JPH09199819A - Connection structure between wiring terminal on substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture HIC at low cost making it compact by connecting the first land as a soldering part formed on the end part of the first wiring to the second land as the soldering part oppositely provided to the first land using a soldering agent. SOLUTION: In the properly intersecting wirings 1, 2, the wiring 2 is continuously formed on the intersecting part, while the wiring 1 is cut off on both sides of the wiring 2 to be respectively separated into the first wiring la and the second wiring 1b so as to respectively form the first and second lands 3, 4 on the end parts thereof. At this time, the soldering agent 8 is continuously formed on the first and second lands 3, 4 as well as a resist film 5 and the second insulating film 6. These elements are contained in an electric furnace, etc., to be formed by melting down a solder. Through these procedures, the manufacturing manhours can be cut down since the application of any conventional jumper wire or jumper chip can be eliminated using less number of parts simply spreading and melting down a creamy solder by screen printing step, etc.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a hybrid IC.
The present invention relates to a connection structure between wiring terminals on a board for electrically connecting a wiring end portion of a wiring pattern formed on a printed circuit board (hereinafter referred to as HIC) and another wiring end portion. More specifically, when the wirings intersect with each other in the wiring pattern, one wiring is cut to form a wiring pattern, and the ends of the cut wirings are electrically connected to each other or a plurality of wirings are formed on the substrate. The present invention relates to a connection structure between wiring terminals on a substrate when circuit wiring is formed and one of the circuits is selected and connected to the wiring terminal.

[0002]

2. Description of the Related Art Conventionally, HICs are assembled by mounting discrete components, ICs, etc. on a substrate on which a wiring pattern is formed. The wiring pattern is formed by etching a metal coating made of copper or the like, which is coated on the entire surface of the substrate in advance. Therefore, both wirings cannot be formed in advance at the intersection of the wirings. In such a case, as shown in FIG. 3, one of the wirings is cut into wirings 21a and 21b, and pads 23 and 2 are formed on both sides of the other wiring 22 that intersects.
Jumper wire or jumper chip 2 when discrete components or ICs are assembled to form 4
By connecting 5 between both lands 23, 24,
The cut wirings 21a and 21b are connected.

Further, when the circuit to be connected is undecided at the stage of the substrate on which the wiring pattern is formed, a plurality of types of circuit wiring patterns are formed, and later selected as the wiring end portion of the main wiring pattern. The end portion of the formed circuit wiring is connected. Even in such a case, lands are provided at both ends of the main wiring and both ends of the plurality of types of circuit wiring, and the lands at both ends of the circuit wiring selected when assembling with other parts and the main wiring HI by connecting the land at the end of the wiring with a jumper wire or jumper chip.
C is assembled.

As another method for electrically connecting the ends of the respective wirings of these wiring patterns, a through-hole board having through-holes provided in a board such as a printed board on which discrete components and ICs are assembled is used. A method of electrically connecting on the back surface of the substrate is also adopted.

[0005]

In the conventional method of electrically connecting the wiring terminals of the wiring pattern using the jumper wire or the jumper chip, the number of parts is increased and the jumper chip is 1 mm at the smallest. It has a certain length, and requires a large space between the wiring terminals of the wiring pattern. As a result, the mounting density of parts is reduced, and H
IC miniaturization cannot be achieved.

Further, a jumper chip, for example, 1
If the size is reduced to about mm, there is a problem that it is difficult to handle when mounting and soldering on a substrate.

Further, the method using the through-hole board has a problem that the board is expensive and the number of mounting steps is large, so that the cost of the HIC is increased.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a connection structure between wiring terminals on a substrate which can manufacture an HIC at a low cost and can be made small. And

[0009]

A connection structure between wiring terminals on a substrate according to the present invention is a wiring pattern formed on a substrate and soldering formed on an end portion of a first wiring of the wiring pattern. A first land, which is a portion, and a second land, which is a soldering portion that is provided at an end of the second wiring of the wiring pattern and that is provided so as to face the first land, An insulating coating provided on the substrate in the gap between the first and second lands, and a soldering agent continuously formed on the first and second lands and the insulating coating. The first wiring and the second wiring are electrically connected.

The first and second lands are formed so that the gap between the facing portions of the first and second lands is 0.5 mm or less. It is preferable because the soldering agent is continuously formed between the two.

The facing portions of the first and second lands are each formed in a linear shape, and the other portions have a width that does not exceed the length of the linear portion and increases as the distance from the facing portion increases. It is preferable that the width is formed so that the solder tends to form a spherical shape over both lands, and thus solder breakage is unlikely to occur.

Here, the width means the width of the land on a straight line parallel to the straight line of the linear portion of the facing portion of the two lands. Further, the width becoming smaller as it goes away from the facing portion means that the width becomes smaller as the land is farther from the facing portion, and there are portions having the same width, and the magnitude relation of the width is reversed. Including those that have parts to do.

The other portion is formed in a shape having an arc shape, a rectangular shape, or a combination thereof.

The fact that the second insulating film is further provided on the insulating film in the gap between the facing portions of the first and second lands, even if the insulating film made of resist has a defect such as a pinhole. Even if there is, a short circuit with other wiring therebelow can be avoided, which is preferable.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, when wiring patterns are formed on a substrate, when wiring patterns intersect, or when a plurality of types of circuits are selected and one of the circuit wirings is connected, Has a structure in which a wiring pattern cannot be formed in advance and is connected later by a jumper wire or the like.

The present inventor has conducted extensive studies in order to simplify the subsequent connection and to make the HIC small, and as a result, devised the structure of the pad at the end of the wiring to use a soldering agent. I found that I can connect. That is, when trying to connect the wiring terminals with a soldering agent, it is possible that solder breakage may occur on the insulating film between the terminals.
Conventionally, a jumper chip or the like is used, and no connection with a soldering agent is made. However, as a result of earnest studies by the inventor, for example, the interval between the facing portions of the land at the wiring end portion is set to 0.5 mm or less, or the land shape is a linear shape at the facing portion and the other portion is an arc. By making the width of the land smaller than the length of the linear portion of the facing portion as it goes away from the facing portion in a shape or polygonal shape, it is possible to ensure reliable electrical connection without solder breakage. I found it. If the land has two lands facing each other in a straight line shape and the other part is formed in an arc or polygonal shape, the solder will not be rounded in each land but will be rounded between the two lands. It is thought that this is because solder breakage is less likely to occur.

Further, the wiring is insulated by applying a resist on the lower wiring which intersects. However, when the resist has pinholes or chips, a short circuit is generated between the wiring and the soldering agent. Can happen. For this problem,
To solve the problem, a resist is further applied on the crossing portion to make it thicker, or a second insulating film is provided by applying another insulating material such as white paint such as silk used for marking or the like. I was able to.

Next, the connection structure between the wiring terminals of the present invention will be specifically described with reference to the drawings.

FIG. 1A is an explanatory plan view showing a state where lands are formed at the ends of one of the cut wirings at the intersection of the wirings, and FIG. 1B is a sectional view taken along the line BB of FIG. 1A. FIG. 2 is a diagram for explaining a line cross section, and FIG. 2 is a diagram showing a configuration example of a circuit arrangement for selecting and connecting any of a plurality of sets of circuit wiring.

In FIG. 1, reference numerals 1 and 2 are wirings that originally intersect with each other, the wirings 2 are continuously formed at the intersecting portions, and the wiring 1 is cut on both sides of the wiring 2 to form the first wiring 1a and the first wiring 1a. It is separated into two wirings 1b, and first and second lands 3 and 4 are formed at the ends thereof. The first and second lands 3 and 4 have a large area for soldering or the like, and are formed by etching the same coating film of copper as the wiring of the wiring pattern formed on the substrate 10 by etching. ing. 5
Is a resist film used as an insulating film, and the portions on and without the wiring pattern are also covered with the resist film 5. However, the resist film 5 is removed by etching at the connection portion with other parts, such as the surface of the first and second lands 3 and 4 (enclosed by the one-dot chain line in FIG. 1A). See section 9).

Reference numeral 6 is a second insulating film such as white paint called silk which is often used for marking and the like.
It is provided on the resist film 5 on the substrate by screen printing or the like. This is to prevent short circuit between the wirings 1a and 1b and the wiring 2 due to the penetration of the solder 7 when the resist film 5 on the wiring 2 has an abnormality such as a pinhole or chip. It is not necessary if there is no abnormality in 5. However, it is preferable to provide the second insulating coating 6 from the viewpoint of improving reliability. The second insulating coating 6 is not limited to the silk described above, and may be a coating having an insulating effect. For example, the same resist film material as the resist film 5 may be applied again. In this case, although it may be formed hot together with other portions, it is preferable to apply it in two or more times in consideration of preventing insulation failure due to pinholes.

Reference numeral 7 denotes a recess formed between the first and second lands 3 and 4 and the resist film 5 formed on the surface of the wiring 2, and C denotes the width thereof. 8 is the first and second lands 3 and 4, the resist film 5 and the second insulating coating 6
It is formed by applying cream solder by screen printing or the like with the solder agent continuously formed above and placing it in an electric furnace at the same time as soldering other electronic components and melting the solder. As a result, the soldering agent is continuously formed on the resist film 5 and the second insulating coating 6, and the first and second lands 3 and 4 are connected to each other, and further, the first and second wirings 1a and 1b are connected to each other. Can be electrically connected. The soldering agent 8 is not shown in FIG.

In the present invention, the portions 3a and 4a of the first and second lands 3 and 4 facing each other are formed in a straight line shape, and the other portions are formed in an arc shape, and each is formed in a semicircular shape. . It should be noted that the semicircular shape does not need to be a perfect semicircle, and may be an arc shape smaller than the semicircle, and it goes without saying that the first and second wiring portions are not arcs. Further, the arcuate portion may have a shape mixed with a polygonal shape described later. The point is that it should have an arc shape and be close to a substantially semi-circular shape. The reason why each of the first and second lands 3 and 4 is formed in a semicircular shape is as follows. That is, when the solder melts, it tends to be rounded into a spherical shape due to its habit. Therefore, in the case of the conventional rectangular land as shown in FIG. 3, the land gap is 0.55 mm.
With the above intervals, the solder tends to be spherical in each land, and it is difficult to prevent the solder from breaking. However, in the case of a semi-circular shape, since a spherical surface is to be drawn centering on the facing portion, solder is likely to collect sufficiently at the facing portion of both lands. Therefore, if the land is formed in a semicircular shape, solder breakage does not occur.

In terms of utilizing the habit of this solder, even if the land is not arcuate, the opposing portion is linear and the width of the land on the wiring side is smaller than the length of the linear portion of the opposing portion. If so, similarly, it tries to draw a spherical surface centering on the facing portion. Therefore, if the width of the land is equal to or less than the length of the linear portion of the facing portion and is gradually narrowed to be about the width of the wiring in the wiring portion, the polygonal shape works similarly to the semicircular shape. Therefore, a square shape can be used instead of the circular arc portion, but the larger the number of corners of the square shape, the closer to the circular arc it is preferable. However, in an extreme case, it may be formed in a triangular shape having a straight part of the facing part as one side. The point is that the width of the land is smaller than the length of the straight portion of the facing portion, and becomes smaller toward the side opposite to the facing portion. Therefore, the arc portion and the straight portion may be mixed. It should be noted that the reduction of the width of the land means the case of the entire land as described above, and does not mean the magnitude relation of the partial width of the land.

Further, in the present invention, the interval A between the opposing portions 3a, 4a of both lands 3, 4 is formed to be 0.5 mm or less. Interval A between facing parts of both lands
Is set to the above-mentioned interval because if the interval is too wide, solder breakage easily occurs when the solder melts, and within the above range, almost no solder breakage occurs. Also, if the space between both lands is too narrow, there is no space for forming other wiring that intersects, so it is necessary to provide a space for forming wiring, but when joining to the land of the selected circuit without intersecting, It suffices that an interval is maintained so that insulation is maintained without wiring, that is, an interval of about 0.25 mm or more.

As a result of extensive studies by the inventor of the present invention, in order to prevent solder breakage, the land interval is set to 0.5 m as described above.
It is most effective to make the thickness m or less, and the reliability is further improved by the shape of the land. However, if the thickness of the screen mask during screen printing for providing the soldering agent is set to 250 to 300 μm, it is more effective in preventing solder breakage.

FIG. 2 is a diagram showing another example in which the connection structure between the wiring terminals of the present invention is applied. When a circuit to be connected to the main wiring of the wiring pattern is undecided, a plurality of circuits E and F are provided. Form the circuit wirings 11 and 12 to be formed respectively,
The wirings 13 and 14 of the main circuits G and H are selectively connected. That is, the wirings 13 and 14 are branched and the lands 15a, 15b, 15c and 16 are provided at the ends thereof so that the circuit wirings 11 and 12 or the case where the circuits are not connected can be selected.
a, 16b and 16c are formed respectively. Further, the wirings 13 and 1 are provided on both ends of the circuit wirings 11 and 12, respectively.
4 lands 15b, 16b and 15c, 16c
To the lands 17a, 17b and 18a, 18
b are formed respectively. As described above, in the set of the facing lands, the facing portions are straight portions, and the interval and the shape of each land are formed in the same manner as described above. As a result, when assembling the HIC, for example, when the circuit F is selected, the land 15c at the end of the wiring 13, the land 18a at the end of the circuit wiring 12, and the land 16c at the end of the wiring 14 and the circuit wiring 12 are selected. Land 18 at the end of
The circuit F can be connected between the wirings 13 and 14 by providing a soldering agent (not shown) between the wirings b and b.

[0028]

According to the present invention, it is possible to electrically connect the wiring terminals of the wiring pattern formed on the substrate with a soldering agent, so that it is not necessary to use a conventional jumper wire or jumper chip. Also, the number of parts is small, and since it is sufficient to manufacture by applying cream solder by screen printing or the like and manufacturing, it is possible to significantly reduce the number of manufacturing processes.

Furthermore, since no parts such as jumper chips are used, the space for connection is narrowed, the density of the parts on the substrate can be increased, and the electronic device can be miniaturized.

Further, it is not necessary to use an expensive board such as a through-hole board, the cost of parts can be reduced, and
There is no need to consider the pattern on the backside of the board, and design efficiency is greatly improved.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a connection structure between wiring terminals of the present invention.

FIG. 2 is a diagram showing a relationship of connection portions when a plurality of circuit wirings are formed on a substrate and selected and connected.

FIG. 3 is a diagram showing a conventional connection structure between wiring terminals.

[Explanation of symbols]

 1a 1st wiring 1b 2nd wiring 3 1st land 4 2nd land 5 Resist film 6 2nd insulating film 8 Solder agent 10 Substrate

Claims (6)

[Claims] 1. A wiring pattern formed on a substrate, a first land which is a soldering portion formed at an end of the first wiring of the wiring pattern, and a second wiring of the wiring pattern. A second land, which is a soldering portion that is provided at an end portion and that faces the first land, and a gap portion between the first and second lands, is provided on the substrate. An insulating coating and a solder agent continuously formed on the first and second lands and the insulating coating, and the first wiring and the second wiring are electrically connected to each other. Connection structure between wiring terminals on the same board. 2. The first and second lands so that the gap between the facing portions of the first and second lands is 0.5 mm or less.
2. The connection structure between wiring terminals on a substrate according to claim 1, wherein the land is formed. 3. The facing portions of the first and second lands are each formed in a linear shape, and the width of the other portion does not exceed the length of the linear portion and is away from the facing portion. The connection structure between wiring terminals on a substrate according to claim 1 or 2, wherein the width is formed so as to decrease. 4. The connection structure between wiring terminals on a substrate according to claim 3, wherein the other portion is formed in a shape having an arc shape such that the width thereof is shorter than the length of the linear portion. 5. The connection structure between wiring terminals on a substrate according to claim 3, wherein the other portion is formed in a shape having a rectangular shape such that the width of the other portion is shorter than the length of the linear portion. 6. The substrate according to claim 1, wherein a second insulating coating is further provided on the insulating coating in the gap between the facing portions of the first and second lands. Connection structure between wiring terminals.