JPH0726858Y2 - Printed circuit board - Google Patents

Description

[Detailed description of the device]

[0001]

This invention relates to improvements in printed circuit boards.

[0002]

2. Description of the Related Art When connecting a printed circuit board and external parts, wires are usually connected to the circuit with an anisotropic conductive connector or fixed with solder or a conductive adhesive. .

However, the parts to be mounted have become finer and more diversified, and such conventional methods have a problem that the connection is troublesome and the work efficiency cannot be improved.

In addition, in recent years, a three-dimensional board shape such as a box shape or a transformer shape is required, and a dedicated mounting machine is required to attach an electric wire or the like to a board having such a shape, and only workability is required. However, there was a problem in manufacturing cost.

[0005]

[Problems to be solved by the device]
Proposed in view of the above-mentioned problems, the circuit film is provided with a free portion which is not bonded to the substrate body, and the connector is directly connected to an external component at the free portion, The present invention provides a novel printed circuit board that can simplify the process such as soldering for connecting with external parts and dramatically improve the workability.

[0006]

[Means for Solving the Problems] That is, this invention is
A substrate body is integrally formed on the back surface side of the base film of a circuit film in which a circuit pattern made of a conductor forming a printed circuit is formed on the upper surface of a base film of synthetic resin, and in a part of the substrate body, The printed circuit board is characterized in that the circuit film has a free portion that is not joined to the substrate body, and the free portion is connected to an external component.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. 1 is an enlarged cross-sectional view of a main part of a printed circuit board according to the present invention, FIG. 2 is a cross-sectional view showing another embodiment, FIG. 3 is an enlarged cross-sectional view of a main part of a circuit film used in the present invention, and FIG. It is a principal part expanded sectional view which shows another example.

As shown in FIG. 1, the printed circuit board 10 of this embodiment has a circuit film 13 in which a circuit pattern 12 made of a conductor such as copper forming a printed circuit is formed on a base film 14. The substrate body 11 is integrally formed on the back surface side of the base film 14. The printed circuit board 10 is characterized in that at the end portion 15 thereof, the circuit film 13 has a free portion 16 which is not joined to the substrate body 11.
A connection terminal 17 from an external device (not shown) or the like is connected to the free portion 16.

FIG. 2 shows another example of this invention.
The printed circuit board 20 has a central portion 25 provided with a free portion 26 where the circuit film 23 is not joined to the substrate body 21. A desired number of free portions 26 can be provided not only in the central portion 25 of the main body but also in any portion of the substrate, and the connection terminals 27 allow direct connector connection with external parts without the need for soldering. Reference numeral 22 is a circuit pattern made of a conductor, and 24 is a base film.

In the above structure, the substrate body 11,
21 is preferably a general-purpose resin such as ABS resin or polycarbonate, or a heat resistant resin called super engineering plastic represented by PEI or PES.

In the circuit films 13 and 23, circuit patterns 12 and 22 made of copper foil or the like are formed on the upper surfaces of the base films 14 and 24, and the back surfaces of the base films 14 and 24 are formed at the time of molding. It is placed in the mold on the (cavity) side and molded integrally with the substrate body. The base film used for the circuit films 13 and 23 has a softening temperature according to the melting temperature of the substrate resin, and is preferably a polyester film having a thickness of 50-100 μm. The circuit film used in this example is a so-called single-sided flexible circuit board, but it is also possible to use a multilayer flexible circuit board in which circuit patterns are formed on both sides of the base film.

FIG. 3 shows an example of a circuit film used in this invention. This circuit film 30 is a preferable example when a general-purpose resin having a relatively low melting temperature is used for the substrate body, and the circuit pattern is integrally formed by adhering it to the substrate body. That is, the base film 34 having a melting temperature sufficiently higher than that of the substrate resin material.
And a circuit pattern 32 made of a conductor such as copper provided on one surface of the base film 34 and an adhesive layer 37 provided on the back surface of the base film 34. The substrate is placed in a molding die. At the time of molding, it is integrally bonded to the substrate by the adhesive layer 37.

A free end portion 39 is provided on a part of the circuit film 30. No adhesive layer is provided on the free end portion 39, and the free end portion 39 becomes a free portion that is not joined to the substrate body after molding and is connected to an external component connector or the like.

On the other hand, when a resin having a high heat resistance, for example, a so-called super engineering plastic such as PEI or PES is used for the substrate body, a circuit film as shown in FIG. 4 is used.

This circuit film 40 is adapted to be fused and integrally formed with a substrate body during molding of a molded product to form a circuit pattern integrally with the base film 41 and a circuit pattern 42 made of a conductor such as copper foil. It has a free end portion 49 which is a free portion of the molded product. A release layer 47 is provided on the free end portion 49 so as not to be fused with the substrate body during molding. As the release layer 47, it is preferable to stick a release paper coated with an adhesive on one surface or to coat a release agent such as silicone.

[0016]

As shown and described above, according to the printed circuit board of the present invention, the circuit film has a free portion which is not joined to the substrate body in a part of the substrate body, and the free portion is the surface. It can be pulled out to the side and directly connected to external parts. Therefore, a process such as soldering for adhering an electric wire or the like to a circuit is greatly simplified, work efficiency is improved, and cost can be reduced at the same time.

Further, since this free portion can be provided at any position on the board, it is possible to connect the connector from any position on the board, such as taking out the connector part from the end face of the board, and to design the board freely. The present invention has a great advantage.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of a main part of a printed circuit board according to the present invention.

FIG. 2 is a cross-sectional view showing another embodiment.

FIG. 3 is an enlarged sectional view of an essential part of a circuit film used in the present invention.

FIG. 4 is an enlarged cross-sectional view of a main part showing another example of the circuit film.

[Explanation of symbols]

 10 Printed Circuit Board 11 Board Body 12 Circuit Pattern 13 Circuit Film 14 Base Film 16 Free Portion 17 Connection Terminal

Claims (1)

[Scope of utility model registration request] 1. A substrate body integrally formed on a back surface side of the base film of a circuit film, wherein a circuit pattern made of an electric conductor forming a printed circuit is formed on a top surface of a synthetic resin base film. A printed circuit board, wherein a part of the circuit film has a free portion which is not bonded to the substrate body, and the free portion is connected to an external component.