as possible.
Therefore, in this modified embodiment, a positive dry film in which the exposed portion can be dissolved and removed is used as the test etching resist layer. Accordingly, in accordance with this, the light shielding pattern of the mask at the time of exposure is also changed to a negative / positive inversion.
[0064]
Even when such a positive test etching resist layer is used, the test conductor layer is formed in the test conductor layer forming process, the disconnection failure is detected in the disconnection detecting process, and the short circuit is detected in the detecting process such as a short circuit. Since it is possible to detect the presence or absence of defects or insulation defects, detailed description is omitted.
Further, when those defects occur, the defective part can be easily found, and the cause can be determined from the form. However, the form of the defective portion and the cause of the defect will be described below because there are different portions between the first embodiment using the negative resist and the present modified embodiment.
[0065]
In this modification, when a disconnection failure occurs, it is almost the same as in the case of the first embodiment, and will be described with reference to FIGS. First, when the positive type test etching resist layer 218 is normally present on the disconnected portion 21R (see FIG. 8A), the test is performed as shown in FIG. 8B or FIG. 8C. This is probably because foreign matter FM or void V entered between the etching resist layer 218 (positive test etching resist layer 216) and the test metal layer 14, and the test etching resist layer 218 was lifted.
On the other hand, in the case where the test etching resist layer 218 is also missing at the disconnection site 21R (see FIG. 9A), in handling up to the post-development etching, it comes into contact with jigs and other substrates. It is considered that a part of the test etching resist layer 218 was lost and a broken portion 21R was generated.
As described above, even in this modified embodiment, since the test etching resist layer 218 is left without being removed, it is possible to estimate the cause of the disconnection failure. Therefore, it is easy to examine the countermeasures against the failure and easily achieve the effect. Can be measured.
[0066]
On the other hand, in the case of short-circuit failure or insulation failure, as described with reference to FIG. 10, in addition to the case where the short-circuit metal layer 14S remains due to the foreign matters FM3 and FM4, as shown in FIG. Exposure failure due to the adhesion of foreign matter can be considered and can also be identified. That is, as shown in FIG. 10A, when the positive test etching resist layer 218 does not remain on the short-circuit metal layer 14S, the foreign matter FM3 or FM4 is the same as described in the first embodiment. Is considered to act as an etching guard and the short-circuit metal layer 14S remains undissolved (see FIGS. 10B and 10C).
On the other hand, as shown in FIG. 11A, when the positive type connection test etching resist layer 218S exists also on the short-circuit metal layer 14S, as shown in FIG. Foreign matter FM5 adhered on the test etching resist layer 216 causes a shadow at the time of exposure, and an unexposed portion (218S) remains undissolved at the time of development, and becomes a connected test etching resist layer 218S and a short-circuit metal layer 14S. It is estimated to be.
Therefore, when the foreign matters FM3, FM4, and FM5 remain, as well as when they disappear, whether or not the test etching resist layer 218 remains on the short-circuit metal layer 14S and the vicinity of the short-circuit metal layer 14S. By checking the lift of the test etching resist layer 218, it may be possible to identify which is due.
[0067]
In this way, when an electrical failure occurs in the test conductor layer, the cause can be easily investigated, and therefore, measures against electrical failure can be facilitated. Furthermore, after taking countermeasures against electrical defects, if the inspection is performed again by the inspection method of the conductor layer forming step, the effect of the countermeasures can be easily evaluated.
[0068]
( Reference form 1 )
Next, Embodiment 2 will be described with reference to FIGS.
Book Reference form 1 First, since the conductor layer forming process of the wiring board to be inspected is different from that of the first embodiment, the test conductor layer forming process is also different. Further, the shape of the test wiring layer formed in the test conductor layer forming step is also a spiral shape (see FIG. 12) unlike the test wiring layers (first test wiring layer 21 and second test wiring layer 22) of the first embodiment. It is said. However, the others are almost the same. Therefore, the description will focus on parts different from the first embodiment, and description of similar parts will be omitted or simplified.
[0069]
Book Reference form 1 The wiring board 300 according to the conductor layer forming process inspected by the inspection method is the same as that of the first embodiment as described below, but the shape is the same (see FIG. 1). 36 (= 9 × 4) product parts 301 (40 × 40 mm) and a connecting part 302 for connecting them are included.
This wiring board 300 is also a book Reference form 1 Through various processes including the conductor layer forming process inspected by the inspection method, circuit wiring and others are built into the product part 301, and after completion in a large format, each product part 301 is cut, solder reflow, etc. After performing necessary processing, the wiring substrate 310 is separated (see FIG. 3). Similarly to the first embodiment, the wiring board 310 has a large number of solder bumps 311 that can be connected to the IC chip CH on the upper surface 310A, and a large number of solder bumps 312 that can be mounted on the upper surface MBA of the motherboard MB. .
[0070]
Book Reference form 1 The conductor layer formed in the conductor layer forming step inspected by the inspection method is substantially the same as that in the first embodiment (see FIG. 2), and the conductor layer 303 is mainly formed in the product portion 301. The pattern of the conductor layer 303 formed in each product part 301 is also a pattern that includes a large number of wiring layers 304 that extend substantially radially from the vicinity of the center toward the periphery.
It is not easy to inspect each of these wiring layers 303. So book Reference form 1 However, the test conductor layer is formed on the test wiring board by the same test conductor layer forming process as that for forming the conductor layer 303, and the test conductor layer is inspected. And from the result, the conductor layer forming process is evaluated, or the yield of products after the next process can be predicted. For this reason, for example, before and after the start of the day's work, in the middle, or before, after, or during the insertion of the wiring board 300 in the conductor layer forming process, periodically insert the test wiring board, It is good to do an inspection.
In addition, since it is possible to evaluate the suitability of countermeasures against defects, the magnitude of effects, etc., it is preferable to perform an inspection when various improvements are made.
[0071]
Book Reference form 1 The conductor layer 303 (wiring layer 304) is formed as follows. That is, a resin insulating layer made of an epoxy resin is formed in advance on the surface of the wiring board 300, and a negative photosensitive resin is formed on a metal layer, specifically a copper layer, formed in advance on the resin insulating layer. A dry film made of resin is attached, exposed and developed to form a plating resist layer having a predetermined pattern. Thereafter, an electrolytic copper plating layer is formed on the exposed copper layer to increase the thickness of the portion. Further, after removing the plating resist layer, the exposed copper layer is dissolved and removed by etching to form a conductor layer 303 composed of a copper layer and an electrolytic copper plating layer.
[0072]
Book Reference form 1 The test wiring board 1 (see FIG. 4) manufactured in the same manner as in the first embodiment is composed of the test board 10 and has the same shape as the large-sized wiring board 300 described above. The test wiring board 1 includes 36 connection test areas 3 corresponding to the product part 301 and an unnecessary part 5, and the connection area 3 includes four test areas 32 each having a substantially square shape. Therefore, one test wiring board 1 includes 144 test areas 32. As will be described below, the test conductor layer 33 having a spiral pattern shown in FIG. 12 is formed in each test region 32 (not shown in FIG. 4).
Book Reference form 1 However, a test area and an unnecessary portion are similarly formed on the lower surface side (not shown) of the test wiring board 1.
[0073]
Next, a plan view of the test region 32 of the test wiring board 1 is shown in FIG.
In each test region 32, a test conductor layer 33 is formed on the test insulating layer 12 made of the same epoxy resin material as the surface of the wiring board 300. The test conductor layer 33 includes two test wiring layers (a first test wiring layer 34 and a second test wiring layer 35).
Further, the first test wiring layer 34 and the second test wiring layer 35 are formed at both ends of thin and long disconnection test portions 34A and 35A having substantially the same line width (45 μm) as the wiring layer 304 (see FIG. 2). And a pair of check pads 34B1 and 34B2, 35B1 and 35B2 (each 1 × 1 mm) capable of contacting a probe for measuring electrical characteristics such as conduction. Further, in the region 36 surrounded by the alternate long and short dash line in the figure, the disconnection test portions 34A and 35A are formed in a spiral wiring pattern, and any length of the disconnection test portions 34A and 35A has a length in the region 36. Although it is long, it is made into the size reduction long parts 34C and 35C reduced in size so that the area occupied by the spiral wiring pattern may be accommodated in the region 36.
[0074]
Further, the first test wiring layer 34 and the second test wiring layer 35 also constitute short-circuit test portions 34D and 35D that are kept at a distance of 40 μm from each other in the region 36 so that a short circuit can be easily caused by a malfunction. . Further, the short-circuit test portions 34D and 35D have a double spiral pattern in which two test wiring layers 34 and 35 are paired and extend in a spiral shape in parallel with each other. The area occupied by the entire pattern is miniaturized by the shape of the wiring pattern, and the parallel miniaturized long portions 34E and 35E are also used.
Like this Reference form 1 Then, the miniaturized long parts 34C and 35C are short circuit test parts 34D and 35D, and are also parallel miniaturized long parts 34E and 35E.
[0075]
Next, an inspection method for the conductor layer forming step of the wiring board will be described with reference to FIGS.
Book Reference form 1 In the step of forming the conductor layer of the wiring substrate 300 to be inspected, as described above, a plating resist layer having a predetermined pattern is formed on the metal layer formed on the resin insulating layer, and the exposed metal layer is electrolytically plated. A layer is formed, the plating resist layer is removed, and the exposed metal layer is removed by etching to form a conductor layer 303 having a predetermined pattern. Therefore, as described below, the test conductor layer 33 of the test wiring board 1 is also formed by electrolytic plating and etching on the metal layer.
[0076]
First, as shown in a partially enlarged cross-sectional view in FIG. 13A, a test substrate 10 having test insulating layers 12 and 13 formed on and under a test core substrate 11 made of a glass-epoxy resin composite material is prepared. Test metal layers 41 and 42 made of copper having a thickness of 0.7 μm are formed in advance on both surfaces 10A and 10B, respectively. The test metal layers 41 and 42 are formed by a known method such as laminating a copper foil on the test insulating layers 12 and 13 or performing electroless plating on the test insulating layers 12 and 13. The test metal layers 41 and 42 serve as a common electrode in the electrolytic plating described below. It is preferable to form the test metal layers 41 and 42 by the same method as that for manufacturing the actual product wiring board 300 (310).
[0077]
Next, in the test conductor layer forming step, first, as shown in FIG. 13B, a negative photosensitive dry film is pasted on substantially the entire surface of each of the test metal layers 41 and 42, and the test plating resist layer 43 is formed. , 44 are formed. The material of the dry film (test plating resist layers 43 and 44) is the same as that used in the conductor layer forming step of the wiring substrate 300 to be inspected, and the manufacturing conditions such as the application conditions and the exposure and development conditions described later are also used. Same as when manufacturing the product.
[0078]
Next, as shown in FIG. 14A, the attached test plating resist layers 43 and 44 are exposed to a predetermined pattern (see FIG. 12), and thereafter developed to develop the first test wiring layer 34 and the second test wiring layer 34. Test plating resist layers 45 and 46 having openings 45P and 46P having predetermined patterns corresponding to the test wiring layer 35 and the like are formed, respectively. Book Reference form 1 Since the dry film used in step 1 is a negative type in which the exposed portion is cured, the exposed portion becomes the test plating resist layers 45 and 46 having a predetermined pattern after development.
[0079]
Next, as shown in FIG. 14B, electrolytic copper plating is performed using test plating resist layers 45 and 46 having a predetermined pattern as a common electrode, and electrolytic plating layers 47 and 48 are formed on the test metal layers in the openings 45P and 46P. (Thickness 15 μm) is formed.
Further, as shown in FIG. 14C, the test plating resist layers 45 and 46 are removed, and the exposed test metal layers 41 and 42 are removed by etching. Accordingly, the test conductor layer 33 including the first test wiring layer 34 and the second test wiring layer 35 including the test metal layer 41L and the electrolytic plating layer 47 is formed on the upper surface 10A, and the test conductor layer 39 is also formed on the lower surface 10B. Is formed.
[0080]
Next, in the disconnection detection process, as in the first embodiment, probe pins are brought into contact with the check pads 34B1 and 34B2 of the first test wiring layer 34 to check the continuity between the check pads 34B1 and 34B2, and the disconnection test is performed. The presence or absence of disconnection failure of the part 34A and the downsized long part 34C is detected. Similarly, for the second test wiring layer 35, the presence or absence of disconnection failure in the disconnection test part 35A and the downsized long part 35C is detected. Unlike the first embodiment, there is no resist layer on the check pad 34B1 or the like.
Further, in the short circuit detection process, as in the first embodiment, either the check pad 34B1 or 34B2 of the first test wiring layer 34 or the check pad 35B1 or 35B2 of the second test wiring layer 35 (for example, 34B1). 35B1), probe pins are brought into contact with each other, and continuity and insulation resistance between them are examined, and there is a short circuit failure or insulation failure between the short circuit test parts 34C and 35C (between the parallel miniaturized long parts 34D and 35D). Is detected.
[0081]
Thus, since the first test wiring layer 34 and the second test wiring layer 35 are respectively provided with the check pads 34B1, 34B2, 35B1, and 35B2, the probe pins are easily brought into contact with each other. Electrical inspection can be done.
After inspecting one test region 32 for the disconnection or short circuit, such inspection is also performed for the other test regions 32, and all 144 test regions 32 in the test wiring board 1 are tested. Inspection is performed to detect the presence of disconnection failure, short circuit failure, or insulation failure. The test conductor layer 37 (the third test wiring layer 38 and the fourth test wiring layer 39) formed on the lower surface 10B is also inspected in the same manner.
[0082]
In this way, the yield of the test wiring layers 34, 35, 38, 39 by the same conductor layer forming process can be found, not the yield of the conductor layer forming process itself of the wiring board to be inspected. Therefore, unlike the prior art, it is not necessary to inspect the wiring substrate 310 or 300 until it is almost completed, and it is possible to easily estimate and evaluate the yield for each conductor layer forming process.
Also book Reference form 1 However, since the shape of the test conductor layer 33 is small enough to fit in the test region 32 shown in FIGS. 4 and 12, depending on the data aggregation method, for example, the vicinity of the four corners of the test wiring board 1 It is also possible to calculate the difference in defect occurrence rate near the center, the difference in defect occurrence rate between the test conductor layer 33 on the upper surface 10A and the test conductor layer 37 on the lower surface 10B, and the like to search for the cause of the defect. Is also possible.
Furthermore, since the test wiring board 1 is used, problems associated with the inspection such as a part of the wiring layer in the wiring board 100 to be a product are damaged by the probe pins.
[0083]
In addition, book Reference form 1 In the test conductor layer forming method, the first test wiring layer 34 and the second test wiring layer 35 having thin and long disconnection test portions 34A and 35A on the upper surface 10A of the test substrate 10 (test insulating layer 12) in the test conductor layer forming step. Is forming. In particular, the disconnection test parts 34A and 35A have the same thinness (conductor width) as that of the wiring layer 304 (see FIG. 2) of the product part 301, and are longer and smaller than the lengths 34C and 35C. I have. For this reason, if there are various problems, disconnection occurs at a much higher probability than in the case of the conductor layer forming process of the wiring substrate 300 to be inspected, so only a small amount of the test conductor layer 33 is formed. A defective product appears. Accordingly, in the conductor layer forming step of the wiring board 300, even when the possibility of disconnection failure is low, disconnection defects appear by inspecting a small number of test wiring layers 34 and 35. Alternatively, it is not necessary to inspect the product portion 301), and the yield of the conductor layer forming process can be estimated and evaluated.
[0084]
Also book Reference form 1 In this test method, the short-circuit test section 34D that maintains a small distance from each other over a distance longer than any of the parallel portions of the wiring layers 304 that extend in parallel in the test conductor layer forming step at a distance (40 μm) that is equal to the parallel portion. A first test wiring layer 34 and a second test wiring layer 35 having 35D (parallel miniaturized long portions 34E, 35E) were formed. For this reason, between the short-circuit test portions 34D and 35D, if there are various defects, a short-circuit failure or insulation failure occurs with a much higher probability than in the case of the conductor layer forming step of the wiring board 300. A defective disconnection appears only by forming a small amount of the test conductor layer 33.
Therefore, even when there is a low possibility that a short circuit failure or the like occurs in the conductor layer forming process of the wiring substrate 300 to be inspected, a short circuit failure or an insulation failure appears by inspecting a small number of test wiring layers 34 and 35. Therefore, it is not necessary to inspect a large number of wiring boards 301 (product portions 301), and the yield of the conductor layer forming process can be estimated and evaluated.
However, this Reference form Then, unlike the first embodiment, the test plating resists 45 and 46 cannot be left.
[0085]
( Reference form 2 )
Then above Reference form 1 Will be described.
the above Reference form 1 Then, a negative dry film was used as the test plating resist layer. However, when a positive dry film is used in the conductor layer forming step of the wiring substrate 300 to be inspected, it is preferable to form the test conductor layer using the same type of dry film. This is because the test conductor layer is formed under the same conditions as the wiring board 300 as much as possible.
So book Reference form 2 Then, as the test plating resist layer, a positive type dry film in which the exposed portion can be dissolved and removed is used. Accordingly, in accordance with this, the light shielding pattern of the mask at the time of exposure is also changed to a negative / positive inversion.
[0086]
Even if such a positive type test plating resist layer is used, a test conductor layer is formed in the test conductor layer forming process, a disconnection failure is detected in the disconnection detection process, and a short circuit failure or insulation failure is detected in the detection process such as a short circuit. Can be above Reference form 1 Therefore, detailed description is omitted.
[0087]
( Reference form 3 )
Embodiment 1 above Modification 1 and Reference Embodiments 1 and 2 In either case, as shown in FIG. 5 or FIG. 12, in addition to the presence or absence of disconnection of the test wiring layers 21, 22, 34, 35, etc., a short circuit or insulation between the test wiring layers 21 and 22, 34 and 35 is provided. In order to be able to determine the defect, the one having two test wiring layers 21, 22, or 34, 35 is shown.
However, if it is only necessary to detect disconnection failure, for example, a test conductor layer having a zigzag pattern shown in FIG. 15 may be formed. That is, the test wiring layer 51 including one disconnection test portion 51A and check pads 51B1 and 51B2 at both ends thereof may be formed in the test region 2. In the test wiring layer 51, in the region 52 indicated by the alternate long and short dash line, the disconnection test portion 51A is formed in a zigzag wiring pattern, and the area occupied by the zigzag wiring pattern is long in this region 52. Is a downsized long portion 51C that has been downsized so as to fit within the region 52.
For this reason, a disconnection failure is likely to occur, and the yield of the test conductor layer 51 due to the disconnection failure is estimated to estimate the yield of the actual conductor layer forming step of the wiring substrate 100, and various improvements are measured. be able to. In particular, since the miniaturized long portion 51C is provided, a difference in yield depending on the location of the test wiring board 1 (wiring board 100) can be calculated. Further, in most cases, it is sufficient to look for the broken disconnection portion in the small region 52, that is, the miniaturized long portion 51C. Therefore, the disconnection defective portion can be easily found.
In addition to the test conductor layer forming step shown in the first embodiment, the shape may be modified form 1, Reference form 1 , Reference form 2 It can be applied to any test conductor layer forming process.
[0088]
( Reference form 4 )
In addition, a test conductor layer having a spiral pattern shown in FIG. 16 may be formed. That is, the test wiring layer 61 including one disconnection test portion 61A and check pads 61B1 and 61B2 at both ends thereof may be formed in the test region 2. Also in the test wiring layer 61, in the region 62 indicated by the alternate long and short dash line, the disconnection test portion 61A is formed in a spiral wiring pattern, and the area occupied by the spiral wiring pattern is long in this region 62. Is a downsized long portion 61 </ b> C that has been downsized so as to fit within the region 62.
Because of this, the book Reference form 4 However, a disconnection failure is likely to occur, and the yield due to the disconnection failure of the test conductor layer 61 is used to estimate the actual yield of the conductor layer forming process of the wiring substrate 100, or the cause investigation or various improvement effects. Can be measured. In particular, since the miniaturized long portion 61C is provided, a difference in yield depending on the location of the test wiring board 1 (wiring board 100) can be calculated. In addition, in most cases, it is sufficient to look in the small area 62 to find the disconnection failure portion, and therefore, the disconnection failure portion can be easily found.
In addition to the test conductor layer forming step shown in the first embodiment, the shape may be modified, Reference form 1 , Reference form 2 It can be applied to any test conductor layer forming process.
[0089]
( Reference form 5 )
On the other hand, when it is sufficient to detect only a short circuit failure or insulation failure, for example, a test conductor layer having a comb-like pattern in which a pair of test wiring layers mesh with each other may be formed as shown in FIG. That is, the two test wiring layers 71 and 72 formed in the test region 2 include check teeth 71B and 72B, as well as comb-teeth portions 71A and 72A formed in a comb-teeth shape with a small gap therebetween. Connection portions 71C and 72C are provided to connect the comb-like portions 71A and 72A and the check pads 71B and 72B. Although the area occupied by the test wiring layers 71 and 72 is reduced by the comb upper portions 71A and 72A, the length maintaining a small interval between the two test wiring layers can be increased.
For this reason, even in a small area, there is a high probability that a short circuit failure or insulation failure will appear between the test wiring layers 71 and 72 (comb-like portions 71A and 82A), and it is easy to investigate the cause and evaluate the effect of the countermeasures. it can. Further, the yield of the conductor layer forming process of the actual wiring board 100 can be estimated by using the yield due to defects such as short circuits of the test wiring layers 71 and 72. In particular, since the comb-like portions 71A and 72A are provided, a difference in yield depending on the location of the test wiring board 1 (wiring board 100) can be calculated. Further, in most cases, it is sufficient to look for a defective portion such as a short circuit in the small area 73, that is, between the comb-like portions 71A and 72A. Therefore, it is possible to easily find a defective portion such as a short circuit.
[0090]
In the above, the embodiments of the present invention are described. , Deformation and reference forms However, it goes without saying that the present invention is not limited to the above-described embodiment and the like, and can be appropriately modified and applied without departing from the gist thereof.
For example, the above embodiments 1st The disconnection test portion 21A and the like having the same width as the width of the wiring layer 104 of the product wiring board 100 are formed. However, the width of the disconnection test portion 21A and the like can be changed as appropriate. At this time, if the width of the disconnection test portion is reduced, disconnection defects are more likely to occur. Therefore, it is preferable that a disconnection defect product appears only by forming a small amount of the test conductor layer.
[0091]
Moreover, in the said embodiment etc., although the test etching resist layers 16 and 17 or the test plating resist layers 43 and 44 were formed using the dry film which photosensitive resin was made into the semi-hardened state previously, varnish-like photosensitive property is formed. Each resist layer may be formed by applying and drying a resin. Further, although a negative or positive photosensitive resin is used as the resist layer, a non-photosensitive resin may be applied in a predetermined pattern by a screen printing method or the like to form a resist layer.
In each of the above-described embodiments, the check pad is provided at the end of the test wiring layer. However, the present invention is not limited to this. For example, the check pad can be provided in the middle of the disconnection test part.
[0092]
Moreover, in the said embodiment etc., although the test conductor layer was formed in both surfaces of the test board | substrate by the test conductor layer formation process, it is clear that you may form only in one side.
In the above-described embodiments and the like, the test substrate 10 is formed by forming the epoxy resin-based test insulating layers 12 and 13 on the top and bottom of the test core substrate 11 made of a glass-epoxy resin composite material. What is necessary is just to consider a material, a process, etc. so that it may become the same conditions as the conductor layer formation process of the wiring board which is object.
In addition, prior to the conductor layer forming step of the wiring board, for example, when a rough surface treatment or the like is applied to the insulating layer serving as the base of the conductor layer, the same applies to the surface of the test insulating layer of the test board. It is preferable to carry out the treatment.
In addition, the first embodiment Modification 1 and Reference Embodiments 1 and 2 In FIG. 2, the two test wiring layers 21, 22, and 34, 35 are formed, but three or more test wiring layers may be formed to measure the presence or absence of a short circuit or insulation failure between them.
[Brief description of the drawings]
FIG. 1 is a plan view of a wiring board (an intermediate process product, large format) on which a conductor layer is formed in a conductor layer forming process to be inspected according to the first embodiment.
FIG. 2 is a plan view showing a planar shape of a formed conductor layer.
FIG. 3 is an explanatory diagram of wiring boards separated after completion.
4 is a plan view of a test wiring board according to Embodiment 1. FIG.
FIG. 5 is a plan view showing a planar shape of a test conductor layer (test wiring layer) formed in a test region of the test wiring board according to the first embodiment.
6A shows a test conductor layer forming process for forming a test conductor layer according to Embodiment 1. FIG. 6A shows a double-sided copper-clad board, and FIG. 6B shows a test etching resist layer on the upper and lower surfaces of the double-sided copper-clad board. It is a partial expanded sectional view which shows the state formed.
7A shows a state in which a test etching resist layer having a predetermined pattern is formed, and FIG. 7B shows a state in which a test etching resist layer is formed. It is a partial section perspective view showing the state where a test wiring layer was formed, leaving.
8A is a partial cross-sectional perspective view showing a state in which a disconnection occurs in the test wiring layer while the test etching resist layer is connected, and FIG. 8B is a perspective view of the test etching resist layer according to the first embodiment; FIG. 4C is a partially enlarged cross-sectional view showing a state in which foreign matter is sandwiched underneath, and FIG.
9A is a partial enlarged cross-sectional view illustrating a state where both the test etching resist layer and the test wiring layer are disconnected, and FIG. 9B is a diagram illustrating a state in which foreign matter adheres to the test etching resist layer. It is explanatory drawing which shows a mode that exposure failure produces.
FIG. 10 is a partial cross-sectional perspective view showing a state in which a short circuit occurs between test wiring layers although the test etching resist layers are not connected to each other, and (b) is a test etching resist layer according to the first embodiment. FIG. 6C is a partially enlarged cross-sectional view showing a state in which foreign matter has adhered between and between the metal layer and the test etching resist layer.
11A is a partial cross-sectional perspective view showing a state in which the test etching resist layers are connected to each other to cause a short circuit between the test wiring layers, and FIG. It is explanatory drawing which shows a mode that a foreign material adheres and an exposure defect arises.
FIG. Reference form 1 It is a top view which shows the planar shape of the test conductor layer (test wiring layer) formed in the test area | region of the test wiring board which concerns on this.
FIG. 13 Reference form 1 (A) shows a test substrate body in which a copper layer is formed on both sides, and (b) shows a state in which a test plating resist layer is formed on this copper layer. It is a partial expanded sectional view shown.
FIG. 14 Reference form 2 In the test conductor layer forming step of forming the test conductor layer according to the above, (a) is a state in which a test plating resist layer having a predetermined pattern is formed, (b) is a state in which an electrolytic plating layer is formed, and (c) is an etching process. It is a fragmentary sectional perspective view which shows the state in which the test wiring layer was formed.
FIG. 15 Reference form 3 It is a top view which shows the planar shape of the test conductor layer (test wiring layer) concerning.
FIG. 16 Reference form 4 It is a top view which shows the planar shape of the test conductor layer (test wiring layer) concerning.
FIG. 17 Reference form 5 It is a top view which shows the planar shape of the test conductor layer (test wiring layer) concerning.
[Explanation of symbols]
100,300 Wiring board
101,301 Product Department
102,302 connection part
103,303 Conductor layer
104,304 Wiring layer
110,310 wiring board
1 Test wiring board
2,32 test area
5 Unnecessary parts
10 Test board
11 Test core board
12, 13 Test insulation layer
14,15 Copper layer (test metal layer)
16, 17 Test etching resist layer
18, 19, 218 Test etching resist layer of predetermined pattern
21, 34 First test wiring layer
21A, 34A Disconnection test section (of first test wiring layer)
21B, 34B (first test wiring layer) check pad
21C, 34C Miniaturized long section (of the first test wiring layer)
21D, 34D (first test wiring layer) short-circuit test section
21E, 34E Parallel miniaturized long section (of the first test wiring layer)
22, 35 Second test wiring layer
22A, 35A Disconnection test section (of second test wiring layer)
22B, 35B (second test wiring layer) check pad
22C, 35C downsized long part (of second test wiring layer)
22D, 35D (second test wiring layer) short circuit test section
22E, 35E Parallel miniaturized long section (of second test wiring layer)
23, 33 Test conductor layer
41, 42 Test metal layer
43, 44 Test plating resist layer
44, 45 Test plating resist layer of predetermined pattern
44P, 45P opening
47, 48 Electrolytic plating layer
51, 61, 71, 72 Test wiring layer
71A, 72A comb teeth

Claims (6)

A conductor layer forming step of forming an etching resist layer having a predetermined pattern on a metal layer formed on an insulating layer, removing the exposed metal layer by etching, and removing the etching resist layer to form a conductor layer having a predetermined pattern A method for inspecting a conductor layer forming step of a wiring board for inspecting
A test etching resist layer having a predetermined test pattern is formed on the test metal layer formed on the test insulating layer, and the exposed test metal layer is removed by etching to leave the test etching resist layer, and a thin and long disconnection test portion is formed. A test conductor layer forming step of forming a test conductor layer including a test wiring layer having,
In the state where the test etching resist layer remains, the continuity of the disconnection test part is examined, the presence or absence of disconnection failure in the disconnection test part is detected, and when the disconnection defect occurs, the test etching is performed at the disconnection site. Disconnection detection step for checking whether or not the resist layer remains ,
An inspection method for a conductor layer forming step of a wiring board, comprising: It is an inspection method of the conductor layer formation process of the wiring board according to claim 1,
The disconnection test section is provided with a downsized long section in which the area occupied by the entire wiring pattern is reduced by a wiring pattern such as a meandering shape, a zigzag shape, and a spiral shape while being long. An inspection method of a conductor layer forming process of a substrate. A conductor layer forming step of forming an etching resist layer having a predetermined pattern on a metal layer formed on an insulating layer, removing the exposed metal layer by etching, and removing the etching resist layer to form a conductor layer having a predetermined pattern A method for inspecting a conductor layer forming step of a wiring board for inspecting
A test etching resist layer having a predetermined test pattern is formed on the test metal layer formed on the test insulating layer, and the exposed test metal layer is removed by etching, leaving the test etching resist layer, and being spaced apart from each other over a long distance. A test conductor layer forming step of forming a test conductor layer including a plurality of test wiring layers having a short-circuit test portion for maintaining
With the test etching resist layer left, the continuity or insulation resistance between the short-circuit test parts was examined, the presence or absence of a short-circuit defect or insulation failure between the short-circuit test parts was detected, and the short-circuit defect or insulation defect occurred. When detecting the test etching resist layer remains in the occurrence site, such as a short-circuit detection step,
An inspection method for a conductor layer forming step of a wiring board, comprising: It is an inspection method of the conductor layer formation process of the wiring board according to claim 3,
In the short-circuit test section, the test wiring layers that form a pair extend in parallel with each other, and while being long, the area occupied by the entire wiring pattern is reduced by a wiring pattern such as a meandering shape, a zigzag shape, and a spiral shape. A method for inspecting a conductor layer forming step of a wiring board, comprising: a parallel miniaturized long section. It is an inspection method of the conductor layer formation process of the wiring board according to claim 4,
While leaving the test etching resist layer, the continuity of the short-circuit test part is examined, the presence or absence of a disconnection defect in the short-circuit test part is detected, and when the disconnection defect occurs, the test etching is performed at the disconnection part. An inspection method for a conductor layer forming step of a wiring board, comprising a disconnection detecting step for checking whether or not a resist layer remains . It is an inspection method of the conductor layer formation process of the wiring board according to claim 3,
A test method for a conductor layer forming step of a wiring board, wherein the short-circuit test part of the pair of test wiring layers includes a comb-teeth part of a comb-teeth wiring pattern that meshes with each other.

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