JPS5951158B2 - Double-sided wiring board and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides double-sided wiring in which connecting portions are provided at the edges of a glass substrate to electrically connect circuit wiring formed on the upper and lower surfaces of the glass substrate. The present invention relates to a method of manufacturing a substrate.

BACKGROUND ART Conventionally, printed wiring boards are known, which are formed by printing and applying a conductive material prepared in a paste form in a desired pattern onto an inorganic insulating board such as a ceramic plate, and then firing the coated conductive material.

This printed wiring board has superior mechanical strength, heat resistance, weather resistance, and electrical properties compared to, for example, a copper-clad wiring board.In particular, with the advancement of screen printing technology, precise printing of circuit wiring conductors has become possible. In addition, IC
, LSI, etc. can be directly mounted on the wiring board, so it can be said that it is a wiring board suitable for downsizing various electronic devices.

However, since this printed wiring board uses materials such as ceramics for the substrate, it is expensive and has a problem in terms of economic efficiency.

Therefore, a method has been devised and put into practical use in which the substrate on which the printed wiring is printed as described above is made of an inexpensive and easily available glass plate, and the circuit wiring is formed on this glass substrate by screen printing or the like. It is becoming more and more common. However, in this case, it is extremely difficult to form through holes in the glass substrate, so through-hole connections cannot be made, and circuit wiring is generally printed only on one side of the substrate in most cases.

Therefore, printed wiring boards using glass substrates have problems in terms of high-density mounting, and if you dare to achieve high-density mounting, it is necessary to create multiple layers on the same surface of the board using a crossover method etc. However, there were problems in that the manufacturing process became complicated and expensive.

The present invention has been made in view of the above-mentioned circumstances, and includes providing a notch in the edge of a glass substrate, filling and depositing a conductive material in this notch to form a connecting portion, and using this connecting portion to connect the substrate. To provide a method for manufacturing a double-sided wiring board having a structure in which circuit wiring printed on the upper and lower surfaces of the board is connected, and double-sided wiring can be easily formed at low cost.

That is, the present invention includes a step of forming a notch in the edge of a glass substrate, a step of continuously applying a conductive material to the edge where the notch is formed, and a step of continuously applying a conductive material to the edge of the glass substrate. a step of removing the conductive material adhered to at least a deep part of the notch of the glass substrate; a step of adhering and forming circuit wiring on the upper and lower surfaces of the glass substrate; A method for manufacturing a double-sided wiring board, comprising the step of depositing connection conductor portions on the upper and lower surfaces of the glass substrate to be connected to the connection portions made of conductive material.

Further, the present invention provides a step of forming a notch in an edge of a glass substrate, a step of continuously applying a conductive material to the edge where the notch is formed, and a step of continuously applying a conductive material to the edge of the glass substrate. a step of removing a conductive material deposited on a portion of the notch portion except for at least a deep portion; a step of depositing and forming an insulating coating layer on the conductive material deposited in the notch portion;
A process of depositing circuit wiring on the upper and lower surfaces of the glass substrate, and connecting each of the circuit wiring to a connection portion made of a conductive material deposited on the cut portion. The method of manufacturing a double-sided wiring board is characterized by comprising the step of: forming connection conductor portions on the upper and lower surfaces of the glass substrate.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a double-sided wiring board and a method for manufacturing the same according to the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 is a glass substrate. First, as shown in FIG. Cut it out with a cutter made of etc.
A notch 2 is formed 4.

In this case, the shape of the notch 2 is appropriately selected to be a triangular shape or a semicircular shape as shown in the figure, or a shape that is easy to cut out. Further, the depth of cut of the cut portion 2 is not particularly limited, but it is preferably at least 1 mm or more, and more preferably 2 mm or more. Furthermore, if the number of connections between circuit wiring A and B on the upper and lower surfaces, which will be described later, increases, the notch 2 may be connected to the other three side surfaces other than the edge 1d on the side IC side. It may also be formed on any edge. Next, the preset circuit wiring on the upper and lower surfaces is divided into two blocks A and B, and as shown in FIG. Printing is applied using a printing method, etc.

Furthermore, a connecting conductor 3a for connecting one circuit wiring A and the other circuit wiring B is attached at the same time as the printing of the circuit wiring A, or after the printing of the circuit wiring A. The first circuit wiring A and its connecting conductor 3 are printed and coated so as to be continuous with the notch 2, and then fired.
a is deposited and formed on the upper surface 1a of the substrate 1. Similarly, the other circuit wiring B is connected to the lower surface 1b of the glass substrate J board 1.
Then, a connecting conductor 3b for connecting the circuit wiring B and the circuit wiring A is printed and applied by a screen printing method or the like, and a connecting conductor 3b connecting the circuit wiring B and the circuit wiring A is printed and applied in a continuous manner from the circuit wiring B to the corresponding notch 2, and then baked. The bottom surface 1 of the glass substrate 1
A circuit wiring B and its connecting conductor 3b are deposited on the substrate 3b.

In this way, the upper surface 1a and the lower surface Ib of the glass substrate 1
After forming the circuit wirings A and B thereon, a conductive material 4 is applied to the side surface 1c of the glass substrate 1, as shown in FIG. 1c.

This conductive material 4 is made of the same conductive material used in printing the circuit wiring A and B, for example, a mixture of silver and a small amount of glass frit mixed with a binder agent into a paste form. The coating is applied to a sufficient thickness using a brush, roller, etc. so that an electrical connection is formed in the notch 2. In this case, it is preferable to apply the conductive material 4 so that at least the bottom of the notch 2 is filled with the conductive material 4. Further, the conductive material 4 applied to the notch 2 is applied sufficiently so that it oozes out from the upper and lower ends of the notch 2, wets the connecting conductors 3a and 3b, and connects them. Thereafter, the conductive material 4 is deposited on the cut portion 2 by firing. By the way, this first
In the state shown in FIG. c, each connecting conductor 3a, 3b is in a short-circuited state due to the conductive material 4 deposited on the side surface 1C. Therefore, next, the side surface 1C is ground, cut, or cut to a width that is sufficiently thin compared to the depth of the cut portion 2, and unnecessary conductive material adhered to the side surface 1C is removed. , and each adjacent connection conductor 3
Eliminate the short circuit between a and 3b. Therefore, as shown in FIG.
A connecting portion 5 is formed to electrically connect the connecting conductors 3a and 3b which are formed facing each other with the glass substrate 1 in between.
The circuit wirings A and B formed on the substrate are connected to form the double-sided wiring board 6.

That is, in the double-sided wiring board 6 made according to the present invention, a notch 2 is provided at the edge 1d of the glass substrate 1, a conductive material 4 is applied to the notch 2 to form a connection part 5, and the connection part 5 is On the other hand, connecting conductors 3a and 3b are connected to the circuit wirings A and B formed on the upper and lower surfaces of the glass substrate 1, respectively, to connect the circuit wirings A and B.

Therefore, circuit wiring formed on the top and bottom surfaces of the substrate can be electrically connected without making through-hole connections, making it possible to realize double-sided wiring using glass substrates, which was previously considered difficult. .

By the way, in the embodiment described above, the conductive material 4 of the connecting portion 5 remains exposed.

Therefore, if the case housing the double-sided wiring board 6 is made of metal, or if other conductive members are placed near the connection portion 5, short circuits may occur. There is a risk. Therefore, in such a case, as shown in an enlarged view of the main part in FIG. 2, for example, a low melting point glass frit is pasted with a binder agent to the cut portion 2 after the conductive material 4 has been deposited. The insulating coating layer 7 obtained by preparing the mixture may be applied and baked to form an insulating coating.

In this case, since the insulating coating layer 7 acts to cover the conductive material 4 exposed within the notch 2, the insulating coating layer 7 is attached to the side surface 1C. Of course, this can be carried out in any step before or after the step of removing the conductive material 4 that is present.

Further, in the embodiment described above, after forming the cut portion 2 in the edge portion 1d of the glass substrate 1, the circuit wirings A and B and the connecting conductors 3a and 3 are formed on the upper surface 1a and the lower surface 1b of the glass substrate 1.
In this example, the circuit wirings A and B and the connecting conductors 3a and 3b are first formed, and then the notches 2 are formed and the conductive material 4 is applied thereto. It may be made to adhere.

Further, after forming a notch 2 in the edge 1d of the glass substrate 1, a conductive material 4 is applied to the notch 2, and then circuit wiring A and B are formed on the upper surface 1a and the lower surface 1b of the glass substrate 1. and the tangential conductors 3a and 3b may be formed by adhesion. Furthermore, in the above embodiment, an example was described in which the conductive material 4 is applied from the side surface 1C side, but the conductive material 4 is applied almost to the edge 1d of the glass substrate 1 where the notch 2 is formed. A master having the same shape is placed on the edge of the upper surface 1a or the lower surface 1b, and a conductive material 4 is printed and coated by, for example, screen printing, so that the conductive material 4 is adhered to the cut portion 2. You can.

In addition, the present invention is not limited to the embodiments described above and shown in the drawings, but can be implemented with various modifications without changing the gist thereof.

As described above, the first method of manufacturing a double-sided wiring board according to the present invention uses an inexpensive and easily available glass plate as the substrate material, provides a notch at the edge of the glass substrate, and conducts electricity therein. After applying a conductive material to the edge of the substrate where the notch has been formed, in addition to applying a material to form a connection part, the part of the edge excluding the deep part of the notch. Since the connection portion is formed by removing the conductive material adhered to the cut portion by means such as grinding or cutting, mechanical methods such as rolling or printing are not required to apply the conductive material to the cut portion. It is possible to use a continuous method, and there is no need to pay particular attention to the application state and method, which makes work management extremely easy, promotes automation, and improves productivity. We can expect it.

Moreover, since the wiring circuits on the upper and lower surfaces are connected at the edges without using through holes as described above, the positioning when attaching the wiring circuits on the upper and lower surfaces is done by positioning the conductive material in the notch at the edge. The position can be used as a reference, making the alignment work easier and greatly improving work efficiency.

Furthermore, according to the second manufacturing method of the double-sided wiring board according to the present invention, an insulating coating layer is formed on the conductive material deposited on the cut portion, so that the second manufacturing method according to the first manufacturing method described above is In addition to this effect, the conductive material at the edge of the board is not contaminated during the manufacturing process of the double-sided wiring board after the insulating coating layer is applied, which prevents the occurrence of defective products and further improves manufacturing efficiency. It has an improving effect.

[Brief explanation of the drawing]

1A to 1D are diagrams showing one embodiment of the manufacturing process of a double-sided wiring board according to the present invention, and FIG. 2 is an enlarged view of main parts showing another embodiment of the present invention. 1...Glass substrate, 2...Notch, 3a, 3
b... Connection conductor, 4... Conductive material, 5... Connection portion, A, B... Wiring circuit.

Claims (1)

[Scope of Claims] 1. A notch is formed at the edge of the glass substrate, and a conductive material is continuously applied to the edge where the notch is formed,
The conductive material deposited on the edge of the glass substrate except for the inner part of the notch is removed, and circuit wiring is deposited on the top and bottom surfaces of the glass substrate, and the circuit wiring on the top and bottom surfaces is removed. 1. A method for manufacturing a double-sided wiring board, characterized in that connecting conductor portions are formed on the upper and lower surfaces of a glass substrate to be connected to the positions of the connecting portions made of a conductive material that are adhered to the notch portions. 2. Forming a notch in the edge of the glass substrate, and continuously depositing a conductive material on the edge where the notch is formed,
An insulating coating layer is deposited on the conductive material deposited on the edge of the glass substrate except for the deep part of the notch, and circuit wiring is deposited on the top and bottom surfaces of the glass substrate. ,
A double-sided wiring board, characterized in that connection conductor parts are formed on the upper and lower surfaces of the glass substrate to extend from the position of each circuit wiring to the position of the connection part made of a conductive material deposited on the notch part. manufacturing method.