JP4823201B2 - Circuit board - Google Patents

Description

  The present invention relates to a mounting land for chip parts, and more particularly to a solder resist pattern for a mounting land.

In recent years, there has been an increasing trend toward miniaturization and high functionality of devices such as mobile phones and portable digital music players. For this reason, printed circuit boards incorporated into devices have been miniaturized. In addition, the number of new products to be developed and the number of varieties are increasing significantly, and there is a strong tendency for short-term development. Therefore, in order to accurately perform the evaluation at the time of development, the wiring of the printed circuit board is designed to be partially opened and a check terminal attached. In such open wiring, it is necessary to electrically short-circuit the check terminals in the middle of development or the final product stage, and the check terminals are connected to soldering lands (mounting). For example, a jumper chip component (hereinafter, a surface mounting component is simply referred to as a component) is mounted, or is simply short-circuited by solder.
In addition to short development lead times, it is necessary to change the components to be mounted on a short day or instantly due to circumstances, that is, characteristic requirements, functional changes, or price circumstances. For this reason, it is necessary to make the land which mounts components into the shape which can mount components of various sizes.

JP 2007-67019 A Japanese Patent Application Laid-Open No. 06-232537 JP-A-2003-243814

The land used as the evaluation terminal in the printed circuit board described above is often unnecessary at the time of commercialization. Also, when commercialized, it is necessary to connect the cut wires for evaluation. Therefore, when mounting a component, a resistor with a resistance value of 0 [Ω] for the jumper is mounted, or connected with a brazing material such as solder or a conductive adhesive.
Further, as described above, due to characteristic requirements, function changes, or price circumstances, it is necessary to change the components to be mounted on a short day or instantaneously. For this reason, it is necessary to make it possible to mount components of various sizes on the same land as the land shape for mounting the components. In this case, of course, there is a case where the component is not mounted, but is simply short-circuited or left open.
However, Patent Document 1 is a technique for short-circuiting a soldering device that conventionally has been mounted with a chip resistor of 0 [Ω] in order to connect a pattern that has been cut for printed circuit board evaluation. For this reason, in order to bridge the lands between the lands at the time of reflow, the distance between the lands on which the normal chip parts are mounted is set narrower. Therefore, when a normal chip component is mounted on this land, there is a very high probability that a solder bridge will be generated and become defective.
Further, Patent Document 2 is a composite circuit component such as a hybrid IC, in which a solder paste is printed on a land for closed circuit connection of a wiring pattern cut for resistance trimming, and heated and melted by solder reflow or the like. The solder bridge is used for connection. For this purpose, the solder paste is printed on an area larger than the land area. However, in Patent Document 2, there is no description about mounting a component on this short-circuit land, and as in Patent Document 1, when a component is mounted, a solder bridge is likely to occur with a high probability.
Further, Patent Document 3 provides a mounting land that does not require a pattern change even if the size of the component to be mounted changes. However, it does not disclose a technique for short-circuiting the printed circuit board by a solder bridge.
As described above, the conventional circuit board cannot realize an electrical short circuit by a solder bridge and a land on which parts of different sizes can be mounted with a pair of lands.
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems and realize a circuit board and a circuit board capable of realizing an electrical short circuit by a solder bridge and a land on which parts of different sizes can be mounted with a pair of lands. It is to provide an implementation method.

In order to achieve the above object, according to the circuit board and the circuit board mounting method of the present invention, two opposing lands can be electrically short-circuited by a solder bridge, and two-terminal components of different sizes can be mounted. A land having a solder resist opening that is smaller than the width of the land and larger than the maximum width of a mountable component between the two lands.
The circuit board mounting method of the present invention is a method of selectively attaching a solder paste to the land by at least one of printing or dispensing, and simultaneously mounting a component by heating means such as solder reflow or heat beam irradiation. Short circuit between lands or mounting of parts.

That is, the circuit board of the present invention includes a plurality of conductors provided on an insulating substrate and a resist provided on the surface of the insulating substrate and the conductor, and an opening is formed in a part of the resist on each conductor. In the circuit board in which a plurality of lands are formed on the insulating substrate by forming , the plurality of lands include at least a first land and a second land, and the resist includes the first land and the first land. An inter-land opening formed across two lands is formed, and a width of the inter-land opening in a direction perpendicular to a straight line connecting the first land and the second land is the first. The first land and the second land are smaller than the width of the first land and the second land, and are connected by solder in the inter-land opening.
Preferably, the circuit board includes a plurality of conductors provided on the insulating substrate and a resist provided on the surface of the insulating substrate and the conductor, and an opening is formed in a part of the resist on each conductor. In the circuit board in which a plurality of lands are formed on the insulating substrate by forming, the plurality of lands include at least a first land and a second land, and the resist includes the first land and the first land. An inter-land opening formed across two lands is formed, and a width of the inter-land opening in a direction perpendicular to a straight line connecting the first land and the second land is the first. It is smaller than the width of the first land and the second land, and the chip component can be mounted across the first land and the second land.
Preferably, in the circuit board, the first across the land and the second land the solder to the opening portion is printed or dispensed, after heating, the first land and the second land Are short-circuited by the solder .
Preferably, in the circuit board, the width between the land openings are 1 approximately 3 minutes of the width of the first land and the second land.
Further preferably, in order to mount the chip parts having different sizes on the circuit board, the opening portions of the first land and the second land are convex.

  The circuit board mounting method of the present invention includes a plurality of lands formed on an insulating substrate including at least a first land and a second land, and formed on the insulating substrate so as to expose at least the lands. In the circuit board mounting method including the resist, the first land and the second land are short-circuited when the resist opening straddling the first land and the second land is short-circuited. When solder is attached over the resist opening straddling and the chip component is mounted on the first land and the second land, the solder is separated into the first land and the second land. The circuit board is mounted by mounting the chip component by applying solder and heating.

  According to the present invention, it is a land necessary for mounting a component for imposition, and even a component of a different size can be mounted by a solder heating process such as a solder reflow process, and when the component is not mounted, By selectively attaching the solder by replacing the solder mask or solder dispensing, the solder can be bridged in a solder heating process such as a solder reflow process to short-circuit the lands. As a result, it was possible to shorten the development delivery time of the printed circuit board and the product made of the printed circuit board, reduce the development cost, and reduce the product price.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In each figure, components having common functions are denoted by the same reference numerals, and description thereof will be omitted to avoid duplication as much as possible.

An embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram for explaining the shape of an opening of a solder resist (hereinafter, solder resist is simply referred to as a resist) of a land portion (component mounting pattern) of a circuit board according to an embodiment of the present invention. is there. Reference numeral 101 denotes a circuit board base material, reference numeral 102 denotes a conductor formed on the base material 101, reference numeral 103 denotes a resist, and reference numeral 104 denotes a resist opening (a region where the resist 103 is not present). The land shape of the embodiment of FIG. 1 is a land intended for (1) circuit short-circuiting, (2) mounting of 1005 type components, and (3) mounting of 1608 type components. The 1005 type is a chip part having a length of 1.0 [mm] and a width of 0.5 [mm], and the 1608 type is a length of 1.6 [mm] and a width of 0.8 [mm]. This is a chip component of the size. Of course, a size between 1005 type and 1608 type can also be implemented.
Further, the shape of the chip component may be anything as long as surface mounting is possible, such as a rectangular shape (square shape), a cylindrical shape, or the like.

1A is a plan view showing a partial region of wiring (component mounting pattern) formed on a circuit board, FIG. 1B is a cross-sectional view taken along the line AA in FIG. FIG.1 (c) is sectional drawing in the BB line of Fig.1 (a).
As shown in FIG. 1, a region on the conductor 102 where the resist 103 is not present is called a land. The base material 101 is, for example, a glass cloth epoxy material, and the conductive film 102 is, for example, a copper foil. A printed circuit board, which is a circuit board, is coated with a pre-flux after the printed circuit board is manufactured to prevent oxidation of the copper foil surface. a is the distance between the two lands, b is the distance to the outside of the two lands, W is the width of the lands, and R is the width of the resist opening 104 between the lands.
In FIG. 1, the land surface is lower than the resist 103 surface and is in a recessed position surrounded by the resist 103. The width R of the resist opening 104 between the lands is smaller than the width W of the lands.

FIG. 2 is a diagram illustrating an embodiment in which a solder paste is selectively printed and attached to the circuit board of FIG. 1 in order to form a solder bridge and short-circuit between lands using a solder mask. is there. 201 is a solder paste. 2 (a) is a plan view, FIG. 2 (b) is a sectional view taken along line AA in FIG. 2 (a), and FIG. 2 (c) is a sectional view taken along line BB in FIG. 2 (a). It is.
As shown in FIGS. 1 and 2, the solder paste is printed up to the area between the lands of the resist opening 104.

FIG. 3 is a view showing an embodiment in which a solder paste is selectively printed and attached to the circuit board of FIG. 1 in order to mount components using a solder mask different from that of FIG. . 310 is a part, 311 is one electrode of the part 310, 312 is the other electrode of the part 310, 321 and 322 are solder pastes, and 331 and 332 are solders. 3 (a) is a plan view, FIG. 3 (b) is a cross-sectional view taken along line AA in FIG. 3 (a), and FIG. 3 (c) is a solder mount taken along line AA in FIG. 3 (a). FIG.
As shown in FIGS. 1 and 3, solder pastes 321 and 322 are printed between the lands of the resist opening 104. After the solder paste 321 is melted through a solder reflow process, it becomes solder 331, and the electrode 311 of the component 310 is fixed to the land 102. Similarly, after the solder paste 322 is melted through the solder reflow process, the electrode 312 of the component 310 is fixed. It adheres to the land 102.

  The circuit board is mounted with various types of components such as electric parts and mechanical parts of various sizes, and in addition to the pattern including the land of the configuration shown in the embodiment of the present invention such as FIG. Various component mounting patterns are formed in accordance with the mounting of these components. Also, the land circuit board and the circuit board mounting method described in the embodiment of the present invention, such as FIG.

In the embodiment of FIG. 3, a component having a small size is mounted. FIG. 8 shows a cross-sectional view of an example in which a large-sized component is mounted, as in FIG.
FIG. 7 is a diagram showing an example of the actual land shape and dimensions.
In the component mounting pattern of FIG. 7, the land width W is 0.18 [mm], and the width R of the resist opening 104 between the lands is 0.55 [mm]. In the example of this figure, R≈W / 3.

  As described above with reference to FIGS. 1 to 3, 7, and 8, the width R of the resist opening 104 between the lands is smaller than the width W of the lands. The amount of solder when forming is small. Further, when components are mounted, the probability of occurrence of defects due to bridging is small. Therefore, both short circuit and component mounting can be achieved.

  FIG. 4 is a view for further explaining the resist opening 104 in the embodiment of FIGS. The resist 403 on the substrate has a resist-free region, that is, a resist opening. When viewed in plan view, the resist opening is divided into a region (land) where the conductor 402 is present and a region where the conductor 402 is not present and the base material 101 is exposed (base material 401). When the substrate 401 has a large width or length, it is difficult to bridge, and when the substrate 401 is small, it is easy to bridge. The shape of the resist opening in FIGS. 1 to 4 was a square. However, the shape and dimensions are not limited to the above embodiment.

  FIG. 5 is a diagram showing another embodiment of the shape of the resist opening of the present invention. Representative examples are shown in FIGS. 5A to 5C, and there are circular, polygonal, and combinations thereof as the shape of the resist opening.

  FIG. 6 is also a diagram showing another embodiment of the shape of the resist opening of the present invention. A typical example is shown in FIGS. 6 (a) to 6 (b). As shown in FIG. 6 (a), the corners of the land are separated into islands, and FIG. 6 (b) As shown, there are resist corners such as a ribbon knot or butterfly shape, the shape of the corner of the land, the shape of the region where the substrate is exposed, and combinations thereof.

In the above embodiment, the shape of the opening of the resist and the land shape were left-right symmetric and vertically symmetric. However, it is of course not necessary to be symmetric.
Moreover, in the said Example, the case where the height of the upper surface of a resist was higher than the height of the upper surface of a conductor was demonstrated. However, the present invention can also be applied to the case where the height may be the same as in the case of a substrate on which solder coating is performed instead of the preflux, and the upper surface of the conductor is higher.

  Moreover, in the said Example, in order to carry out a solder bridge and to short-circuit a circuit wiring, a solder paste is adhered to the whole circuit board for solder printing, and it reflows simultaneously with other mounting components, and a short circuit is performed. However, for example, a solder paste for mounting components uses a solder paste with a small solder particle size for high-density mounting, and a solder paste with a large solder particle size is separately provided by a dispenser at a location to be bridged ( Alternatively, solder cream) may be used.

  Even when the same solder paste is used, in order to bridge, it is different from the normal solder reflow conditions, for example, reflow at a slightly low temperature, or the fall time at the final temperature drop at the time of reflow is short. A circuit board having many short-circuited portions may be mounted, for example, by time.

Moreover, in the above-mentioned Example, the mounting by soldering is performed by solder reflow. However, there is no need for solder reflow. For example, the components may be mounted by heating means such as irradiation with a heat beam such as a laser beam, manual work with a soldering iron, melting with a heating furnace, or the like.
Moreover, in the said Example, it demonstrated with circuit boards, such as a glass epoxy board | substrate. However, as long as it is an insulating substrate or a dielectric substrate, it may not be an organic substrate, and a method for forming a conductor pattern or a resist film on the substrate and a material to be used are also free. Further, instead of the resist, a silk material may be used, and both resist and silk may be used. Further, a ceramic substrate, a glass substrate, or the like may be used.

According to the above embodiment, the circuit board and the circuit board mounting method of the present invention is a land in which two opposing lands can be electrically short-circuited by a solder bridge and two-terminal parts of different sizes can be mounted. A solder resist opening having a width smaller than the width of the land and larger than the maximum mountable component width is provided between the two lands, and a pair of lands are electrically short-circuited by a solder bridge, and have different sizes. It is possible to realize a land on which the parts can be mounted.
Further, according to the above embodiment, the lands in the circuit board can be short-circuited or opened, or a chip component of a different size can be selected and mounted. When changing the circuit board, it is not necessary to change the pattern of the circuit board, thereby reducing the development cost and the development period.

Further, according to the above embodiment, the circuit board mounting method of the present invention is such that the solder paste is selectively attached to the lands by at least one of printing or dispensing, and heating means such as solder reflow or heat beam irradiation is used. By short-circuiting between lands or mounting components simultaneously with component mounting, it is possible to realize a land in which a pair of lands can be electrically short-circuited by a solder bridge and components of different sizes can be mounted.
The pair of lands are two lands in the above embodiment, but need not be two.

The figure for demonstrating the shape of the opening part of the soldering resist of the land part of the circuit board of one Example of this invention. The figure for demonstrating the solder bridge of one Example of this invention. The figure for demonstrating the component mounting of one Example of this invention. The figure for demonstrating the shape of the opening part of the soldering resist of the land part of the circuit board of one Example of this invention. The figure for demonstrating the shape of the opening part of the soldering resist of the land part of the circuit board of one Example of this invention. The figure for demonstrating the shape of the opening part of the soldering resist of the land part of the circuit board of one Example of this invention. The figure for demonstrating the shape of the opening part of the soldering resist of the land part of the circuit board of one Example of this invention. The figure for demonstrating the component mounting of one Example of this invention.

Explanation of symbols

  101: Base material, 102: Conductor, 103: Resist, 104: Resist opening, 201: Solder paste, 310, 310 ′: Parts, 311, 311 ′, 312, 312 ′: Electrode, 321 and 322: Solder paste 331, 331 ′, 332, 332 ′: solder, 401, 401-1, 401-2, 401-3: base material, 402-1, 402-2, 402-3: conductor, 403, 403-1, 403-2, 403-3: Resist.

Claims (4)

A plurality of conductors provided on an insulating substrate, and a resist provided on the surface of the insulating substrate and the conductor, and forming an opening in a part of the resist on each of the conductors on the insulating substrate. In a circuit board formed with a plurality of lands ,
The plurality of lands include at least a first land and a second land,
The resist has an inter-land opening formed across the first land and the second land, and connects the first land and the second land in the inter-land opening. The width in the direction perpendicular to the straight line is smaller than the width of the first land and the second land,
The circuit board according to claim 1, wherein the first land and the second land are connected by solder in the opening between the lands . A plurality of conductors provided on an insulating substrate, and a resist provided on the surface of the insulating substrate and the conductor, and forming an opening in a part of the resist on each of the conductors on the insulating substrate. In a circuit board formed with a plurality of lands,
The plurality of lands include at least a first land and a second land,
The resist has an inter-land opening formed across the first land and the second land, and connects the first land and the second land in the inter-land opening. The width in the direction perpendicular to the straight line is smaller than the width of the first land and the second land,
A circuit board, wherein a chip component can be mounted across the first land and the second land. 2. The circuit board according to claim 1 , wherein the solder is printed or dispensed in the opening across the first land and the second land, and after heating, the first land and the second land. Are short-circuited by the solder . In the circuit board according to any one of claims 1 to 3, wherein the width between the land opening is substantially one-third of the width of the first land and the second land A circuit board characterized by that.

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