JPH0279493A - Electronic parts mounting body - Google Patents

Abstract

PURPOSE:To make it possible to provide a strong electronic parts mounting body with a reduced cost without soldering by connecting terminals of various electronic parts with conductive adhesive, and partially fusing a flexible board and a reinforcing board, thereby mounting the electronic parts. CONSTITUTION:A conductive pattern 11 formed of aluminium foil by etching is formed on a flexible board made of a thermoplastic resin film such as polyester. A terminal 22 of a light receiving element 21 is bonded with a conductive adhesive to an end part of the pattern 11, and thereon, a reinforcing board 24 made of the same resin material with the board 10 is layed. A portion D where no terminal 22 is positioned is fused by ultrasonic welding, and the element 21 is mounted on the board 10, then the element 21 and the board 10 are integrated by a molding process with resin material. The adhesive 23 is composed of a mixture of a polyester resin and nickel powder whose weight ratios are, respectively, 8-30% and 20-70%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic component package in which various electronic components are mounted on a flexible substrate made of a resin film.

[Prior art]

BACKGROUND ART In various electronic devices, an electronic component mounting body in which various electronic components are mounted on a printed circuit board is housed in a case. Most of these electronic component mounting bodies have various electronic components mounted on a hard printed circuit board made of resin material, but in recent years, the shape of the electronic equipment that houses the electronic component mounting body has changed. Considering the unique effects and the connection between the cable and the printed circuit board, we use a flexible board made of a flexible synthetic resin film for the printed circuit board, and mount various electronic components on the flexible board. Attempts have been made to deform and arrange the flexible board according to the shape of the device and to make the flexible board function as a cable.

[Problem to be solved by the invention]

However, in the above conventional electronic component mounting body using a flexible board, electronic components are mounted by soldering.
A resin film with high heat resistance, such as a polyimide resin film, is used for the flexible substrate. However, such highly heat-resistant resin films are expensive;
This is not practical for providing an inexpensive electronic component mounting body.

In addition, in recent years, flexible substrates have been developed that are made by printing silver paste, etc. on thermoplastic resin films such as polyester optical films, but the lands and patterns of these flexible substrates are formed by printing conductive paste. Therefore, the specific resistance of these lands and patterns is large, making it difficult to obtain a large current capacity, and since they are thermoplastic films, they cannot be soldered, making it impossible to firmly mount electronic components. There was a problem. The present invention has been made in view of the above-mentioned points, and provides an electronic component mounting body that uses an inexpensive thermoplastic resin film, has a large current capacity, and firmly mounts electronic components without using soldering. There is a particular thing.

[Means to solve the problem]

In order to solve the above problems, the present invention connects the terminals of various electronic components to the conductor pattern of a flexible substrate made of a thermoplastic film on which the conductor pattern is formed, using a conductive adhesive, and connects the terminals of various electronic components to the conductor pattern. The method is characterized in that various electronic components are mounted on the flexible substrate by covering the flexible substrate with a reinforcing plate made of the same resin film and locally welding the flexible substrate and the reinforcing plate using ultrasonic welding.

Further, the present invention is characterized in that predetermined electronic components among various electronic components mounted on the flexible substrate are resin-molded together with the flexible substrate, and the electronic components and the flexible substrate are integrated.

Further, the present invention is characterized in that the conductor pattern formed on the flexible substrate is formed by etching aluminum foil provided on the substrate.

Further, the conductive adhesive is characterized in that it is made by kneading polyester resin with a weight ratio of 80% to 30% and nickel powder with a weight ratio of 20% to 70%.

[Effect]

By configuring the electronic component mounting body as described above, the terminals of various electronic components are connected to the conductive pattern of the flexible substrate made of thermoplastic film with a conductive adhesive,
Since various electronic components are mounted by locally welding the flexible substrate and the reinforcing plate, it is possible to firmly mount the electronic components without using soldering, thereby realizing an inexpensive electronic component mounting body.

In addition, since a predetermined electronic component is resin-molded together with a flexible substrate and the electronic component and flexible substrate are integrated, it can be incorporated into an electronic device, such as a receiving element of a pickup mechanism of a CD device, with high positioning accuracy. For electronic components that require this, by molding the electronic component with a flexible substrate and integrating it, the electronic component can be fixed with high positioning accuracy by fixing this resin molded body to the positioning location. .

Additionally, since the conductor pattern formed on the flexible substrate is formed by etching aluminum foil, it is possible to increase the capacitance compared to one formed by printing silver paste. .

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a diagram showing the appearance of an electronic component mounted body according to the present invention, and in this embodiment, an electronic component mounted body used in a pickup device of a CD device will be explained as an example. As shown in the figure, the electronic component mounting body includes a flexible board 10, a light receiving element is mounted on the flexible board 10 as described later, and a light receiving part 20 is integrated by molding the light receiving element and the flexible board 10 with resin. , a light emitting element mounting section 30 for mounting a light emitting element such as a laser diode, a terminal section 40 for connecting the pickup device and external equipment, and an electronic component mounting section 50 for mounting a plurality of electronic components. . The configuration of each of the above sections will be specifically explained below.

The flexible substrate 10 is made of a thermoplastic resin film such as polyester, and the upper surface of the flexible substrate 10 has a conductor pattern 11 formed by etching aluminum foil, as shown in FIGS. 2(a) and 2(b). is formed. A resin film is laminated onto the flexible substrate 10 to insulate the conductor pattern 11, except for the portions on the conductor pattern 11 where electronic component terminals and terminal pieces are connected.

Note that FIG. 2(a) is a back view showing the right side of the flexible substrate 10 taken along the line AA, and FIG. 2(b) is a back view showing the left side. As shown in FIG. 3, the light receiving section 20 is constructed by bonding the terminal 22 of the light receiving element 21 to the end of the conductor pattern 11 of the flexible substrate 10 with a conductive adhesive 23, and then attaching a terminal 22 of the light receiving element 21 on the end of the conductive pattern 11 of the flexible substrate 10. The light-receiving element 21 is mounted on the flexible substrate 10 by covering it with a reinforcing plate 24 made of a resin material and welding the part where the terminal 22 is not located by ultrasonic welding, and then the part shown by the dotted line C in FIG. 2(b) is covered with a resin material. The light receiving element 21 and the flexible substrate 10 are integrally formed by molding with a material. The molding of the light receiving section 20 is carried out by sandwiching the flexible substrate 10 on which the light receiving element 21 is mounted between an upper mold and a lower mold, and applying a thermal expansion coefficient and an absorption expansion coefficient to the gap formed by the upper mold and the lower mold. The flexible substrate 10 and the light-receiving element 21 are integrally fixed by injecting a molten resin material such as polyphenylene sulfide or liquid crystal polymer with a small amount of high-performance resin material. At this time, the mold is specially designed so that the molten resin is not exposed on the light-receiving surface of the light-receiving element 21. Note that FIG. 3 is a sectional view taken along the line A--A in FIG. 2(b). The resin molding method described above is disclosed in detail in Japanese Patent Application No. 155632/1983, previously filed by the present applicant, so the details thereof will be omitted here.

4 and 5 are diagrams for explaining the structure of the terminal portion 40 and its formation process. The formation of the terminal portion 40 is performed in the fourth step.
Four terminal pieces 41 and a frame 42 as shown in Figure (a)
are integrally formed by sheet metal processing, etc., and as shown in FIG. Apply a conductive adhesive (not shown) to the surface. 5(a) and (b) on top of this conductive adhesive.
The terminal piece 41 is placed as shown in FIG. Thereafter, a reinforcing plate 43 made of a resin film of the same quality as the flexible substrate 10 is placed, and the reinforcing plate 43 in a portion J excluding the portion where the terminal piece 41 is located is welded to the flexible substrate 10 using ultrasonic waves. 41 to flexible substrate 10 (7)
Securely secure the ends. After that, H-H in FIG. 5(a)
Cut the terminal piece 41 on the line and the I-I line, and attach the frame 4
By removing 2, the terminal portion 40 is completed. Note that FIG. 5(b) is a sectional view taken along line E--E in FIG. 5(a), and FIG. 5(c) is an enlarged view of portion F in FIG. 5(b).

As shown in the figure, a conductive adhesive 4 is attached to an end 11-1 of a conductor pattern 11 formed on a flexible substrate 10.
4, the terminal piece 41 is connected, and the reinforcing plate 43 is placed on top of the terminal piece 41.
The structure covers the

Further, a plurality of protrusions 41a are completely formed at the end of the terminal piece 41, and by locally welding the reinforcing plate 43 and the flexible substrate 10, the protrusions 41a are caught on the welded part, and the terminal piece 41 Increases the pull-out strength of

A phosphor bronze plate is used as the metal for the terminal piece 41, and its surface is solder-plated to improve workability. In this case, the phosphor bronze plate will be solder plated, but since aluminum and lead are incompatible, a low-lead solder containing less than 10% lead in the solder is used. Also, terminal piece 4
As the metal plate used in 1, a metal plate that can be soldered or a metal plate that has been subjected to solder plating may be used.

FIGS. 6 and 7 are diagrams for explaining the structure of the light emitting element mounting section 30 and its formation process. Light emitting element mounting section 3
0 is prepared by integrally forming three terminal pieces 31 and a frame 32 by sheet metal processing as shown in FIG. 6(a), and a light emitting element as shown in FIG. 6(b). A conductive adhesive 3 is placed on the end portion 11-1 of the conductive pattern 11 on the flexible substrate 10 in the portion where the mounting portion 30 is to be formed.
Apply 4. Then, on top of this conductive adhesive, as shown in Figure 7 (
The terminal piece 31 is placed as shown in a) and (b), and the terminal piece 31 is connected to the end 11-1 of the conductor pattern 11. Thereafter, a reinforcing plate 33 made of a resin film of the same quality as the flexible substrate 10 is placed, and the reinforcing plate 33 and the flexible substrate 10 are locally welded using ultrasonic waves except for the area where the terminal piece 31 is located. Then, the light emitting element mounting section 3
0 terminal piece 31 is firmly fixed to the end of the flexible substrate 10.

Further, a plurality of protrusions 31a are formed at the end of the terminal piece 31, and by locally welding the reinforcing plate 33 and the flexible substrate 10, the protrusions 31a are caught on the welded part, and the terminal piece 31 The pull-out strength of is increased.

Thereafter, the terminal piece 31 is cut along the line MM in FIG.
is completed. In addition, FIG. 7(b) is GG in FIG. 7(a).
This is a line sectional view, and FIG. 7(c) is an enlarged view of the L portion of FIG. 7(b). As shown in the figure, a flexible substrate 10
A terminal piece 31 is connected to the end 11-1 of the conductive pattern 11 formed on the conductor pattern 11 with a conductive adhesive 34, and a reinforcing plate 33 covers the terminal piece 31.

As for the metal used for the terminal piece 31, a phosphor bronze plate is used like the terminal piece 41, and its surface is soldered with low lead solder to improve soldering workability. A hole 31b into which a metal plate and a terminal are inserted,
The laser diode can be mounted on the light emitting element mounting portion 30 by soldering the shapes 31c and 31d to the terminals of the laser diode.

As shown in FIG. 1, the electronic component mounting section 50 has a hard reinforcing board 51 attached to the top of the flexible board 10.
A semi-fixed resistor 52, a tantalum capacitor 53, connectors 54, 55, etc. are mounted at predetermined positions on the reinforcing board 51.

FIG. 8(a) shows the mounting structure of the connector 55.
(A sectional view taken along the line PP in FIG. 1), and FIG. 8(b) is an enlarged view of the Q portion in FIG. 8(a). The connector 55 is a male connector with a large number of bottles 55-1 protruding from inside a resin case 55-2, and the male connector 55 has a female connector having a bottle (not shown) that is inserted into the bottle 55-1. The connectors are designed to mate. A terminal 55-3 connected to the bin 55-1 protrudes from the bottom of the connector 55, and the terminal 55-3 is passed through a hole formed in the reinforcing board 51 and the flexible board to connect the flexible board 10.
Bend the surface. A conductive pattern 11 is formed on the surface of the flexible substrate 10 at a position where the terminal 55-3 is bent.
A conductive adhesive 56 is applied to the surface of the conductive pattern 11, and the bent terminal 55-3 is brought into contact with the conductive adhesive to form the terminal 55-3. 3 is connected to the conductor pattern 11. A reinforcing plate 57 made of a film of the same quality as the flexible substrate 10 is placed on the terminal 55-3, and a portion R excluding the portion where the terminal 55-3 is located is locally welded by ultrasonic welding. The mounting structure of the connector 54 is also similar to the mounting structure of the connector 55, so its explanation will be omitted.

Also, although the mounting structure of the semi-fixed resistor 52 is not shown,
Terminals 52-1 of three semi-fixed resistors 520 are fitted into holes formed in the reinforcing substrate 51, bent on the flexible substrate 10, and connected to the conductive pattern 11 using a conductive adhesive. Then, a reinforcing plate made of a film of the same quality as the flexible substrate 10 is placed thereon, and the parts other than the parts where the terminals are located are locally welded by ultrasonic welding.

Although the mounting structure of the tantalum capacitor 53 is not shown in the drawings, two terminals 53-1 of the tantalum capacitor 530 are inserted into the holes formed in the reinforcing board 51, bent on the flexible board 10, and the conductor pattern 11 is Connect with conductive glue on top. A reinforcing plate made of a film of the same quality as the flexible substrate 10 is then placed thereon, and the parts except for the parts where the terminals are located are locally welded by ultrasonic welding.

Conductive adhesive for bonding the terminal piece 31.41, the terminal of the connector 54.55, the terminal of the semi-fixed resistor 52, and the terminal 53-1.53-2 of the tank capacitor 53 to the conductive pattern 11. uses a conductive paste made by kneading nickel powder into polyester resin. Normal conductive paste is made by properly kneading metal flakes and spheres, but in this example, the electrical conductivity between the terminal piece and the single conductor pattern 11 in the film thickness direction is In order to achieve electrical conduction, good metal contact is required, and stable conduction can be obtained by using spherical nickel powder as the metal powder. Furthermore, if the particle size is too small, many conductive buses will be formed in the direction of the film thickness, so the particle size is preferably about several μm. In addition, if the content of nickel powder is too low, electrical conduction will become unstable, and if it is too high, the mechanical adhesion will be weakened due to the lack of polyester resin.Furthermore, the polyester resin in the conductive paste seals the bonded area and can be used in various environments. Because it has the effect of protecting the contact area from humidity and harmful gases, etc.
If the amount of polyester resin in the conductive paste is small, the sealing effect of this fixed portion will be small, making it unsuitable as a conductive paste. In this example, the nickel content was 50% by weight, but it was confirmed that it could be used if it was 20% to 70%. Such a conductive paste is applied to the conductive pattern 11, a terminal piece to be connected is placed thereon, and the terminal piece is heated and dried to read the terminal piece directly onto the conductive pattern 11.

In the above embodiment, an electronic component mount body used in a pickup device of a CD device was explained as an example, but the electronic component mount body according to the present invention is not limited to this, and in short, the electronic component mount body according to the present invention is not limited to this. Terminals of various electronic components are connected to the conductor pattern of a flexible substrate made of a thermoplastic resin film using a conductive adhesive, and a reinforcing plate made of a resin film of the same quality as the flexible substrate is attached to the connection part. Any structure may be used as long as the flexible substrate and the reinforcing plate are locally welded by overlapping or ultrasonic welding, and this electronic component mounting body can be used as an electronic component mounting body for many electronic devices. In particular, since electronic components can be mounted on the flexible substrate 10 made of a thermoplastic resin film without soldering, an electronic component mounted body can be provided at low cost.

In addition, for mounted electronic components that require a high degree of positioning accuracy, the flexible substrate and the electronic component are integrally molded using a high-performance resin material with a high coefficient of thermal expansion and absorption expansion. This makes it possible to achieve high positioning accuracy without dimensional changes or distortions.

〔Effect of the invention〕

As explained above, according to the present invention, the following excellent effects can be obtained.

(1) The terminals of various electronic components are connected to the conductive pattern of the flexible substrate made of thermoplastic film using conductive adhesive, and the flexible substrate and reinforcing plate are locally welded to mount the various electronic components. , a strong electronic component mounting body can be realized at low cost without using soldering.

(2) Since a predetermined electronic component is resin molded together with a flexible substrate and the electronic component and flexible substrate are integrated, the positioning accuracy is high when it is incorporated into an electronic device, for example, as a receiving element of a pickup mechanism of a CD device. When it comes to electronic parts that require a flexible board, the electronic parts are resin molded and integrated with a flexible board, and this resin molded body is fixed at a position.
Electronic components can be fixed with high positioning accuracy.

(3) Since the conductor pattern formed on the flexible substrate is formed by etching aluminum foil, it is possible to increase the current capacity compared to one formed by printing silver paste. becomes.

(4) Since the electronic components are mounted on the flexible substrate, there is an extremely large degree of freedom in accommodating and arranging the electronic component mounting body in the case.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the appearance of an electronic component mounting body according to the present invention,
Figure 2 (a) is a back view showing the right side from line A-A of the flexible board, Figure 2 (b) is a back view showing the left side from line B-B, and Figure 3 is the same as Figure 2 (b). A sectional view taken along line A-A, FIG. 4(a). (b) and FIGS. 5(a), (b), and (c) show the terminal portion 40.
Fig. 6 is a diagram explaining the structure and its formation process.
a), (b) and FIG. 7(a). (b) and (c) are diagrams for explaining the structure of the terminal portion 3o and its formation process, FIG. 8(a) is a sectional view taken along the line P-P of FIG. It is an enlarged view of the Q part of figure (a). In the figure, 10...Flexible board, 11...Conductor pattern, 20...Light receiving section, 21...Light receiving element, 22...Terminal, 23...Conductivity glue,
24... Reinforcement plate, 30... Light emitting element mounting part, 3
1...Terminal piece, 32...Frame, 33...
- Reinforcement plate, 34... Conductive adhesive, 41... Terminal piece, 42... Frame, 43... Reinforcement plate, 4
4... Conductive adhesive, 50... Electronic component mounting part, 51... Reinforcement board, 52... Semi-fixed resistor, 5
3... Tantalum capacitor, 54.55... Connector, 5G... Reinforcement plate.

Claims (4)

[Claims] (1) Terminals of various electronic components are connected to the conductor pattern of a flexible substrate made of a thermoplastic resin film on which a conductor pattern is formed using a conductive adhesive, and the connection portion is made of resin of the same quality as the flexible substrate. 1. An electronic component mounting body, characterized in that the various electronic components are mounted on the flexible substrate by covering the flexible substrate with a reinforcing plate made of a film manufactured by the Company, and locally welding the flexible substrate and the reinforcing plate by ultrasonic welding. (2) Claim (1) characterized in that a predetermined electronic component among various electronic components mounted on the flexible substrate is resin-molded together with the flexible substrate, and the predetermined electronic component and the flexible substrate are integrated. Electronic component mounting body described. (3) Claim (1) characterized in that the conductor pattern formed on the flexible substrate is formed by etching aluminum foil provided on the substrate.
) or the electronic component assembly described in (2). (4) Claim (1) characterized in that the conductive adhesive is made by kneading 80% to 30% of polyester resin by weight and nickel powder of 20% to 70% by weight.
), or the electronic component mounted body according to (2) or (3).