JP2004048042A - Manufacturing method for printed-wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a printed-wiring board of high reliability by which wiring of high density is realized even near a land with a tear drop. <P>SOLUTION: Left and right tear drops 40A and 40B are formed for the land 32 that can secure an enough insulating interval from a line. On the other hand, for the land 30 in proximity to the line 24 and 26, the tear drop 40B, in which the angle of one side is 30°, is formed on the left side in the figure, and the tear drop 44A, in which the angle of one side is 50°, is formed on the right side in the figure. By forming the tear drop 44A, in which the angle is large, that is, which has a small shape, on the right side of the land 30 in this way, the two lines 24 and 26 can be arranged between the lands 30 and 32. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a method for manufacturing a printed wiring board having a conductor circuit composed of a line and a land, and forming a teardrop at a connection portion between the line and the land.

In the case of a printed wiring board having a conductor circuit composed of lines and lands, as shown in FIG. 10A, a teardrop 140 may be provided in order to increase the reliability of the connection between the line 120 and the lands 130. is there.
In recent years, fine patterning of printed wiring boards has been progressing due to high-density mounting, and small-diameter through holes are frequently used. ing. That is, when the through hole 154 can be arranged at the center of the land 130 as shown in FIG. 10A, there is no problem in the electrical conduction, but as shown in FIG. If 154 is formed near line 120, the reliability of conduction between land 130 and line 120 is lacking. Therefore, it is indispensable to provide the teardrop 140.

In particular, in the case of a flexible substrate, when the line 120 is directly connected to the land 130 as shown in FIG. 10C, when the substrate is bent, a stress is applied to a connection portion C between the line 120 and the land 130. May be concentrated, and a disconnection may occur at the connection portion C between the line 120 and the land 130. To avoid this and improve the reliability of electrical conduction, a tear drop as shown in FIG. 140 are provided.

Here, when the teardrop 140 is added to the land 30, 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 teardrop 140 is not added.
Japanese Patent No. 2519068

Here, according to Japanese Patent No. 2519068, when the teardrop 140 is added to the land 130, the applicant assigns the right teardrop 140A to the other conductor circuit 122 as shown in FIG. A technique has been disclosed in which, when a predetermined insulation interval d cannot be obtained, as shown in FIG. 10E, there is no problem with the insulation interval only on the left teardrop 140B, that is, on only one side. However, there is no mention of a specific method for disposing only on one side.

In addition, when teardrops are provided on only one side as described above, the risk of electrical continuity and disconnection can be avoided, as compared with the case where no teardrops are provided, but the normal teardrops are not provided. I could not deny that it was inferior in performance.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and an object of the present invention is to provide a method for manufacturing a highly reliable printed wiring board capable of high-density wiring near a land with teardrops. Is to do.

In order to achieve the above object, the invention of claim 1 has a conductor circuit composed of a line and a land in order to achieve the above object. In a method of manufacturing a printed wiring board forming a tear drop of
Judging whether the teardrops arranged on the left and right of the line have a predetermined interval from the other conductor circuits,
Adding a teardrop to the side having the predetermined interval.

In the method for manufacturing a printed wiring board according to the present invention, the teardrop having one shape disposed on the left and right of the line determines whether the right and left sides of the land have a predetermined distance from other conductive circuits, respectively. Judgment is made, and teardrops having different angles of shapes that can provide a predetermined interval are added. Therefore, the right and left tear drops can be formed so as to be able to keep a predetermined distance from the conductor circuit.

In the method for manufacturing a printed wiring board according to the present invention, it is determined whether the teardrops each having one shape disposed on the left and right sides of the line have predetermined intervals on the right and left sides of the land from the other conductor circuits. Then, teardrops having different angles of shapes capable of providing a predetermined interval are added. For this reason, the right and left teardrops can be formed so as to be able to keep a predetermined distance from the conductor circuit, and high density wiring can be performed also near the land with the teardrop.

Hereinafter, a method for manufacturing a printed wiring board according to the first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a partially enlarged plan view of a printed wiring board 10 provided with a teardrop 40 according to the first embodiment. In the figure, L1 to L10 and M1 to M11 indicate tracks that can pass through the line.

In this embodiment, the left and right teardrops 40A and 40B are formed on the land 32 having a sufficient insulation interval from the line. On the other hand, for the land 30 adjacent to the lines 24 and 26, the teardrop 40B is attached only to the left side in the figure. In this way, by attaching the teardrop 40B to the land 30 only on the side opposite to the land 32, it is possible to arrange two lines 24 and 26 between the land 30 and the land 32. ing.

A type of teardrop according to the first embodiment formed on a printed wiring board will be described with reference to FIG. 2. FIG. 2A shows a teardrop having a teardrop angle of 80 degrees on both sides of line 20. Drops 40A and 40B are shown. The teardrops 40A and 40B shown in FIG. 2A are formed when a predetermined insulation interval (for example, 100 μ) can be maintained from the surrounding conductor circuit like the land 32 shown in FIG.

FIG. 2B shows teardrops 42A and 42B in which the teardrop angle is formed at 90 degrees on the left and right of the line 20. When the teardrops 42A and 42B shown in FIG. 2B are formed with the teardrops 40A and 40B of 80 degrees described above with reference to FIG. 2A, one of the teardrops is insulated from the surrounding conductor circuit by a predetermined amount. Although an interval cannot be obtained, it is used when a predetermined insulating interval can be obtained by forming the tear drop angle at 90 degrees.

FIG. 2C shows a state in which the right-side teardrop 40A of 90 degrees shown in FIG. 2B is formed between the right-side conductor circuit (not shown) and the right-side conductor circuit as shown in FIG. Cannot be taken, but even if an 80-degree teardrop 40B is formed on the left side, the teardrop 40B is used when the insulation gap can be taken.

FIG. 2D shows a case where the insulation gap cannot be obtained when the teardrop is formed on the left side as in FIG. 2C, but the insulation gap can be obtained even when the teardrop 40A of 80 degrees is formed on the right side. Used for

FIG. 2 (E) shows a case where the insulation gap cannot be obtained from the right teardrop, the insulation gap cannot be obtained from the left teardrop, and no teardrop is added.

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

{Circle around (1)} First, teardrops 40A and 40B are added to the land including all the lines so that the teardrop angle becomes 80 degrees described above with reference to FIG. 2A (S12). Thereafter, it is checked whether the tear drops 40A and 40B of each of the added lands can maintain a predetermined insulation interval (for example, 100 μ) from the surrounding conductor circuit (S14). Here, if a predetermined insulation interval can be maintained for all teardrops (Yes in S18), the process ends.

On the other hand, if the insulation interval cannot be maintained for the teardrops of some of the lands (No in S18), the process proceeds to step 20, and for the land where the insulation interval cannot be maintained, see FIG. Then, the above-described 90-degree tear drops 42A and 42B are added. Thereafter, it is checked whether or not a predetermined insulation interval can be maintained from the surrounding conductor circuits for the teardrops 42A and 42B of each added land (S22). Here, if a predetermined insulation interval can be maintained for all teardrops (Yes in S24), the process ends.

On the other hand, if the insulation interval cannot be maintained for the teardrops of some of the lands (No in S24), the process proceeds to step 26, and for the land where the insulation interval cannot be maintained, see FIG. Then, it is checked whether the insulation interval can be maintained from the above-described left tear drop 40B and whether the insulation interval can be maintained from the above-described right tear drop 40A with reference to FIG. Here, when the insulation interval can be maintained from the left tear drop 40B, the left tear drop 40B is added as shown in FIG. 2C, and when the insulation interval can be maintained from the right tear drop 40A, FIG. The right teardrop 40A shown in (D) is added (S28). Thereafter, it is determined that no teardrop is to be added to the land to which the teardrop cannot be added so as to keep the insulation interval on either the left or right, as shown in FIG. 2E (S30), and the process ends.

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

(4) As shown in FIG. 4 (A), a copper-clad laminate 60a formed by laminating a 18 μm copper foil 62 on both sides of a substrate 60 made of glass epoxy or BT (bismaleimide triazine) having a thickness of 1 mm is used as a starting material. Then, the photosensitive resin 64 is uniformly applied (FIG. 4B), the mask film 66 on which the above-described conductive circuit pattern 66a is formed is placed (FIG. 4C), and exposed and developed. Then, a non-exposed portion of the photosensitive resin 64 is removed to form a resist 68. Thereafter, 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 (the land 30 and the line 20) (FIG. 4). (F)). Thereafter, a through-hole 76 for a through-hole is formed, and a through-hole 154 is formed by applying copper plating 78 to electrically connect the wiring layers on the front surface and the rear surface (FIG. 4G). By laminating several printed wiring boards formed in this way, a multilayer printed wiring board is completed.

Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a partially enlarged plan view of a printed wiring board 10 provided with tear drops according to the second embodiment. In the figure, L1 to L10 and M1 to M11 indicate tracks that can pass through the line.

In this embodiment, the left and right teardrops 40A and 40B are formed on the land 32 having a sufficient insulation interval from the line. On the other hand, a teardrop 40B having a single angle of 30 degrees is attached to the land 30 adjacent to the line 24 on the left side in the figure, and a teardrop 44A having a single angle of 50 degrees is attached to the right side. Thus, by attaching the teardrop 44A having a large angle, that is, a small shape to the right side of the land 30, the two lines 24 and 26 are arranged between the land 30 and the land 32. Is possible.

The type of teardrop according to the second embodiment formed on a printed wiring board will be described with reference to FIG. 6. FIG. 6A shows a teardrop 40 </ b> A formed on the left and right of the line 20 and having a single angle of 30 degrees. , 40B. The teardrops 40A and 40B shown in FIG. 6A are formed when the distance from the surrounding conductor circuit is large as in the land 32 shown in FIG.

FIG. 6B shows a state in which a teardrop 40B having a 30-degree angle is formed on the left side of the line 20 and a teardrop 42A having a 40-degree angle is formed on the right side. The teardrops 40B and 42A have a distance from the surrounding conductor circuit on the left side and a predetermined insulation interval (for example, 100 μ) from the conductor circuit on the right side (not shown) by forming the teardrop 42A with a single angle of 40 degrees on the right side. Is formed when can be maintained.

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

FIG. 6 (D) shows a state in which teardrops 42A and 42B each having an angle of 40 degrees are formed on the left and right of the line 20. The teardrops 42A and 42B are formed when a predetermined insulation interval can be maintained by forming the teardrops 42A and 42B at an angle of 40 degrees from the conductor circuits on the right and left sides, respectively.

FIG. 6E shows a state in which a teardrop 42B with a single angle of 40 degrees is formed on the left side of the line 20 and a teardrop 44A with a single angle of 50 degrees is formed on the right side. This is formed when a predetermined insulation interval can be maintained by making the right side a teardrop 44A with a single angle of 50 degrees.

テ ィ ア shows teardrops 44A and 44B formed with a single angle of 50 degrees on the left and right of the line 20. The teardrops 44A and 44B are formed when a predetermined insulation interval can be maintained by forming the teardrops 44A and 44B at a single angle of 50 degrees from the right and left conductor circuits, respectively.

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

First, the conditions for adding the teardrop angle shown in FIG. 7A are read (S112). Next, a variable J indicating the teardrop addition condition is initialized to 1 (S114). Then, it is checked whether a line is included in each land buyer (S116). That is, it is necessary to add a teardrop to a land such as the land 30 shown in FIG. 5, but a land buyer (not shown) having no line is required to add a teardrop. This is because there is no need to add a drop. Then, a teardrop is added to the land buyer including 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. , 40B (see FIG. 6A).

(4) Subsequently, it is checked whether the tear drops 40A and 40B of each of the added lands can maintain a predetermined insulation interval (for example, 100 μ) from the surrounding conductor circuit (S120). Here, if the predetermined insulation interval can be maintained for all teardrops (Yes in S122), the process is terminated.

On the other hand, 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 first time (No in S124), the process proceeds to step 126, where 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 teardrop is added to the land buyer for which the insulation interval could not be maintained (S128). That is, as shown in FIG. 6B, a teardrop having an angle of 30 degrees is added to one side of the line 20 and a teardrop having an angle of 40 degrees is added to the opposite side.

{Circle around (2)} Then, it is checked whether or not a predetermined insulation interval can be maintained from the surrounding conductor circuit with respect to the added teardrop of each land (S120). Here, if the predetermined insulation interval can be maintained for all the teardrops (Yes in S122), 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 through the determination in step 124, and 1 is added to the number of times (variable J), and FIG. The teardrop is added to the land buyer under the third condition of the addition condition shown in (1) (S128). That is, as shown in FIG. 6 (C), a teardrop having an angle of 30 degrees is added to one side of the line 20 and a teardrop having an angle of 50 degrees is added to the opposite side.

Further, as a result of checking whether or not the interval is equal to or more than a certain value (S120), if the insulation interval cannot be maintained for some teardrops (No in S122), the fourth condition of the additional condition shown in FIG. Under the conditions, for the land buyers whose insulation spacing could not be maintained, teardrops 42A and 42B with a single angle of 40 degrees are added to both sides of the line 20 as shown in FIG. 6D (S128).

If the insulation interval cannot be maintained for some teardrops (No in S122), under the fifth condition of the additional condition, as shown in FIG. A teardrop is added to the opposite side with a teardrop of one angle of 50 degrees (S128).

If the insulation interval cannot be maintained for some of the teardrops (No in S122), under the condition of the sixth (final) additional condition, as shown in FIG. Tear drops 44A and 44B with a single angle of 50 degrees 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 (final) (Yes in S124), the process proceeds to step 130, where the teardrops 44A and 44B for which the insulation interval cannot be maintained are deleted, and the process ends.

Here, the creation of the mask film based on the data created by the above processing and the formation of the conductive circuit of the printed wiring board using the mask film are the same as in the first embodiment described above with reference to FIG. .

Subsequently, a modified example of the second embodiment will be described with reference to the additional condition of FIG. 7B and the explanatory diagram 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, the process of adding the teardrop of the modified example is the same as the example described above with reference to the flowchart of FIG. 8, and thus only the additional condition will be described.
As the first additional condition, teardrops 47A and 47B having a length of 2.0 mm from the ends of the land and buyers are formed on the left and right of the line 20, as shown in FIG. 9A. 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.

As a second additional condition, as shown in FIG. 9B, one side of the line 20, for example, a teardrop 47B having a length of 2.0 mm on the left side and a teardrop 48A having a length of 1.8 mm on the right side. Form. The teardrops 47B and 48A have a distance from the surrounding conductor circuit on the left side and a 1.8mm-long teardrop 48A on the right side so that a predetermined insulation interval (for example, 100 μm) is provided from the conductor circuit on the right side (not shown). ) Is formed when it can be maintained.

As a third additional condition, as shown in FIG. 9C, 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 long tear drop 49A on the right side. Form. The teardrops 47B and 49A are formed when the left side is at a distance from the surrounding conductor circuits and the right side is a teardrop 49A having a length of 1.6 mm so that a predetermined insulation interval can be maintained.

As the fourth additional condition, as shown in FIG. 9D, teardrops 48A and 48B having a length of 1.8 mm are formed on the left and right of the line 20. The teardrops 48A and 48B are formed when a predetermined insulation interval can be maintained by forming 1.8 mm long teardrops 42A and 42B from the right and left conductor circuits, respectively.

As a fifth additional condition, as shown in FIG. 9E, a 1.8 mm long tear drop 42B is formed on the left side of the line 20, and a 1.6 mm long tear drop 44A is formed on the right side of the line 20. This is formed when a predetermined insulation interval can be maintained by making the right side a tear drop 44A having a length of 1.6 mm.

(9) As the sixth (final) additional condition, teardrops 49A and 49B are formed at a length of 1.6 mm and 50 degrees on the left and right of the line 20, as shown in FIG. The teardrops 49A and 49B are formed when a predetermined insulating interval can be maintained by forming teardrops 49A and 49B having a length of 1.6 mm from the right and left conductor circuits, respectively.

FIG. 2 is a partially enlarged plan view of the printed wiring board according to the first embodiment of the present invention. FIGS. 2A to 2E are explanatory diagrams showing the teardrop shape according to the first embodiment. It is a flowchart of a tear drop addition process according to the first embodiment of the present invention. FIG. 4A to FIG. 4G are process diagrams when forming a conductor circuit of the printed wiring board according to the first embodiment. FIG. 6 is a partially enlarged plan view of a printed wiring board according to a second embodiment of the present invention. FIGS. 6A to 6F are explanatory views showing the teardrop shape according to the second embodiment. FIGS. 7A and 7B are tables showing conditions for adding teardrops according to the second embodiment. It is a flow chart of tear drop addition processing concerning a 2nd embodiment of the present invention. FIGS. 9A to 9F are explanatory diagrams showing the teardrop shapes according to a modification of the second embodiment. FIGS. 10A to 10E are explanatory diagrams of teardrops according to the related art.

Explanation of reference numerals

Reference Signs List 10 Printed wiring board 20, 22, 24, 26 Line 30, 32 Land 40, 40A, 40B, 42A, 42B Tear drop 54 Through hole

Claims (1)

In a method for manufacturing a printed wiring board, having a conductor circuit composed of a line and a land, and forming one teardrop in a predetermined shape on the left and right at a connection portion between the line and the land,
Determining whether the teardrops of one shape arranged on the left and right sides of the line have a predetermined distance from the other conductor circuits on the right and left sides of the land, respectively;
Adding a teardrop having a different angle of the shape capable of providing the predetermined interval.

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