TWI231876B - Package structure for a LCD driver IC - Google Patents

Abstract

A package structure for a LCD drive IC comprises a drive IC having a plurality of IC leads, a flexible carrier for packaging the drive IC thereon, and a LCD panel having a plurality of cell leads for bonding with the IC leads. The pitch between each IC leads and the area of IC leads increase from an alignment center gradually, and the pitch between each cell leads and the area of cell leads increase from the alignment center gradually. When the IC leads bond with the cell leads, the shift arose from the variation of temperature will be eliminated from increasing the pitch and area of leads.

Description

1231876 V. Description of the invention (1) * The technical field to which the invention belongs ... The present invention relates to a packaging structure for a liquid crystal display driver 丨 c, especially a method for combining a driving IC with a display panel by using a pin pressing technology . Previous technology: With the rapid advancement of thin film transistor (TFT-LCD) manufacturing technology, ^: equipped with ㈣, power saving, and no radiant rays, etc., make the liquid crystal display to be used in personal digital assistants ( PDA), notebook computers, digital computers: video cameras, video cameras, mobile phones and other electronic products. In addition, the investment in R & D and the use of large-scale production equipment have led to the continuous increase of σσ and σ scallops and the continuous decline in prices of liquid crystals. Therefore, the application area of liquid crystal displays has rapidly expanded. The board is shown in Fig. 1. It is a side view of the liquid crystal display module 2 of the conventional technology. It includes a display panel ",-backlight module 1 2,-soft shell carrier board 1, and a circuit board. 1 4 and a frame 1 5. The display panel 11 is composed of a glass substrate, and a plurality of liquid crystal cells are formed thereon, and each liquid crystal f has a pixel electrode, which is extended to an electrode panel 11 using an electrode pin. around. The backlight module 12 is located on the moon surface of the display surface 11: it is composed of light tubes, light guide plates, and reflective plates. The above 7L pieces can produce uniform light output to provide the display panel 11 required for displaying images The light source. The driver board is packaged with a driver 1C 16 using Tape Automated Bondings (TAB). The driver 10 1 6 can be used for gate & In an active way

Page 6 1231876 V. Description of the invention (2) Control the pixel electrode switch or provide a signal. In addition, there are a plurality of IC pins on the surface of the soft carrier board 1 (see Figure 2). One end of the IC pin is an inner pin and the other end is an outer pin. Combined with the bumps of c 1 6, the outer pins are extended around the soft carrier board 13 and connected to the electrode pins of the display panel 11 or the circuit board 14 respectively, and the frame 15 is installed. It is outside the LCD module 10 and protects its internal components from external forces. Please refer to FIG. 2, which is a schematic diagram showing the combination of the pins 2 1 outside the conventional soft carrier board 1 3 and the electrode pins 2 2 of the display panel 1. The outer pins 2 1 in the figure are arranged in a linear arrangement. Around the soft carrier board 13, the area (a) of each of the outer pins 21 is the same, and the distance (D) between any two adjacent outer pins 21 is the same. Similarly, the electrode pins 2 2 are also arranged around the display panel 1 1 in a linear arrangement. The area (A ′) of each electrode pin 2 2 is the same, and the distance between any two adjacent electrode pins 22 ( D) All the same 'where the area (A) of the outer lead 21 and the area (A') of the electrode lead 2 2 may be the same or different, but the distance (D) between the outer lead 21 and the electrode lead The distance between 2 and 2 (D) must be the same to ensure that each outer pin 2 1 can correspond to a pin electrode 2 2 in order to perform thermocompression bonding. When the outer bow 丨 foot 2 1 and the electrode pin 2 2 are thermally pressed, a layer of anisotropic conductive film 2 3 (ACF) is provided between the soft carrier plate 13 and the display panel 丨 丨There are a plurality of anisotropic conductive balls 24 inside. After the anisotropic conductive film 23 is heat-pressed, the inner anisotropic conductive balls 24 are connected to the outer pins 21 and the electrode pins 22 respectively, and the soft carrier 13 is driven. 1C is electrically connected to the pixel electrodes of the display panel 11.

Page 7 1231876 V. Description of the invention (3) However, the conventional technology must be aligned with the machine before thermocompression to ensure that the outer pin 2 1 and the electrode pin 2 2 can be correctly connected. The alignment method is mainly to select an external pin among the above external pins 21 as the alignment pin 2 1 a, and select the corresponding electrode pin among the above electrode pins 21 as the corresponding electrode pin. Counter electrode pin 2 2 a. Taking Figure 2 as an example, if a pin other than the middle is used as the counter pin 2 1 a, the electrode pin also located in the middle becomes the counter electrode pin 2 2 a, and the counter pin 2 1 a The pressing place with the counter electrode pin 2 2 a is the counter center. After the crimping machine determines that the alignment pins 2 1 a and the alignment electrode pins 2 2 a have been aligned, all the pins 2 1 and the electrode pins 2 2 are thermally crimped to make them soft. The ® driver IC on the carrier plate 1 3 and the pixel electrodes of the display panel 11 1 are electrically connected. Under ideal conditions, the conventional technology can indeed accurately combine each external pin with its corresponding electrode pin, but in fact, because the external pin and the electrode pin are respectively provided on a soft carrier board and a glass substrate, Above, the material of the soft carrier board is mainly a polymer film, and its thermal expansion coefficient is significantly higher than that of the glass substrate, so the change in thermal expansion and contraction is also larger than that of the glass substrate. However, because the conventional technology does not consider the difference in thermal expansion coefficients of different materials, in addition to the precise alignment of the alignment pins and the electrode pins, the remaining external pins and electrode pins are subject to temperature changes. Effect, there will be a phenomenon of U-bit offset, especially the farther away from the center of the alignment, the more obvious the phenomenon of alignment offset, and the result will occur between the outer pin and the electrode pin Open or short circuit. Please refer to FIG. 3A, which shows that the pin 2 1 and the electrode pin 2 2 outside the conventional technology are not pressed properly due to a change in temperature during the thermocompression bonding process.

Page 8 1231876 V. Description of Invention (4). It can be seen from the figure that the thermocompression-bonding offset phenomenon of the outer pin 2 1 and the electrode pin 2 2 gradually increases outward from the center of the alignment, wherein the alignment pin 2 1 a and the counter electrode Pin 2 2 a is the center of the alignment, so there will be no offset during the compression. On the other hand, the farther away from the center of the alignment, the offset caused by the compression will increase significantly. . If the outer pin 2 1 and the electrode pin 2 2 are staggered and out of contact because of too much offset, or because the contact area of the outer pin 2 1 and the electrode pin is too small to catch the anisotropic conductive ball 2 4 to form If it is turned on, it will be disconnected. In addition, if the external pin 2 1 is in contact with the electrode pins 22 on the two sides due to bit shift, or the electrode pin 2 2 is separated due to bit shift. If it comes into contact with the pins 2 1 other than the two sides, a short circuit will occur. Figure 3B shows the expansion of the outer pin 21 during the thermocompression process, which is smaller than the alignment of the electrode pin 22. In view of the fact that the current manufacturing technology of electronic components inside liquid crystal displays is becoming more and more precise, relatively, the requirements for the area of IC pins and the distance between IC pins are becoming more and more precise. The misalignment misalignment caused by the combination not only prevents the product yield from being effectively improved, but also prevents the IC pin design from becoming more sensitive, which in turn affects the product quality. Summary of the invention: il

1231876 V. Description of the invention (5) Including a driving IC, a soft carrier board and a display panel. Driver IC junction. Combined on the soft carrier board, the driver IC surface is provided with a plurality of bumps, the soft carrier board is provided with a plurality of IC pins, one end of which is an inner pin and the other end is an outer pin, soft The carrier board is combined with the inner pins and the bumps of the driving IC, and the outer pins are distributed around the soft carrier board in a linear arrangement. The display panel is composed of a glass substrate, and a plurality of liquid crystal cells (cel 1) are provided thereon. Each of the liquid crystal cells has a pixel electrode, and an electrode pin is used to extend around the display panel. The electrode pins are also distributed around the display panel in a linear arrangement so as to be thermocompression-bonded to the IC pins around the soft carrier board. The outer pin has a pair of ® bit pins, and the electrode lead has a pair of bit electrode pins, which correspond to the pin pins. The junction is the counterpoint center. The present invention is characterized in that the area of the outer pin and the electrode pin gradually increases outward from the center of the alignment, and at the same time, the distance between each pin and each electrode pin gradually increases outward from the center of the alignment to compensate Due to the temperature change between the soft carrier board and the display panel, the alignment offset between each pin and its corresponding electrode pin is caused. During the thermocompression process, the alignment pin and the alignment electrode pin 4 are used as the alignment center, so the temperature change is caused by the alignment deviation caused by the thermal compression for the soft carrier board and the display panel. The shifting system gradually increases outward from the center of the alignment. However, as disclosed in the present invention, the area of the outer pins and electrode pins gradually increases outward from the center of the alignment, and the distance between the outer pins and the distance between the electrode pins gradually increases outward from the center of the alignment. , Which increases

Page 10 1231876 V. Description of the invention (6) The added part can exactly compensate the misalignment of each pin and its corresponding electrode pin due to temperature-part change, so that each pin of the flexible carrier board has It can accurately align the corresponding electrode pin on the display panel to avoid short circuit or open circuit. In order to allow your reviewers to have a better understanding and recognition of the purpose, features and effects of the present invention, the detailed description with the drawings is as follows: Brief description of the drawings: Figure 1 is a conventional LCD display module Side view of the group; Figure 2 is a schematic diagram of the alignment of the pin and the electrode pin outside the conventional technology; β Figures 3A and 3B are the conventional technology because the outer pin and the electrode are in the case of temperature changes Schematic diagram of pin misalignment; Figures 4A and 4B are schematic diagrams of the packaging structure of a liquid crystal display driver IC of the present invention, and Figure 5A is the process of thermal compression bonding of the present invention. Alignment of pins; Figure 5B In the process of the present invention, the expansion phenomenon of the outer pins is smaller than that of the electrode pins. ❸ 1 1 ~ Display panel 1 3 ~ Soft carrier board 1 5 ~ Frame 2 1 ~ Outer pin 23 ~ Anisotropic conductive film pattern drawing number description: 1 0 ~ LCD module 1 2 ~ Backlight module 1 4 ~ Circuit board

1 6 to drive I C 2 2 to electrode pins

Page 11 1231876 V. Description of the invention (7) 24 ~ Anisotropic conductive ball 4 1 1 ~ Bump 4 3 ~ Display panel 44 BU bow | foot 4 5 ~ electrode pin 4 5 a ~ counter electrode pin 4 6 ~ Package 4 8 ~ Anisotropic conductive ball 4 1 ~ Driver IC 4 2 ~ Soft carrier board 4 4 ~ IC pin 4 4 2 ~ Xibu pin 4 4 2a ~ Outer pin 0 ~ Center 4 ~ Circuit board 4 9 ~ Frame adhesive implementation: The present invention discloses a packaging structure for a liquid crystal display drive IC. Its purpose is to make sure that the pins outside the drive IC and the electrode pins of the display panel can be reliably pressed together. Alignment shift due to temperature change. The application scope of the present invention includes, but is not limited to, the technical fields of tape auto-bonding (TAB), die soft film bonding (C 0 F), or flexible circuit board (FPC). However, for convenience of explanation, the present invention will use TAB packaging technology. As a preferred embodiment, the following describes the related embodiments of the present invention in detail. Please refer to FIG. 4A, which is a schematic diagram of a packaging structure of a liquid crystal display driving IC according to the present invention. The packaging structure of the present invention includes a driving I c 4 1, a flexible carrier board 4 2 (T ape), and a display panel. 4 3. The driving IC 4 1 can be a gate control chip or a source control chip, and actively control the pixel electrode switch or provide a signal. A plurality of bumps 41 1 (bumps) are provided on the surface of the driving 1C 41. The material of the soft carrier plate 42 is mainly a polymer film, and a plurality of I C pins are arranged thereon. 4 4

Page 121231 V. Description of the invention (8) (Lead), each 1C pin 44 includes an inner pin 441 and an outer pin 4 4 2 in which the driving IC 41 and the soft carrier 4 2 are combined As a whole, the inner pins 4 4 1 are respectively coupled to the bumps 4 1 1 of the driving IC 4 1, and the outer pins 44 2 extend to the periphery of the flexible carrier board 42 and are arranged linearly so as to The display panel 43 is thermocompression-bonded (as shown in Fig. 4b). Among the outer pins 4 4 2, the outer pin 4 4 2 in the middle is usually used as the alignment pin 44 2a 'the area of each outer pin 4 42 and the distance between each outer pin 44 2 It gradually increases outward from the alignment pin 442a. The display panel 4 3 is composed of a glass substrate with a plurality of liquid crystal cells (ce 1 1), each of which has a pixel electrode, and _ is extended to the display with an electrode pin 4 5 Around the panel 43, the above-mentioned electrode pins 45 are also linearly arranged and correspond to the outer pins 4 42 so as to be able to be interconnected with the 1C pins 44 around the soft carrier board 42. The above-mentioned electrode pin 45 also uses the middle electrode pin as the counter-electrode pin 45 &, which corresponds to the counter-pin 4 42a of the soft substrate 42. In addition, the area of each of the above-mentioned electrode pins 45 And the distance between each electrode pin 45 is gradually increased outward from the counter electrode pin 45a (as shown in FIG. 4b).

Please refer to Figs. 5A and 5B. In the present invention, when pressing by a machine, the invention uses the combination of the alignment pin 442a and the alignment electrode pin 45a as the neutral position. The bit pin 4 仏 is aligned with the counter electrode pin 45a, and f is then pressed on each outer pin 44 2 and each electrode pin 45. From the description of the prior art, it can be seen that the hot-bonded central pin 44 2 a and the counter electrode pin 45 a can be accurately aligned. In addition, the other outer pins 442 and the electrode pin 45 will be affected. Temperature change

1231876 V. Explanation of the invention (9) will cause registration offset, especially the farther away it is from the registration center, the higher the offset will be. However, due to the feature of the present invention, the areas of the outer pin 4 4 2 and the electrode pin 4 5 are gradually increased outward from the center of the alignment, thereby increasing the contact area of the pin 44 2 and the electrode pin 45 provided outside the outer side. In order to avoid that the outer pins 4 4 2 and the electrode pins 4 5 are disconnected because the contact area is too small, the increased area is to compensate for the heat generated by the outer pins 442 and the electrode pins 45 due to changes in heat. Alignment offset is the principle. In addition, another feature of the present invention is that the distance between the outer pin 442 and the electrode pin 45 is gradually increased outward from the center of the alignment, so that each outer pin 4 4 2 and the electrode pin on the side thereof · 4 5 Increase the distance, or increase the distance between each electrode pin 45 and its outer pins 442 to prevent the outer pins 44 2 from coming into contact with the electrode pins 45 on their sides due to misalignment, or The electrode pin 45 is short-circuited due to the misalignment due to the contact with the pins 4 4 2 on the side. The increased distance is to compensate for the difference between the outer pin and the electrode pin due to temperature changes. Bit offset is the principle. Among them, Figure 5B shows the expansion of the outer pin 4 4 2 during the thermocompression bonding process, which is smaller than the alignment of the electrode pin 45. It is worth mentioning that although the increase in the distance between the outer pins and the outer pin area may increase the overall area of the flexible carrier board, since the invention uses the center of the alignment 4 as the alignment reference, in theory, the alignment guide The alignment of the foot and the counter electrode pin is the most accurate and the offset is the smallest, so the area of the counter pin and the counter electrode pin can be reduced to the minimum area required to catch the opposite conductive ball. Therefore, the present invention can reduce the area of the pins outside the center of the alignment (including the pitch) and reduce the area of the pins outside the center of the alignment at the same time.

Page 14 1231876 V. The description of the invention (including the distance) is increased, so that the overall area of the flexible carrier board will not change much. In summary, the package structure of the driving IC disclosed in the present invention can make the pin design more precise, and can improve the reliability of pin pressing. Of course, the present invention is not limited to the packaging structure of a liquid crystal display driver IC. Any person skilled in the art will not violate the spirit of the present invention and apply the present invention to the pin thermocompression technology of electronic components of two different materials. It should belong to the scope of the present invention, so the protection scope of the present invention should be based on the scope of patent application described below.

Page 1231876 Brief description of the drawings * Brief description of the drawings: Figure 1 is a side view of a liquid crystal display module of conventional technology; Figure 2 is the alignment of pins and electrode pins outside the conventional technology Schematic diagrams; Figures 3A and 3B are conventional techniques because of the misalignment between the outer pin and the electrode pin due to temperature changes; Figures 4A and 4B are liquid crystal displays of the present invention. The package structure of the driver IC is not intended; Figure 5A: The expansion of the outer pins is larger than that of the electrode pins during the thermocompression process; > Figure 5B: The process of the invention during thermocompression The expansion of the outer pins is smaller than the case of the electrode pins.

Page 16

Claims (1)

I Fine coffee book 1 round * Application for patent scope 1. A packaging structure of LCD driver IC, including 1C, its carrier board, pins, the above pins and the outside of the panel board are opposite The pair will be described above: The above-mentioned changes in the outer gradual pins are patented in the electrical film, the above-mentioned external connection. Please patent a driver IC, the surface of which is provided with a plurality of bumps; a soft carrier board, including a plurality of IC pins and one of the IC pins as an alignment of the above-mentioned outer pins; a display of a soft carrier The pins are centered, and their characteristic centers are directed to the electrodes to compensate because of the temperature. 2. Rushen structure, anisotropic conductive balls, ball conduction 3. Rushen, each IC pin has an inner pin and an inner lead The pins are respectively coupled to the bumps of the driving IC, and extend linearly to the periphery of the soft carrier board. A plurality of electrode pins are arranged around the pins and correspond to the pins, respectively. The electrical pin of the pin, the soft carrier board, the pin of the display panel and the pin of the counter electrode are aligned as the middle pin and the outer pin, and the outer pin and the electrode lead are pressed together. The area of the foot is increased by the alignment, and the distance between the pins and the distance between the pins are gradually increased outward from the center of the alignment. When the outer pins and the corresponding electrode pins are pressed together, The bit offset. In the package of the liquid crystal display drive IC described in the first item, a layer is provided between the outer pin and the electrode pin, and there are a plurality of anisotropic pins and the electrode pin inside the anisotropic conductive film. Package of liquid crystal display driver IC described in item 2 of anisotropic conduction range Page 17 1231876 VI. Scope of patent application Structure, in which the area of the registration pin and the registration electrode pin is the minimum area required to be able to catch the anisotropic conductive ball during lamination. 4. The packaging structure of a liquid crystal display driver IC as described in item 1 of the scope of the patent application, wherein the material of the soft carrier board is a polymer film, and the display panel is a glass substrate with a plurality of pixels provided thereon electrode. 5. The packaging structure of the LCD driver IC as described in item 4 of the patent application scope, wherein the driver IC is a gate control chip or a source control chip, and actively controls the pixel electrode switch and provides a signal. 6. The packaging structure of the LCD driver IC according to item 1 of the scope of the patent application, wherein the soft carrier board is provided with an IC pin in the middle as an alignment pin, and the display panel is also provided in the middle The electrode pin is used as the counter electrode pin. 7. The packaging structure of the liquid crystal display driving IC as described in item 1 of the patent application scope, wherein the soft carrier board is packaged with the driving IC using a tape and tape automatic bonding technology (TAB). 8. The packaging structure of the liquid crystal display driving IC as described in item 1 of the scope of patent application, wherein the soft carrier board is packaged with the driving IC using die-bonding film bonding technology (COF). Page 18 also replaces i Seven years ^ 1§. Ί 0 3 > l