TW201943031A - Chip-on-film package structure - Google Patents

Abstract

A chip-on-film package structure includes a flexible substrate, a plurality of leads, two chips, a buffer component, and an encapsulant. The leads are disposed on the flexible substrate and extend outwardly from a chip bonding area. The two chips are arranged side by side in the chip bonding area, and are respectively electrically connected with the leads. Each chip has an active surface, a back surface opposite to the active surface, and a plurality of side surfaces connecting the active surface and the back surface. These side surfaces include a short side surface connecting a short side of the active surface. The two chips are arranged side by side with their short side surfaces facing each other. The buffer component is disposed on the flexible substrate and between the two chips. The encapsulant at least fills in the space between each chip and the flexible substrate and covers the side surfaces of each chip. The buffer component is coupled to the two chips through the encapsulant.

Description

Thin-film flip-chip packaging structure

The present invention relates to a packaging structure, and more particularly, to a thin-film flip-chip packaging structure.

Because liquid crystal displays have the advantages of low power consumption, light weight, high resolution, high color saturation, and long life, they are widely used in mobile phones, notebook computers or desktop computers, LCD screens, and LCD TVs. Electronics related to life. In order to cope with the ultra-high amount of electrical signal transmission in liquid crystal display devices, tape automatic bonding (TAB) technology is currently commonly used to drive chip packaging, and the chip on film (COF) packaging structure is One of them is a package structure using a tape and reel automatic bonding technology.

With the continuous advancement of technology, the functional requirements of electronic products are also increasing, so the volume and circuit density of the chip must be continuously improved, as is the driving chip of the liquid crystal display device. The high number of I / O endpoints on the driver chip of the liquid crystal display device makes the configuration of the I / O endpoints concentrated on the opposite sides of the active surface of the chip. Therefore, the shape of the driver chip is designed to be a slender type with a large difference in width. To accommodate more I / O endpoints, the length of the driver chip must also be increased. However, although a growing wafer can increase the number of endpoints, an elongated wafer that is too long is very easy to break and difficult to handle. Therefore, two side-by-side wafers are used instead of one extension wafer. However, when there are no barriers between the two side-by-side wafers, bending of the flexible substrate may cause the two side-by-side wafers to collide and squeeze each other. When the filling and encapsulating gel is used as a barrier between two wafers, and because the position between the two wafers lacks support, the encapsulating colloid filled in it shrinks when curing, resulting in the entire thin-film flip-chip packaging structure being generated between the two wafers. The phenomenon of warping downwards and upwards on both sides may also cause the two chips to collide and squeeze each other, which in turn affects the reliability of electronic products.

The invention provides a thin-film flip-chip packaging structure, which can avoid warping and cause two chips side by side to collide with each other and squeeze, and can have better reliability.

The thin-film flip-chip packaging structure of the present invention includes a flexible substrate, a plurality of pins, two chips, a buffer, and a packaging gel. The flexible substrate has a wafer bonding area. A plurality of pins are disposed on the flexible substrate and extend outward from the wafer bonding area. The two chips are arranged side by side in a wafer bonding area of a flexible substrate, and these pins are electrically connected respectively. Each wafer has an active surface, a back surface opposite the active surface, and a plurality of side surfaces connecting the active surface and the back surface. These side surfaces include short side side surfaces that connect the short sides of the active surface. The two wafers are arranged side by side with the short side surfaces facing each other. The buffer is disposed on the flexible substrate and is located between the two wafers. The encapsulant is filled at least between each wafer and the flexible substrate and covers these side surfaces of each wafer. The buffer member is coupled to the two chips through the packaging gel.

Based on the above, the thin-film flip-chip packaging structure of the present invention utilizes a buffer member disposed between the short side surfaces of two wafers arranged side by side, so as to provide a barrier and support at a position between the two wafers, and then filled with a packaging gel. The region between the short side surface of each wafer and the buffer member is used to strengthen the relative position between the buffer member and each wafer and to strengthen the hardness of the region between the two wafers. The buffer member provides a barrier and support between the two wafers, which can prevent the two wafers from colliding and squeezing due to the warpage of the thin-film flip-chip packaging structure due to the curing and shrinkage of the packaging colloid. In addition, due to the arrangement of the buffer, the amount of the encapsulating gel filled between the two wafers is reduced, so that the shrinkage of the encapsulating gel is reduced accordingly. In this way, warpage of the thin-film flip-chip packaging structure can be avoided, which can cause two wafers to collide and squeeze with each other, thereby improving the reliability of the thin-film flip-chip packaging structure.

In order to make the above features and advantages of the present invention more comprehensible, embodiments are hereinafter described in detail with reference to the accompanying drawings.

FIG. 1A is a schematic diagram of a thin-film flip-chip packaging structure according to an embodiment of the present invention. FIG. 1B is a schematic cross-sectional view of the thin-film flip-chip packaging structure of FIG. 1A along A-A '. Please refer to FIGS. 1A and 1B. In this embodiment, the thin-film flip-chip packaging structure 100 includes a flexible substrate 110, a plurality of pins 120, two chips 130, a buffer 150, and a packaging gel 160. The material of the flexible substrate 110 is, for example, polyimide (PI), polyester resin (PET), or other flexible insulating materials. The flexible substrate 110 has a wafer bonding region 112. These pins 120 are disposed on the flexible substrate 110 and extend outward from the wafer bonding area 112. Next, the two wafers 130 are arranged side by side in the wafer bonding region 112 of the flexible substrate 110, and the pins 120 are electrically connected through the bumps 138 respectively. In this embodiment, the distance D between the two wafers 130 is, for example, not more than 10 mm.

In detail, each wafer 130 has an active surface 132, a back surface 134 opposite to the active surface 132, and a plurality of side surfaces 136 connecting the active surface 132 and the back surface 134. The active surface 132 of each wafer 130 has two short sides 1322 and two long sides 1324, respectively. In this embodiment, the length H of the short side 1322 is, for example, not more than 4 mm. In this embodiment, these side surfaces 136 include two short side surface 1362 which respectively connect the two short sides 1322 of the active surface 132, and two long side side surfaces which respectively connect the two long sides 1324 of the active surface 132. 1364. The two wafers 130 are arranged side by side with the short side surfaces 1362 facing each other. The buffer member 150 is disposed on the flexible substrate 110 and is located between the two wafers 130. The encapsulant 160 is filled at least between the wafers 130 and the flexible substrate 110 and covers the side surfaces 136 of the wafers 130. In other words, the encapsulant 160 covers the active surface 132 of each chip 130, and the encapsulant 160 covers two short side surfaces 1362 and two long side surfaces 1364 of each chip 130.

The buffer member 150 is coupled to the two chips 130 through the packaging gel 160. Furthermore, in this embodiment, the arrangement of the buffer 150 is as follows. After the two wafers 130 are respectively disposed in the wafer bonding area 112 of the flexible substrate 110 and the lead pins 120 are electrically connected, the buffer member 150 is first disposed on the flexible substrate 110 so that the buffer member 150 is located on the second substrate 130. The two wafers 130 are located between the short side surfaces 1362 of the two wafers 130. At this time, the buffer member 150 may be fixed on the flexible base material 110 by, for example, adhesive or thermocompression bonding, but is not limited thereto. Next, the encapsulant 160 is filled between each chip 130 and the flexible substrate 110 to cover the active surface 132, the short side surface 1362 and the long side surface 1364 of the two chips 130. The encapsulant 160 fills the area between the short side surface 1362 of each chip 130 and the buffer member 150, so that the buffer member 150 is coupled to the two wafers 130 to fix the buffer member 150 and ensure that the buffer member 150 and two The relative position between the wafers 130 and strengthens the hardness of this area. In this embodiment, the buffer member 150 includes, for example, a heat-resistant material, and can withstand a temperature of not less than 150 ° C., for example, phenol resin (bakelite), polyetheretherketone (PEEK), Teflon, polyimide, graphene or other suitable heat-resistant materials.

In this embodiment, the thin-film flip-chip packaging structure 100 further includes a solder resist layer 170. The solder mask 170 is disposed on the flexible substrate 110 and partially covers the leads 120 but exposes the wafer bonding area 112.

In this embodiment, the flexible substrate 110 also has two transmission regions 116 and 117 and a plurality of transmission holes 118 opposite to each other. The transmission holes 118 are respectively located in the transmission regions 116 and 117 and penetrate the flexible substrate. 110. The transmission holes 118 are arranged along a direction perpendicular to the long side 1324 of the active surface 132, and the transmission holes 118 are configured to cooperate with the transmission mechanism to drive the flexible substrate 110 to move. In practice, after the tape-and-reel film-on-chip packaging is completed, the two opposite transmission regions 116 and 117 in the flexible substrate 110 are removed, that is, the film-on-chip packaging structure 100 obtained at the end is not The transmission region 116 and 117 are provided. The two transmission regions 116 and 117 are illustrated in the drawing to explain that the thin film flip chip packaging structure 100 is made by a tape and reel thin film flip chip packaging technology.

Based on the above design, the buffer 150 is arranged between the short side surfaces 1362 of the two side-by-side wafers 130 to provide the barrier and support at the position between the two wafers 130. The region between the short side surface 1362 of the wafer 130 and the buffer 150 strengthens the relative position between the buffer 150 and each wafer 130 and strengthens the hardness of the region between the two wafers 130. The buffer member 150 provides a barrier and support between the two wafers 130, which can prevent the thin-film flip-chip packaging structure 100 from warping due to the curing shrinkage of the encapsulant 160 and causing the two wafers 130 to collide with each other. In addition, due to the provision of the buffer 150, the amount of the encapsulating gel 160 filled between the two wafers 130 is reduced, and the degree of shrinkage of the encapsulating gel 160 is reduced accordingly, thereby avoiding warping of the thin-film flip-chip packaging structure 100 and causing The wafers 130 collide with each other and are squeezed.

Other embodiments will be listed below for illustration. It must be noted here that the following embodiments use the component numbers and parts of the foregoing embodiments, in which the same reference numerals are used to indicate the same or similar components, and the description of the same technical content is omitted. For the description of the omitted parts, reference may be made to the foregoing embodiments, and the following embodiments are not repeated.

FIG. 2A is a schematic diagram of a thin-film flip-chip packaging structure according to another embodiment of the present invention. FIG. 2B is a schematic cross-sectional view of the thin-film flip-chip packaging structure of FIG. 2A along B-B '. Please refer to FIGS. 2A and 2B. The main difference between the thin-film flip-chip packaging structure 100a of FIG. 2A (FIG. 2B) and the thin-film flip-chip packaging structure 100 of FIG. 1A (FIG. 1B) is that the packaging colloid 160 further includes two first colloids. 162, 163 and the second colloid 164. The active surface 132 and the side surface 136 of each wafer 130 are covered by corresponding first colloids 162 and 163, and the second colloid 164 is coupled to the two first colloids 162 and 163 and the buffer 150. In this embodiment, the second gel 164 may include a heat-dissipating / thermal-conductive glue, a UV-curing glue, or other suitable materials.

In detail, please continue to refer to FIGS. 2A and 2B. Each of the first colloids 162 and 163 has an inner portion 1622 and 1632 covering the short side surface 1362 of the corresponding wafer 130. A space 114 is provided between the inner portions 1622 and 1632 corresponding to the two wafers 130, and the buffer 150 is located in the space 114. In addition, the second colloid 164 covers the periphery of the two first colloids 162 and 163 and the buffer 150 and fills the space 114. The second colloid 164 further covers the back surfaces 134 of the two wafers 130 and the top surface 152 of the buffer member 150.

FIG. 3A is a schematic diagram of a thin-film flip-chip packaging structure according to another embodiment of the present invention. 3B is a schematic cross-sectional view of the thin-film flip-chip packaging structure of FIG. 3A along C-C '. Please refer to FIGS. 3A and 3B. The main difference between the thin-film flip-chip packaging structure 100 b of FIG. 3A (FIG. 3B) and the thin-film flip-chip packaging structure 100 a of FIG. 2A (FIG. 2B) is that the second gel 164 does not cover the two chips 130 These back surfaces 134 and the top surface 152 of the buffer member 150.

In detail, please continue to refer to FIGS. 3A and 3B. The active surface 132, the short side surface 1362 and the long side surface 1364 of each chip 130 are covered by the corresponding first colloids 162 and 163. In addition, the second colloid 164 covers the periphery of the two first colloids 162 and 163 and the buffer 150 and fills the space 114. The second gel 164 exposes the back surface 134 of the two wafers 130 and the top surface 152 of the buffer member 150. The second colloid 164 is coupled to the two first colloids 162 and 163 and the buffer member 150. In this embodiment, the back surfaces 134 of the two wafers 130 are not covered by the second colloid 164 and are exposed. The heat generated by the chip 130 during operation can be dissipated through the back surface 134, so the heat dissipation efficiency can be increased.

FIG. 4A is a schematic diagram of a thin-film flip-chip packaging structure according to another embodiment of the present invention. 4B is a schematic cross-sectional view of the thin-film flip-chip packaging structure of FIG. 4A along D-D '. Please refer to FIG. 4A and FIG. 4B. The main difference between the thin-film flip-chip packaging structure 100c of FIG. 4A (FIG. 4B) and the thin-film flip-chip packaging structure 100b of FIG. 3A (FIG. 3B) is that the buffer 150 has two adjacent two Two opposite second side surfaces 156 of the inner portions 1622 and 1632 of the first colloids 162 and 163. The second colloid 164 is not filled between the inner portions 1622 and 1632 and the second side surface 156.

In detail, in this embodiment, each of the first colloids 162 and 163 has two outer portions 1626 and 1636 covering two long side surfaces 1364 of the corresponding wafer 130 and a short side covering an edge of the adjacent wafer bonding region 112. On the outer portions 1628 and 1638 of the side surface 1362, the buffer member 150 has two opposite first side surfaces 154 adjacent to the two long side surface 1364 of each wafer 130, respectively. The second colloid 164 covers the outer portions 1626, 1628, 1636, 1638 of the two first colloids 162, 163 and the first side surfaces 154 of the buffer member 150. In other words, in this embodiment, the buffer member 150 is coupled to the two chips 130 by connecting the first side surface 154 and the outer portions 1626 and 1636 of the first gels 162 and 163 through the second gel 164.

FIG. 5A is a schematic diagram of a thin-film flip-chip packaging structure according to another embodiment of the present invention. 5B is a schematic cross-sectional view of the thin-film flip-chip packaging structure of FIG. 5A along the line E-E '. Please refer to FIG. 5A and FIG. 5B. The main difference between the thin-film flip-chip packaging structure 100 d of FIG. 5A (FIG. 5B) and the thin-film flip-chip packaging structure 100 c of FIG. The inner portions 1622 and 1632 of the colloids 162 and 163 and the second side surface 156 of the buffer member 150.

In detail, the second colloid 164 covers the inner portions 1622, 1632 of the two first colloids 162, 163, the first side surface 154 of the buffer member 150, the second side surface 156 of the buffer member 150, and the top surface 152 of the buffer member 150. In other words, in the present embodiment, the buffer member 150 is coupled to the two wafers 130 by connecting the second side surface 156 and the inner portions 1622 and 1632 of the first gels 162 and 163 through the second gel 164.

In summary, in the thin-film flip-chip packaging structure of the present invention, a buffer is arranged between the short side surfaces of two wafers arranged side by side to provide blocking and support at the position between the two wafers, and then the package is packaged. The colloid is filled in the region between the short side surface of each wafer and the buffer member to strengthen the relative position between the buffer member and each wafer and to strengthen the hardness of the region between the two wafers. The buffer member provides a barrier and support between the two wafers, which can prevent the two wafers from colliding and squeezing due to the warpage of the thin-film flip-chip packaging structure due to the curing and shrinkage of the packaging colloid. In addition, due to the arrangement of the buffer, the amount of the encapsulating gel filled between the two wafers is reduced, so that the shrinkage of the encapsulating gel is reduced accordingly. In this way, warpage of the thin-film flip-chip packaging structure can be avoided, which can cause two wafers to collide and squeeze with each other, thereby improving the reliability of the thin-film flip-chip packaging structure.

Although the present invention has been disclosed as above with the examples, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field can make some modifications and retouching without departing from the spirit and scope of the present invention. The protection scope of the present invention shall be determined by the scope of the attached patent application.

100, 100a, 100b, 100c, 100d

110‧‧‧ flexible substrate

112‧‧‧ Wafer Land

114‧‧‧ spacer

120‧‧‧pin

130‧‧‧Chip

132‧‧‧active surface

1322‧‧‧Short side

1324‧‧‧long side

134‧‧‧back surface

136‧‧‧side surface

1362‧‧‧Side side surface

1364‧‧‧Long side surface

138‧‧‧ bump

150‧‧‧ buffer

152‧‧‧Top

154‧‧‧first side

156‧‧‧second side

160‧‧‧ encapsulated colloid

162‧‧‧The first colloid

1622‧‧‧Inner part

1626, 1628‧‧‧ Outer part

163‧‧‧The first colloid

1632‧‧‧Inner part

1636, 1638‧‧‧outside

164‧‧‧Second Colloid

170‧‧‧solder mask

D‧‧‧distance

H‧‧‧ length

FIG. 1A is a schematic diagram of a thin-film flip-chip packaging structure according to an embodiment of the present invention. FIG. 1B is a schematic cross-sectional view of the thin-film flip-chip packaging structure of FIG. 1A along A-A '. FIG. 2A is a schematic diagram of a thin-film flip-chip packaging structure according to another embodiment of the present invention. FIG. 2B is a schematic cross-sectional view of the thin-film flip-chip packaging structure of FIG. 2A along B-B '. FIG. 3A is a schematic diagram of a thin-film flip-chip packaging structure according to another embodiment of the present invention. 3B is a schematic cross-sectional view of the thin-film flip-chip packaging structure of FIG. 3A along C-C '. FIG. 4A is a schematic diagram of a thin-film flip-chip packaging structure according to another embodiment of the present invention. 4B is a schematic cross-sectional view of the thin-film flip-chip packaging structure of FIG. 4A along D-D '. FIG. 5A is a schematic diagram of a thin-film flip-chip packaging structure according to another embodiment of the present invention. 5B is a schematic cross-sectional view of the thin-film flip-chip packaging structure of FIG. 5A along the line E-E '.

Claims (10)

A thin-film flip-chip packaging structure includes: a flexible substrate having a wafer bonding area; a plurality of pins disposed on the flexible substrate and extending outward from the wafer bonding area; two wafers And are arranged side by side in the wafer bonding area of the flexible substrate and are electrically connected to the pins, respectively, wherein each of the wafers has an active surface, a back surface opposite to the active surface, and the active surface is connected to the chip. And a plurality of side surfaces of the back surface, the side surfaces including a short side surface connected to a short side of the active surface, wherein the two chips are arranged side by side with the short side surface facing each other; a buffer Components are disposed on the flexible substrate and are located between the two wafers; and an encapsulant is filled at least between each of the wafers and the flexible substrate and covers the sides of each of the wafers Surface, and the buffer member is coupled to the two chips through the packaging gel. The thin-film flip-chip packaging structure according to item 1 of the scope of the patent application, wherein the packaging colloid includes two first colloids and a second colloid, and the active surface of each wafer and the first surfaces corresponding to the side surfaces are corresponding. The colloid is covered, and the second colloid is coupled to the two first colloids and the buffer member. The thin-film flip-chip packaging structure according to item 2 of the scope of patent application, wherein each of the first colloids has an inner portion covering the corresponding short side surface of the wafer, and the inner portions corresponding to the two wafers. There is a gap between them, and the buffer is located in the gap. According to the thin-film flip-chip packaging structure described in item 3 of the patent application scope, wherein the second colloid covers the two first colloids and the periphery of the buffer member, and fills the gap region. According to the thin-film flip-chip packaging structure described in item 4 of the patent application scope, wherein the second colloid further covers the back surfaces of the two wafers and the top surface of the buffer member. The thin-film flip-chip packaging structure according to item 3 of the scope of patent application, wherein the side surfaces of each of the wafers include two long-side side surfaces that are respectively connected to two long sides of the active surface, and each of the first colloids has Two outer side portions covering the two long side side surfaces, the buffer member having two opposite first side surfaces adjacent to the two long side side surfaces of each of the wafers respectively, and the second colloid covering the two second side surfaces The outer portions of a colloid and the first sides of the buffer member. The thin-film flip-chip packaging structure according to item 3 of the patent application scope, wherein the buffer member has two opposite second sides respectively adjacent to the inner portions of the two first colloids, and the second colloid is filled Within the gap area, the inner portions and the second side surfaces are covered. According to the thin-film flip-chip packaging structure described in item 1 of the scope of patent application, wherein the length of the short side of each of the wafers is not greater than 4 mm. The thin-film flip-chip packaging structure according to item 1 of the scope of patent application, wherein the distance between the two wafers is not greater than 10 mm. The thin-film flip-chip packaging structure according to item 1 of the patent application scope, wherein the buffer member is a heat-resistant material.