JPH06326434A - Printed circuit board - Google Patents

Abstract

PURPOSE:To provide a printed circuit board wherein an application difference between conductive resist and terminal patterns can be easily ascertained, printed circuit boards can be easily discriminated from each other, and the terminal patterns can be surely prevented from being short-circuited with conductive resist. CONSTITUTION:When conductive resist 7 is applied onto terminal patterns 3 provided at an outer equipment connector, a wedge-shaped index 8 is provided to the tip of each conductive resist 7. A mark 9 which identifies a terminal pattern 3 is provided to the tip of the index 8 of the conductive resist 7 when the conductive resist is applied, and a small hole 10 is bored between the terminal patterns 3 after the conductive resist 7 is applied and dried up.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing having a circuit pattern forming portion having a predetermined circuit pattern formed therein and a tail portion having a plurality of terminal patterns continuous with the circuit pattern and connected to an external device. Regarding circuit boards, especially when applying conductive resist by wrapping each terminal pattern to protect each terminal pattern in the external device connection part, you can easily check the lap state of each terminal pattern and conductive resist Printed circuit board.

[0002]

2. Description of the Related Art Conventionally, various printed circuit boards have been proposed. Among them, a printed circuit board used for a keyboard or the like is generally a circuit pattern forming portion having a predetermined switch circuit pattern and a circuit pattern forming portion. And a tail portion formed with a plurality of terminal patterns continuous with the circuit pattern for outputting the switch signal generated in step 1 to an external device. Then, the tail portion is connected to a connector or the like having a plurality of connection terminals to electrically connect the printed circuit board and the external device. At this time, each terminal pattern in the tail portion of the printed circuit board is connected to each connection terminal of the connector, and at the time of such connection, each connection terminal of the connector slides on each terminal pattern of the tail portion. While both are connected. If such a connecting operation is repeated, each terminal pattern may be damaged by the connecting portion of the connector. Therefore, in the printed circuit board, in general, each terminal pattern should be protected in order to protect each terminal pattern. A conductive resist made of carbon paint or the like is applied and formed on. When applying the conductive resist on each terminal pattern of the tail portion, the conductive resist is applied on each terminal pattern while positioning and fixing the printed circuit board by using an automatic applying device.

When the printed circuit board as described above is incorporated in a device such as a keyboard, the circuit board is rarely used alone, and a plurality of circuit boards are used in combination. Often. In such cases,
If the wrong combination of circuit boards is installed, the device such as the keyboard may not operate normally and may become defective.So far, the assembler has been checking the combination of each printed circuit board. It was being assembled.

Further, in the printed circuit board, the circuit pattern and the terminal pattern formed in the circuit pattern forming portion may be deteriorated due to oxidation or the like for a long period of time, so that these circuit pattern and the terminal pattern are protected. Therefore, an insulating resist made of an insulating paint such as an epoxy type, an acrylic type, a polyester type, or a rubber type is often applied except the external device connecting portion in the terminal pattern. Then, after applying the insulating resist, the conductive resist is generally applied on each terminal pattern in the external device connecting portion as described above. In this case, the conductive resist may flow while bleeding toward the terminal pattern adjacent to the insulating resist along the boundary that defines the external device connection portion. Thus, if the conductive resist bleeds, there is a risk of short-circuiting between the terminal patterns, and in order to prevent this, conventionally, for example, as described in Japanese Patent Laid-Open No. 64-5096. The shape of the boundary portion of the insulating resist in the external device connecting portion is configured to cross each terminal pattern.

[0005]

By the way, in the above-mentioned conventional printed circuit board, when a conductive resist is applied to each terminal pattern in the tail portion, it is applied while positioning and fixing the circuit board by an automatic application device. However, when the coating operation is continued, the conductive resist may be misaligned with the terminal pattern. A printed circuit board having such a coating deviation cannot effectively protect the terminal pattern from the wear that occurs when connecting to the external terminals, and therefore should not be excluded from the inspection stage and used in products such as keyboards. However, in the conventional printed circuit board, it is extremely difficult to quickly identify the coating deviation occurring between each terminal pattern and the conductive resist, and a product using the printed circuit board having the coating deviation is manufactured. There was a possibility that it would be lost.
As a result, there has been a problem that the inspection pass rate of the product deteriorates when the product is inspected.

Further, when assembling a plurality of printed circuit boards into a product such as a keyboard, an assembler checks the combination of the printed circuit boards and assembles them. However, the circuit patterns on the respective circuit boards are very similar to each other. As such, it can be difficult at first glance to quickly distinguish between printed circuit boards during assembly. Than this,
There is a possibility that a defective product may be manufactured due to an incorrect assembly of the printed circuit board, and as a result, there remains a problem that the inspection pass rate of the product deteriorates.

Further, when the conductive resist is applied, the shape of the boundary portion of the insulating resist in the external device connecting portion is changed so as to prevent each terminal pattern from being short-circuited due to the bleeding of the conductive resist. Although the patterns were obliquely intersected with each other, even if such a configuration was adopted, there was still a possibility that the terminal patterns would still be short-circuited.

The present invention has been made to solve the above-mentioned problems, and easily confirms the coating deviation between the conductive resist and each terminal pattern, and the discrimination between each printed circuit board. Therefore, it is possible to reliably eliminate the printed circuit board having coating deviation between the conductive resist and each terminal pattern to prevent the occurrence of defective products using the printed circuit board having coating deviation, and An object of the present invention is to provide a printed circuit board capable of preventing the occurrence of defective products caused by a combination of boards. Further, the present invention surely prevents the terminal patterns from being short-circuited with each other when the conductive resist is applied to the plurality of terminal patterns formed on the tail portion of the printed circuit board. It is an object of the present invention to provide a printed circuit board.

[0009]

To achieve the above object, the present invention provides a circuit pattern forming portion having a predetermined circuit pattern and a plurality of terminal patterns continuous with the circuit pattern and connected to an external device. In a printed circuit board having a formed tail portion and applying a conductive resist so as to wrap each of the external device connection portions in each terminal pattern, in each of the conductive resist,
The indicator portion is formed so as to indicate the state of wrapping with each terminal pattern. Further, the indicator portion is provided in a wedge shape toward the circuit pattern forming portion, and
A symbol for identifying each terminal pattern is formed near the conductive resist. Further, an insulating resist is applied to the circuit pattern forming portion and the tail portion except for the external device connecting portion, and between the terminal patterns in the vicinity of the boundary of the insulating resist partitioning the external device connecting portion. The small holes are formed.

[0010]

According to the present invention having the above-mentioned structure, the conductive resist is applied so as to wrap around each of the plurality of terminal patterns formed on the tail portion of the printed circuit board. A wedge-shaped index portion indicating the wrapped state is provided. Thereby, the coating deviation between the conductive resist and each terminal pattern can be easily confirmed through the index portion, and the printed circuit board having the coating deviation between the conductive resist and each terminal pattern can be surely removed to prevent the coating deviation. It is possible to prevent the occurrence of defective products using a certain printed circuit board.

Further, a symbol for identifying each terminal pattern is formed at a position near each terminal pattern in the tail portion of the printed circuit board, and when a plurality of circuit patterns are incorporated into a product from this, the symbol is used to intervene. It is possible to easily identify the difference between the printed circuit boards and prevent the generation of defective products caused by the combination of the printed circuit boards.

Further, in the printed circuit board according to the present invention, an insulating resist is applied to the circuit pattern forming portion and the tail portion except for the external device connecting portion, and the insulating resist is in the vicinity of the boundary defining the external device connecting portion. A small hole is formed between the terminal patterns. Based on this configuration,
Even if the conductive resist bleeds along the boundary of the insulating resist when applying the conductive resist onto each terminal pattern, the insulation between the terminal patterns is reliably maintained through each small hole. As a result, it is possible to reliably prevent the terminal patterns from being short-circuited with each other.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a flexible circuit board will be described in detail below with reference to the drawings. FIG. 1 is an overall view of a printed circuit board, a part of which is omitted. The printed circuit board PC is formed of a film substrate such as a polyester film, and a circuit pattern forming section 2 provided with a predetermined circuit pattern 1 such as a switch circuit using a conductor such as copper foil, and a circuit pattern 1. It is integrally formed from a tail portion 4 formed with a terminal pattern 3 which is continuous and connected to an external device.

An insulating resist 6 made of an epoxy-based, acrylic-based, polyester-based, rubber-based, or other insulating coating material over the entire surface of the circuit pattern forming portion 2 (see FIG. 2, etc.).
Is applied, and the circuit pattern 1 is protected by the insulating resist 6. The insulating resist 6 is also applied to a portion of the tail portion 4 on the side of the circuit pattern forming portion 2 with the boundary line K that defines the external device connecting portion 5 as a boundary, thereby protecting each terminal pattern 3. ing. The external device connecting section 5 is provided on the end side (downward from the boundary line 5 in FIG. 1) of the boundary line K of the tail section 4, and the external device connecting section 5 is connected via a connector or the like. It is connected to an external device such as a computer.

Next, the detailed structure of the tail portion 4 will be described with reference to FIG. FIG. 2 is an explanatory view schematically showing the tail portion in an enlarged manner. In the external device connecting portion 5 defined by the boundary line K, the conductive resist 7 made of carbon paint or the like is wrapped around each terminal pattern 3. Is formed by coating. The conductive resist 7 is caused by the fact that each terminal pattern 3 provided in the external device connecting portion 5 is slidably inserted into the inside of a connector or the like, and thus the connecting operation is repeated. Each terminal pattern 3 is prevented from being worn or peeled off by
It is formed by coating in order to maintain the durability and reliability of the.

The coating shape of the conductive resist 7 is shown in FIG.
As shown in FIG. 5, the tip end portion toward the circuit pattern forming portion 2 is formed in a wedge shape, and the tip end portion of the conductive resist 7 having the wedge shape is an index portion indicating a lap state between each terminal pattern 3 and the conductive resist 7. Make up 8. The lapped state between each terminal pattern 3 and each conductive resist 7 configured as described above can be easily confirmed by visually observing how much the wedge-shaped index portion 8 is displaced from the center of each terminal pattern 3 in the width direction. Can be judged. Therefore, when the printed circuit board is inspected or when the printed circuit board PC is incorporated into a product such as a keyboard, the terminal pattern 3 and the conductive resist 7 are checked by the wrapping state based on the index portion 8 so as to check each terminal pattern. It is possible to reliably eliminate the printed circuit board PC in which the coating deviation has occurred between 3 and each conductive resist 7.

Further, at a position slightly apart from the tip of the index portion 8 in each conductive resist 7, a symbol 9 for identifying each terminal pattern 3 (in FIG. 2, the English character "ABCDEF") is specified.
Corresponding to each terminal pattern 3) are formed. These symbols 9 are formed by coating when the conductive resist 7 is formed by coating, and different symbols are formed by coating for each printed circuit board PC. As a result, the printed circuit board PC can be easily identified by referring to the symbol 9. Therefore, when a plurality of printed circuit boards PC are combined and incorporated into a product such as a keyboard, the symbol 9 is confirmed. As a result, it is possible to identify the printed circuit board PC corresponding to each work process and prevent the occurrence of defective products due to a wrong assembly of the printed circuit boards PC. As a result, the product inspection passing rate of the final product can be significantly increased. Further, by referring to each symbol 9, it is possible to very easily identify which circuit pattern 1 in the circuit pattern forming portion 2 each terminal pattern 3 is connected to, and from this, maintenance of products such as keyboards can be performed. When performing an inspection or the like, it is possible to easily find a defective portion and quickly perform maintenance or inspection.

Small holes 10 are provided on the boundary K between the terminal patterns 3, respectively. Each of these small holes 10 is formed after the conductive resist 7 is applied and formed and dried. With this configuration, when the conductive resist 7 is applied and formed on each terminal pattern 3 in the external device connection portion 5, the conductive resist 7 is a boundary portion of the insulating resist 6 (partitioned by the boundary line K). Even if the terminal patterns 3 are short-circuited with each other through the conductive resist 7 by flowing while flowing along the conductive resist, the small holes 10 are bored to short-circuit the terminal patterns 3 with each other. 7 can be reliably removed. Therefore, there is no possibility that the terminal patterns 3 are short-circuited with each other, and the terminal patterns 3 can be reliably insulated.

As described in detail above, in the printed circuit board PC according to the present embodiment, when the conductive resist 7 is applied and formed on each terminal pattern 3 in the external device connecting portion 5, the tip end portion of each conductive resist 7 is formed. Since the wedge-shaped index portion 8 is formed on the upper surface of the terminal pattern 3, the wedge-shaped index portion 8 can be used to determine the overlapped state of each terminal pattern 3 and each conductive resist 7 from the center in the width direction of each terminal pattern 3. It can be easily determined by visually observing whether there is a deviation. As a result, when the printed circuit board is inspected or the printed circuit board PC is incorporated into a product such as a keyboard, the indicator portion 8
By confirming the lapped state of the terminal pattern 3 and the conductive resist 7 on the basis of the above, it is possible to surely eliminate the printed circuit board PC in which the application deviation occurs between each terminal pattern 3 and each conductive resist 7. You can

Further, when each conductive resist 7 is applied and formed, the symbol 9 for identifying each terminal pattern 3 is formed at the tip of the index portion 8 in each conductive resist 7, so that each symbol 9 is replaced by the symbol 9. By referring to the printed circuit board PC, the printed circuit board PC can be easily identified. Therefore, when a plurality of printed circuit boards PC are combined and incorporated into a product such as a keyboard, the printed circuit board PC corresponding to each work process can be identified by checking the symbol 9, and each printed circuit board PC can be identified. Occurrence of defective products due to mistakes can be prevented, and as a result, the product inspection passing rate of the final products can be significantly increased. Further, by referring to each symbol 9, it is possible to very easily identify which circuit pattern 1 in the circuit pattern forming portion 2 each terminal pattern 3 is connected to. Therefore, maintenance of a product such as a keyboard can be performed. When performing an inspection or the like, it is possible to easily find a defective portion and quickly perform maintenance or inspection.

Further, since the conductive resist 7 is applied and dried and then the small holes 10 are formed between the terminal patterns 3, the conductive resist 7 is formed on each terminal pattern 3 in the external device connecting portion 5. Even when each terminal pattern 3 is short-circuited with each other through the conductive resist 7 due to the conductive resist 7 flowing along the boundary of the insulating resist 6 while being formed by coating, Hole 1
By forming 0, the conductive resist 7 that short-circuits the terminal patterns 3 can be reliably removed. Therefore, there is no possibility that the terminal patterns 3 will be short-circuited to each other, and the terminals can be reliably insulated.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various improvements and modifications can be made without departing from the gist of the present invention. For example, in the above-mentioned embodiment, the wedge-shaped index portion 8 is provided at the tip of each conductive resist 7, but if the index portion 8 has an acute-angled vertex within the width of each terminal pattern 3. Obviously, any shape may be used. For example, as shown in FIG. 3, the conductive resist 7 may have a wedge-shaped index portion 11 formed toward the external device connection portion 5 side.

In the above embodiments, the flexible circuit board formed of the film base material has been described as an example. However, even a hard circuit board formed of a paper-phenol base material, a glass-epoxy base material or the like can be used. Of course, the same effect as that of the embodiment can be obtained. Further, the symbol 9 applied and formed on the tip of each conductive resist may be any symbol as long as it is a symbol that can identify each terminal pattern 3 in addition to the English letters.

[0024]

As described above, according to the present invention, it is possible to easily confirm the coating misalignment between the conductive resist and each terminal pattern and the discrimination between each printed circuit board. The printed circuit board with coating misalignment between the terminal patterns can be reliably eliminated to prevent the occurrence of defective products using printed circuit boards with coating misalignment. It is possible to provide a printed circuit board capable of preventing the occurrence. Further, the present invention surely prevents the terminal patterns from being short-circuited with each other when the conductive resist is applied to the plurality of terminal patterns formed on the tail portion of the printed circuit board. A printed circuit board can be provided.

[Brief description of drawings]

FIG. 1 is an overall view of a printed circuit board with a part omitted.

FIG. 2 is an explanatory diagram schematically showing an enlarged tail portion.

FIG. 3 is an enlarged explanatory view of a tail portion showing another example of the indicator portion formed on the conductive resist.

[Explanation of symbols]

 1 Circuit pattern 2 Circuit pattern forming part 3 Terminal pattern 4 Tail part 5 External device connection part 6 Insulating resist 7 Conductive resist 8 Index part 9 Symbol 10 Small hole 11 Wedge shaped index part

Claims (4)

[Claims] 1. A circuit pattern forming portion having a predetermined circuit pattern formed therein, and a tail portion having a plurality of terminal patterns continuous with the circuit pattern and connected to an external device. In a printed circuit board formed by applying a conductive resist so as to wrap each of the external device connection parts, each of the conductive resists is formed with an indicator portion indicating a wrap state with each of the terminal patterns. A printed circuit board characterized by. 2. The printed circuit board according to claim 1, wherein the indicator portion is provided in a wedge shape toward the circuit pattern forming portion. 3. The printed circuit board according to claim 1, wherein a symbol specifying each of the terminal patterns is formed at a position near the conductive resist. 4. An insulating resist is applied to the circuit pattern forming portion and the tail portion except the external device connecting portion,
The printed circuit board according to claim 1, wherein small holes are formed between the terminal patterns in the vicinity of a boundary of the insulating resist that defines the external device connection portion.