JPH02192196A - Acoustic equipment circuit unit - Google Patents

Abstract

PURPOSE:To prevent an acoustic signal from being distorted by a method wherein a circuit conductor is formed of an oxygen free copper wire possessed of a texture unidirectionally solidified in a lengthwise direction, the end of the oxygen free copper wire is directly connected to the lead of an electronic component without interposing a heat fusion connecting auxiliary member such as solder between them. CONSTITUTION:An electronic component 20 is arranged on a shielding board 15, and a lead 21 of the component 20 is put through a hole 19 of a insulating sheet 16 and a hole 14 of an insulating board 12. An end 13a of an oxygen free copper wire 13 possessed of a texture unidirectionally solidified in a lengthwise direction and wired so as to form a required circuit pattern is connected to the lead 21 by pressure bonding. The pressure bonding is executed in such a manner that the lead 21 and the end 13a of the oxygen free copper wire 13 are covered with a common metal sleeve 23, which is compressed with a caulking device from the outer surface of the sleeve 23. And, the connection of the ends 13a of the hydrogen free copper wire with each other is executed through pressure bonding the same above. By this setup, an acoustic signal is prevented from being distorted inside a circuit board and at a connected part.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a circuit unit for audio equipment.

[Conventional technology and its issues]

A conventional circuit unit for audio equipment is constructed by mounting electronic components on a printed circuit board. The circuit conductor of a printed circuit board is usually made of copper foil formed into a desired circuit pattern, but when viewed microscopically, copper foil is an aggregate of many copper crystals, and it also contains copper oxides and other materials. Because it contains impurities, the acoustic signal current flowing through it is susceptible to distortion due to the influence of numerous crystal grain boundaries and impurities. Since this distortion becomes noise and is felt by the human ear, it is desirable to eliminate it as much as possible.

[Means for solving problems and their effects]

By the way, in cables for audio equipment, in order to eliminate signal distortion due to grain boundaries and impurities, oxygen-free copper wire is used as a conductor, as it does not have grain boundaries in the direction across the signal transmission direction (wire length direction). is commercially available with good results. The above-mentioned oxygen-free copper wire is obtained by producing an oxygen-free copper ingot having a single crystal or long unidirectionally solidified structure by the OCC method (heated mold continuous casting method) and drawing the ingot. Note that if the oxygen-free copper ingot is in the form of a thin wire, it may be used as is without being drawn.

Therefore, in order to eliminate distortion of the acoustic signal within the circuit unit, it is possible to use oxygen-free copper wire as described above as the conductor of the circuit board. However, if electronic components are mounted by soldering as in the past, the heat may cause recrystallization of the oxygen-free copper wire and destroy the single crystal state. There is a risk that the acoustic characteristics will deteriorate due to the solder interposed between the lead and the lead.

The present invention provides a circuit unit for audio equipment that solves the above-mentioned problems, and has a structure in which an oxygen-free copper wire having a unidirectional solidification structure in the longitudinal direction is wired as a circuit conductor on an insulating substrate. The present invention is characterized in that the end portion of the oxygen-free copper wire and the lead of the electronic component are directly connected to each other without using a heat-fusion connection auxiliary member such as solder.

In this way, there is no risk of acoustic signal distortion occurring within the conductors of the circuit board, and even at the connection between the circuit conductor and the lead of the electronic component, the two are directly connected without heating, resulting in an acoustic signal. There is no possibility of signal distortion occurring.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. In the figure, 11 is a circuit board, and this circuit board 11 is a paper phenol board,
It is composed of an insulating substrate 12 made of a glass epoxy substrate or the like, and an oxygen-free copper wire 13 having a unidirectional solidification structure in the length direction and wired to form a desired circuit pattern on one side of the insulating substrate 12. The end portion 13a of the oxygen-free copper wire 13 is bent at a substantially right angle, and the hole 1 formed in the insulating substrate 12 is bent.
4 and is pulled out to the opposite side. Note that, in addition to the circuit pattern of the oxygen-free copper wire 13, a circuit pattern through which current other than acoustic signals flows may be formed on the insulating substrate 12 using copper foil.

Further, 15 is a shield plate, and this shield plate 15 is composed of an insulating sheet 16, a metal foil (copper foil, aluminum foil, etc.) 17 pasted on one side of the insulating sheet 16, and an insulating resist 18 applied to the surface. has been done. Insulating sheet 1
6 has a hole 19 through which the lead 21 of the electronic component 20 is inserted.
The metal foil 17 is removed by etching or the like so that the hole 19 is slightly larger than the hole 19, so that it does not come into contact with the lead 21. This shield plate 15 is bonded to the circuit board 11 with an adhesive 22.

The electronic component 20 is placed on the side of the shield plate 15, and its leads 21 pass through the hole 19 of the insulating sheet 16 and the hole 14 of the insulating substrate 12. The lead 21 and the end portion 13a of the oxygen-free copper wire are connected by crimping.

This crimping is performed by covering the lead 21 and the end 13a of the oxygen-free copper wire with a common metal sleeve 23 as shown in Figure 2(a), and then inserting the metal sleeve 23 from the outer periphery as shown in Figure 2(b). This can be done by compressing with a crimping device. After crimping, trim the ends as shown in the dotted line, then
As shown in the same figure (C), low temperature solder or sealant 24
Sometimes it is added. Further, as shown in FIG. 3, an insulating coating 25 may be provided on the outer periphery of the metal sleeve 23 in advance. Furthermore, the lead 21 and the end 1 of the oxygen-free copper wire
The crimping with 3a can also be performed by directly pressing the two together to bring them into pressure contact, as shown in FIG.

Additionally, the ends 13a of the oxygen-free copper wires are similarly connected by crimping.

In the above embodiment, an example was described in which the shield plate 15 was attached to the circuit board 11, but the shield plate 15 is provided as necessary and may be omitted. In addition, although the material of the lead of the electronic component is not specified in the above example, it is possible to use an oxygen-free copper wire having a unidirectional solidification structure in the longitudinal direction for the lead, which is more effective in improving the acoustic characteristics. It is. Furthermore, in order to directly connect the end of the oxygen-free copper wire and the lead, in addition to the pressure welding method described above, a wrapping method or the like can be applied.

[Effects of the Invention] As explained above, according to the present invention, the circuit conductor through which the acoustic signal flows is composed of an oxygen-free copper wire having a unidirectional solidification structure in the longitudinal direction, and the end portion of the oxygen-free copper wire is Since the leads of electronic components are directly connected without the use of heat-melting connection auxiliary materials such as solder, it is possible to prevent distortion of acoustic signals within the circuit conductor and at the connection between the circuit conductor and the lead of the electronic component. This has the advantage that audio equipment with excellent acoustic characteristics can be constructed.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the main parts of a circuit unit for audio equipment according to an embodiment of the present invention, and Figures 2 (a) to (C1 are methods for crimping the ends of oxygen-free copper wires and leads of electronic components. 3 is a sectional view showing an example of a metal sleeve for crimping, and FIG. 4 is a perspective view showing another example of the crimping method. 11: circuit board, 12: insulating board, 13: Oxygen-free copper wire having a unidirectional solidification structure in the length direction, 15: Shield plate,
16: Insulating sheet, 17: Metal foil, 20: Electronic component, 2
1: Lead, 22: Adhesive, 23: Metal sleeve. Shi-1

Claims (1)

[Claims] 1. A circuit board is constructed by wiring an oxygen-free copper wire having a unidirectional solidification structure in the longitudinal direction as a circuit conductor on an insulating board,
A circuit unit for audio equipment, characterized in that an end of the oxygen-free copper wire and a lead of an electronic component are directly connected.