JP2003179318A - Printed wiring board and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reliable printed wiring board and a manufacturing method therefor, capable of wiring in high density even near a land with a teardrop. <P>SOLUTION: Left and right teardrops 40A and 40B are formed to a land 32 which can assure sufficient insulation interval from a line. Meanwhile, to a land 30 close to lines 24 and 26, a teardrop 40B of side angle 30° is fitted on the left side in the figure while a teardrop 44A of side angle 50° is fitted on the right side. By fitting a small, or large side angle, teardrop 44A on the right side of the land 30, two lines 24 and 26 can be disposed between the land 30 and the land 32. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed wiring board having a conductor circuit composed of lines and lands, and a tear drop formed at a connecting portion between the lines and lands, and a method for manufacturing the printed wiring board. Is.

[0002]

2. Description of the Related Art In a printed wiring board having a conductor circuit composed of lines and lands, as shown in FIG. 140 may be provided. In recent years, printed wiring boards are becoming finer patterns due to high-density mounting, and small-diameter through holes and the like are frequently used, and land 13 is used to increase reliability of electrical continuity.
The addition of teardrop 140 to 0 is mandatory. That is, as shown in FIG.
When 4 can be arranged in the central portion of the land 130, there is no problem in electrical conduction, but when the through hole 154 is formed near the line 120 as shown in FIG. The reliability of conduction between the land 130 and the line 120 is lacking. Therefore, it is indispensable to dispose the tear drop 140.

Particularly, in the case of a flexible substrate, FIG.
If the line 120 is directly connected to the land 130 as shown in FIG.
In some cases, stress concentrates on the connecting portion C between the 0 and the land 130, and disconnection occurs at the connecting portion C between the line 120 and the land 130. In order to avoid this, the reliability of electrical conduction is improved. A tear drop 140 is arranged as shown in FIG.

Here, the teardrop 14 on the land 30
When 0 is added, the area of the land 130 becomes large, and there is a problem that the density cannot be increased as compared with the case where the tear drop 140 is not added.

[0005]

Here, the applicant of the present invention is
According to Japanese Patent No. 2519068, when the tear drop 140 is added to the land 130, the right tear drop 140A cannot have a predetermined insulation distance d from the other conductor circuit 122 as shown in FIG. 10D. Sometimes FIG.
As shown in (E), a technique has been disclosed in which the tear drop 140B on the left side, which has no problem with the insulation distance, is arranged only on one side, that is, the tear drop. However, no reference was made to a specific method for disposing on only one side.

In addition, when the teardrop is arranged on only one side as described above, compared with the case where no teardrop is provided, the electrical conductivity and the risk of disconnection can be avoided, but a normal teardrop is provided. It was undeniable that the performance was inferior to the drop.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a highly reliable printed wiring board capable of high-density wiring in the vicinity of a land with a tear drop. It is to provide a method for manufacturing a printed wiring board.

[0008]

In order to achieve the above object, the invention of claim 1 has a conductor circuit composed of a line and a land, and a print in which a tear drop is formed at the connecting portion of the line and the land. A technical feature of the wiring board is that a teardrop that is asymmetrical to the left and right is provided in a portion where a line is inserted in the land.

According to a second aspect of the present invention, there is provided a printed circuit board having a conductor circuit composed of a line and a land, and forming left and right tear drops at a connecting portion between the line and the land. It is a technical feature that it has a step of judging whether the teardrops arranged in each of them have a predetermined distance from other conductor circuits, and a step of adding a teardrop to the side having the predetermined distance. .

According to a third aspect of the present invention, there is provided a printed circuit board having a conductor circuit composed of a line and a land, and forming a tear drop within a preset shape on the left and right at a connecting portion of the line and the land. In the manufacturing method, the step of determining whether each of the teardrops having the shape 1 disposed on the left or right of the line has a predetermined distance from another conductor circuit, and And a step of adding a teardrop.

In the printed wiring board according to the first aspect, since the left and right asymmetrical teardrops 40B and 44A are provided at the portion where the line 20 enters the land 30, the right and left teardrops 40B and 44A are respectively provided in the conductor circuit. It can be formed so that a predetermined distance from 24 can be maintained.

In the method of manufacturing a printed wiring board according to the present invention, the teardrops arranged on the left and right of the line are
It is determined whether or not each conductor circuit has a predetermined distance from another conductor circuit, and a tear drop is added to the side having the predetermined distance. Therefore, the tear drop can be formed so as to keep a predetermined distance from the conductor circuit.

In the method of manufacturing a printed wiring board according to a third aspect of the present invention, it is determined whether each of the teardrops having the shape 1 arranged on the left or right of the line has a predetermined distance from another conductor circuit, A teardrop having a shape capable of providing a predetermined interval is added. Therefore, the right and left teardrops can be formed so as to be able to maintain a predetermined distance from the conductor circuit.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION A printed wiring board according to a first embodiment of the present invention will be described below with reference to the drawings. Figure 1
FIG. 3 is a partially enlarged plan view of the printed wiring board 10 on which the tear drop 40 according to the first embodiment is arranged. L1 in the figure
L10 and M1 to M11 indicate tracks that can pass through the line.

In this embodiment, the left and right tear drops 40A and 40B are formed on the land 32 which has a sufficient insulation distance from the line. On the other hand, line 2
The land drop 40B is attached only to the left side of the drawing with respect to the land 30 which is close to the Nos. 4 and 26.
In this way, by attaching the tear drop 40B to the land 30 only on the side opposite to the land 32, the two lines 24, 26 are provided between the land 30 and the land 32.
It is possible to arrange.

The type of tear drop according to the first embodiment formed on the printed wiring board will be described with reference to FIG. 2. In FIG. 2 (A), the tear drop angle is 80 degrees on the left and right of the line 20. Teardrop 40A,
40B is shown. The teardrops 40A and 40B shown in FIG. 2A are formed when a predetermined insulation distance (for example, 100 μ) can be maintained from the surrounding conductor circuit like the land 32 shown in FIG.

FIG. 2B shows a teardrop 42 formed with a teardrop angle of 90 degrees to the left and right of the line 20.
A and 42B are shown. When the teardrops 42A and 42B shown in FIG. 2B are formed with the 80-degree teardrops 40A and 40B described above with reference to FIG. 2A, one of them has a predetermined insulation from the surrounding conductor circuit. It is used when a predetermined insulation distance can be secured by forming the tear drop angle at 90 degrees, although the spacing cannot be secured.

As shown in FIG. 1C, when the teardrop 40A on the right side of 90 degrees shown in FIG. 2B is formed, FIG. 2C shows a conductor circuit on the right side not shown. Although a predetermined insulation distance cannot be provided between them, even if a tear drop 40B of 80 degrees is formed on the left side, the tear drop 40B is used when the insulation distance can be obtained.

Similar to FIG. 2 (C), FIG. 2 (D) does not allow insulation when the tear drop is formed on the left side, but even if the tear drop 40A of 80 degrees is formed on the right side, the insulation interval is not formed. It is used when can be taken.

FIG. 2 (E) shows a case in which an insulation interval cannot be obtained from the right teardrop and also an insulation interval cannot be obtained from the left teardrop, and the teardrop is not added.

In the present embodiment, the conductor circuit such as the land tear drop line described above is formed by photoetching. A process for forming a pattern on the mask film for photoetching will be described with reference to the flowchart of FIG. Here, the pattern creation process for forming conductor circuits such as lands and lines has already been completed,
The description starts with the process of adding a teardrop to the formed land.

First, for the land including all the lines, the teardrops 40A and 40 are adjusted so that the teardrop angle becomes 80 degrees described above with reference to FIG.
B is added (S12). After that, it is checked whether or not the tear drops 40A and 40B of the respective added lands can maintain a predetermined insulation distance (for example, 100 μ) from the surrounding conductor circuits (S14). Here, if it is possible to maintain a predetermined insulation interval for all tear drops (S18 is Y
es), and the process ends.

On the other hand, if the insulation distance cannot be maintained for the teardrops of some lands (S18 is N
o), the process proceeds to step 20, and the 90 ° tear drops 42A and 42B described above with reference to FIG. 2B are added to the land that cannot maintain the insulation distance. Then, it is checked whether or not the tear drops 42A and 42B of the respective added lands can maintain a predetermined insulation distance from the surrounding conductor circuits (S22). Here, in the case where the predetermined insulation interval can be maintained for all teardrops (Yes in S24).
s), the process ends.

On the other hand, if the insulation distance cannot be maintained for the teardrops of some lands (S24 is N
o), the process proceeds to step 26, and is it possible to maintain the insulation distance from the left tear drop 40B described above with reference to FIG. 2C for the land that cannot maintain the insulation distance, and FIG.
It is checked with reference to (D) whether the insulation distance can be maintained from the above-mentioned right tear drop 40A. Here, when the insulation distance can be maintained from the left tear drop 40B, FIG.
When the left teardrop 40B is added as shown in FIG. 2 and the insulation distance from the right teardrop 40A can be maintained, the right teardrop 40A shown in FIG. 2D is added (S28). After that, it is determined that the tear drop is not added to the land to which the tear drop cannot be added so as to maintain the insulation interval on either side (S30), and the process is ended.

The pattern forming data is completed by the above processing, and the mask film is completed by forming a pattern corresponding to the conductive circuit on the resin film using the data. Here, formation of a conductive circuit of a printed wiring board using the mask film will be described with reference to FIG.

As shown in FIG. 4A, a starting material is a copper clad laminate 60a in which a copper foil 62 of 18 μm is laminated on both sides of a substrate 60 made of glass epoxy or BT (bismaleimide triazine) having a thickness of 1 mm. And And
The photosensitive resin 64 is uniformly applied (FIG. 4 (B)), the mask film 66 having the above-described conductor circuit pattern 66a formed thereon is placed (FIG. 4 (C)), exposed and developed. A resist 68 is formed by removing the non-exposed portion of the photosensitive resin 64. After that, electrolytic plating is performed to form a plating layer 70 (FIG. 4E), and the resist 68 and the copper foil 62 under the resist are removed to complete the conductor circuit (land 30 and line 20) (FIG. 4). (F)). After that, through-holes 76 for through holes are formed, and copper plating 78 is applied to form through holes 154, and the wiring layers on the front surface and the back surface are electrically connected (FIG. 4G). By sticking several printed wiring boards formed in this way,
Complete a multilayer printed wiring board.

Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a partially enlarged plan view of the printed wiring board 10 on which the tear drop is arranged according to the second embodiment. L1-L10, M1-M in the figure
Reference numeral 11 indicates a track that can pass through the line.

In this embodiment, the left and right tear drops 40A and 40B are formed on the land 32 which has a sufficient insulation distance from the line. On the other hand, line 24
For the land 30 which is adjacent to the land 30, a tear drop 40B having a one-sided angle of 30 degrees is attached to the left side in the drawing, and a tear drop 44A having a one-sided angle of 50 degrees is attached to the right side. Thus, by mounting the tear drop 44A having a large one-sided angle, that is, a small shape on the right side of the land 30, between the land 30 and the land 32,
It is possible to arrange two lines 24 and 26.

The type of tear drop according to the second embodiment formed on the printed wiring board will be described with reference to FIG. 6 in FIG. 6 (A).
It shows 0 degree teardrops 40A and 40B. The teardrops 40A and 40B shown in FIG.
It is formed when the distance from the surrounding conductor circuit is large like the land 32 shown in FIG.

FIG. 6B shows a state in which a teardrop 40B having a one-sided angle of 30 degrees is formed on the left side of the line 20 and a teardrop 42A having a one-sided angle of 40 degrees is formed on the right side. The teardrops 40B and 42A have a distance from the surrounding conductor circuit on the left side, and the right side is a teardrop 42A having a one-sided angle of 40 degrees, so that a predetermined insulation distance (for example, 100 μ) from the conductor circuit on the right side not shown Is formed if it can be kept.

FIG. 6C shows a state in which a teardrop 40B having a one-sided angle of 30 degrees is formed on the left side of the line 20 and a teardrop 44A having a one-sided angle of 50 degrees is formed on the right side. The teardrops 40B and 44A are formed on the left side with a distance from the surrounding conductor circuit, and on the right side when the teardrop 44A has a one-sided angle of 50 degrees so that a predetermined insulation distance can be maintained.

FIG. 6D shows a state in which tear drops 42A and 42B having an angle of 40 degrees are formed on the left and right of the line 20. These teardrops 42A and 42B are
It is formed when a predetermined insulation interval can be maintained by forming tear drops 42A and 42B having a one-sided angle of 40 degrees from the right and left conductor circuits, respectively.

FIG. 6 (E) shows a state in which a teardrop 42B having a one-sided angle of 40 degrees is formed on the left side of the line 20 and a teardrop 44A having a one-sided angle of 50 degrees is formed on the right side. By forming the tear drop 44A having a one-sided angle of 50 degrees on the right side, it is formed when a predetermined insulation interval can be maintained.

Teardrops 44A and 44B are formed on the left and right of the line 20 with one angle of 50 degrees. These teardrops 44A and 44B are formed from the conductor circuits on the right side and the left side, respectively, and teardrops 4 with a single angle of 50 degrees.
4A and 44B are formed when a predetermined insulation interval can be maintained.

A process for creating pattern forming data on a mask film for forming such wiring on a printed wiring board will be described with reference to the flowchart of FIG. Here, a process of forming a conductor circuit pattern such as a land and a line has already been completed, and a process of adding a tear drop to the formed land will be described.

First, the additional condition of the tear drop angle shown in FIG. 7A is read (S112). Next, the variable J indicating the teardrop addition condition is initialized to 1 (S11).
4). Then, it is checked whether or not each land / buyer has a line (S116). That is, it is necessary to add a tear drop to a land 20 such as the land 30 shown in FIG. 5, but for a land buyer without a line, which is not shown,
This is because it is not necessary to add a teardrop. Then, a tear drop is added to the land buyer having the line (S118). Here, according to the condition of the number of times 1 (variable J is 1) in the additional condition shown in FIG. 7A read in step 112, the left and right tear drops 40A with one side angle of 30 degrees are attached to each land buyer. ,
40B (see FIG. 6A) is added.

Subsequently, it is checked whether or not the added tear drops 40A and 40B of each land can maintain a predetermined insulation distance (for example, 100 μ) from the surrounding conductor circuits (S).
120). Here, in the case where the predetermined insulation interval can be maintained for all tear drops (Yes in S122,
s), the process ends.

On the other hand, when the insulation interval cannot be maintained for some teardrops (No in S122), it is determined whether the number of times (variable J) has reached the upper limit number N (6 times) (S124). Here, since the number of times (variable J) is the first time (No in S124), the process proceeds to step 126, 1 is added to the number of times (variable J), and the second time of the additional condition shown in FIG. Under the conditions, a tear drop is added to the land / buyer whose insulation distance cannot be maintained (S128). That is, as shown in FIG.
Add a teardrop with a 30 degree angle to one side of 0 and a teardrop with a 40 degree angle to the other side.

Then, it is checked whether or not a predetermined insulation distance can be maintained from the surrounding conductor circuit for the tear drop of each added land (S120). Here, if a predetermined insulation interval can be maintained for all teardrops (S1
22 is Yes), and the process ends.

On the other hand, if the insulation interval cannot be maintained for some teardrops (No in S122), the process proceeds to step 126 after the determination in step 124, and 1 is added to the number of times (variable J). The teardrop is added to the land / buyer under the third addition condition shown in (A) (S128). That is, as shown in FIG. 6C, a teardrop with a one-sided angle of 30 degrees is added to one side of the line 20, and a teardrop with a one-sided angle of 50 degrees is added to the opposite side.

Further, as a result of checking whether the interval is a certain value or more (S
120), if the insulation interval cannot be maintained for some teardrops (No in S122), the land that cannot maintain the insulation interval under the fourth additional condition shown in FIG. 7 (A). As shown in FIG. 6D, teardrops 42A and 42B having a single angle of 40 degrees are added to both sides of the line 20 (S128).

If the insulation interval cannot be maintained for some teardrops (No in S122), one angle on one side of the line 20 as shown in FIG. 6 (E) under the fifth additional condition. A teardrop of 40 degrees and a teardrop of 50 degrees on one side are added to the opposite side (S128).

If the insulation interval cannot be maintained for some teardrops (No in S122), the line 20 as shown in FIG. 6 (F) is set under the sixth (final) additional condition. Teardrop 4 with a 50 degree angle on each side
4A and 44B are added (S128).

If the insulation interval cannot be maintained for some teardrops (No in S122), it is determined whether the number of times (variable J) has reached the upper limit number N (6 times) (S124). . Here, since the number of times (variable J) is the sixth time (final) (Yes in S124), the process proceeds to step 130, and the tear drop 44 in which the insulation interval cannot be maintained.
A and 44B are deleted, and the process ends.

The formation of the mask film based on the data produced by the above processing and the formation of the conductive circuit of the printed wiring board by the mask film are the same as those in the first embodiment described above with reference to FIG. Is omitted.

Next, a modified example of the second embodiment will be described with reference to the additional conditions of FIG. 7B and the explanatory view of FIG. In the example described above with reference to FIG. 7, the teardrop defined by the angle is added, but in this modified example, the teardrop defined by the length from the end of the land buyer is added.

Here, since the processing of adding the teardrop in the modified example is similar to the example described above with reference to the flowchart of FIG. 8, only the adding condition will be described. As a first additional condition, as shown in FIG. 9A, teardrops 47A and 47B formed to a length of 2.0 mm from the land and bay end are formed on the left and right of the line 20.
The teardrops 47A and 47B shown in FIG. 9A.
Are formed when the distance from the surrounding conductor circuit is large as in the land 32 shown in FIG.

The second additional condition is shown in FIG.
As shown in, one side of the line 20, for example, a 2.0 mm long tear drop 47B on the left side and a 1.8 mm length on the right side.
Form a mm teardrop 48A. These teardrops 47B and 48A have a distance from the surrounding conductor circuit on the left side and a teardrop 48A with a length of 1.8 mm on the right side.
By this, it is formed when a predetermined insulation distance (for example, 100 μ) can be maintained from the conductor circuit on the right side (not shown).

The third additional condition is shown in FIG.
As shown in, one side of the line 20, for example, a 2.0 mm long tear drop 47B on the left side and a 1.6 mm length on the right side.
Form a mm teardrop 49A. These teardrops 47B and 49A have a distance from the surrounding conductor circuit on the left side and a teardrop 49A with a length of 1.6 mm on the right side.
By this, it is formed when a predetermined insulation interval can be maintained.

The fourth additional condition is shown in FIG.
As shown in FIG. 1, 1.8 mm long tear drops 48A and 48B are formed on the left and right of the line 20. The teardrops 48A and 48B are formed when the predetermined insulating distance can be maintained by forming the teardrops 42A and 42B having a length of 1.8 mm from the right and left conductor circuits, respectively.

The fifth additional condition is shown in FIG.
As shown in, a tear drop 42B having a length of 1.8 mm is formed on the left side of the line 20, and a tear drop 44A having a length of 1.6 mm is formed on the right side. This is formed when a predetermined insulation distance can be maintained by forming the tear drop 44A having a length of 1.6 mm on the right side.

As the sixth (final) additional condition, as shown in FIG.
Teardrops 49A and 49B are formed at 50 degrees. These teardrops 49A and 49B are 1.6 mm long teardrops 4 from the right and left conductor circuits, respectively.
9A and 49B are formed when a predetermined insulation distance can be maintained.

[0053]

As described above, in the printed wiring board according to the first aspect, since the left and right asymmetrical teardrops are provided at the portion where the line enters the land, the right and left teardrops are respectively separated from the conductor circuit. It can be formed so that a predetermined space can be maintained, and high-density wiring can be performed in the vicinity of the land with the teardrop.

In the printed wiring board manufacturing method of the second aspect, the teardrops arranged on the left and right of the line are
It is determined whether or not each conductor circuit has a predetermined distance from another conductor circuit, and a tear drop is added to the side having the predetermined distance. Therefore, the tear drop can be formed so as to be able to maintain a predetermined distance from the conductor circuit, and wiring can also be performed at high density near the land with the tear drop.

In the method of manufacturing a printed wiring board according to the third aspect, it is determined whether or not the teardrops having the shape 1 arranged on the left or right of the line have a predetermined distance from other conductor circuits, respectively. A teardrop having a shape having a predetermined interval is added. Therefore, the right and left teardrops can be formed so as to be able to maintain a predetermined distance from the conductor circuit, and it is possible to perform high-density wiring near the land with the teardrop.

[Brief description of drawings]

FIG. 1 is a partially enlarged plan view of a printed wiring board according to a first embodiment of the present invention.

FIG. 2A to FIG. 2E are explanatory views showing the shape of the teardrop according to the first embodiment.

FIG. 3 is a flowchart of teardrop addition processing according to the first embodiment of the present invention.

FIG. 4 (A) to FIG. 4 (G) are process diagrams when forming a conductor circuit of the printed wiring board according to the first embodiment.

FIG. 5 is a partially enlarged plan view of a printed wiring board according to a second embodiment of the present invention.

FIG. 6A to FIG. 6F are explanatory views showing the shape of the teardrop according to the second embodiment.

FIG. 7A and FIG. 7B are charts showing teardrop addition conditions according to the second embodiment.

FIG. 8 is a flowchart of teardrop addition processing according to the second embodiment of the present invention.

9 (A) to 9 (F) are explanatory views showing the shape of a tear drop according to a modified example of the second embodiment.

FIG. 10 (A) to FIG. 10 (E) are explanatory diagrams of a tear drop according to a conventional technique.

[Explanation of symbols]

10 Printed wiring board 20, 22, 24, 26 Line 30, 32 Land 40, 40A, 40B, 42A, 42B Teardrop 54 Through hole

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Claims (6)

[Claims] 1. A printed wiring board having a conductor circuit composed of lines and lands, wherein a tear drop is formed at a connecting portion between the line and the land, and a portion where the line enters the land has a left-right asymmetrical pattern. A printed wiring board featuring a tear drop. 2. A method of manufacturing a printed wiring board, comprising: a conductor circuit composed of lines and lands; and forming left and right tear drops at the connecting portions of the lines and lands, the left and right sides of the lines being arranged. A method of manufacturing a printed wiring board, comprising: determining whether each teardrop has a predetermined distance from another conductor circuit; and adding a teardrop to the side having the predetermined distance. 3. A method of manufacturing a printed wiring board, comprising a conductor circuit composed of lines and lands, and forming one tear drop within a preset shape on the left and right at a connecting portion of the lines and lands, A step of determining whether each of the one-shaped teardrops arranged on the left or right of the line has a predetermined distance from another conductor circuit; and adding a teardrop having a shape capable of providing the predetermined distance. And a step of manufacturing a printed wiring board. 4. A printed wiring board having a conductor circuit composed of lines and lands, wherein a tear drop is formed at a connecting portion between the line and the land, and a tear line is provided on the left and right at a portion where the line is inserted with respect to the land. A printed wiring board, in which a drop is formed and a left-right asymmetrical tear drop, which is a tear drop in which one side angle of one tear drop is large and the other side angle is small, is provided. 5. A printed wiring board having a conductor circuit composed of lines and lands, wherein a tear drop is formed at a connecting portion of the lines and lands, wherein a line is inserted into the land and one of the lines is inserted into the land. The printed wiring board is characterized by asymmetrical teardrops with short lengths on the other side. 6. A method for manufacturing a printed wiring board, comprising a conductor circuit composed of lines and lands, and forming one tear drop within a preset shape on the left and right at a connecting portion of the lines and lands, A step of determining whether the teardrops having the shape 1 disposed on the left and right of the line have a predetermined distance from the other conductor circuits on the right side and the left side of the land, respectively; And a step of adding teardrops having different angles, the method for manufacturing a printed wiring board.