FR2611294A1 - PLANAR DISPLAY DEVICE, PARTICULARLY ELECTROLUMINESCENT DISPLAY DEVICE - Google Patents

Abstract

FLAT DISPLAY DEVICE, IN PARTICULAR ELECTROLUMINESCENT WITH INTEGRATED SOLIDARITY CIRCUITS, INCLUDING A PRINTED CIRCUIT BOARD 1 WITH AT LEAST A FIRST SET G OF CONTACT PLATES; A VISUALIZATION PANEL 3 SPACE AND AT LEAST SENSITIVELY PARALLEL TO THE SAID PLATE 1 AND THE EDGE OF WHICH INCLUDES AT LEAST ONE SECOND SET H OF CONTACT PLATES; MOUNTING MEANS 5, 6 FOR FIXING THE PRINTED CIRCUIT BOARD 1 TO THE PANEL 3; AND AT LEAST ONE SET OF CONTACT MEANS 7 ... 9 INCLUDING CONDUCTORS 8, 9 FOR THE ELECTRICAL CONNECTIONS FROM THE FIRST SET G TO THE SECOND SET H OF PLOTS. EACH OF THE CONTACT MEANS INCLUDES AT LEAST ONE INTEGRATED CIRCUIT 7, A SET 8 OF INPUT CONDUCTORS FOR THE CONNECTION OF THE INTEGRATED CIRCUIT 7 TO THE FIRST SET G OF PLOTS, AND A SET 9 OF OUTPUT CONDUCTORS FOR THE CONNECTION OF THE INTEGRATED CIRCUIT 7 IN THE SECOND SET H OF PLOTS. THE NUMBER OF 8 INPUT CONDUCTORS, WHICH IS EQUAL TO THE NUMBER OF PLOTS IN THE FIRST SET G, IS SIGNIFICANTLY LOWER THAN THE NUMBER OF OUTPUT 9 CONDUCTORS, WHICH IS EQUAL TO THE NUMBER OF PLOTS IN THE SECOND SET H.

Description

The present invention relates to a device

  plan display, and in particular to a device

  electroluminescent display, comprising a plate

  printed circuit board, the edge of which includes at least a first set of contact pads, a display panel, preferably made of glass, which is placed at least substantially parallel to and spaced from the printed circuit board and the edge of which comprises at least a second set of contact pads, mounting means placed between the

  printed circuit board and the display panel

  tion for the physical fixing of the circuit board

  baked printed and display panel, and at least

  a set of contact means comprising conduc-

  tors for the electrical connections between the first

  together and the second set of contact pads.

  A typical display device of the prior art usually comprises a printed circuit board, with integrated control circuits,

  and a plane display panel spaced ap-

  propriée of the printed circuit board. The display panel is connected to the printed circuit board by a mounting structure placed between the board and the panel. Appropriate wiring between the display panel and the plate is made

by means of jumpers.

  Patent FI 71 860 describes a display device

  filing of the aforementioned type, based on the use of a

  flexible double-sided self-adhesive tape for performing

  kill the attachment of the integrated circuit board to the panel. Figure 1 attached schematically illustrates a display device commonly used in the art. According to this figure, a plate

  circuit board (1) is attached to a display panel

  sation (3) with a copper finger strip (15) pre-

  coated with a layer of Sn60 / Pb40 solder alloy and

  whose number of conductors is equal to the number of con-

  tacts on the display panel (3) or also the number of contacts on the printed circuit board (1). In this case, the integrated circuits (7) are placed on the printed circuit board (1). A hatched area (A) indicates the area allocated to the functional electronic components on the printed circuit board (1). Consequently, since integrated circuits

  (7) take up a significant part of the available surface

  nible, the remaining surface (A) is relatively small.

  The technology according to the prior art, described above, also has the following drawbacks:

  complicated assembly, insecure connection, handling

  delicate relationship and difficult automation of production. The object of the present invention is to avoid the various drawbacks of the technology of the prior art and to provide a completely new type of display device. The invention is based on the installation of integrated circuits outside the printed circuit board, so that they can be produced in the form of easily applicable circuit components which are connected to the printed circuit board of a go

  and to the display panel on the other hand, through

  of their appropriate drivers. More

  specific, the display device conforms to the

  vention is characterized in that each of the contact means comprises: at least one integrated circuit, - input conductors which connect the integrated circuit to the first set of contact pads, and - output conductors which connect the integrated circuit to second set of contact pads, so that the number of input conductors, which is equal to the number of contact pads in the first corresponding set, is significantly smaller than the number of output conductors, which is equal to the number of contact pads in the second corresponding set.

  In a preferred embodiment of the invention,

  vention, the integrated circuits are fixed by their conductors on a thin carrier strip, so as to constitute components, called TAB components in

  the following, obtained by the self-transfer process

matic on tape (TAB).

  The invention provides remarkable advantages.

  in particular: - easy replacement of integrated circuits, - simplified installation of the printed circuit board and a reduced surface of the printed circuit board, while still providing an increase in the area A reserved for functional components (see Figure 2), - a reduction in linkage operations, by a factor of two, due to the fact that the integrated circuit is not mounted on the printed circuit board, - easier automation of the installation of the TAB components on the circuit board

  printed and a simplified adaptation to production

  tion in series, thanks to the larger solder pad areas on the printed circuit board in relation to the widths of the conductors of the TAB components,

  - easier realization of an elastic junction-

  tick required by thermal variations

at the junctions, and

  - greater overall reliability of the junction.

  In addition to the foregoing, the invention

  tion includes other provisions which stand out

  from the description which follows.

  The invention will be better understood using the

  further description below which refers to the

  attached sins in which: Figure 1 illustrates a display device according to the prior art;

  Figure 2 shows schematically an af-

  electroluminescent plug according to the invention, seen from the side of the printed circuit board; Figure 3 illustrates a detail of the structure shown in Figure 2, in side view and on a larger scale;

  Figure 4 shows half of a compound

  sant TAB illustrated in FIG. 2, in partial section and in top view from the side of the printed circuit board; FIG. 5 illustrates the connections of the TAB component, represented in FIG. 4, to the printed circuit board; and

  Figure 6 illustrates the connections of the

  posing TAB, shown in Figure 4, to the display panel. It should be understood, however, that these drawings and the corresponding descriptive parts are given solely by way of illustration of the subject of the invention of which they do not in any way constitute

a limitation.

  In the illustrated embodiment, a plate

  as glass 3, constituting an electroluminescent display panel, and a printed circuit board 1 are fixed to each other by means of a double-sided adhesive foam sheet 5 and a glass plate

encapsulation 6 (Figure 3).

  A TAB component 7, 10 is designed to allow

  be to directly connect the conductors 9 of an integrated circuit case 7 to contact pads H (FIG.

  3) on the rear face of the glass plate 3 of the pan-

  level of visualization. Likewise, conductors 8 of the integrated circuit case 7 are directly linked to

  contact pads G on the circuit board im-

  award-winning 1. Thus, the number of conductors (12 units) of the TAB component 7, 10 connected to the printed circuit board 1 is significantly smaller than the number of conductors (64 units) connected to the glass plate

  3 of the display panel. Therefore, the invention

  tion is advantageously implemented using the com-

  posing TAB 7, 10 which incorporates an integrated circuit 7.

  The integrated circuit 7, placed in the center of the

  laying TAB 7.10 (Figure 4), has a total number of 2 x 36 conductors leaving the integrated circuit, namely a set of 2 x 32 conductors (conductors 9) serving as actual signal conductors and a set

  of 2 x 4 conductors (conductors 16,17) serving as con-

  earth conductors. The contact pads E of the conduc-

  output sensors 9 have a pitch of 62 x 0.762 mm + 2 x 0.381 mm which is equal to the pitch of the contact pads on the glass plate 3 of the display panel. As a result, the rectangular contact pads E of the output conductors 9, having a pad area of 0.406 x 2,000 mm2, are compatible in size with the solder pads of the display panel 3 which are pre-coated with a

Welding alloy Sn60 / Pb40.

  The number of drivers entering the circuit

  integrated cook 7 is 2 x 4 conductors (conductors 8), these conductors being suitably linked. In

  in addition, 15 conductors (2 x 2 conductors) are used

  as earth conductors. Contact pads C

  and D of conductors 8 and 15 are also rectangular

  res with an area of 0.5 x 2.0 mm2 (C) and 1.0 x 2.0 mm2 (D), respectively. Conductors 8 and 15 of the

  Figure 4 are supplied by the following control signals

  wings (from left to right): - Vsc (GND) - Supply OK

- DATA OUTPUT

- POL - HVcc

- Vss (GND).

  Control signals connected to the conductors of

  the other half (not shown) of the symmetric TAB component

  plate 6 are, correspondingly and from right to left: - Vccl (12 V) - LE

- DATA INPUT

  - BL - HVcc - Vss (GND) The TAB component 7, 10 is fully supported by a carrier strip 10, 11 made of Kapton film which is used to place the component in a desired position. Matter

  of Kapton's film is a poly- type plastic

  imide having an average thickness of 150 Nm. The conduc-

  components of the TAB component 7.10 consist of a sheet

  copper, 35 Nm thick, coated with a layer of

  0.5 Nm thick Sn60 / Pb40 solder bond. The conductors 8 have a width of 0.5 mm, the conductors 15 have a width of 1.0 mm and the conductors 9 have a

  width of 0.406 mm. The smallest width of the conduc-

  teurs 8 and 9, which enter the integrated circuit 7 of a

  convergently, is 0.0965 mm.

  TAB component mounting technology

  applied in the invention is based on the method

  bare thin carrier strip, in which a

  carrier band or film, in a first stage. This pha-

  behaves the perforation of drive holes 16 'on the edge of the strip and the punching of cutouts 12, 13 and 14 which facilitate the detachment of the component

  TAB 7, 10 of the carrier strip. The second stage com-

  takes the stratification of the carrier strip with a thin sheet of copper and attacks a conductive configuration for conductors 8, 9, 15, 16 and 17 of the TAB component. In a third stage, the conductors are coated with a tin-lead alloy and stamped. The next phase is the internal linking operation of the

  conductors, which connects the integrated circuit 7 to the

  conductors of the TAB component. The fifth stage is the

  encapsulation of the integrated circuit 7 and the sixth stage, or operation of external connection of the conductors, comprises the installation and the connection of the TAB component 7, 10, comprising its encapsulated integrated circuit 7, so as to

  connect the glass plate 3 of the display panel

  tion to the integrated circuit board 1.

  To make the bond or weld,

  appropriately obstructs conductors 8 and 15 of the

  placing TAB 7, 10 on the contact pads G (FIG. 5) of the printed circuit board 1, while avoiding the coincidence of the edges of the carrier strip 10 and the

  printed circuit board 1. The pitch of the contact pads

  rectangular tact G on the circuit board im-

  award-winning 1 is 2.0 mm and the pad area is 2.0

  mm2. This leaves a significant margin for the position-

  the connection pads C of the conductors 8 on the

contact pads G on the board.

  The pitch of the conductors 9 of the TAB component 7, is equal to the pitch of the pre-coated contact pads H on

  the glass plate 3 of the display panel (fig.

  gure 6). The area of the contact pads H of the glass plate 3 of the display panel is larger than the area of the contact pads E of the conductors

  9, the studs H having a width of 0.5 mm and a length

  about 3.0 mm. The length of the studs

  conductor 9 tact is 2.0 mm. The black border line shown in Figure 6 represents a band

  of silicone 18, necessary in the manufacture of the pan-

  electroluminescent display 3.

  When the TAB component 7, 10 is detached from the carrier strip along its oblong cuts

  12 ... 14 (figure 4), its shape is substantially trapezoid

  zoidal, the input conductors 8 starting from the shortest

  parallel sides and the output conductors 9 par-

  both from the longest of these sides. This form of composition

  sants TAB 7,10 allows easy installation of the components

  adjacent poses, as shown in the illustration

figure 2.

  As is clear from the above, the information

  vention is by no means limited to those of its modes of

  implementation and application which have just been described more explicitly; on the contrary, she embraces

  all the variations that can come to mind from tech-

  nician in the matter, without departing from the framework or the

  scope of the present invention. So in addition to the ap-

  illustrated layout of the connection of a glass plate

  of electroluminescent display panel to one plate

  printed circuit board, the TAB component structure comprising an integral integrated circuit can be used in general for any application for connecting a component to a printed circuit board. In addition, several integrated circuits can be combined in the same

TAB component.

Claims (3)

Claims   1. Plan display device with internal circuits   integral tégrés (7), in particular a display device   electroluminescent plug, comprising - a printed circuit board (1) the edge of which comprises at least a first set (G) of contact pads, - a display panel (3), preferably   made of glass, which is placed at least sensitive-   parallel to the printed circuit board   mé (1) and spaced therefrom, and the edge of which   carries at least a second set (H) of contact pads,   - mounting means (5,6) placed between the plate -   printed circuit board (1) and the display panel   reading (3) for the physical fixing of the plate-   printed circuit board (1) and the display panel   reading (3), and - at least one set (7 ... 9) of contact means   comprising conductors (8, 9) for the connections   electrical elements between the first set (G) and the second set (H) of contact pads,   characterized in that each of the contact means comprises   takes: - at least one integrated circuit (7), - input conductors (8) which connect the integrated circuit (7) to the first set (G) of contact pads, and - output conductors (9) which connect the integrated circuit (7) to the second set (H) of contact pads, so that the number of input conductors (8), which is equal to the number of contact pads in the first corresponding set (G), is significantly smaller than the number of output conductors (9), which is equal to the number of contact pads in the second set corresponding (H).   2. Display device according to the claim   tion 1, characterized in that each of the contact means,   its integral integrated circuit (7) as well as the conduc-   input tores (8) and the output conductors (9) are attached to a thin film strip (10,11) to form a   single TAB component according to the trans- automatic band fert (TAB).   3. Display device according to the claims   cations 1 and 2, characterized in that the TAB components (7,10) have at least substantially a trapezoidal shape, so that the input conductors (8) protrude   on the smallest of the parallel sides and the conduc-   exit teurs (9) start from the longest of these sides.