The present application relates to the technical field of display, in particular to a display panel, a preparation method thereof and a display device.
Now, mobile phones have entered an era of full screens, and all large mobile phone manufacturers are pursuing extreme full screens and a high screen-to-body ratio. A left narrow frame and a right narrow frame are mature, and an upper frame can be achieved through a bangs screen, a water drop screen or even a lifting camera. In the process of pursuing the full screens, the width of a lower frame becomes the maximum bottleneck limiting the improvement of the screen-to-body ratio. Therefore, how to realize an ultra-narrow lower frame is an urgent technical problem to be solved for current display panels.
The present application discloses a display panel, a preparation method thereof and a display device, which are configured to provide an ultra-narrow frame solution of a rigid display panel.
A display panel includes:
a base substrate which is rigid;
a flexible insulating layer including a first part and a second part, the first part being disposed on the base substrate, and the second part exceeding a side edge of the base substrate; and
an integrated circuit chip and a flexible printed circuit respectively bonded and connected with the second part of the flexible insulating layer.
Optionally, the flexible printed circuit is located on a side, away from the first part of the flexible insulating layer, of the integrated circuit chip.
Optionally, the base substrate includes a display region and a connecting region on a side of the display region.
A projection of the first part of the flexible insulating layer on the base substrate is in the connecting region, and the second part exceeds a side edge of the connecting region of the base substrate.
Optionally, a width of the connecting region in a direction away from the display region ranges from 200 μm to 400 μm; and a width of the first part in the direction away from the display region ranges from 200 μm to 300 μm.
Optionally, the display panel further includes a buffer layer disposed on a side, away from the base substrate, of the flexible insulating layer, and the buffer layer completely covers a surface of the side, away from the base substrate, of the flexible insulating layer.
Optionally, a projection of a part, arranged over the base substrate, of the buffer layer on the base substrate is in the connecting region.
Optionally, the display panel further includes a drive circuit disposed on a side, away from the base substrate, of the buffer layer.
Optionally, a material of the flexible insulating layer is polyimide; and a material of the base substrate is glass.
Optionally, the display panel further includes a color film substrate, and a side edge, close to the second part of the flexible insulating layer, of the color film substrate is aligned with the side edge of the base substrate.
Optionally, the second part of the flexible insulating layer is bent to a side, facing away from the first part of the flexible insulating layer, of the base substrate.
A display device includes any one of the above mentioned display panels.
Optionally, the display device further includes a circuit board located on a side, facing away from the first part of the flexible insulating layer, of the base substrate.
The second part of the flexible insulating layer is bent to the side, facing away from the first part of the flexible insulating layer, of the base substrate.
The integrated circuit chip is electrically connected with the circuit board.
A method for preparing a display panel includes:
providing a base substrate which is rigid, wherein the base substrate includes a first region and a second region on a side of the first region;
forming a flexible insulating layer on the base substrate, wherein the flexible insulating layer includes a first part on the first region and a second part on the second region;
bonding an integrated circuit chip and a flexible printed circuit on the second part of the flexible insulating layer respectively;
stripping the second part of the flexible insulating layer from the second region of the base substrate; and
cutting off the second region of the base substrate.
Optionally, the first region includes a display region and a connecting region, and the connecting region is located between the display region and the second region.
The forming the flexible insulating layer on the base substrate includes:
forming the flexible insulating layer on the connecting region and the second region of the base substrate.
Optionally, the forming the flexible insulating layer on the base substrate includes:
forming the flexible insulating layer on the base substrate in a silk-screen printing process.
Optionally, before bonding the integrated circuit chip and the flexible printed circuit on the second part of the flexible insulating layer, the method further includes:
forming a pattern of a drive circuit on the base substrate in an array process.
Optionally, before forming the pattern of the drive circuit on the base substrate in the array process, the method further includes:
forming a buffer layer on the flexible insulating layer, wherein a projection of the buffer layer on the base substrate encompasses a projection of the flexible insulating layer on the base substrate.
Optionally, the stripping the second part of the flexible insulating layer from the second region of the base substrate includes:
stripping the second part of the flexible insulating layer from the second region of the base substrate by adopting a laser lift off technology.
Optionally, the cutting off the second region of the base substrate includes:
cutting the base substrate along a boundary line between the first region and the second region from a side, away from the flexible insulating layer, of the base substrate, wherein a cutting depth is smaller than a thickness of the base substrate; and
separating the first region and the second region of the base substrate along the boundary line by external force.
Optionally, after cutting off the second region of the base substrate, the method further includes:
bending the second part of the flexible insulating layer to a side, facing away from the first part of the flexible insulating layer, of the base substrate for packaging.
The technical solution in embodiments of the present disclosure will be described clearly and fully hereinafter in combination with the accompanying drawings in the embodiments of the present disclosure. It is apparent that the described embodiments are only part of the embodiments of the present disclosure, not all embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those ordinarily skilled in the art without involving any inventive effort are within the scope of protection of the present disclosure.
As shown in
a rigid base substrate 1;
a flexible insulating layer 2, including a first part 21 and a second part 22, wherein the first part 21 is disposed on the base substrate 1, and the second part 22 exceeds a side edge of the base substrate 1; and
an integrated circuit chip (IC) 3 and a flexible printed circuit (FPC) 4 which are respectively bonded and connected with the second part 22 of the flexible insulating layer 2.
According to the above display panel, the flexible insulating layer 2 is disposed on the rigid base substrate 1, the first part 21 of the flexible insulating layer 2 is disposed on the base substrate 1, and the second part 22 extends a side edge of the base substrate 1 and is bonded with the IC 3 and the FPC 4. In a display cell preparation stage, the second part 22 of the flexible insulating layer 2 can be bent to a back surface of the base substrate 1 for packaging as shown in
Specifically, as shown in
In some embodiments, a material of the flexible insulating layer 2 may be polyimide (PI); and a material of the base substrate 1 may be glass.
In some embodiments, the base substrate 1 includes a display region AA and a connecting region BB located on a side of the display region AA. A projection of the first part 21 of the flexible insulating layer 2 on the base substrate 1 is in the connecting region BB and the second part 22 extends a side edge of the connecting region BB of the base substrate 1. That is, there is no flexible insulating layer 2 on the display region AA of the base substrate 1, and the flexible insulating layer 2 is disposed only on a frame region (the connecting region BB) on a side of the display region AA and partially exceeds the frame region.
Furthermore, only simple signal wires are disposed on the flexible insulating layer 2, and pixels do not need to be prepared on the flexible insulating layer 2 like in the display region AA, so that the requirement for the surface of the flexible insulating layer 2 is not high, the requirement for a process of preparing the flexible insulating layer 2 on the base substrate 1 is simple, and the process can be realized through conventional silk-screen printing and other processes. Therefore, slit coating equipment in a flexible OLED preparation process does not need to be purchased, so that the cost of the scheme is greatly reduced.
Specifically, the above-mentioned ‘display region’ and ‘connecting region’ of the base substrate, and the later-referred ‘first region’ and ‘second region’ all refer to respective part structures of the base substrate in the extending direction, and do not represent a region range.
In some embodiments, when the display panel of the embodiment of the present application is applied to a mobile phone display cell, a width d of the connecting region BB in a direction away from the display region AA may be designed to be about 200 μm to 400 μm. The width is much smaller than a width (greater than 1 mm) of a bonding region of the COF. Further, a width of the first part 21 of the flexible insulating layer 2 in a direction away from the display region AA may be about 200 μm to 300 μm.
In some embodiments, as shown in
Further, the display panel of some embodiments of the present application further includes a drive circuit disposed on a side, away from the base substrate 1, of the buffer layer 5.
Specifically, the drive circuit in some embodiments of the present application includes all pattern structures required for implementing pixel driving, including pixel circuits within the display region AA, metal wires extending to the flexible insulating layer 2, connection terminals located on the second part 22 of the flexible insulating layer 2 and used for being bonded with the IC 3 and the FPC 4 or the like, for example, as shown in
Specifically, the flexible insulating layer 2 has strong water absorption capacity, the buffer layer 5 is disposed before the drive circuit (including the metal wires) is formed, the flexible insulating layer 2 and a drive circuit layer are isolated through the buffer layer 5, water vapor can be effectively blocked, and corrosion of the metal wires in the drive circuit is prevented.
Exemplarily, a material of the buffer layer 5 may include silicon nitride (SiNx), silicon oxide (SiOx), or a combination thereof. Specifically, silicon nitride (SiNx) has a good water vapor insulating effect, silicon oxide (SiOx) is relatively soft, and the SiNx and the SiOx are very suitable for being prepared on the flexible insulating layer 2.
Exemplarily, as shown in
Specifically, as shown in
In some embodiments, as shown in
Exemplarily, as shown in
Existing LCD narrow frame processes all need to perform a bonding process (such as IC and/or FPC bonding) in a frame region of the array substrate, so that edges, on the side of the bonding region, of the color film substrate and the array substrate cannot be aligned, and the color film substrate needs to be cut to expose the bonding region of the array substrate. According to the LCD panel provided by the embodiments of the present application, since the IC 3 and the FPC 4 are bonded on the second part 22 of the flexible insulating layer 2 and the second part 22 exceeds the frame edge of the base substrate 1, part of the frame of the base substrate 1 does not need to be exposed for bonding, and therefore the edges, on the side of the bonding region, of the color film substrate 6 and the array substrate of the display panel of the embodiments of the present application can be aligned, and thus the overall appearance and process of an LCD cell are improved.
Of course, the display panel of the embodiments of the present application may also be designed according to a conventional scheme at present, as shown in
In some other embodiments, the display panel of the embodiments of the present application may be a rigid OLED. In this situation, the base substrate is configured to be a base substrate of a drive back plate of the OLED.
In some embodiments, as shown in
Specifically, embodiments of the present application further provide a display device, and the display device includes the display panel according to any one of the above embodiments.
In some embodiments, as shown in
Specifically, under the condition that the display device is a liquid crystal display (LCD), the display device is provided with a backlight source, a circuit board is arranged on a side, facing away from the display panel, of the backlight source, and the second part of the flexible insulating layer is bent to a back surface of the backlight source for packaging. Under the condition that the display device is an organic light emitting display (OLED), no backlight source exists, the circuit board is directly disposed on the back surface of the display panel, and the second part of the flexible insulating layer is directly bent to the back surface of the display panel for packaging.
Specifically, based on the display panel provided by the embodiments of the present application, embodiments of the present application further provides a method for preparing a display panel, and as shown in
step 101, a rigid base substrate is provided, the base substrate includes a first region and a second region on a side of the first region.
step 102, a flexible insulating layer is formed on the base substrate, the flexible insulating layer includes a first part on the first region and a second part on the second region.
step 103, an integrated circuit chip (IC) and a flexible printed circuit (FPC) are respectively bonded on the second part of the flexible insulating layer.
step 104, the second part of the flexible insulating layer is stripped from the second region of the base substrate.
step 105, the second region of the base substrate is cut off
Specifically, in the above preparation method, when bonding the IC and the FPC on the flexible insulating layer, since the rigid base substrate is provided under the flexible insulating layer, the process does not have the difficulty of flexible bonding, that is, in the process of pressing the IC or the FPC through a bonding apparatus to perform the bonding connection, crimping between the IC or the FPC and connection terminals can be more easily implemented due to the presence of the rigid base substrate, the yield of crimping is better, and a COG bonding process of a traditional LCD production line can be adopted. Moreover, after the bonding is finished, the second part of the flexible insulating layer is stripped off, and then the stripped base substrate region is cut, so that the first part, which is not stripped, of the flexible insulating layer still has strong bonding force with the base substrate, a COF bonding process can be replaced, and the function of the COF can be replaced with the flexible insulating layer.
According to the display panel formed by the above preparation method, as shown in
In addition, the above preparation method specifically includes various processes such as flexible film deposition, bonding, flexible film stripping, and base substrate cutting, so that the preparation method is implemented only by adopting part of the process in COG packaging and a simple flexible deposition process, the process is simple, compared with the COF packaging scheme, the defect of COF resource shortage can be avoided, the yield loss problem caused by the COF bonding process can also be avoided, and the practicability is high. Specifically, the preparation method of the display panel can be simultaneously suitable for the rigid OLEDs and the rigid LCDs, so that the rigid OLEDs and the rigid LCDs still have strong competitiveness in the era of full screens.
In some embodiments, a material of the flexible insulating layer 2 may be polyimide (PI); and a material of the base substrate 1 may be glass.
In some embodiments, as shown in
In some embodiments, in step 102, forming the flexible insulating layer 2 on the base substrate 1 may specifically include: forming the flexible insulating layer 2 on the base substrate 1 by adopting a silk-screen printing process.
Specifically, after patterns of the flexible insulating layer 2 are formed by adopting the printing process, the flexible insulating layer 2 may also be subjected to thermal curing treatment.
Specifically, since there is no flexible insulating layer 2 in the display region AA, pixels do not need to be prepared on the flexible insulating layer 2, and only simple signal wires are provided, so that the requirement for the surface of the flexible insulating layer 2 is not high, and the process can be realized through conventional silk-screen printing and other processes. Therefore, slit coating equipment in a flexible OLED preparation process does not need to be purchased, so that the cost of the scheme is greatly reduced.
In addition, the edge(s) of the flexible insulating layer 2 formed in the silk-screen printing process has/have a certain slope angle, so that wire breakage caused when the wires pass through the junction of edges of a PI film is prevented.
In some embodiments, before step 103, that is, before the IC and the FPC are bonded on the second part of the flexible insulating layer, the method may further include the following step.
As shown in
Specifically, the drive circuit in the embodiments of the present application specifically includes all pattern structures required for implementing pixel driving, including pixel circuits (not shown in figures) within the display region AA, metal wires (not shown in figures) extending to the flexible insulating layer 2, connection terminals located on the second part 22 of the flexible insulating layer 2 used for being bonded the IC and the FPC or the like. For example, as shown in
In some embodiments, before the patterns of the drive circuit are formed on the base substrate in the array process, the method may further include the following step.
As shown in
Specifically, the flexible insulating layer 2 has strong water absorption capacity, the buffer layer 5 is arranged before the drive circuit (including the metal wires) is formed, the flexible insulating layer 2 and a drive circuit layer are isolated through the buffer layer 5, water vapor can be effectively blocked, and corrosion of the metal wires in the drive circuit is prevented.
Exemplarily, a material of the buffer layer 5 may include silicon nitride (SiNx), silicon oxide (SiOx), or a combination thereof. Specifically, silicon nitride (SiNx) has a good water vapor insulating effect, silicon oxide (SiOx) is relatively soft, and the SiNx and the SiOx are very suitable for being prepared on the flexible insulating layer 2.
Exemplarily, as shown in
Specifically, as shown in
In some embodiments, after the patterns of the drive circuit are formed on the base substrate in the array process, a cell process may also be performed. For example, for the LCD panel, processes such as liquid crystal drop and aligning may be included; and for the OLEDs, processes of depositing a light emitting unit film layer, preparing a packaging layer and the like are included.
In some embodiments, in step 104, stripping the second part of the flexible insulating layer from the second region of the base substrate specifically includes:
the second part of the flexible insulating layer is stripped from the second region of the base substrate by adopting a laser lift off (LLO) technology.
In some embodiments, in step 105, cutting off the second region of the base substrate specifically includes:
the base substrate is cut along a boundary line between the first region and the second region from a side, facing away from the flexible insulating layer, of the base substrate, wherein a cutting depth is smaller than a thickness of the base substrate; and
after the cutting operation, the first region and the second region of the base substrate are separated along the boundary line by external force, specifically, the base substrate can be directly broken along the boundary line between the first region and the second region. In this way, damage to the flexible insulating layer by the cutting operation can be avoided.
As shown in
Further, before step 103, that is, before the IC and the FPC are bonded on the second part of the flexible insulating layer, the method further includes the following step.
The large-sized substrate 8 is divided by a cutting process to obtain the independent base substrates 1.
Specifically, as shown in
Specifically, in case of the LCD panel, in the substrate cutting process, the edge of the color film substrate may be cut inward to expose the connecting region of the base substrate as in a conventional cutting operation. Since the connecting region does not need a bonding operation, the cutting edge of the color film substrate can be aligned with the cutting edge of the base substrate in the cutting process.
Specifically, after the large-sized substrate is divided by the cutting process to obtain the independent display cells, each display cell is subjected to the bonding process, that is, the IC 3 and the FPC 4 are bonded on the second part 22 of the flexible insulating layer 2 as shown in
Specifically, as shown in
In some embodiments, in step 105, after the second region of the base substrate is cut off, the method further includes the following steps: as shown in
Specifically, as shown in
Although preferred embodiments of the present application have been described, additional variations and modifications of these embodiments will be made by those skilled in the art upon attaining the basic inventive concept. Therefore, it is intended that the appended claims are interpreted as including the preferred embodiments and all variations and modifications that fall within the scope of the present application.
It will be apparent to those skilled in the art that various changes and variations can be made to the embodiments of the present application without departing from the spirit or scope of the embodiments of the present application. Thus, the present application is also intended to cover the changes and variations of the embodiments provided if they fall within the scope of the appended claims of the present application and their equivalents.
The present application is a national phase entry under 35 U.S.C. § 371 of International Application No. PCT/CN2019/114889, filed on Oct. 31, 2019.
Filing Document | Filing Date | Country | Kind |
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PCT/CN2019/114889 | 10/31/2019 | WO | 00 |