JPH0438151B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a matrix circuit board used in manufacturing a dot matrix light emitting display.

Conventional technology The conventional matrix circuit board of this type is
First and second electrode patterns are formed on the front and back sides of the insulating substrate, and the second electrode pattern formed on the back side of the insulating substrate is connected to the above-mentioned second electrode pattern on the front side of the insulating substrate through a through hole. It is connected to a conductive part formed separately from the first electrode pattern, and the thus formed conductive part and a part of the first electrode pattern constitute a light emitting part base. A light emitting element such as a light emitting diode chip is attached to the upper surface of the light emitting part base thus formed to form a light emitting part.

Problems to be Solved by the Invention Recently, attempts have been made to increase the brightness of the light emitting part of such a matrix circuit board, by connecting a plurality of light emitting elements in series or in parallel to the light emitting part. We are trying to solve the above problems.

However, in consideration of the manufacturing process of the matrix circuit board, the following problems arise when solving the above problems.

(1) The simplest method is to provide a plurality of light emitting elements in parallel on the light emitting unit base.

According to this method, an existing matrix circuit board (herein, one in which one light emitting element is attached to a light emitting part base) can be used, and a conductive part forming the light emitting part base can be used. It is only necessary to attach a plurality of light emitting elements to one of the parts of the first electrode pattern forming the light emitting part base, and to connect the attached light emitting elements to the other part with a bonding wire. However, with this method, the drive current that passes through each light emitting section increases in proportion to the number of light emitting elements, so the attached drive device must have a large current capacity, which increases the cost. increases significantly.

(2) The next method is to provide a plurality of light emitting elements in series on the light emitting unit base.

In this method, in addition to the conductive parts that have already been formed, conductive lands that are isolated from each other (here, isolated conductive parts that are not connected to other parts) are placed on the base of the light emitting element. Form according to the number.

However, compared to other conductive parts, it is necessary to form an electrolytic plating layer on the light emitting part base in order to ensure the bonding of bonding wires and the like, so this method complicates the plating process.

In other words, since the light emitting part base will be electrolytically plated later, it is necessary to prepare for this at the time of manufacturing the matrix circuit board. Normally, preparations for this case are made by providing a plating wiring pattern for each newly provided conductive land. However, forming such a plating wiring pattern on a matrix circuit board complicates the manufacturing process of the matrix circuit board itself.
This becomes especially difficult as the number of light emitting bases increases. Moreover, this hinders the integration of light emitting parts formed on the matrix circuit board, requires unnecessary space, and increases loss of insulating substrates. Furthermore, it is difficult to form a plating wiring pattern with a uniform thickness for each conductive land, and as the number of plating wiring patterns increases, the electrical resistance during electrolytic plating increases, making the plating layer more likely to become uneven. . Furthermore, if the thickness of the plating wiring pattern is uneven, the thickness of the plating layer to be formed will vary, resulting in a large number of defective matrix circuit boards.

Means for Solving the Problems The present invention is proposed to solve the above-mentioned problems, and has a simple manufacturing process, low cost,
The purpose is to provide a matrix circuit board with less variation.

That is, in the matrix circuit board of the present invention, a part of the plurality of electrode patterns is formed on the front side of the insulating substrate, a part is formed separately from the electrode pattern on the front side of the insulating substrate, and a part is formed on the back side of the insulating substrate. In a matrix circuit board in a dot matrix light-emitting display body, the conductive part is connected to a plurality of electrode patterns formed in the through-holes via through holes, and the base of the light-emitting part is constituted by the matrix circuit board corresponding to the base of the light-emitting part. The gist is that a plurality of conductive lands different from the conductive part are formed in the part, and these conductive lands are connected to the conductive part or the first electrode pattern via a connecting part. be.

Effects of the Invention Since the matrix circuit board of the present invention is characterized by the above-described structure, the following unique effects are produced due to its structural features.

(1) Since a plurality of conductive lands are formed in the portion corresponding to the light emitting unit base, a plurality of light emitting elements can be connected in series using the conductive lands as electrical paths. Therefore, when increasing the brightness of the light emitting section, a drive device with a small current capacity can be used.

In this case, a driving device with high withstand voltage is required, but since the driving voltage of light-emitting elements such as light-emitting diodes is originally low, even if multiple light-emitting elements are connected in series, the withstand voltage will be low. It has a wide tolerance range, so it can be used as a general-purpose transistor.
Because it has sufficient voltage resistance to be driven by ICs, etc.
Since increasing the withstand voltage is relatively easier than increasing the current capacity, there is an advantage that the cost can be significantly reduced compared to increasing the current capacity.

(2) In the case of forming a plating layer on the light emitting part base, the conductive land is connected to the first electrode pattern or the conductive part of the light emitting part base, that is, the second electrode pattern, via the connecting part. The plating wiring required for plating the first and second electrode pattern parts can be shared, which has the advantage of reducing the number of plating wirings, which can simplify and reduce the manufacturing effort of the circuit board. Since the electrical resistance during electrolytic plating can be reduced, the plating layer can be made less likely to have unevenness. Therefore, the subsequent work of attaching the light-emitting elements becomes easier, and a light-emitting display with less variation can be obtained.

Embodiment FIG. 1 is a diagram showing an electrode pattern on the front side of a matrix circuit board of the present invention, and FIG. 2 is a diagram showing an electrode pattern on the back side thereof.

As shown in the figure, the matrix circuit board A has first and second electrode patterns 21, 22..., 31, 32... formed on the front and back sides of the insulating substrate 1, respectively, and the first electrode pattern 21, 22... make up an X electrode group, and second electrode patterns 31, 32... make up a Y electrode group.

Further, a part of the second electrode patterns 31, 32... formed on the back side of the insulating substrate 1 are connected to the conductive parts 6... formed on the front side of the insulating substrate 1 via through holes 5a... This conductive part 6...
A part of the first electrode patterns 21, 22 forms a light emitting unit base 4 (indicated by a broken circle in the figure).

A conductive land 7 (an isolated conductive part that is not directly connected to the first electrode patterns 21, 22, etc. when the light emitting part is formed) is formed in a portion corresponding to the light emitting part base 4. In the embodiment shown in FIG. 3, the conductive land 7 is connected to the conductive part 6, which forms the light emitting part base together with a part of the first electrode patterns 21, 22, through a connecting part 71. connected. Note that the conductive portions 91a extending from each of the first electrode patterns 21, 22... and the second electrode patterns 31, 32...
. . , 92a . . . are board wire portions of plating wirings 91 and 92 used when applying electrolytic plating to the light emitting unit base.

In addition, the through holes 5 provided in a row horizontally in the center of the insulating substrate 1 constitute connector terminals.
When driving the matrix circuit board A to light up, a pin connector (not shown) or the like is inserted and connected.

In addition, although only one matrix circuit board A is shown in FIGS. 1 and 2, in actual manufacturing, one large insulating board is used with a first matrix circuit board A corresponding to the matrix circuit board A to be manufactured. , 2nd 21, 2
A plurality of electrode patterns 2..., 31, 32... are formed independently, and the plurality of electrode patterns thus formed are commonly connected by plating wirings 91, 92 to form a plurality of matrix circuit boards. The light emitting unit bases 4 of A are simultaneously plated and then cut into sizes according to the matrix circuit boards A to be manufactured to manufacture individual matrix circuit boards A.

FIG. 5 shows an electrical equivalent circuit when two light emitting elements are connected in series to the light emitting portion of the matrix circuit board A to form a dot matrix display board.

In addition, in the figure, X1, X2..., Y1, Y2...
correspond to the first and second electrode patterns, respectively.

Further, FIG. 6 shows another example of a conductive land, in which a first conductive land 7a is connected to the conductive part 6 of the light emitting part base 4 via a connecting part 71, and a first conductive land 7a forming the light emitting part base is connected to the conductive part 6 of the light emitting part base 4. An example is shown in which a second conductive land 7b is formed on a part of the electrode pattern 21 via a connecting portion 72.

In any case, the conductive land as described above is
It is formed simultaneously when forming the first and second electrode patterns by etching the copper foils provided on both the upper and lower surfaces of the copper-clad laminate. By forming an arbitrary number of conductive lands on a conductive part connected to the first electrode pattern or the second electrode pattern via a through hole via a connecting part, an arbitrary number of light emitting elements can be connected to the light emitting part. Needless to say, they can be provided in series.

Note that FIG. 4 shows the light emitting unit base 4 shown in FIG.
FIG. 7 shows an example in which a light-emitting element is attached to the light-emitting part base 4 shown in FIG. 6, where 8 is a light-emitting element and 9 is a bonding wire.

Further, in this embodiment, an example of an 8.times.8 dot matrix circuit board is shown, but it goes without saying that the same applies to a 16.times.16 dot matrix circuit board.

Next, the procedure for manufacturing a dot matrix light emitting display using the matrix circuit board A of the present invention will be described below.

The part of the matrix circuit board A other than the part that forms the light emitting part base (indicated by the broken line circle in Figure 1) is covered with a resist film such as epoxy resin, and electrolytic plating is applied to form the light emitting part base. A conductive plating layer is formed in a portion corresponding to the area. In this case, the plating layer is formed for the convenience of attaching the light emitting element to the light emitting part base using silver paste in a later step and for facilitating the bonding process. Normally, this plating treatment is performed by applying a base plating of nickel to a thickness of about 3 to 4 μm and, if necessary, finishing plating with silver or gold to a thickness of about 0.3 μm.

After performing the plating process in this way, the connecting portion formed on the conductive land of the light emitting part base is removed by drilling or patching.
The light emitting element is attached to the light emitting unit base using silver paste or the like, and connections are made using bonding wires.

After the light emitting elements are attached to each light emitting unit base of the matrix circuit board in this way,
A dot matrix light-emitting display is manufactured by coating the upper surface of the circuit board with a transparent thermosetting resin to form a protective film.

The thus manufactured matrix light-emitting display can be used as a display panel, etc. by selectively driving the light-emitting elements attached to each light-emitting part using a dynamic drive device, etc., to display characters and symbols by lighting. used.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the electrode pattern on the front side of the matrix circuit board of the present invention, FIG. 2 is a rear view showing the electrode pattern on the back side, and FIG. 3 is the light emitting unit base shown in FIG. 1. 4 is an enlarged view of the light emitting part base shown in FIG. 3 showing an example of how the light emitter element is mounted. FIG. 5 is a dot matrix light emitting display using the matrix circuit board shown in FIG. 1. Figure 6 is an enlarged view of another example of the light emitting part base (another example of conductive land), and Figure 7 is an electrical equivalent circuit diagram when a light emitting element is formed on the light emitting part base shown in Figure 6. It is an enlarged view when attaching and forming a light emitting part. (Explanation of symbols), 1...Insulating substrate, 21, 22
...First electrode pattern, 31, 32... Second electrode pattern, 4... Light emitting part base, 5, 5a...
...Through hole, 6...Conductive part, 7, 7a, 7b
. . . Conductive land, 8 . . . Light-emitting element.

Claims (1)

[Claims] 1 A part of the plurality of electrode patterns formed on the front side of the insulating substrate and a part of the plurality of electrode patterns formed on the front side of the insulating substrate, which are formed separately from the above electrode patterns, and formed on the back side of the insulating substrate. In a matrix circuit board in a dot matrix light-emitting display body in which a light-emitting part base is formed by a conductive part connected through a through hole, a part different from the conductive part is attached to a part corresponding to the light-emitting part base. A dot matrix light-emitting display characterized by having a structure in which a plurality of conductive lands are formed and these conductive lands are connected to the conductive part or a part of the first electrode pattern through a connecting part. Matrix circuit board.