JPH04359592A - Manufacture of electronic circuit device - Google Patents

Abstract

PURPOSE:To provide a step of forming a through hole jumper at a large-sized printed board with high reliability and high productivity adapted for a large current circuit in a method for manufacturing an electronic circuit device using a both-side printed board to be used for various type electronic apparatuses. CONSTITUTION:Through holes 7 for assembling two jumper wires are formed on surfaces of copper foils 2, 2a for constituting circuits on one side surface of a both-side printed board separately from other electronic component solder- connecting land 11, and a land 10 for solder-connecting a jumper wire is formed at the intermediate. A method having the steps of printing cream solder 12 having a wider area than that of the land 10 on the land 10, mounting the wire 10 and an electronic component 6, then thermally solder-connecting them, solder-connecting both ends 5a of the wire 5 and a land 11a simultaneously with the other electronic component 6 on the other surface by using a jet type soldering device, and connecting the foils 2, 2a of both the surfaces through the wire 5 without using a special facility process, is provided.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an electronic circuit device using a double-sided printed circuit board used in various electronic devices.

0002

BACKGROUND OF THE INVENTION Conventionally, printed circuit boards used in various electronic devices have been double-sided printed circuit boards that allow electrical circuit wiring on both sides in order to increase the density and reduce the size of component mounting. However, when partially connecting the circuits on both sides of this double-sided printed circuit board, it is necessary to provide through holes in the copper foil lands that make up the circuit configuration on both sides. , a through-hole jumper wire construction method was used, which incorporated jumper wires and soldered connections on both sides.

A method of manufacturing an electronic circuit device using the conventional through-hole jumper construction method will be described below. Figure 6
1 shows a cross section of an electronic circuit device in which various electronic components are mounted on a double-sided printed circuit board using the conventional through-hole jumper construction method. In addition, FIGS. 7, 8(a) and (b) are
This figure shows the work process of this jumper-through construction method. FIG. 7 shows copper foil 22 on both sides of a base material 21 of paper phenol, glass epoxy, etc. that constitutes the base material of the printed circuit board.
An electric circuit is formed by etching 22a. A solder resist 23, 23a is applied to the surface to ensure the necessary solder area, and copper foil 22, 22a on both sides is applied.
After installing the jumper wire 25 into the connection through-hole hole 27, pressure presses 30, 31a are used to reduce the floating dimension H of the jumper wire 25 from the surface of the printed circuit board.
Pressurize with.

Further, as shown in FIGS. 8(a) and 8(b), after applying cream solder 24 for soldering the jumper wire 25, copper foil 22, and electronic component 26, the electronic component 26 is attached and connected by heating solder. .

Furthermore, as shown in FIG. 6, after applying an adhesive 29 for fixing electronic components to the surface of the copper foil 22a, the electronic components 26a are attached and hardened, and the jumper wires 25 and the electronic components 26a are attached.
The solder 28 is connected to the copper foil 22a using a jet soldering device or the like.

[0006]

However, in the above conventional configuration, as shown in FIGS. 7, 8(a) and 8(b), the jumper wire 25 which connects the copper foils 22, 22a on both sides of the printed circuit board by soldering is After incorporating into the through hole 27,
In order to print the cream solder 24 using a metal mask and a squeegee, jumper wires 2 are placed on the surface 23 of the printed circuit board.
If 5 protrudes more than 0.2 mm, it will damage the squeegee and the uniformity of printing of the cream solder 24 will be impaired.
The diameter of the jumper wire to be used is also limited to a thin wire, and therefore the allowable current flowing through the jumper wire 25 is also limited to a minute current such as a signal current.

[0007] Also, the through hole 27 of the jumper wire 25
The pressurization of the jumper wire 25 with the printed circuit board sandwiched between the printed circuit boards after assembly is carried out to prevent cracks in the printed circuit board base material 21, breakage of the land portions 22, 22a, and the jumper wires 25 themselves, etc., and to adjust the pressure of the press. This method required advanced technology to ensure the dimensional accuracy of the press, making it unsuitable for mass production or large-area printed circuit boards, and it could not be used for printed circuit boards that make up the circuits of power supplies that carry large currents. .

The present invention improves the above-mentioned problems and provides an electronic circuit device using a large double-sided printed circuit board and a high-current circuit using a through-hole jumper construction method, which is highly productive and reliable, without using special equipment construction methods. The purpose is to provide a manufacturing method.

[0009]

[Means for Solving the Problems] In order to achieve the above object, the method for manufacturing an electronic circuit device of the present invention provides a method for manufacturing an electronic circuit device, in which a land for solder connection of other electronic components is provided on one side of a double-sided printed circuit board, in addition to lands for solder connection of other electronic components.
Two through-holes for assembling jumper wires are provided on the copper foil surface for circuit configuration, a land is provided in the middle of the holes, and cream solder with an area larger than the land area is printed on the land at the same time as for fixing other electronic components. After assembling a jumper wire and attaching other electronic components on top of it, the land part and the electrodes of the jumper wire and electronic components were connected by heating and soldering in a reflow oven, etc., and then the electronic components were fixed to the other side with adhesive, etc. rear,
The electrodes of the electronic component and the lands for the circuit configuration, and both ends of the jumper wires and the lands are soldered using a jet soldering device or the like, and the copper foils on both sides are connected through the jumper wires.

0010

[Operation] With this method, soldering of through-holes, which require the highest reliability on double-sided printed circuit boards, can be done simultaneously with the electrodes and lands of other electronic components, and also at low cost and with high reliability without the need for special equipment or construction methods. Through-hole connections can be realized.

[0011]

Embodiments Examples of the present invention will be described below with reference to the drawings. First, FIG. 1 is a sectional view of an electronic circuit device in which copper foils on both sides are connected with jumper wires using a jumper through-hole construction method on a double-sided printed circuit board of the present invention, and electronic components are mounted and soldered on both sides.

The assembly process is shown in FIGS. 2(a) and 2(a) below.
b), Figure 3 (a), (b), Figure 4, Figure 5 (a), (b)
Explain using. Figures 2 (a) and (b) show a copper foil 2 formed in a predetermined pattern by etching on both sides of a base material 1 made of paper phenol, glass epoxy, etc.
, 2a are provided, and two through-holes 7 pass through conductive jumper wires 5 whose surfaces can be soldered to connect the copper foils 2 and 2a on both sides. This figure shows a double-sided printed circuit board that is sandwiched between the two sides. Furthermore, lands 11 for soldering and connecting electronic components are also provided in accordance with the shape of the components.

Furthermore, lands 11a for solder connection with both ends of the jumper wire 5 after the jumper wire 5 is assembled are provided on the copper foil portion on the back side of the jumper wire soldering land 10. The surface of the printed circuit board other than the solder connection lands 10, 11, 11a is coated with solder resists 3, 3a for reliable formation of solder frets and positioning of electronic components by self-alignment effect during solder melting. .

Furthermore, on the surface of this double-sided printed circuit board,
Preliminary flux is applied to the entire surface to facilitate soldering in the subsequent process.

This double-sided printed circuit board is shown in FIGS. 3(a) and 3(b).
), using a metal mask prepared in advance and a cream solder printing device, land 1 for soldering electronic components is printed.
On top of 1, apply cream solder 4 with the same area as the land area.
In addition, on the land 10 for connecting the jumper wire, in order to secure the amount of solder necessary for spherically enclosing the surface of the central part of the jumper wire 7 on the land 10 when the solder is heated and melted, the area is smaller than the area of the land 10. Cream solder 12 having a 20 to 30% larger area is printed at a height h corresponding to the thickness of the metal mask.

Further, the cream solder 12 on the jumper wire connection land 10 is used when the jumper wire 5 is assembled into the through hole 7 of the printed circuit board in the subsequent process.
A distance W (W≦1.5) is provided to prevent the particles 2 from flowing into the through hole 7 or from adhering to the built-in device.

As shown in FIG. 4, on the double-sided printed circuit board on which the cream solder 12 has been printed, the jumper wire 5 is first inserted into the through hole 7 for installing the jumper wire, and the bent portion of the jumper wire 5 and the through hole 7 are inserted. At the same time, the jumper wire ends 5a are bent inward so that the jumper wires 5 are fixed at the end faces thereof, and at the same time, the jumper wires 5 are buried in the cream solder 12.

Next, the electrode portion 13 of the electronic component 6 is mounted on the cream solder 4 at a predetermined position, and the electrode portion 13 of the electronic component 6 is
The electronic component 6 is pressurized to such an extent that it is slightly buried in the cream solder 4, thereby preventing the electronic component 6 from shifting.

FIGS. 5(a) and 5(a) show a state in which the jumper wire 5 and the printed circuit board with the electronic components 6 mounted thereon are connected by soldering using a heat source such as far infrared rays or a reflow oven using hot air.
Shown in b) and (c). The cream solder 12 printed on the land 10 of the jumper wire 5 to be 20 to 30% wider than the land area is once liquefied when the solder is heated in a reflow oven, etc., and the solder is liquefied on the land surface 10 due to the surface tension of the liquid solder. The solder is solidified into a spherical shape 12a at the center of the jumper wire 5, and its cross section is shown in FIGS. 5(b) and 5(c).
It is possible to form a spherical fret shape 12a on the land 10, which is ideal for ensuring reliability.

[0020] Also, the electrode portion 13 and land portion 1 of the electronic component 6
The cream solder 4 used to solder connect the electronic components 1 to 1 is also regulated in position on the land 11 by the surface tension and alignment effect of the liquid solder while the solder is heated, and at the same time a solder fillet 4a is formed along the surface of the electrode 13 of the electronic component 6. .

As shown in FIGS. 5(a), 5(b), and 5(c), the other side of the printed circuit board has jumper wires 5 and electronic components 6 heat-connected on lands 10 and 11 with cream solders 4 and 12, respectively. Furthermore, as shown in FIG. 1, the surface of the solder resist 3a on the other side is connected by heating and soldering the electrode 13 and land 11 of the electronic component 6 and the jumper wire 5 and land 10 with cream solder 4 and 12, respectively, in a reflow oven. To,
After applying the adhesive 9 and fixing the electronic component 6a, the electrode 13a of the electronic component 6a and the land 11 are connected using a jet soldering device or the like.
Also, by simultaneously connecting both ends 5a of the jumper wire 5 and the land 11a with heated solder 8, the copper foils 2 and 2a of the double-sided printed circuit board can be connected via the jumper wire 5 passing through the through hole 7. can do.

[0022]

[Effects of the Invention] As is clear from the above description, according to the present invention, a method for manufacturing an electronic circuit device using the jumper through-hole method used for connecting copper foils on both sides of a double-sided printed circuit board is provided by printing cream solder. After mounting other electronic components on one side of the printed circuit board at the same time as installing jumper wires, solder connecting the land of the printed circuit board and the center of the jumper wire using solder heat in a reflow oven, etc. This is a method in which both ends of the jumper wire and the electrodes and lands of other electronic components fixed with adhesive are simultaneously soldered using a jet soldering device, etc., and the copper foil on both sides of the printed circuit board can be connected through the jumper wire. Moreover, compared to a double-sided printed circuit board using the copper plating through method, the production process can be simplified, and a highly reliable and inexpensive electronic circuit device can be realized.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an electronic circuit device obtained by a method for manufacturing an electronic circuit device in an embodiment of the present invention.

[Fig. 2] (a) Plan view of a double-sided printed circuit board in the same example. (b) Cross-sectional view of a double-sided printed circuit board in the same example.

[Fig. 3] (a) Plan view of a double-sided printed circuit board printed with cream solder (b) Cross-sectional view of Fig. 3 (a)

[Figure 4] Cross-sectional view of the double-sided printed circuit board with jumper wires and electronic components installed

5(a) A plan view of the double-sided printed circuit board in a heated state in FIG. 4, (b) a sectional view thereof, and (c) a sectional view taken along the line A-A'' in FIG. 5(b).

[Figure 6] Cross-sectional view of a conventional electronic circuit device

[Figure 7] Cross-sectional view of a conventional double-sided printed circuit board with jumper wires installed

FIG. 8 (a) A cross-sectional view of a double-sided printed circuit board printed with cream solder in a conventional example. (b) A cross-sectional view of a double-sided printed circuit board with electronic components mounted and heated after the cream solder printing of (a) above.

[Explanation of symbols]

1 Printed circuit board base material 2, 2a Copper foil 3, 3a Solder resist 4, 4a, 12, 12a Cream solder 5 Jumper wire 6, 6a Electronic component 7 Through hole 8 Solder 9 Adhesive 10, 11, 11a Land 13, 13a Electrode

Claims (2)

[Claims] [Claim 1] Cream solder is printed on a land provided between two through-holes for attaching jumper wires on one side of a double-sided printed circuit board, various electronic components are attached to this double-sided printed circuit board, and jumper wires are attached. A method for manufacturing an electronic circuit device, in which electronic components on one side are soldered and connected by built-in heating, a jumper wire is soldered to a land, and electronic components mounted on the other side and both ends of the jumper wire are soldered to the land. . 2. The method of manufacturing an electronic circuit device according to claim 1, wherein the cream solder printed on the land connecting the intermediate portion of the jumper wire is printed in an area larger than the land portion.