JPH0520367U - Surface mount circuit board - Google Patents

Abstract

(57) [Abstract] [Purpose] In a surface-mounting circuit board, a circuit board in which bridging and unfavorable electrical coupling between adjacent circuit patterns hardly occur, soldering is good, and chip standing does not easily occur provide. A circuit board having a surface on which terminal electrodes of a surface-mounted electronic component are overlapped and soldered to the terminal electrodes, the electronic component of the connecting lands being It is a surface-mounting circuit board in which a corner portion of a connection region protruding from an overlapping region is cut out in a linear shape or an arc shape.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a surface mount circuit board on which a flat package type electronic component or a chip type electronic component without a lead terminal is placed and soldered. More specifically, the present invention relates to a land for connecting to these electronic components. The present invention relates to a surface mounting circuit board having an improved shape.

[0002]

[Prior Art]

 Conventionally, as a surface mounting circuit board, as shown in FIGS. 3 and 4, a pair of rectangular connecting lands (3) and (5) are formed on one surface of the circuit board (1), and these connecting lands are formed. It is well known that the circuit patterns (3a) and (5a) are derived from the lands (3) and (5).

In such a surface mounting circuit board, solder paste is applied in advance to the connection lands (3) and (5), and for example, electrodes (9a) at both ends of the chip type electronic component (7), (9b) is placed so as to overlap with one half of the connection lands (3) and (5), and the solder paste is melted by heating to form the connection land (3) and the electrode (9a), and the connection land (5) and the electrode. (9b) is soldered, or the electronic component (7) is placed and temporarily fixed so that the electrodes (9a) and (9b) on both ends overlap with one half of the connection lands (3) and (5). It was dipped in a molten solder bath for soldering. In FIG. 3, reference numeral (11) is solder.

[0004]

[Problems to be solved by the device]

 However, in the surface-mounting circuit board having the above-described configuration, the connection lands (3) and (5) have a rectangular shape, and thus have the following drawbacks.

That is, among the connection lands (3) and (5), the connection regions (3b) and (5b) that do not overlap with the electronic component (7) have corners (3c) and (5c) protruding. For example, when another circuit pattern (13) is formed in proximity as shown in FIG. 4, bridging due to the solder (11) or undesired electrical coupling is likely to occur.

Further, when the solder (11) melts, it tends to spread into a spherical shape, but since the corners (3c) and (5c) protrude, the solder surroundings from melting to solidification are not good.

Further, when the corners ((3c), (5c) are projected, the center of the surface tension of the solder applied to the electronic component (7) during solidification of the solder is above the connection lands (3), (5). Since the electronic component (7) is located away from the electronic component (7), stress is easily applied to the electronic component (7).

Therefore, if there is an imbalance of stress in the connection lands (3) and (5), there is a possibility that one side of the electronic component rises as shown by the dashed line in FIG. It was

The present invention has been made in order to solve the above-mentioned conventional drawbacks. Bridging or coupling is unlikely to occur between adjacent circuit patterns, soldering is good, and chip standing is unlikely to occur. A circuit board for surface mounting is provided.

[0010]

[Means for Solving the Problems]

 In order to solve such problems, the surface mounting circuit board of the present invention has a substantially rectangular shape in which the terminal electrodes of the electronic components to be surface mounted are stacked on the surface of the circuit board body and soldered thereto. It has connection lands, and the corners of the connection area protruding from the side overlapping the electronic component are cut out.

[0011]

[Action]

 In the present invention equipped with such means, in the connection land formed on the surface of the circuit board main body, the corners of the connection area that do not overlap with the electronic component do not significantly project, so that the circuit pattern is different from other circuit patterns in the vicinity. Is sufficiently spaced.

Further, the center of tension of the melted solder is located near the electronic component.

[0013]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. The same parts as those in the conventional example are designated by the same reference numerals.

FIG. 1 is a sectional view of an essential part showing one embodiment of a surface mounting circuit board according to the present invention.

In the figure, reference numeral (1) is a conventionally known insulating circuit board body, and a pair of substantially rectangular connection lands (15) and (17) are formed on the upper surface by a known method such as photoetching. Has been done.

The spacing between the connection lands (15) and (17) is selected so that the tip ends of the electronic parts (7) placed on the connection lands (15) and (17) extend to the middle of the connection lands (15) and (17). About half of the connection lands (15) and (17) are projected from the tip of the electronic component (7).

In the connection lands (15) and (17), the corner portions (15c) and (17c) of the connection regions (15b) and (17b) that do not overlap the electronic component (7) and project from the front ends thereof are formed. It is notched linearly, and the circuit patterns (15a 1) and (17a) are led out from between the notches.

In such a surface mounting circuit board, as in the case of FIG. 3 of the conventional example, solder paste or the like is applied in advance to the connection lands (15) and (17), and the terminal electrodes of the electronic component (7) are The poles (9a) and (9b) are placed so as to overlap with one half of the connection lands (15) and (17) and soldered by heating, or the electronic component (7) is mounted on the circuit board body (1). Temporarily fix and solder in the molten solder bath.

In the above-described embodiment, the protruding connection areas (15b) and (17b) of the connection lands (15) and (17) are formed by linearly cutting out the corner portions (15c) and (17c). However, the present invention is not limited to this.

For example, as shown in FIG. 2, it is possible to have a configuration in which the corner portions of the connection regions of the connection lands (19) and (21) are cut out in a curved shape.

Further, although not shown, a polygonal cutout may be formed, or the connection region may be substantially cutout by a solder resist.

[0022]

[Effect of the device]

 As described above, in the surface mounting circuit board of the present invention, the connection lands (15), (17), (19) and (21) having a substantially rectangular shape formed on the surface of the circuit board body (1) are Since the corners (15c) and (17c) of the connection regions (15b) and (17b) protruding when the electronic components (7) are stacked are cut out, maintain a good distance between adjacent circuit patterns. It is possible to prevent bridging and undesired electrical coupling, and the soldering area is also improved.

Moreover, since the center of the surface tension of the solder when the solder is melted and solidified approaches the electronic component (7), stress is not easily applied to the electronic component (7), and chip standing is less likely to occur.

[Brief description of drawings]

FIG. 1 is a main part plan view showing an embodiment of a surface mounting circuit board according to the present invention.

FIG. 2 is a plan view of an essential part showing another embodiment of the present invention.

FIG. 3 is a cross-sectional view (partially shown in side view) of a main part of a conventional surface mounting circuit board.

FIG. 4 is a plan view of an essential part of FIG.

[Explanation of symbols]

(1) Circuit board body (3) (5) (15) (17) (19) (21) Connection land (3b) (5b) (15b) (17b) Connection area (3c) (5c) (15c) ( 17c) Corner (7) Electronic component (9a) (9b) Terminal electrode (11) Solder (13) Other circuit pattern

Claims (1)

[Scope of utility model registration request] 1. A surface-mounting circuit board in which terminal electrodes of a surface-mounting electronic component are overlapped and soldered with the terminal electrodes are formed on the surface of a circuit board body. A surface mounting circuit board, characterized in that a corner portion of a connection region protruding from a region of the land overlapping with the electronic component is cut out.