TW201640624A - Film packaging substrate, chip on film package and packaging method thereof - Google Patents

Abstract

A film packaging substrate includes a flexible base and a plurality of leads. The flexible base has a first surface with a chip bonding area disposed thereon. The leads are configured on the first surface, and each of the leads has an inner lead extending into the chip bonding area. The flexible base has a plurality of roulette perforations encircling a tear-off area. A chip on film (COF) package and a manufacturing method thereof use the foregoing film packaging substrate to enhance the heat dissipation effect of the COF package without changing the thickness of the COF package.

Description

Thin film packaging substrate, thin film flip chip package and film flip chip packaging method

The present invention relates to a thin film package substrate, a thin film flip chip package structure and a film flip chip package method using the same, and in particular, the present invention relates to a thin film package substrate capable of increasing heat dissipation effect, using the film package substrate The film flip chip package structure and the film flip chip packaging method.

The chip on-film (COF) package structure is a technology for packaging a chip on a flexible substrate or a flexible substrate, and is generally used for packaging a driver IC in a liquid crystal display.

Referring to FIG. 1 , FIG. 1 is a schematic diagram showing a prior art thin film flip chip package 1 . As shown in FIG. 1 , the film flip chip package 1 includes a flexible substrate 10 , a wire 12 , a solder resist layer 14 , a wafer 16 , and an encapsulant 18 , wherein the wires 12 are disposed on a surface of the flexible substrate 10 , and Partially covered by the solder resist layer 14, the wafer 16 is disposed in the predetermined wafer bonding region of the surface and electrically connected to the wire 12, and the encapsulant 18 is filled between the wafer 16 and the flexible substrate 10 to fix and protect the wafer. 16 and the junction of the wafer 16 and the wire 12.

In the prior art, the wafer 16 generates heat when the film flip chip package 1 is connected to other circuit structures for operation. With the miniaturization of the integrated circuit, the function of the wafer 16 The upper lift also generates more heat. If the heat cannot be effectively dissipated from the wafer 16 or the thin film flip chip 1, the performance of the wafer 16 or the thin film flip chip 1 will be reduced, and moreover, It is possible to damage the wafer 16 or the film flip chip package 1. Therefore, the film flip chip package 1 needs to be provided with a heat dissipation mechanism to help dissipate heat.

Therefore, the prior art thin film flip chip package 1 is usually provided with a heat sink attached to a metal material or a heat dissipating adhesive to help dissipate heat. For example, in FIG. 1, the wafer flip chip package 1 is over the wafer 16 and Or a heat dissipation layer S is provided under the flexible substrate 10. The heat dissipation layer S can absorb the heat generated by the operation of the wafer 16 in a conductive manner and dissipate the heat into the surrounding air to help the film flip chip package 1 to dissipate heat.

However, whether the heat dissipation layer S is disposed above the wafer 16 or under the flexible substrate 10 increases the thickness of the thin film flip chip package 1. At present, various electronic products tend to be miniaturized and lightweight, so the space design of the internal circuit or various modules is important. The heat dissipation layer S of the prior art increases the thickness of the film flip chip package 1 and makes the film flip chip package 1 pair. The miniaturization of electronic products will have an adverse impact. On the other hand, the heat dissipation layer S also lowers the flexibility of the film flip chip package 1 and increases the difficulty in the process or assembly.

Based on the above problems, it is necessary to develop a structure or method that can effectively help the thin film flip chip package to dissipate heat without increasing the thickness of the film flip chip package, in order to meet the demand for miniaturization and light weight of today's electronic products.

One aspect of the present invention is to provide a thin film package substrate that can help dissipate heat. According to a specific embodiment, the thin film encapsulation substrate of the present invention comprises a flexible substrate and a plurality of wires. The flexible substrate has a first surface and has a wafer bond on the first surface Area. A plurality of wires are disposed on the first surface, and each of the wires has an inner lead extending into the wafer bonding region. The flexible substrate has a plurality of seating holes located within a vertical projection range of the wafer bonding area and surrounding a removed area.

Another aspect of the present invention is to provide a thin film flip chip package which has a good heat dissipation effect without additionally increasing the thickness. According to a specific embodiment, the film flip chip package of the present invention comprises a flexible substrate, a plurality of wires, a wafer, and an encapsulant. The flexible substrate has a first surface, and the first surface has a wafer bonding region, the flexible substrate forms a through hole in the wafer bonding region, and the flexible substrate has a residue on the sidewall of the through hole structure. A plurality of wires are disposed on the first surface, and each of the wires has an inner lead extending into the wafer bonding region. The wafer is disposed in the wafer bonding region and electrically connected to the inner leads of the wires. The encapsulant is filled between the wafer and the flexible substrate, and the through hole exposes a portion of the encapsulant.

Another aspect of the present invention is to provide a film flip chip packaging method that can help the film flip chip package to dissipate heat without increasing the thickness of the film flip chip package. According to a specific embodiment, the film flip chip packaging method of the present invention comprises the steps of: preparing a thin film package substrate having a flexible substrate and a plurality of wires, wherein the flexible substrate has a first surface having a first surface a wafer bonding region, the wires are disposed on the first surface, each of the wires has an inner lead extending into the wafer bonding region, and the flexible substrate has a plurality of riding holes located in a vertical projection range of the wafer bonding region and surrounding the exiting Dividing the wafer in the wafer bonding region and electrically connecting the wafer to the inner leads of the respective wires; forming an encapsulant between the wafer and the flexible substrate; and removing the flexible substrate from the saddle hole In addition to the area, the flexible substrate is formed into a through hole to expose a portion of the encapsulant.

The advantages and spirit of the present invention will be further understood from the following detailed description of the invention.

1‧‧‧film flip chip package

10‧‧‧Flexible substrate

12‧‧‧ wire

14‧‧‧ solder mask

16‧‧‧ wafer

18‧‧‧Package colloid

S‧‧‧heat layer

2, 5‧‧‧ film package substrate

20, 30, 50‧‧‧Flexible substrates

52‧‧‧Wire

22, 32, 24, 34, 54‧‧‧ solder mask

200a, 300a, 500a‧‧‧ first surface

200b, 300b, 500b‧‧‧ second surface

202, 302, 502‧‧‧ wafer bonding area

204, 504‧‧‧ Riding holes

206, 506‧‧‧Removed area

3, 3'‧‧‧ film flip chip package

36, 6‧‧‧ wafer

360, 60‧‧ ‧ bumps

38, 7‧‧‧Package colloid

304, 508‧‧‧ hole

308, 509‧‧‧Residual structure

40, 8‧‧ ‧ heat sink

T1, T2‧‧‧ thickness

FIG. 1 is a schematic view showing a prior art thin film flip chip package.

2A is a bottom plan view of a thin film package substrate in accordance with an embodiment of the present invention.

Figure 2B is a cross-sectional view showing the thin film package substrate according to Figure 2A.

Figure 3A is a cross-sectional view showing a film flip chip package in accordance with an embodiment of the present invention.

FIG. 3B is a bottom view of the film flip chip package of FIG. 3A.

4 is a cross-sectional view showing a thin film flip chip package according to another embodiment of the present invention.

FIG. 5A to FIG. 5E are structural diagrams showing the steps of a method of film flip chip packaging according to another embodiment of the present invention.

Referring to FIG. 2A and FIG. 2B, FIG. 2A is a bottom view of a thin film package substrate 2 according to an embodiment of the present invention, and FIG. 2B is a cross section of the thin film package substrate 2 according to FIG. Figure. As shown in FIG. 2A and FIG. 2B, the thin film package substrate 2 of the present invention comprises a flexible substrate 20, a plurality of wires 22 and a solder resist layer 24, wherein the wires 22 and the solder resist 24 are disposed on the flexible base. Above the material 20.

The flexible substrate 20 has opposing first and second surfaces 200a, 200b, and the first surface 200a is pre-formed with a wafer land 202. Multiple wires 22 are separately set On the first surface 200a, and each of the wires 22 has an inner lead extending into the wafer bonding region 202, respectively. The solder mask layer 24 partially covers the wires 22 and exposes the die bond region 202. Generally, the range of the die bond regions 202 is defined by an opening of the solder resist layer 24. Within the vertical projection range of the wafer bond area 202, the flexible substrate 20 also includes a plurality of bayonet holes 204. The saddle hole 204 surrounds the removal region 206 in the vertical projection range of the wafer bond region 202, and the inner pins of the wire 22 may be located outside the removal region 206. Each of the riding holes 204 is arranged at a spaced apart interval to surround the removal region 206. In the present embodiment, each of the riding holes 204 is a blind hole penetrating the second surface 200b, that is, each of the riding holes 204 does not completely penetrate the flexible substrate 20, so that the flexible substrate 20 is close to the first surface 200a. A thickness T1 is left unpenetrated by the piercing hole 204, and the remaining thickness T1 may be between about 1/6 and 1/3 of the thickness T2 of the flexible substrate 20. However, the form of the riding hole 204 is not limited to the embodiment of the present embodiment, and may be a through hole that completely penetrates the flexible substrate 20 or a blind hole that penetrates the first surface 200a.

In the present embodiment, the removal region 206 surrounded by the burr hole 204 is rectangular, but in practice, it may be circular, elliptical or other suitable shape. On the other hand, the shape of the riding hole 204 may also include different shapes such as a circle, an ellipse or a rectangle, and is not limited to the elliptical shape of the specific embodiment.

The thin film package substrate 2 can be used on the film flip chip package, so that the film flip chip package has a good heat dissipation effect without increasing the thickness of the film flip chip package. Referring to FIG. 3A and FIG. 3B together, FIG. 3A is a cross-sectional view of a thin film flip chip package 3 according to an embodiment of the present invention, and FIG. 3B is a thin film flip chip of FIG. A bottom view of the package 3. As shown in FIG. 3A, the film flip chip package 3 includes a flexible substrate 30, A plurality of wires 32, a solder resist layer 34, a wafer 36, and an encapsulant 38 are disposed, wherein the plurality of wires 32, the solder resist layer 34, the wafer 36, and the encapsulant 38 are disposed on the flexible substrate 30, respectively.

In the present embodiment, the flexible substrate 30 has a first surface 300a and a second surface 300b opposite to the first surface 300a. The first surface 300a is provided with a wafer bonding region 302, and the flexible substrate 30 is provided. A through hole 304 is formed in the wafer bonding region 302. A plurality of wires 32 are disposed on the first surface 300a of the flexible substrate 30, and each of the wires 32 has an inner lead extending into the wafer bonding region 302. The solder mask layer 34 partially covers the wires 32 and exposes the wafer land 302. The wafers 36 are disposed in the wafer bonding region 302 and can be electrically connected to the inner leads of the plurality of wires 32, for example, through the plurality of bumps 360. The inner pins of each of the wires 32 may be located outside the through hole 304, and each of the wires 32 has a pin other than the inner pin. In practice, the external circuit structure may be electrically connected to enable the chip 36 and the external circuit. Structure communicates with each other. The encapsulant 38 is filled between the wafer 36 and the first surface 300a of the flexible substrate 30 for securing and protecting the connection between the wafer 36 and the wires 32. The through hole 304 penetrates the flexible substrate 30 and exposes a portion of the encapsulant 38 as shown in FIG. 3B.

In the present embodiment, the flexible substrate 30 has a residual structure 308 on the sidewall of the through hole 304. The residual structure 308 is formed by tearing off a portion of the flexible substrate 30 originally located in the through hole 304. Residual formation. In particular, the flexible substrate 30 is originally formed with a plurality of seating holes in the vertical projection range of the wafer bonding region 302 to surround the removed regions, as shown in the foregoing embodiments, while the wafer 36 and the encapsulant 38 are included. After being disposed on the flexible substrate 30, the flexible substrate 30 as in the removal region of the foregoing embodiment is removed along the burr hole to form the penetration hole 304. Since the penetration hole 304 is formed by tearing the flexible substrate 30 along the saddle hole, the flexible substrate 30 leaves a residual knot on the side wall of the penetration hole 304. Structure 308. The residual structure 308 is a regularly arranged relief structure in this embodiment, but the shape of the residual structure 308 in practice differs depending on the material properties of the different flexible substrates, the form of the snap holes, or the tools and methods of tearing. May be toothed, wavy or other shapes.

The through hole 304 is located in the wafer bonding region 302 and exposes a portion of the encapsulant 38. Therefore, the heat generated by the operation of the wafer 36 can be conducted to the encapsulant 38, and then dissipated into the air by the penetration hole 304 contacting the air. Therefore, the through hole 304 can help the film flip chip package 3 to dissipate heat without increasing the thickness of the film flip chip package 3 or affecting the flexibility of the film flip chip package 3.

Referring to Figure 4, there is shown a cross-sectional view of a thin film flip chip package 3' according to another embodiment of the present invention. As shown in FIG. 4, the present embodiment differs from the thin film flip chip package 3 of the previous embodiment in that the film flip chip package 3' of the specific embodiment further includes a heat sink 40. The heat sink 40 is disposed in the penetration hole 304 and contacts the encapsulant 38, and thus does not increase the thickness of the film flip chip 3'. The heat sink 40 can absorb heat from the encapsulant 38 and dissipate heat to the air. The heat dissipating member 40 can be a heat dissipating glue in practice. Since the heat dissipating rubber is generally an elastic material, the heat dissipating member 40 does not affect the flexibility of the film flip chip package 3'.

Referring to FIG. 5A to FIG. 5E, FIG. 5A to FIG. 5E are schematic structural diagrams showing steps of a film flip chip packaging method according to another embodiment of the present invention. As shown in FIG. 5A, a thin film package substrate 5 is prepared, wherein the thin film package substrate 5 includes a flexible substrate 50, a plurality of wires 52, and a solder resist layer 54. The flexible substrate 50 has opposing first and second surfaces 500a, 500b, and the first surface 500a has a wafer land 502 thereon. 52 points for each wire It is not disposed on the first surface 500a and has an inner lead extending into the wafer bonding region 502. Solder mask layer 54 partially covers wire 52 and exposes wafer bond region 502. The flexible substrate 50 has a plurality of seating apertures 504 in a vertical projection range of the wafer bonding region 502 that surrounds the removal region 506 in a vertical projection range of the wafer bonding region 502. The inner pins of the wires 52 can be located outside of the removal region 506. Each of the riding holes 504 is arranged at a spaced apart interval to surround the removal region 506. In the present embodiment, each of the riding holes 504 is a blind hole penetrating the second surface 500b such that the flexible substrate 50 retains a thickness T1 near the first surface 500a without being penetrated by the riding hole 504, and this retention is retained. The thickness T1 may be between about 1/6 and 1/3 of the thickness T2 of the flexible substrate 50. However, the form of the riding hole 504 is not limited to the embodiment of the present embodiment, and may be a through hole that completely penetrates the flexible substrate 50 or a blind hole that penetrates the first surface 500a. The burrowing aperture 504 can be circular, elliptical, rectangular or other suitable shape in practice. Likewise, the removal region 506 can also be rectangular, circular, elliptical or other suitable shape.

Next, as shown in FIG. 5B, the wafer 6 is disposed in the wafer bonding region 502 of the flexible substrate 50. The wafer 6 is electrically connected to the inner leads of the wires 52 by the bumps 60. Next, as shown in FIG. 5C, an encapsulant 7 is formed between the wafer 6 and the flexible substrate 50.

As shown in FIG. 5D, the removed region 506 of the flexible substrate 50 is removed along the aforementioned burr hole 504, so that the flexible substrate 50 forms a through hole 508 in the wafer bonding region 502, and the through hole 508 exposes a portion of the encapsulant 7 . The step of removing the removal region 506 described above can be performed in a manner that can be torn off in practice. Since the removal regions 506 are defined by successive spacing of the bayonet apertures 504, the flexible substrate 50 will have a residual structure 509 at the sidewalls of the penetration apertures 508 after the removal of the removal regions 506, and this residual structure 509 For the perspective of looking up Go to the irregular structure of the regular arrangement (as shown in Figure 3B). The shape of the residual structure 509 may be a toothed structure, a wavy structure, or other shape depending on the shape and spacing of the burrowing holes 504.

The film flip chip package produced according to the method of the embodiment has a through hole on the flexible substrate relative to the position of the wafer, so that the area of the package gel contacting the air is increased to help dissipate heat of the wafer. While helping to dissipate heat, the penetration holes do not increase the thickness of the film flip chip and do not affect the flexibility of the film flip chip. The method for forming a saddle hole on the flexible substrate by the film encapsulating substrate of the embodiment can pre-position the removal region, and can be removed only by a simple tearing action after forming the film flip chip package. In addition to the regions to form the through holes, the process is simple and does not damage the thin film flip chip package. In contrast, the prior art thin film package substrate without a burr hole must be subjected to a process such as laser or etching to form a through hole on the flexible substrate, which is complicated in process and may damage the film cover. Other components in the crystal package, such as package pins, wafers, bumps or internal pins of wires.

In addition, referring to FIG. 5E, the heat sink 8 may be further formed in the penetration hole 508 to contact the heat sink 8 to the encapsulant 7. The heat generated by the operation of the wafer 6 of the film flip chip package is conducted to the encapsulant 7 and further to the heat sink 8 and finally dissipated into the air by the heat sink 8. The heat dissipating member 8 can be a heat dissipating glue in practice, so that the heat dissipating member 8 helps the film flip chip package to dissipate heat, and does not increase the thickness of the film flip chip package, nor does it affect the flexibility of the film flip chip package. Sex.

In summary, the thin film encapsulation substrate of the present invention has a plurality of saddle holes surrounding the removal region on the flexible substrate. The film flip-chip encapsulation method of the thin film encapsulation substrate of the invention can produce a good heat dissipation effect without increasing the thickness and without affecting The flexible film flip chip package meets the needs of today's electronic products for miniaturization and weight reduction.

The features and spirit of the present invention will be more apparent from the detailed description of the preferred embodiments. On the contrary, the intention is to cover various modifications and equivalents within the scope of the invention as claimed.

2‧‧‧Film package substrate

20‧‧‧Flexible substrate

22‧‧‧Wire

24‧‧‧ solder mask

200b‧‧‧ second surface

202‧‧‧ wafer junction area

204‧‧‧Sitting holes

206‧‧‧Remove area

Claims (17)

A thin film package substrate comprising: a flexible substrate having a first surface and a second surface, the first surface having a wafer bonding region; and a plurality of wires disposed on the flexible substrate On the first surface of the material, each of the wires has an inner lead, each of the inner leads extending into the wafer bonding region; wherein the flexible substrate has a plurality of riding holes, and the riding holes are located on the wafer A vertical projection range of the land is located and surrounds a removed area. The thin film package substrate of claim 1, wherein the inner leads of the wires are located outside the removal region. The film package substrate of claim 1, wherein the piercing holes comprise blind holes extending through the second surface. The film package substrate of claim 1, wherein the shape of the socket holes comprises a circle, an ellipse or a rectangle. A film flip chip package comprising: a flexible substrate having a first surface having a wafer bonding region, the flexible substrate forming a through hole in the wafer bonding region And the flexible substrate has a residual structure on the sidewall of the through hole; a plurality of wires are disposed on the first surface of the flexible substrate, each of the wires has an inner lead, each of the wires The inner lead extends into the die bond region; a wafer is disposed in the die bond region and electrically connected to the inner leads of the wires; and an encapsulant filled on the wafer and the flexible Between the substrates, and the penetration holes expose a portion of the encapsulant. The film flip chip package of claim 5, further comprising a heat dissipating member disposed in the through hole and contacting the encapsulant. The film flip chip package of claim 5, wherein the wires are The inner pin is located outside the through hole. The film flip chip package of claim 5, wherein the residual structure is formed by tearing off the flexible substrate in the through hole. The film flip chip package according to claim 5, wherein the residual structure is a regularly arranged uneven structure. A film flip chip packaging method comprising the steps of: preparing a film package substrate, wherein the film package substrate has a flexible substrate and a plurality of wires, the flexible substrate having a first surface and a first surface a second surface having a wafer bonding region disposed on the first surface of the flexible substrate, each of the wires having an inner lead, each of the inner leads extending to the wafer In the joint region, the flexible substrate has a plurality of seating holes located in a vertical projection range of the wafer bonding region and surrounding a removal region; and a wafer is disposed on the flexible substrate a wafer bonding region, and electrically connecting the wafer to the inner leads of the wires; forming an encapsulant between the wafer and the flexible substrate; and removing the flexible along the riding holes The removed region of the substrate causes the flexible substrate to form a through hole to expose a portion of the encapsulant. The film flip chip packaging method of claim 10, further comprising the step of: forming a heat sink in the through hole to contact the encapsulant. The film flip chip packaging method of claim 10, wherein the inner leads of the wires are outside the removal region. The film flip chip packaging method of claim 10, wherein the piercing holes comprise blind holes penetrating the second surface. The film flip chip packaging method of claim 10, wherein the removal of the removed region of the flexible substrate comprises tearing. The film flip chip packaging method of claim 10, wherein the shape of the piercing holes comprises a circle, an ellipse or a rectangle. The film flip chip packaging method of claim 10, wherein the flexible substrate has a residual structure on a sidewall of the through hole. The film flip chip packaging method according to claim 16, wherein the residual structure is a regularly arranged uneven structure.