JPH03160767A - Printed circuit board for led display panel - Google Patents

Abstract

PURPOSE:To simply obtain a printed circuit board for a LED display panel for freely forming a large display screen by retreating many pins for forming the panel from the board inward. CONSTITUTION:A bending space R for bent parts 21b of outer leads 21a is positively formed by integrating a lead frame 21 having many outer leads 21a with upper and lower side insulating boards 22, 23 to be held. The bent parts 21b are bent in the space R to dispose the outer surfaces of the leads 21a inward from the end face of a printed circuit board 20. Thus, even if many LED display panels 100 are arranged in the vicinity, an interval of all the LED elements 11 can be equally set, and a large display screen can be freely formed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a printed wiring board, particularly a printed wiring board suitable for configuring an LED display panel.

(Prior art) LEDs (light emitting diodes), whether lamp-type or chip-type, emit high-intensity light and can be miniaturized, so they are arranged in a matrix to selectively emit light. This allows characters and designs to be clearly displayed. Various display panels constructed using such LEDs have been proposed in the past, but in order to construct them as a panel and enable selective energization of each LED, there is a need for this. It is essential to have a printed wiring board that can mount.

Conventional printed wiring boards for this type of LED display panel include mounting an LED display panel using epoxy resin or the like on a substrate made of ceramics and having a conductor circuit, and then mounting a conductor for current on this ceramic substrate. It is known that a structure is constructed by planting a large number of bottles. However, in this printed wiring board made of a ceramic substrate, it is necessary to ensure sufficient space, especially at the outer periphery, in order to forcibly fit the conductor pins into the ceramic substrate. yes. If this panel is used to construct a large display surface, a portion where the LED elements are separated by a large distance is formed at the boundary between each panel. In other words, when LED display panels that have a large space on the outer periphery are arranged in succession, the arrangement of each LED element becomes far apart at the border between each panel. Surfaces cannot be formed.

Therefore, the inventors of the present invention have repeatedly considered how to solve the above problem when a large number of LED display panels are arranged side by side.
It was discovered that the above-mentioned problem could be solved by changing the structure of the printed wiring board that constitutes the D display panel, and the present invention was brought to fruition.

(Problems to be Solved by the Invention) The present invention has been made based on the above-mentioned circumstances, and the problem to be solved is to improve the spacing between each LED element when arranging a large number of LED display panels. This is a partial misalignment.

It is an object of the present invention to enable a structure in which a number of bins (generally outer leads) constituting an LED display panel can be retracted inward from the substrate, thereby , Printed wiring for LED display panels that allows the spacing of all LED elements to be the same even when a large number of LED display panels are arranged close to each other, and allows the creation of a large display surface freely. The purpose is to provide a board with a simple configuration.

(Means for Solving the Problems) In order to solve the above problems, the means taken by the present invention are as follows:
The explanation with the reference numerals used in the examples is as follows: ``A large number of LED elements (1l) are arranged in a matrix, and a predetermined light display is performed by selectively energizing each LED element (11). A printed wiring board (2) for constructing a LED display panel (100)
0), this printed wiring board (20) is integrated with a lead frame (21) having a large number of outer leads (21a), and upper and lower insulating substrates (22) supporting and integrating this lead frame (2l). ) (23) and these insulating substrates (22)
(23) and connected to each outer lead (21a) via a through hole (25).
), the lower insulating substrate (23) is formed smaller than the upper one (22), and each outer lead (21a) is bent toward the lower insulating substrate (23). This is a printed wiring board (20) J for an LED display panel (100), characterized in that the outside thereof is located inward from the end surface of the printed wiring board (20).

That is, the printed wiring board (20) according to the present invention has L
A lead frame (21) having a large number of outer leads (21a) for electrically connecting the ED display panel (10(1) to the outside), an upper insulating substrate (22) and a lower insulating substrate (23) In addition to sandwiching and integrating the lower insulating substrate (23) with the upper insulating substrate (22),
) by making each outer lead (21
A bending space (R) for the bending part (2lb) of a) is actively formed, and the bending part (2lb) of the outer lead (21a) is folded within this bending space (R). By bending, the outer surface of each outer lead (21a) is positioned inward from the end surface of the printed wiring board (20).

(Actions of the Invention) The LED display panel (100) according to the present invention configured as described above has the following effects.

That is, in this printed wiring board (20), a lead frame (21) having a large number of outer leads (21a) is connected to an upper insulating substrate (22) and a lower insulating substrate (23).
), but it is integrated by being sandwiched between
By making the lower insulating substrate (23) smaller than the upper insulating substrate (22), a bending space (R) is actively formed below the end of the upper insulating substrate (22). be. This bending space (R) is used for bending the outer leads (21a), which had been formed flat until then, when bending them toward the lower insulating substrate (23).
This not only makes it easier to form the bent part (2lb) in a), but also makes it easier to form each bent outer lead (21b).
This is necessary to position the outer surface of a) inward from the end surface of the printed wiring board (20).

In other words, the printed wiring board (2o) according to the present invention includes an upper insulating substrate (22) and a lower insulating substrate (23) for sandwiching and integrating the lead frame (2l).
), the lower insulating substrate (23) is connected to the upper insulating substrate (2
By making it smaller than 2), a bending space (R) is actively formed at the periphery of the lower surface of the upper insulating substrate (22).

Therefore, by utilizing this bending space (R), the bending portion (2lb) of each outer lead (21a) can be easily formed, and as shown in FIG. The outer surface of the outer lead (21a) is dimension t.
This makes it possible to position the upper insulating substrate (22) inwardly from the end surface of the upper insulating substrate (22).

Of course, in this LED display panel (100), each LED element (11) is connected to the lead frame (21) via the conductor circuit (24) on the upper insulating substrate (22).
These connections are connected to the upper insulating board (22
) through each through-hole (25). In order to make a specific electrical connection in this way, first, the lead frame (21) is integrated on the lower side of the upper insulating substrate (22), and then the necessary through holes (25) are formed. Finally, the lower insulating substrate (23) is integrated with the lower side of the lead frame (21). With the above structure, each LED element (11) integrated into the surface mask (lO) is independently connected to each outer lead (21a).

Furthermore, in this structure, the inner layered lead frame material has a good heat dissipation effect, and the LED element (1l)
This makes it possible to suppress a decrease in brightness due to the heat generated by the LED display panel (100) when it is turned on, and furthermore, it is possible to prevent variations in brightness within the LED display panel (100) due to the uniform heat effect.

An LED display panel having the above configuration (
100) in a continuous manner in the vertical and horizontal directions, for example, as shown in FIG.
), when the end surface of the upper insulating substrate (22) constituting the printed wiring board (20) is placed in contact with the end surface of the upper insulating substrate (22) of the adjacent LED display panel (100), The distance between each LED element (1l) on one LED display panel (100) and the distance between a pair of LED elements (11) located at the ends of both adjacent LED display panels (100) are completely the same. That's what I do. As a result, even if a large number of LED display panels (100) employing the printed wiring board (20) according to the present invention are arranged, each LED element (
l1) Since there is no visual boundary between them, even if a large number of LED display panels (100) are arranged to form a large display surface, the characters and pictures formed by each LED element (l1) It does not cause any discomfort.

This is due to the following reason. That is, the outer lead (21a) in each LED display panel (100)
) is located inward by the dimension t from the end surface of the upper insulating substrate (22) when bent, as shown in FIG. 1. Therefore, as shown in FIG. 2, each LED Even if the display panels (100) are arranged adjacent to each other, there is a distance of 2t between the adjacent outer leads (21a).
There will be a space of Therefore, due to the existence of this 2t space, it goes without saying that the outer leads (21a) do not come into contact with each other;
This is because a space is secured for connecting a) to another board (not shown).

(Example) Next, the printed wiring board (20) according to the present invention will be explained in detail according to the example shown in the drawings. A cross-sectional view of a display panel (100) is shown.

This LED display panel (100) includes a large number of L
This is constructed by connecting a surface mask (10) in which ED elements (l1) are arranged in a matrix to a printed wiring board (20) according to the present invention, and each LED element (ll) in this example Although a chip-type LED element is shown in the figure, a lamp-type LED element may also be used as each LED element (11).

In addition, each LED element (l1) is attached to the surface mask (lO).
In order to efficiently reflect light forward, an aperture is formed to serve as a concave mirror. And this surface mask (
10) The printed wiring board (20) of the present invention will be explained below.
This LED display panel (100) is constructed by integrating the LED display panel (100) with the LED display panel (100).

The printed wiring board (20) has a large number of outer leads (2
A lead frame (2l) having 1a) is supported by an upper insulating substrate (22) and a lower insulating substrate (23) having a conductor circuit (24) on the surface, and is integrated by pressing or other means. It is. In this case, the conductor circuit (24) formed on the upper insulating substrate (22) side is
This is essential because it is used to electrically connect the ED element (11) and the outer lead (21a), but the lower insulation. The conductor circuit (24) formed on the edge board (23) side is used to electrically connect the electronic components (26) mounted on this lower insulating board (23) and each LED element (1l), etc. However, it is not necessarily necessary to carry out the present invention.

Further, in the printed wiring board (20) according to the present invention, as shown in FIG. 1, the lower insulating substrate (23) is formed smaller than the upper insulating substrate (22), and the lead frame ( 2l) is positioned so that a bending space (R) is positively formed on the outer end side of the lower insulating substrate (23). That is, the bending space (R) formed on the outer end side of the lower insulating substrate (23) facilitates bending of each outer lead (21a), and
The outer end surface of the outer lead (21a) is connected to the upper insulating substrate (2
This is for arranging the bent portion (2lb) of each outer lead (21a) so as to be located inward by a dimension t from the end face of (2). In addition, in FIGS. 1 and 2, the upper insulating substrate (22) and the lower insulating substrate (23) are shown in a state after they have integrated the lead frame (21) between them. , the boundary between the two is not shown.

Then, each outer lead (21a) and the upper insulating substrate (
22) In order to selectively connect to the upper conductor circuit (24), in this embodiment, a through hole (25) passing through the upper insulating substrate (22) and the like is formed. Each through hole (25) and conductor circuit (24) allow one LED element (1
1) are electrically connected.

The LED display panel (100) formed by employing the printed wiring board (20) configured as described above can be used alone, but as shown in FIG. It is also used by
The effect of the printed wiring board (20) of the present invention is further enhanced. That is, when the arrangement is as shown in FIG. 3, each outer lead (21) of the adjacent LED display panel (100) is
a) are separated from each other by a dimension of 2t.

(Effects of the Invention) As detailed above, in the present invention, as exemplified in the above embodiment, "a large number of LED elements (1l) are arranged in a matrix, and each LED element (1l) is selectively A printed wiring board (2) for configuring an LED display panel (100) that performs a predetermined light display by energizing the
0), which integrates this printed wiring board (2o) with a lead frame (21) having a large number of outer leads (21a), and upper and lower plane edge boards (21) that sandwich and integrate this lead frame (21). 22) (23) and these insulating substrates (22) (
23) and connected to each outer lead (21a) via a through hole (25).
In addition, the lower insulating substrate (23) is formed smaller than the upper insulating substrate (22), and each outer lead (21a) is bent toward the lower insulating substrate (23). Its structural feature is that its outer side is located inward from the end surface of the printed wiring board (20), and this allows the large number of pins (generally the outer (leads) can be configured to trail inward from the substrate, thereby making the spacing of all LED elements the same even when a large number of LED display panels are arranged closely. Therefore, it is possible to provide a printed wiring board for an LED display panel, which can freely create a large display surface, with a simple structure.

Furthermore, in the LED display panel (100) that employs the printed wiring board (20) according to the present invention, the outer leads (21a) can be easily processed because the lead frame material is used. If this is a J-bend type, display panels (100) can be mounted on both sides of the motherboard.

[Brief explanation of the drawing]

FIG. 1 is an enlarged cross-sectional view of an LED display panel constructed using the printed wiring board according to the present invention, FIG. 2 is a partial cross-sectional view showing a state in which the LED display panels are arranged adjacently, and FIG. The figure is a perspective view of the same. Explanation of code 100...LED display panel, ll...L
ED element, 20... Printed wiring board, 2l... Lead frame, 21a... Outer lead, 22...
Upper insulating substrate, 23... Lower insulating substrate, 24... Conductor circuit, 25... Through hole, R... Bending space. that's all

Claims (1)

[Claims] A large number of LED elements are arranged in a matrix, and each LED
A printed wiring board for configuring an LED display panel that performs a predetermined optical display by selectively energizing D elements, the printed wiring board comprising:
A lead frame having a large number of outer leads, upper and lower insulating substrates that sandwich and integrate this lead frame, and a conductor circuit formed on these insulating substrates and connected to each of the outer leads via through holes. and the lower insulating substrate is formed smaller than the upper insulating substrate,
A printed wiring board for an LED display panel, characterized in that each of the outer leads is bent toward the lower insulating substrate so that the outer side thereof is positioned inward from an end surface of the printed wiring board.