JPH0555582U - Printed wiring board - Google Patents

Abstract

(57) [Summary] [Purpose] To securely fix surface-mounted components that receive external force, such as changeover switches, to the printed circuit board. [Structure] A through hole 16 is provided at or near a land portion 12 of a printed circuit board 11 for fixing a surface mounting component 13 that receives an external force, and this component 13 is used as the land portion 12.
It is fixed by the solder 17 which enters from the through hole 16. Since the solder 17 that has entered the through hole 16 functions like a pile, the component 13 is securely fixed to the printed circuit board 11 and does not separate from the land 12 even when an external force is applied.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a printed wiring board for soldering a surface mount component called a flat package.

[0002]

[Prior Art]

 Conventionally, soldering of surface mount components to this type of printed wiring board has been a flow method in which the surface mount component is positioned on the land part of the printed wiring board and fixed in advance with an adhesive, and then fixed using molten solder. A well-known method is a reflow method in which cream solder is applied to the land portion of a printed wiring board in advance and then melted and fixed.

FIG. 2 shows an example of a printed wiring board adopting the conventional reflow soldering method. (A) is a partial plan view, (b) is a partial bottom view, and (c) is an enlarged partial sectional side view. Is. In FIG. 2, reference numeral 1 is a printed circuit board, and a plurality of land portions 2 for soldering components are formed on a predetermined portion of the surface thereof. Reference numeral 3 denotes a changeover switch which is fixed to the land portion 2 of the printed circuit board 1 as a surface mount component, and is targeted for, for example, a function changeover switch of a telephone (a volume changeover switch, a dial pulse changeover switch, etc.). The changeover switch 3 includes an operation button 4 and a plurality of lead portions 5 fixed to each of the land portions 2. Reference numeral 6 is a solder for fixing the lead portions 5 to the land portion 2.

The solder 6 is applied in advance to the land portion 2 as a cream solder, and the lead portion 5 of the switching switch 3 is positioned on the land portion 2 and temporarily fixed with an adhesive, and then placed in a reflow bath. Then, the cream solder is melted to fix the lead portion 5 to the land portion 2.

[0005]

[Problems to be Solved by the Invention]

 However, when the surface mount component fixed to the printed circuit board 1 is the changeover switch 3 that receives the external force as described above, the lead portion 5 may be separated from the land portion 2 when the operation button 4 is operated. was there. This is because the amount of the solder 6 for fixing the two is small and the fixing is not sufficient. The amount of solder used is not large, not small, and the proper amount is specified, but it is small for parts that receive such external force. Therefore, if the amount of solder is determined based on the component that receives such external force, it will be too large for other components, and defects such as bridges in which adjacent lands are connected by solder will be created. Will be caused.

The present invention solves such a conventional problem, and provides a printed wiring board capable of reliably fixing a surface mounted component that receives an external force in balance with other components. To aim.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a through hole at or near a land portion for fixing a surface mount component that receives an external force, and solders the surface mount component into the through hole from the land portion. It is fixed.

[0008]

[Action]

 According to the present invention, with the above-described configuration, even if the surface mount component receives an external force, such as a changeover switch, the solder enters the through hole from the land and functions like a pile, so that the surface mount component is printed. It can be securely fixed to the wiring board and can be prevented from peeling off from the land.

[0009]

【Example】

 FIG. 1 shows an embodiment of the present invention. (A) is a partial plan view of a printed wiring board, (b) is a partial bottom view, and (c) is an enlarged partial sectional side view. In FIG. 1, reference numeral 11 denotes a printed circuit board, and a plurality of land portions 12 for soldering the portions are formed on a predetermined portion of the surface thereof. Reference numeral 13 denotes a changeover switch as a surface mount component, which has an operation button 14 and a lead portion 15. Reference numeral 16 denotes a through hole which is integrally formed with the land portion 12 substantially at the center of the land portion 12 and penetrates the printed circuit board 11. Reference numeral 17 denotes solder, which fixes the lead portion 15 of the changeover switch 13 to the land portion 12 and also enters the through hole 16 from the land portion 12.

Next, the assembly sequence of the above embodiment will be described. Cream solder is applied in advance to the surface of the land 12 and the inside of the through hole 16. The inside of the through hole 16 may be plated with solder. Next, the lead portion of the changeover switch 13 is positioned on the land portion 12, and the main body portion of the changeover switch 13 is temporarily fixed to the printed board 11 with an adhesive. In this state, put it in the reflow bath and heat it to melt the cream solder. As a result, the solder 17 fixes the lead portion 15 of the changeover switch 13 to the land portion 12, solidifies in the through hole 16 from the land portion 12, and is in a state where the pile is just struck. Therefore, the changeover switch 13 is securely fixed to the land portion 12, and the changeover switch 13 does not peel off from the land portion 12 even if the operation button 14 is slid to apply an external force.

The present invention is not limited to the above-described embodiment, but can be applied to a multilayer printed circuit board and can also adopt a flow soldering method. Further, the through hole may be provided in the vicinity of the land portion as long as the solder in the through hole can be integrated with the solder in the land portion even if it is not on the land portion.

[0012]

【The invention's effect】

 As apparent from the above-described embodiment, the present invention provides a through hole in or near the land portion for fixing the surface mount component that receives an external force, and solders the surface mount component into the through hole from the land portion. Since it is fixed, the surface-mounted components that receive external force can be reliably fixed to the printed circuit board in a balance with other components, and the surface-mounted components can be peeled off from the printed circuit board due to external force. Can be prevented.

[Brief description of drawings]

FIG. 1A is a partial plan view of a printed wiring board showing an embodiment of the present invention. FIG. 1B is a partial bottom view of the printed wiring board. FIG. 1C is an enlarged partial sectional side view of the printed wiring board.

FIG. 2A is a partial plan view of a printed wiring board showing a conventional example. FIG. 2B is a partial bottom view of the printed wiring board. FIG. 2C is an enlarged partial sectional side view of the printed wiring board.

[Explanation of symbols]

 11 Printed Circuit Board 12 Land Part 13 Changeover Switch (Surface Mount Component) 14 Operation Button 15 Lead Part 16 Through Hole 17 Solder

Claims (2)

[Scope of utility model registration request] 1. A printed wiring board in which a through hole is provided at or near a land portion for fixing a surface mount component that receives an external force, and the surface mount component is fixed by solder that enters the through hole from the land portion. 2. The printed wiring board according to claim 1, wherein the surface mount component is a changeover switch.