JP3928152B2 - Printed wiring board - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a printed wiring board, and more particularly to a printed wiring board on which a plurality of types of copper-clad boards having different current capacities to be supplied are formed.
[0002]
[Prior art]
On the printed wiring board, in addition to the signal pattern, a power supply pattern and a ground pattern are formed, and the amounts of current flowing through these conductor patterns are different. Each conductor pattern is formed according to the current capacity to be used, and is designed so that the temperature rise of the conductor pattern is 10 ° C. or less in a normal use state. As a means for satisfying this use condition, a method of changing the width of the conductor pattern according to the amount of current flowing through the conductor pattern is used. In other words, the conductor pattern (for example, weak current signal pattern) through which a small current flows is formed with a narrow width, and the conductor pattern (for example, a power supply pattern) through which a large current flows is formed with a wide width.
[0003]
As another means that satisfies the usage conditions, a method of changing the thickness of the conductor pattern in accordance with the amount of current flowing through the conductor pattern is used. That is, the method is to form a thin conductor pattern in which a small current flows, and to increase the thickness in a conductor pattern through which a large current flows. As a means for thickening the conductor pattern, for example, a method of overlaying solder on the conductor pattern by soldering is employed. Furthermore, as another means satisfying the use conditions, a method of additionally connecting or alternative connecting a conductive material such as a copper plate or a vinyl-coated electric wire by soldering between patterns is used.
[0004]
[Problems to be solved by the invention]
However, with the recent miniaturization of electronic components, the density of components mounted on a printed wiring board has increased, and the line width and space between conductor patterns that connect each component can be finely formed. It has become necessary. Therefore, in the conventional method in which the width of the conductor pattern is changed in accordance with the amount of current flowing to satisfy the above-described use conditions, the area of the conductor pattern through which a large current flows increases, and the conductor pattern is formed finely. However, the printed wiring board cannot be miniaturized.
[0005]
In addition, the conventional method in which the thickness of the conductor pattern is changed in accordance with the amount of current flowing to satisfy the usage conditions is effective in reducing the area of the printed wiring board. There is a possibility that the solder bridges between adjacent conductor patterns to cause a pattern short, or that the conductor pattern is deformed or cut by the heat of the solder.
Furthermore, in order to satisfy the conditions of use, the conventional method of connecting or additionally connecting conductive materials such as copper plates and vinyl-coated wires by soldering between patterns requires burring to connect the copper plate and the printed wiring board. In addition, a dedicated through-hole is required to connect the vinyl-coated electric wire, resulting in a significant increase in work cost and an increase in the size of the printed wiring board.
[0006]
The present invention has been made in order to solve the above-described problems, and can achieve a reduction in the size of a printed wiring board, suppress an increase in processing cost in a manufacturing process, and increase a current capacity of a conductor pattern. The purpose is to provide a wiring board.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the invention of claim 1 is a printed wiring board in which a copper-clad board having an arbitrary shape or width is formed, a soldering portion formed on the copper-clad board, and the copper-clad board. a copper plate to be arranged superimposed on the plate, the shape and the same shape of the copper clad laminate position disposed, or copper plate which is formed by a similar shape to the shape smaller than the copper clad laminate is provided is, the thickness of the copper plate, and the width of the copper plate parameters, thicker in a portion where the width in one of the copper plate is formed narrower, which is thinner at the portion which is wider form, wherein Both ends of the copper plate are surface-mounted by soldering to the soldering portions at corresponding positions formed on the copper-clad plate, respectively , and area expansion portions are formed at both ends of the copper plate. To do.
[0008]
Here, the copper plate is disposed on the copper clad plate so that the shape of the copper plate and the copper clad plate is exactly the same, and the copper plate exactly overlaps the copper clad plate, or the copper plate and the copper clad plate. Although the shape is not exactly the same, the copper plate is disposed in the region of the copper-clad plate and the copper plate does not protrude outside the copper-clad plate. In addition, the shape of the copper plate is formed in substantially the same shape as the copper-clad plate at the position where the copper plate is disposed, in addition to the case where the shape and size of both are formed exactly the same, Including those that are.
Copper-clad plates include signal copper-clad plates, power supply copper-clad plates, and grounded copper-clad plates (hereinafter these copper-clad plates are also referred to as conductor patterns), and a copper plate made of a conductive material is placed on the conductor pattern. This increases the current capacity and suppresses the increase in the conductor pattern width. By making the shape of the copper plate to be overlaid substantially the same as the shape of the conductor pattern at the location where it is placed, the path of the current flowing through the conductor pattern and the copper plate can be made similar, and noise emission characteristics can be improved. Can be planned.
[0009]
In addition , since the thickness of the copper plate placed on the conductor pattern can be changed according to the amount of current flowing through each conductor pattern, the required minimum pattern thickness (thickness of the copper plate on the conductor pattern) can be achieved. Can be set.
[0010]
Further , the contact resistance value between the copper-clad plate and the copper plate is reduced by forming an enlarged area in the vicinity of both ends (both ends of the copper plate) of the copper plate soldered to the copper-clad plate. Further, by forming the area other than both end portions of the copper plate (the center portion of the copper plate) smaller than the area of both end portions of the copper plate, a large insulation distance from the adjacent conductor pattern is ensured.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a printed wiring board according to the present invention will be described below with reference to the accompanying drawings.
[0012]
FIG. 1 is a top view showing one embodiment of the printed wiring board 1, and FIG. 2 is a cross-sectional view taken along the line EE of FIG. On the surface of the insulating substrate 2 made of glass epoxy material or the like, a conductor pattern 3 made of copper foil is pasted and pattern-etched. Here, the conductor pattern 3 includes a signal copper-clad plate, a power supply copper-clad plate, a ground copper-clad plate, and the like. Each designed circuit is formed and etched on the insulating substrate in an arbitrary form. Each copper-clad plate may vary the thickness of the copper foil to be pasted within a range where pattern etching can be performed according to the required current capacity, or the thickness of all copper-clad plates may be constant. .
[0013]
A copper plate 5 made of a conductive material is surface-mounted on the conductor pattern 3 by soldering. Both ends of the copper plate 5 are soldered to soldering portions 6 formed on the conductor pattern 3. Solder 4 deposited on the soldering portion 6 is shown at both ends of the copper plate 5 in FIG. On the conductor pattern 3, an electronic component soldering portion 7 and a through hole 8 for attaching the electronic component are formed at the center of the soldering portion 7. As shown in FIG. 2, the electronic component 9 is attached by the lead wire 10 of the electronic component being passed through the through hole 8 and the end portion of the lead wire 10 being soldered (solder 4 ′) to the soldering portion 7. In this embodiment, the case where the electronic component 9 is provided on the surface of the insulating substrate 2 opposite to the surface on which the conductor pattern 3 and the copper plate 5 are provided has been described. However, the present invention is not limited to this embodiment, and the conductor pattern 3 It may be provided on the same plane as the above.
[0014]
FIG. 3 is a perspective view showing an embodiment of the copper plate 5 that is surface-mounted on the conductor pattern 3. The copper plate 5 is obtained by punching plate-like copper into an arbitrary pattern shape, and has a predetermined thickness t. The shape of the copper plate 5 is the same as the shape (described later) of the conductor pattern 3 at the position where the copper plate 5 is disposed. When the copper plate 5 is disposed on the conductor pattern 3, both end portions 11 and 12 of the copper plate 5 are soldered to the soldering portion 6. The thickness t of the copper plate 5 varies depending on the conductor pattern 3 at the surface-mounted position, that is, according to the magnitude of the current flowing through the circuit formed by the conductor pattern 3, and the thickness t is thick in the circuit through which a large current flows. A copper plate 5 is used. The thickness t of the copper plate 5 is changed in accordance with the magnitude of the current flowing through the circuit to obtain the current capacity required for the conductor pattern 3 portion on which the copper plate 5 is mounted, that is, the conductor.
[0015]
FIG. 4 is a perspective view showing another embodiment of the copper plate 5 that is surface-mounted on the conductor pattern 3. In the form of the copper plate 5 shown in FIG. 3, the case where the thickness t of the copper plate 5 is uniform is shown as a whole, but is not limited to this form. Since the thickness of the copper plate 5 is changed in order to ensure a predetermined current capacity, the copper plate 5 is defined by using the width of the conductor pattern 3 as a parameter in addition to the magnitude of the current flowing through the conductor pattern 3 portion on which the copper plate 5 is mounted. May be set. That is, the copper plate 5 (formed in the same shape as the conductor pattern 3 at the position where it is disposed) has a thickness p of the copper plate 5 of the portion 13 where the width W is formed narrow as shown in FIG. 5 may be formed to be thicker than the thicknesses p ′ and p ″ of the portions 14 and 15 where the widths W ′ and W ″ are widely formed. Even in such a shape, the current capacity required for the conductor can be obtained.
[0016]
FIG. 5 is a diagram showing an embodiment of the conductor pattern 3 in a state where the copper plate 5 is not mounted. The conductor pattern 3 has areas 20 and 21 to which the copper plate 5 and the electronic component 9 are connected (soldered) in order to reduce the connection resistance with the copper plate 5 or the electronic component 9 connected to the conductor pattern 3. Is formed large. The conductor pattern 3 is formed in a constricted shape in which the width (area) of the portion 22 to which the copper plate 5 or the like is not connected is narrower than the width (area) of the portions 20 or 21 to which the copper plate 5 or the like is connected. By making the conductor pattern 3 constricted in this way, it is possible to sufficiently secure the insulation distances h and h ′ (see FIG. 1) from the other conductor patterns 3 ′ and 3 ″, and also on the insulating substrate 2. The mounting density of components and the like can be increased.
[0017]
Further, the copper plate 5 is formed in the same shape as the conductor pattern 3 at the position where the copper plate 5 is disposed so that the copper plate 5 is disposed so as to overlap the conductor pattern 3 when mounted on the conductor pattern 3. That is, the areas 14 and 15 at both ends of the copper plate 5 to be soldered to the conductor pattern 3 have a large area, and the portion 13 disposed on the constricted part 22 of the conductor pattern 3 has a narrow width (small area). (See FIG. 3).
Thus, by forming the copper plate 5 in the same shape as the conductor pattern 3 and arranging the copper plate 5 in an overlapping manner, the path of the current flowing through the conductor pattern and the copper plate can be made the same, and the noise radiation characteristics can be improved. Can do.
[0018]
The copper plate 5 may be disposed so as to overlap the region of the conductor pattern 3 when surface-mounted on the conductor pattern 3. Therefore, the copper plate 5 has not only the same shape and size as the copper clad plate at the position where the copper plate is disposed, but also the substantially same shape, for example, the shape of the copper plate and the conductor pattern is similar. Also included are those in which the width or length of part of the copper plate is narrower or shorter than the shape of the conductor pattern.
[0019]
As described above, since both ends 11 and 12 of the copper plate 5 are fixed onto the conductor pattern 3 by soldering, the copper plate 5 can be easily attached and detached. Therefore, even when the amount of current flowing through the circuit changes due to a design change or the like, the copper plate 5 having a predetermined thickness is selected in order to obtain the necessary current capacity of the conductor according to the magnitude of the current flowing through each circuit. Can be attached.
[0020]
Specifically, when the current capacity of a conductor pattern formed between adjacently arranged parts or between parts arranged at a short distance is insufficient due to a design change, the conductor pattern between those parts By mounting the copper plate having a predetermined thickness on the surface, it is possible to secure the current capacity of the conductor that satisfies the use conditions (suppression of the temperature rise of the conductor in the normal use state).
[0021]
Further, since the conductor pattern 3 is formed on the insulating substrate 2 even when the copper plate 5 is removed, it is not necessary to mount the copper plate 5 on a conductor pattern (for example, a circuit for small signals) with a small flowing current. The copper plate 5 can be attached and detached as necessary.
[0022]
【The invention's effect】
From the above, according to the printed wiring board according to the present invention, the copper plate having a predetermined thickness is formed in the same shape as the copper-clad plate at the position where the copper plate is disposed, and both ends of the copper plate are only soldered. Since it is fixed on the copper-clad plate, no special processing work (burring processing, etc.) is required, the increase in manufacturing cost can be suppressed, and the current path flowing through the conductor (copper plate and conductor pattern) Since it can be made similar, it is possible to improve noise radiation characteristics.
[0023]
Moreover, since the copper plate is fixed on the copper clad plate only by soldering, the copper plate can be easily attached and detached. Therefore, it is possible to easily attach a copper plate having a predetermined thickness in accordance with the amount of current flowing through the circuit, so that workability can be improved and a necessary current capacity of the conductor can be ensured.
Furthermore, since the copper plate is surface-mounted on the copper-clad plate, there is no need to provide a dedicated through hole for connecting the copper plate to the insulating substrate, and the mounting density of components and the like arranged on the insulating substrate can be increased. .
[Brief description of the drawings]
FIG. 1 is a top view showing an embodiment of a printed wiring board according to the present invention.
FIG. 2 is a cross-sectional view taken along the line EE of FIG.
FIG. 3 is a perspective view showing one embodiment of a copper plate that is surface-mounted on a conductor pattern of a printed wiring board according to the present invention.
4 is a perspective view showing an embodiment of a copper plate different from FIG. 3. FIG.
FIG. 5 is a view showing an embodiment of a conductor pattern in a state where a copper plate is not mounted on a printed wiring board according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Printed wiring board 2 Insulation board 3, 3 ', 3 "Conductor pattern 4, 4' Solder 5 Copper plate 6, 7 Soldering part 8 Through hole 9 Electronic component h, h 'Insulation distance

Claims (1)

In a printed wiring board on which a copper-clad board having an arbitrary shape or width is formed,
A soldering portion formed on the copper-clad plate;
A copper plate disposed superimposed on the copper clad laminate was formed shape and same shape of the copper-clad board position disposed, or a similar shape to the shape smaller than the copper clad laminate copper plate is provided,
The thickness of the copper plate is formed so that the width of the copper plate is a parameter, the portion formed with a narrow width in one copper plate is thick, and the portion formed with a wide width is formed thin.
Both ends of the copper plate are surface-mounted by soldering to the soldering portions at corresponding positions formed on the copper-clad plate ,
A printed wiring board, wherein an area enlargement portion is formed at both ends of the copper plate.

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