JP3928578B2 - Electronic board wiring structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wiring structure of an electronic board used for various electronic devices.
[0002]
[Prior art]
Many IC packages are mounted on various electronic substrates. IC packages are becoming smaller with the times. And, in the transition period from the old model (large) to the new model (small) with the same function, that is, in the period when the old model and the new model are used confusingly, either type of IC package may be used. In some cases, a wiring (pattern) that can cope with any type of mounting is formed (see, for example, Patent Document 1).
[0003]
FIG. 2 shows an example of the wiring pattern. In FIG. 2 , lands 3 ₋₁ , 3 ₋₂ ,..., 3 _-14 for connecting lead terminals of the old (large) IC package 2 are formed on the electronic substrate 1, and the old IC package 2 Lands 5 _-1 , 5 _-2 ,..., 5 _-14 for connecting lead terminals of the new (small) IC package 4 are formed side by side in the longitudinal direction of the package to be mounted and wired. Lands 3 _-1 , 3 _-2 , ... 3 _-14 and lands 5 _-1 , 5 _-2 , ..., 5 _{-14 depend} on wiring patterns 6 _-1 , 6 _-2 , ..., 6 _-14 They are commonly connected to each other. A part of the wiring patterns 6 ₋₁ , 6 ₋₂ ,..., 6 _-14 is lower than the part of the land 3 ₋₁ , 3 _{−2 ,.} It passes between the land group 3 and the land group 5 and is connected to a part of the outer tip of the land 5 ₋₁ , 5 _{−2 ,.} The other part of the wiring patterns 6 _-1 , 6 _-2 ,..., 6 _-14 is the outer tip of the other part of the lands 3 _-1 , 3 _{-2 ,.} It is connected to the outer front end or the inner end of the other part of the lands 5 ₋₁ , 5 _{−2 ,.}
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 5-315759
[Problems to be solved by the invention]
In the wiring structure of the conventional electronic substrate described above, the land for the old (large) IC package and the land for the new (small) IC package are juxtaposed, so that the wiring pattern becomes large. There is.
[0006]
The present invention has been made paying attention to the above-mentioned problems, and an object thereof is to provide a miniaturized wiring structure for selectively mounting packages having the same performance and different shape.
[0007]
[Means for Solving the Problems]
The wiring structure of the electronic board according to the present invention is a wiring structure of the electronic board that allows the first and second IC packages having the same performance and different shapes (sizes) to be selectively mounted . The outline of the first IC package is rectangular, the outline of the first IC package is larger than the outline of the second IC package, and the main body mounting position of the first IC package is formed on the surface of the electronic substrate. At the same time, lands for the first IC package for connecting the terminals of the first IC package are juxtaposed along the long sides outside the long sides of the outline of the IC package. On the back surface of the substrate, the long side of the outline of the second IC package is perpendicular to the long side of the outline of the surface of the electronic substrate, so that the main IC mounting position of the second IC package is the first IC package. Pack The second IC package land for connecting the terminals of the second IC package is placed outside both long sides of the outline of the IC package. They are juxtaposed along the long sides .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to embodiments. Figure 1 is a Ru FIG der showing a wiring pattern of the electronic substrate which is an embodiment of the present invention.
[0010]
In this embodiment, a wiring pattern is formed on both the front and back surfaces of the electronic substrate 31. A line 32 indicating the outer shape of the first IC package is formed on the surface of the electronic substrate 31, and a line 33 indicating the outer shape of the second IC package is formed on the back surface of the electronic substrate 31. Here, the outline 32 of the first IC package is larger than the outline 33 of the second IC package. The external lines 32 and 33 of the first and second IC packages are also rectangular, and are arranged so that their longitudinal directions are orthogonal to each other on the front and back sides.
[0011]
The outer surfaces of the long sides of the first IC package outline 32 of the surface, the first land 34 _-1 for terminal connection of the IC package, ..., 34 _-4 and 34 _-5, ..., 34 _{- 8} is formed. Also, terminal lands 35 _-1 ,..., 35 _-4 and 35 _-5 ,..., 35 _-8 are formed outside the long sides of the outline 33 of the second IC package on the back surface. Yes. The lands 34 _-1 ,..., 34 _-4 and 34 _-5 ,..., 34 _-8 for the first IC package are the lands 35 _{-1 ,.} 35 _-5 ,..., 35 _-8 and the corresponding ones are connected in common by throughs 36 _{-1 ,.}
[0012]
In this embodiment, the lands 35 _-1 ,..., 35 _-4 and 35 _-5 ,..., 35 _-8 for the second IC package overlap with the outline 32 of the first IC package, that is, the first lands. Although it is the back surface, it is formed at a position overlapping with the mounting position of one package.
[0013]
【The invention's effect】
According to the present invention, when the first package is mounted, since the land for the second package is formed on the back surface of the portion where the package body overlaps, the large package up to that time has been mounted. It is possible to realize a wiring structure that can cope with any of the same performance and different shape packages without increasing the area.
[Brief description of the drawings]
FIG. 1 is a diagram showing a wiring pattern of an electronic board according to an embodiment of the present invention.
FIG. 2 is a diagram showing an example of a wiring pattern of a conventional electronic substrate.
[Explanation of symbols]
31 Electronic substrate 32 Outline of first IC package 33 Outline of second IC package 34 _-1 ,..., 34 _-8 Land for first IC package 35 _{-1 ,.} 2 IC package land 36 _-1 , ..., 36 _-8 connection pattern line

Claims (1)

A wiring structure of an electronic board that enables selective mounting of first and second IC packages having the same performance and different shapes,
The outline of the first and second IC packages is a rectangle, the outline of the first IC package is larger than the outline of the second IC package,
On the surface of the electronic substrate, a main body mounting position of the first IC package is formed, and a land for the first IC package for connecting the terminals of the first IC package is formed on the outline of the IC package. The two long sides are juxtaposed along the long sides,
On the back surface of the electronic substrate, the long side of the outline of the second IC package is perpendicular to the long side of the outline of the surface of the electronic substrate, so that the main body mounting scheduled position of the second IC package is the first The IC package is formed so as to overlap the main body mounting position of the IC package, and the second IC package land for connecting the terminals of the second IC package is placed outside both long sides of the outline of the IC package. A wiring structure of an electronic board, wherein the wiring structure is arranged along the long sides .

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