JPH02238688A - Printed wiring board - Google Patents

Abstract

PURPOSE:To prevent generation of solder bridge by cutting a pattern region for grounding in circular form and discontinuously, surrounding a ground surface which connects and fixes the lead wire of electronic component electrically. CONSTITUTION:A region 7 for electrically isolating a land 8 provided around one through-hole 3a from a pattern for grounding 2, for example the exposed surface of an insulation substrate forming the main unit of a printed-wiring board 4, is provided. Also, a surface 9 is provided where the insulation substrate is exposed for forming the main unit of the printed-circuit board 4, by cutting the region of the pattern 2 for grounding in circular form and discontinuously, surrounding a ground surface 2a in reference to the center, namely a through- hole 3b penetrating a lead wire 5b of electronic component 5 to be mounted and packaged in the other. Thus, a solder 6 brought up to the side of pattern for grounding by means of the through-hole 3b where the lead wires 5a and 5b of the mounted electronic component 5 and its expansion is easily restricted and prevented at a part where the pattern region for grounding is selectively cut off in circular form and non-discontinuously, thus preventing the danger of generation of solder bridge entirely.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a printed wiring board, and in particular, to a printed wiring board, in which electronic components are mounted and mounted, and the lead wires of the electronic components are connected to a predetermined surface of a grounding pattern. The present invention relates to a printed wiring board that is connected and fixed.

(Prior art) It is widely known that for the purpose of downsizing circuits and circuit components, necessary electronic components are mounted on a printed wiring board to form a high-density circuit device (high-density circuit component). It is being For example, in the plan view of FIG.
As shown in cross section in each figure, a required circuit pattern 1 is formed on one side, a grounding pattern (usually relatively wide area) 2 is formed on the other side, and the required leads of electronic components are formed on the other side. First, a printed wiring board 4 provided with through holes 3a and 3b through which wires are inserted is prepared. Next, necessary electronic components such as
A capacitor 5 is mounted and arranged, and the lead wires 5a and 5b of the capacitor 5 are inserted into the through holes 3a and 3b. Thereafter, the printed wiring board 4 is soldered so that the surface on which the circuit pattern 1 is formed is immersed in a solder bath, and the capacitor 5 is electrically connected to the desired circuit pattern 1, and the lead wire of the capacitor 5 is 5b is electrically connected to the grounding pattern 2 and fixed or mounted to form a required mounted circuit device or the like. In the above, the lead wire 15b of the capacitor 5 is electrically connected to the grounding pattern 2 by soldering 6, but the lead wire 5a of the capacitor 5 is electrically isolated from the grounding pattern 2 (insulating area 7 ) are also fixed by soldering 6. In other words, in the above printed wiring board, the lead wires 5 of the electronic components 5 to be mounted and mounted are
The grounding pattern 2 for b has a configuration that is entirely continuous with the grounding surface.

(Problems to be Solved by the Invention) However, the printer/wiring board having the above configuration has the following disadvantages. That is, when the required electronic components 5 are mounted and mounted as described above, the lead wires 5 of the electronic components 5
On the side where b is inserted, the solder 6 pulled up from the surface where the required circuit pattern 1 is formed through the through hole 3b is applied to the ground plane 2.
In many cases, it spreads and adheres to the two surfaces of the grounding pattern extending beyond and around area a. Such solder 6
Spread adhesion (adhesion to unnecessary areas) not only impairs the appearance of the assembled circuit components, but also causes accidents such as solder bridging when it is desired to increase the mounting density of the electronic components 5. Therefore, it is difficult to say that the reliability is fully satisfactory.

[Structure of the Invention] (Means for Solving the Problems) The present invention has been made in response to the above-mentioned circumstances, and includes a through hole for inserting the lead wire of the electronic component to be mounted and mounted, and a through hole for inserting the lead wire of the electronic component In a printed circuit board 1/wiring board having a grounding pattern including a grounding surface to which the grounding surface is connected and fixed, a structure is adopted in which the grounding pattern area is cut out in an annular and non-continuous manner surrounding the grounding surface. .

(Function) According to the above configuration, when the required electronic components are mounted and the required soldering is performed, the lead wires of the mounted electronic components are pulled up to the grounding pattern side through the through-holes. The spread of the solder is easily suppressed or suppressed in a portion where the grounding pattern area is selectively removed in an annular and non-continuous manner surrounding the grounding surface. In other words, the solder pulled up to the grounding pattern side not only performs the necessary grounding and fixing functions for the mounted electronic components by being connected to the specified grounding surface, but also completely eliminates the risk of solder bridging. removed.

(Example) An example of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a plan view showing the main parts of the printed wiring board according to the present invention, in which 2 is a contact pattern formed on one side of the printed wiring board 4, and 2a is an electronic Ground plane of parts, 3a. 3b is a through hole through which the lead wire of the electronic component to be mounted or mounted is inserted, and 7 is a region provided around one of the through holes 3a to electrically isolate the land 8 from the grounding pattern 2, for example,
This is the exposed surface of the insulating substrate forming the main body of the printed wiring board 4. Further, reference numeral 9 is annularly and non-continuously grounded around the other through hole 3b, that is, surrounding the aforementioned ground plane 2a centered on the through hole 5b through which the lead wire 5b of the electronic component to be mounted and mounted is inserted (inserted). This is the surface where the insulating substrate forming the main body of the pudding 1/wiring board 4 is exposed by cutting out the area of the button 2. On the other side of the printed wiring board 4, a desired circuit pattern is adhered.

Next, an example in which an electronic component 5 such as a capacitor is mounted and mounted on the printed wiring board 4 having the above configuration will be described. FIG. 2 is a cross-sectional view showing the electronic component 5 mounted and mounted on the printed wiring board 4. The lead wires 5a and 5b of the mounted electronic component 5 are connected to the required circuit pattern. 1 and the grounding pattern 2, as well as mounting and fixing the electronic component 5, when soldering is performed by conventional means, the result will be as follows. In other words, the solder 6 to the grounding pattern 2 is attached on the lead wire 5a side.
Spreading of the solder 6 is suppressed by a region 7 provided to electrically isolate the land 8 provided around the through hole 3a from the grounding pattern 2. On the other hand, lead wire 5b
On the side, around the through hole 3b, that is, on the ground plane 2a, a region 9 that is electrically isolated from the grounding pattern 2 is provided in an annular and discontinuous manner. Suppressed or suppressed. Moreover, since the ground plane maintains electrical connection with the grounding pattern 2, the electronic component 5 is grounded as required.

[Effects of the Invention] As described above, when the printed wiring board according to the present invention is mounted and mounted with necessary electronic components, half the time during the mounting is
] 1, the spread of solder on the grounding pattern surface and its adhesion can be easily and reliably completely suppressed or suppressed. Thus, according to the printed wiring board according to the present invention,
It has a good appearance, completely avoids the possibility of solder bridges, etc., and can be said to be suitable for the construction of highly reliable mounted circuit devices.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the main parts of a printed wiring board according to the present invention, FIG. 2 is a cross-sectional view schematically showing a state in which electronic components are mounted on the printed wiring board according to the present invention, and FIG. 4 is a plan view showing essential parts of a conventional printed wiring board, and FIG. 4 is a sectional view schematically showing a state in which electronic components are mounted on the conventional printed wiring board. 1...Circuit pattern 2...Grounding pattern 2a...Ground planes 3a, 3b...Through hole 4...・Printed wiring board 5...Electronic components 6...Solder 7 ・Grounding pattern 8...Randon removal area

Claims (1)

[Scope of Claims] A printed wiring board having a grounding pattern including a through-hole into which a lead wire of an electronic component to be mounted and mounted is inserted, and a ground plane to which the lead wire of the electronic component is electrically connected and fixed. A printed wiring board characterized in that a grounding pattern area surrounding the ground is annularly and discontinuously cut out.