JPS5926614Y2 - printed wiring board - Google Patents

Description

[Detailed description of the invention] This invention uses solder between conductor layers formed on a resin-based insulating substrate such as a paper-based phenolic resin laminate (9) for a paper-based phenol resin laminate (9) for resistors, capacitors, and other circuit components that do not have lead wires. This is a mounting device for circuit components that does not have lead wires for mounting, and allows for strong mounting with a simple configuration, and also prevents circuit components from falling off or being damaged easily even if the insulated board is bent. It is an object of the present invention to provide an excellent mounting device for circuit components that does not have lead wires.

In general, circuit components such as resistors and capacitors that do not have lead wires are composed of a rectangular parallelepiped circuit element 2 and electrodes 3 and 3 provided at both ends of the circuit element 2, which constitutes the resistor, capacitor, etc., as shown in Figure 1.
It is made up of.

In the case of a normal resistor, the circuit element 2 is composed of a rectangular parallelepiped ceramic base and a resistor baked on its surface, and electrode films are formed at both ends of the ceramic base extending from the end face to the upper surface of the end of the resistor. ing.

In the case of a capacitor, an electrode film is formed by coating both ends of a rectangular parallelepiped capacitor element made of barium titanate or the like as a dielectric and baking it.

By the way, when these circuit components without lead wires are attached to an insulating substrate, as shown in FIG. 4, and the electrodes 3 of the circuit component without lead wires are placed opposite to the round portions 4a of the conductor layer 4, and solder 5 is applied around the entire circumference of the electrodes 3, as shown in FIG. 3a, l). It is soldered so that it bulges out.

However, in this type of circuit component, the outer periphery of both ends of the circuit component is almost completely covered with the solder 5, so the insulating substrate is made of a relatively soft resin such as a paper-based phenolic resin laminate or a paper-based epoxy resin laminate. When using an insulated board,
Cracks often occur in the circuit components themselves during the manufacturing process or during use, resulting in damage.

That is, in this type of circuit component, the outer periphery of both ends of the circuit component is almost completely covered and is completely and firmly bonded to the conductor layer 4 by the solder 5, so that external force is applied to the insulating substrate during the manufacturing process or during use, causing it to bend. Even in cases where this occurs, stress cannot be absorbed, and stress is directly applied to the circuit components, causing cracks and damage to the circuit components themselves.

This proposal eliminates the above-mentioned conventional drawbacks,
The amount and state of adhesion of solder can be effectively regulated, and even if the insulating board is bent to some extent, it is easily absorbed by the elasticity of the solder, so that it does not directly lead to damage to circuit parts.

Hereinafter, the mounting device for circuit components without lead wires according to the present invention will be described with reference to drawings of embodiments.

Figures 4 and 5 show the configuration of an embodiment of the electrical component mounting device without lead wires of the present invention, in which 11 is a paper-based phenolic resin laminate board 9 a paper-based epoxy resin laminate. 12 is a conductor layer formed on the insulating substrate 11; 13 is a circuit component that is attached to the insulating substrate 11 and does not have a lead wire electrically connected to the conductor layer 12; It is.

The circuit component 13 includes, for example, a rectangular parallelepiped capacitor element made of barium titanate or the like as a dielectric, and electrodes 14 made of silver, palladium, etc. baked on both ends of this capacitor element.
These electrodes 14 are formed on the insulating substrate 1.
The round portion 12a of the conductor layer 12 formed on the conductor layer 12 is disposed so as to face the round portion 12a.

The width of the round portion 12a of the conductor layer 12 is set to be approximately the same as the width of the electrode 14, and with the electrode 14 in contact with the round portion 12a of the conductor layer 12, the electrode is attached using a solder tape method. 14 and round part 12
The circuit component 13 is electrically connected to the conductor layer 12 by attaching solder 15 between the conductor layer 12 and the conductor layer 12.

In this way, the loud part 12 of the inner conductor layer 12 of the electrode formed on the circuit component 13 is
Solder will adhere between the round portion 12a of the conductor layer 12 and the other surface except the side surface facing a, and
Since the width of the round portion 12a of the conductor layer 12 is formed to be approximately the same as the width of the electrode 14, the amount of solder adhering between the side surface of the circuit component 13 and the round portion 12a is significantly reduced, and the insulating substrate Even if the solder 11 is bent, the stress can be sufficiently absorbed by the elastic force of the solder 15.

Therefore, according to the above embodiment, even if an external force is applied to the insulating substrate 11 and the insulating substrate 11 is slightly bent, the stress is directly applied to the circuit component 11.
3, and the circuit component 13 itself can be easily prevented from being cracked and damaged.

FIG. 6 shows this state, where A shows the characteristics of the conventional mounting device and B shows the characteristics of the mounting device of the above embodiment.

That is, in FIG. 6, circuit components are attached to the center of the insulating substrate by each method, the insulating substrate is supported by mutually opposing supports separated by 9 Qmm, and then an external force is applied to the center of the insulating substrate to This figure shows the change in characteristics of each circuit component when the insulating substrate is bent.

According to the conventional mounting device, the capacitance value of the circuit component was extremely reduced when the center of the insulating board was displaced by just 1 mm, indicating that the circuit component was damaged, but according to the mounting device of the above embodiment, the insulation Even when the center of the board was displaced by 5 mm, there was still no significant change in the capacitance value, indicating that the circuit components were not damaged.

In this way, according to the above embodiment, the width of the round portion 12a that contributes to soldering of the conductor layer 12 is made approximately the same as the width of the electrode 14 of the circuit component 13 to be soldered here, and in addition, Since one side is brought into contact with the round part 12a so that almost no solder 15 adheres thereto, both ends of the circuit component 13 are supported relatively flexibly, and the insulating board is not curved. It has the advantage that almost no circuit components are damaged even if

In the embodiment, the width of the round portion 12a of the conductor layer 12 is formed to be approximately the same as the width of the electrode 14 of the circuit component 13 without a lead wire.
The width may be smaller than the width of the electrode 14 as long as sufficient electrical connection can be made.

In this case, the mechanical bonding of the circuit component 13 without lead wires to the insulating substrate 11 can be sufficiently reinforced by an adhesive (particularly a thermosetting adhesive).

Further, in the embodiment, the round portion 12a of the conductor layer 12 itself is formed to be as small as or smaller than the electrode portion 14 of the circuit component 13, but in addition to that, as shown in FIGS. The round portion 12a itself is shaped sufficiently larger than the electrode portion 14 of the circuit element 13, and the solderable portion 12a of the round portion 12a is formed by the solder resist layer 16.
The same effect can be obtained even if the width of the electrode 14 is made to be the same or smaller than the width of the electrode 14.

As is clear from the examples above, according to the circuit component mounting device without lead wires of the present invention, it is possible to appropriately limit the amount of solder adhesion and the solder adhesion state with a simple configuration.
Even if the insulating substrate bends, the elasticity of the solder itself can be used to prevent the stress from directly acting strongly on the circuit components, which has the advantage of extremely minimizing damage to the circuit components.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of a circuit component without lead wires, Figure 2
The figure is a top view of a conventional circuit component mounting device, Figure 3 a, l)
are respectively A-A' and BB' sectional views in Fig. 2, Fig. 4 is a top view of an embodiment of the circuit component mounting device without lead wires, and Fig. 5 a and l) are respectively sectional views. 4 is a sectional view taken along line CC' and DD' in Figure 4, Figure 6 is a comparative characteristic curve diagram of the conventional circuit component mounting device and the circuit component mounting device of the present invention, and Figure 7 is a top view of another embodiment of the present invention. , FIG. 8 is a sectional view thereof. 11... Insulating substrate, 12... Conductor layer,
12a... Round part, 13... Circuit component, 14... Electrode, 15... Solder,
16...Solder resist layer.

Claims (1)

[Scope of utility model registration request] The width of the portion of the conductor layers formed on the insulating substrate that contributes to soldering that opposes each other shall be the same as or wider than the width of the electrodes formed at both ends of the circuit component that does not have lead wires to be soldered to the conductor layer. set small, with both ends of the circuit component facing the portion of the conductor layer that contributes to soldering, and electrode portions on the other side surfaces and end surfaces of the circuit component other than one side facing the conductor layer and the conductor. A mounting device for a circuit component without a lead wire, in which the circuit component is soldered to the conductor layer by attaching solder between the layers.