JPH02188994A - Multilayer flexible printed wiring board using plural terminal rows - Google Patents

Abstract

PURPOSE:To be easily detachably attach without deformation of a terminal to a connector sold in a market and to alleviate a connecting work by superposing many flexible printed circuit boards each having a thick terminal conductor protruding from the end of the circuit board, inserting a reinforcing plate to the root of the terminal, and so adhering as to become desired number of connections. CONSTITUTION:In two or more layer multilayer flexible printed circuit boards, terminals 3 protruding continuously from circuit conductors of layers are provided at the end, and an insulating reinforcing plate 4 is provided between a circuit conductor continued to the terminal 3 of one layer at the end from which the terminal 3 protrudes and the circuit conductor continued to the terminal 3 of the other layer. Thus, when the terminal of the flexible printed wiring board is inserted to the connector, the deformation of the terminal is prevented, thereby enabling a sure and easy connection of the board.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a multilayer flexible printed wiring board with excellent connections.

(Prior art) In order to connect a conventional flexible printed wiring board to another circuit, a pin of a connector is inserted into a through hole drilled in a connection land formed on the flexible printed wiring board, and soldering, etc. After making the connection with A method of directly inserting into a connector manufactured specifically for printed wiring boards was used, but due to mechanical limitations of the pins of the connector soldered to flexible printed wiring boards, it was not possible to reduce the size between the bins, and reinforcement was required. Even those using boards are difficult to control the dimensions and bonding accuracy of the reinforcing board and flexible printed wiring board, and are not compatible with recent high-density circuits.

Therefore, as shown in Figure 7, the circuit conductor is exposed at the end of the flexible printed wiring board, and on top of that, a flexible printed wiring board with the circuit conductor exposed at the end is layered and bonded, as shown in Figure 8. As shown in Japanese Patent Publication No. 63-23678, a method of connecting such a flexible printed wiring board by inserting it into a specially manufactured connector is disclosed. In addition, a flexible printed wiring board with a thick body terminal has a thick terminal conductor protruding from the end of the flexible printed wiring board, as disclosed in Japanese Patent Application Laid-Open No. 156395/1983, and the flexible printed wiring board It is known to be integral with a circuit conductor formed on top of the circuit conductor.

(Problem to be Solved by the Invention) In a conventional flexible printed wiring board, a connector pin is inserted into a through hole drilled in a connection land and connected with solder, etc., and then inserted into a mating connector, or a flexible printed wiring board is used. In the method of exposing the conductor for connection at the end of the wiring board, pasting a thick plastic reinforcing plate on the back of the insulating film that supports the conductor, and directly inserting it into a connector manufactured specifically for flexible printed wiring boards, It is necessary to form connecting lands and through holes, which makes it difficult to route the circuit pattern, increases the manufacturing process for drilling holes, and requires the connector pin to be inserted into the flexible printed wiring board and soldered. Since the attachments are connected by screws, etc., the work becomes complicated, which causes high costs.

In addition, the circuit conductor is exposed at the end of the flexible printed wiring board, and a flexible printed wiring board with the circuit conductor exposed at the end is layered and adhered on top of it, as shown in Figure 8. The method of connecting by inserting a specially manufactured connector into a printed wiring board requires a special connector, and cannot be inserted into an ordinary standard connector due to its structure.

Furthermore, when using a flexible printed wiring board that has a thick terminal conductor protruding from the end and is integrated with the circuit conductor formed on the flexible printed wiring board, the number of bins is large and the two side When connecting to the above connectors, you can either use the extremely time-consuming method of inserting flexible printed circuit boards with - row terminals into the connector one by one, or - Alternately changing the length of the terminals and using long terminals. The method used was to bend the terminals and insert them into each row of connectors, but when inserting them into the connectors, the terminals could become deformed or
The terminals may break, which limits the number and shape of the terminals that can be used.Furthermore, the bases of the terminals are fragile, and it requires skill to insert the terminals into the connector without damaging them.

The present invention provides a multilayer flexible printed wiring board with excellent connections.

(Means for Solving the Problems) The present invention is a conventional flexible printed wiring board, in which a large number of flexible printed wiring boards having thick terminal conductors protruding from the ends are stacked one on top of the other, and the bases of the terminals are reinforced. It was discovered that the above problem can be solved by sandwiching the plates and gluing them to the desired number of connections.In addition, by sandwiching the reinforcing plates in this way, the spacing between each layer can be relatively freely controlled and the dimensional accuracy can be improved. This was achieved by discovering the unexpected effect of improving the quality of the material.As shown in Figures 1 and 2, in a multilayer flexible printed wiring board with two or more layers, each layer is having a terminal 3 continuously protruding from the circuit conductor, the protruding end of the terminal 3 between the circuit conductor continuous with the terminal 3 of one layer and the circuit conductor continuous with the terminal 3 of another stone; This is a multilayer flexible printed wiring board with terminals having an insulating reinforcing plate 4 at the top.

FIG. 3 is an example of a cross-sectional view of a connector into which the multilayer flexible printed wiring board of FIG. 2 can be inserted;
The figure shows a state in which the multilayer flexible printed wiring board of the present invention is inserted.

Such multilayer flexible printed wiring boards are manufactured by manufacturing multiple flexible printed wiring boards with thick terminal conductors protruding from the ends, then inserting reinforcing plates at the bases of the terminals and laminating the required number of flexible printed wiring boards. , can be manufactured by gluing. A method for manufacturing a flexible printed wiring board having thick terminal conductors protruding from the ends is as shown in the above-mentioned Japanese Patent Application Laid-Open No. 156395/1983.
Copper plate or copper foil (of the thickness required to insert into the connector)
Or, form an etching resist on one side of the copper alloy at the part that will become the terminal and circuit conductor, and use a commonly used copper etching solution such as cupric chloride solution to remove the conductor in unnecessary places to the same thickness. Etch to remove about half of the conductor, form an insulating coating layer on desired parts other than the parts that will become terminals, form an etching resist only on the parts that will become terminals on the other side of the conductor, and then replace the other parts. It is obtained by etching away about half of the conductor thickness to form a thin circuit and thick terminals, and then providing an insulating coating layer in the necessary areas. At this time, if the circuit part and the terminal are straight and the length is about 10 cm or less, an etching resist is formed on one side of the conductor in the shape of the terminal and the terminal on the other side of the circuit. It can also be obtained by etching away unnecessary conductors from both sides.

Next, materials that can be used in the present invention will be described.

Materials that can be used for the terminal 3 include electrical copper and copper alloys such as copper plates (foils) and brass plates (whistles) having a thickness greater than the required terminal thickness. Further, the surface of the terminal can be plated with NrSAu-, Cu, etc. In this case, a copper plate or the like whose initial thickness is thinner than the thickness of the terminal can be used.

The insulating reinforcing plate 4 can be made of a hard material such as a glass-based epoxy laminated film, a polyimide film, a polyester film, etc., and the thickness of the material is as follows:
It is determined by the thickness of the adhesive and insulating layer and the pin pitch of the connector.

For the glabella insulating layer 2, polyimide film with excellent heat resistance is usually used, but any material currently used in flexible printed wiring boards, such as polyester film and polyparabanic acid film, can be used.

For the insulating coating layer 1, any material that can be used for the glabellar insulating layer can be used, and if the FPC other than the terminal portion does not require much flexibility, resist ink or the like can also be used.

In addition, adhesives include acrylic resin, epoxy resin,
Polyimide resin etc. can be used.

(Function) The multilayer flexible printed wiring board according to the present invention can be used in general connectors, and since a reinforcing plate is provided at the base of the terminal, when the terminal of the flexible printed wiring board is inserted into the connector, the terminal Deformation can be prevented and connections can be made reliably and easily.

Further, the multilayer flexible printed wiring board according to the present invention can also be connected by soldering by directly inserting the terminals into through holes formed in another wiring board.

Furthermore, in addition to the protruding terminals as shown in Figure 5, connecting terminals can be provided on the outside, and connections with a large number of pins can be made using a dedicated connector as shown in Figure 6. .

Example Copper plate with a plate thickness of 0.5 ms (JIS H3100, C11
00-H standard, manufactured by Nippon Mining Co., Ltd. Laminate an ultraviolet curable dry film on top and pass the negative film through the U
A resist pattern was formed by exposure to V light and development.

Thereafter, the copper phosphorus was etched with a cupric chloride aqueous solution to form terminals and circuits. Next, as an insulating layer for the circuit, LP-0310 (trade name, DuPont), which is a Kapton film with acrylic adhesive, was applied to the parts other than the terminals at 180°C for 30 minutes.
A single-layer flexible printed wiring board with terminals was manufactured by bonding under conditions of 0 kg/ad.

Two flexible printed wiring boards with terminals thus produced were adhered to each other to produce a two-layer flexible printed wiring board with terminals. At this time, a glass-based epoxy laminate with a thickness of 1.4 mm was placed at the base of the terminal, and two sheets of acrylic adhesive sheet LF-0200 (DuPont, trade name) were used as the adhesive at 180°C. Bonding was carried out under the condition of 35 kg/-.

After adhesion, the terminal portion was plated with gold to a thickness of 0.5 μm.

When the manufactured two-layer flexible printed wiring board with terminals was inserted and removed using a female connector NFS-50A-011 (Yama-Denki Kogyo Co., Ltd., product name), there was no deformation of the terminals, and it was inserted and removed 50 times. Although the test was repeated, there was no deformation of the terminal part.

(Effects of the Invention) As described above, the multilayer flexible printed wiring board of the present invention can be easily attached to and detached from commercially available connectors without deforming the terminals, and the connection work can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a top view showing an embodiment of the present invention, Fig. 2 is a sectional view showing an embodiment of the invention, Fig. 3 is a sectional view of a connector that can be used in an embodiment of the invention, and Fig. 4 is a sectional view showing an embodiment of the invention. The figure is a sectional view showing a connection method using one embodiment of the present invention, FIG. 5 is a sectional view showing another embodiment of the invention, and FIG. 6 is a connection method using another embodiment of the invention. 7 is a sectional view showing a conventional example, and FIG. 8 is a sectional view showing a connection method using the conventional example. Explanation of symbols 1. Insulating coating layer 20, interlayer adhesive layer 3, terminals 3a, 3b, 3c, R body layer 4, reinforcing plate 5. Connector terminal 5a, connector contact part 11a, llb, llc, connector cause diagram →A'

Claims (1)

[Claims] Specification 1. Title of the invention: Multilayer flexible printed wiring board having multiple terminal rows Claim 2. Scope of patent registration claims 1. A multilayer flexible printed wiring board with two or more layers has a terminal that continuously protrudes from the circuit conductor of each layer at the end, and the protruding end of the terminal has a circuit conductor that is continuous to the terminal of one layer and another. A multilayer flexible printed wiring board with terminals having an insulating reinforcing plate between the terminals of the layer and the circuit conductor continuous with the circuit conductor.