CN100428458C - Flexible substrate for packaging - Google Patents

Abstract

The invention discloses a flexible substrate for packaging a semiconductor tube core. The flexible substrate comprises a flexible insulating film, a plurality of first functional pins, a first virtual pin, a plurality of second functional pins and a second virtual pin. According to a preferred embodiment of the present invention, the flexible substrate is characterized in that the first front section of the first dummy lead is isolated from and not connected to the second front section of the second dummy lead.

Description

Flexible Substrates for Packaging

technical field

The invention relates to a flexible substrate for semiconductor die packaging.

Background technique

As information electronic products become thinner and smaller, flexible substrates with the advantages of light weight, ultra-thin, soft, flexible, and large degree of shape freedom have been widely used in notebook computers, liquid crystal displays, digital cameras, mobile phones and many consumer products. Sexual electronic chip package.

The production of flexible substrates mainly uses polyimide (Polyimide, PI) film as the base material, which has the characteristics of cold resistance, UV resistance, softness, lightness and thinness. The base material made of polyimide can withstand high temperature of 500 ℃, and it will produce nitrogen gas when burning. Next, after coating a layer of adhesive on the substrate, it is bonded with copper foil to form a flexible copper foil substrate. The substrate bonded with copper foil becomes a flexible substrate after circuit development.

Please refer to FIG. 1 , which is a schematic diagram of a conventional flexible substrate 1 . The flexible substrate 1 is used for packaging a semiconductor die (not shown in the figure). The flexible substrate 1 includes a flexible insulating film (Flexible insulating film) 10 . The flexible insulating film 10 has a generally rectangular die mounting area (Diemounting area) 12 thereon. That is to say, the die mounting area 12 defines two first edges (Edge) 122, two second edges 124 perpendicular to the first edges 122, and four intersections of the first edges 122 and the second edges 124. Corner. In Fig. 1, only two corners are depicted.

The flexible substrate 1 has a plurality of first functional leads (Functional leads) 14, four first dummy leads (Dummy leads) 142, a plurality of second functional leads 16 and four second dummy leads 162. . In FIG. 1 , only two first dummy pins 142 and two second dummy pins 162 are shown. The plurality of first functional pins 14 are formed at the first edge 122 on the flexible insulating film 10 for providing electrical connection to the semiconductor die. The plurality of second pins 16 are formed at the second edge 124 of the flexible insulating film 10 for providing electrical connection to the semiconductor die. Each first dummy pin 142 is formed at a corner of the die mounting area 12 on the flexible insulating film 10, and is arranged adjacent to a group of first functional pins 14 for supporting the semiconductor tube. core. Each first dummy pin 142 is divided into a first front section 1422 and a first rear section 1424 , as shown in FIG. 1 . Each second dummy 162 pin is formed at a corner of the die mounting area 12 on the flexible insulating film 10, and is positioned adjacent to a first dummy pin 142 and a set of second function pins 16, used to support the semiconductor die. Each second dummy pin 162 is divided into a second front section 1622 and a second rear section 1624 .

It should be emphasized that, as shown in FIG. 1, outside the die mounting area 12, the first front section 1422 of each first dummy pin 142 is connected to the second section of the adjacent second dummy pin 162. The front section 1622 is connected, and the first rear section 1424 of each first dummy pin 142 is connected with the second rear section 1624 of the adjacent second dummy pin 162 .

Generally speaking, through an inner lead bonding (Inner Lead Bonding, ILB) process, the first functional pin 14 and the second functional pin 16 on the flexible substrate 1 are connected to the multiple pins on the semiconductor die. bump thermocompression bonding. Next, an encapsulation process is performed to coat a liquid resin on the semiconductor die. And at a temperature of about 100 degrees Celsius or higher, it is left for several hours to harden the liquid resin to seal the semiconductor die and the first functional pin 14 and the second functional pin 16 .

It can be clearly seen from the above description that, compared with the more flexible flexible insulating film 10, the first dummy lead 142 with higher rigidity combined with the second dummy lead 162 will apply the process to the die mounting area 12. The stress at the first edge 122 of the die mounting area 12 is transmitted to the second edge 124 of the die mounting area 12, and the stress applied to the second edge 124 of the die mounting area 12 during the process is transmitted to the die mounting area 12 at the first edge 124 . When using the above-mentioned flexible substrate 1 to package the semiconductor die, it will go through multiple high and low temperature switching processes. Therefore, under the action of temperature and pressure, the first functional pins 14 located at the first edge 122 of the die mounting area 12 will be subjected to pressure from adjacent second edges via the first dummy pins 142 and the second dummy pins 162. 124, and the second functional pin 16 located at the second edge 124 of the die mounting area 12 will bear the force from adjacent to the first edge 122 by the first dummy pin 142 and the second dummy pin 162. lateral tension. Therefore, in the flexible substrate 1 made by internal pin bonding, the flexible insulating film 10 often bends, and even causes undesirable situations such as displacement or breakage of functional pins and dummy pins. In particular, the first edge 122 (the longer side) and the second edge 124 (the shorter side) of the die mounting area 12 of the general flexible insulating film 10 undergo thermal expansion and contraction as well as different degrees of stress during the process. , the flexible insulating film 10 will be flexed, and even the functional pins and dummy pins will be shifted or broken, which is undesirable.

Therefore, the present invention aims to provide a flexible substrate for packaging a semiconductor die. The flexible substrate according to the present invention can overcome the above-mentioned problems.

Contents of the invention

In order to achieve the above objects and solve the disadvantages discussed above, the present invention provides a flexible substrate for semiconductor die packaging.

A flexible substrate according to a preferred embodiment of the present invention is used for packaging a semiconductor die. The flexible substrate includes a flexible insulating film, multiple first functional pins, a first dummy pin, multiple second functional pins and a second dummy pin. The flexible insulating film has a die mounting area thereon. The die mounting area defines a first edge, a second edge perpendicular to the first edge, and a corner where the first edge meets the second edge. The plurality of first functional pins are formed at the first edge on the flexible insulating film, and are used for providing electrical connection to the semiconductor die. The first dummy pin is formed at the corner of the die mounting area on the flexible insulating film and is positioned adjacent to the first functional pin for supporting the semiconductor die. The first dummy pin area is divided into a first front segment and a first rear segment. The plurality of second pins are formed at the second edge of the flexible insulating film, and are used for providing electrical connection to the semiconductor die. The second dummy pin is formed at the corner of the die mounting area on the flexible insulating film, and is positioned adjacent to the first dummy pin and the second functional pin to support the semiconductor tube. core. The second dummy pin area is divided into a second front segment and a second rear segment. The flexible substrate is characterized in that the first front section of the first dummy lead and the second front section of the second dummy lead are isolated rather than connected outside the die mounting area.

According to another preferred embodiment of the present invention, the flexible substrate is used for packaging a semiconductor die. The flexible substrate includes a flexible insulating film, multiple first functional pins, a first dummy pin, multiple second functional pins and a second dummy pin. The flexible insulating film has a die mounting area thereon. The die mounting area defines a first edge, a second edge perpendicular to the first edge, and a corner where the first edge meets the second edge. The plurality of first functional pins are formed at the first edge on the flexible insulating film, and are used for providing electrical connection to the semiconductor die. The first dummy pin is formed at the corner of the die mounting area on the flexible insulating film and is positioned adjacent to the first functional pin for supporting the semiconductor die. The first dummy pin area is divided into a first front section and a first rear section, only a part of the first front section of the first dummy pin extends into the die mounting area, And the first front section and the first rear section form a bent shape. The plurality of second pins are formed at the second edge of the flexible insulating film, and are used for providing electrical connection to the semiconductor die. The second dummy pin is formed at the corner of the die mounting area on the flexible insulating film, and is positioned adjacent to the first dummy pin and the second functional pin to support the semiconductor tube. core. The second dummy pin area is divided into a second front section and a second rear section, only a part of the second front section of the second dummy pin extends into the die mounting area, And the second front section and the second rear section form a bent shape. The flexible substrate is characterized in that the first rear section of the first dummy pin is isolated from but not connected to the second rear section of the second dummy pin.

The advantages and spirit of the present invention can be further understood through the following detailed description of the invention and the accompanying drawings.

Description of drawings

FIG. 1 is a schematic diagram of a conventional flexible substrate 1 .

FIG. 2 is a schematic diagram of a flexible substrate 2 according to a preferred embodiment of the present invention.

Explanation of reference signs

1, 2: flexible substrate 10, 20: flexible insulating film

12, 22: Die mounting area 122, 222: First edge

124, 224: second edge 14, 24: first function pin

142, 242: first virtual pin 1422, 2422: first front section

1424, 2424: the first rear section 16, 26: the second function pin

162, 262: second virtual pin 1622, 2622: second front section

1624, 2624: Second rear section

Detailed ways

The invention provides a flexible substrate for packaging a semiconductor die. Please refer to FIG. 2 . FIG. 2 illustrates a flexible substrate 2 according to a preferred embodiment of the present invention. The flexible substrate is used for packaging a semiconductor die (not shown in the figure).

As shown in FIG. 2 , the flexible substrate 2 includes a flexible insulating film 20 . The thickness of the flexible insulating film 20 is about tens of microns, and it is flexible. The flexible insulating film 20 has a generally rectangular die mounting area 22 thereon. That is to say, the die mounting area 22 defines two first edges 222, two second edges 224 perpendicular to the first edges 222, and four corners where the first edges 222 meet the second edges 224. . In Fig. 2, only two corners are depicted.

The flexible substrate 2 has multiple first functional pins 24 , four first dummy pins 242 , multiple second functional pins 26 and four second dummy pins 262 thereon. In FIG. 2 , only two first dummy pins 242 and two second dummy pins 262 are shown. The plurality of first functional pins 24 are formed at the first edge 222 on the flexible insulating film 20 for providing electrical connection to the semiconductor die. The plurality of second pins 26 are formed at the second edge 224 of the flexible insulating film 20 for providing electrical connection to the semiconductor die. Each first dummy pin 242 is formed at a corner of the die mounting area 22 on the flexible insulating film 20 and is positioned adjacent to a set of first functional pins 24 for supporting the semiconductor die. . Each first dummy pin 242 is divided into a first front section 2422 and a first rear section 2424 , as shown in FIG. 2 . Each second dummy 262 pin is formed at a corner of the die mounting area 22 on the flexible insulating film 20, and is positioned adjacent to a first dummy pin 242 and a group of second functional pins. The feet 26 are used to support the semiconductor die. Each second dummy pin 262 is divided into a second front section 2622 and a second rear section 2624 .

It should be emphasized that, according to the flexible substrate 2 of the preferred embodiment of the present invention, outside the die mounting area 22, the first front section 2422 of each first dummy pin 242 is connected to the adjacent The second front section 2622 of the second dummy pin 262 is isolated rather than connected, as shown in FIG. 2 .

Likewise, the first functional pins 24 and the second functional pins 26 on the flexible substrate 2 may be thermocompressively bonded to a plurality of bumps on the semiconductor die through an internal pin bonding process. Next, an encapsulation process is performed to coat a liquid resin on the semiconductor die. And placed for several hours at a temperature of about 100 degrees Celsius or higher to harden the liquid resin to seal the semiconductor die and the first functional pin 24 and the second functional pin 26 .

It can be clearly seen from the above description that, compared with the flexible insulating film 20 with better flexibility, the combination of the first dummy lead 242 with higher rigidity and the second dummy lead 262 may still apply pressure on the tube during the process. The stress at the first edge 222 of the die mounting area 22 is transmitted to the second edge 224 of the die mounting area 22, and may transfer the stress applied to the second edge 224 of the die mounting area 22 during the process. Conducted to the first edge 224 of the die mounting area 22 . However, by isolating rather than connecting the first front section 2422 of each first dummy pin 242 with the second front section 2622 of the adjacent second dummy pin 262, it is obvious that the process due to During the process, the flexible insulating film 20 is deflected caused by thermal stress and compressive stress, and even undesired situations such as functional pins and dummy pins are shifted or broken.

In a specific embodiment, according to the flexible substrate 2 of the present invention, the first rear section 2424 of each first dummy pin 242 on it is connected to the second rear section of the adjacent second dummy pin 262 2624 is a link, as shown in Figure 2. In another specific embodiment, according to the flexible substrate 2 of the present invention, the first rear section 2424 of each first dummy pin 242 on it is connected to the second rear section of the adjacent second dummy pin 262 2624 is also isolated rather than connected.

In a specific embodiment, according to the flexible substrate 2 of the present invention, the die mounting area 22 presents an open hole (Open hole). The flexible substrate 2 with the die mounting area 22 having openings can be applied in a tape carrier package (TCP) process.

In another preferred embodiment, the flexible substrate is substantially the same as the flexible substrate 2 in FIG. 2 . Different from the flexible substrate 2 in FIG. 2, the flexible substrate according to another preferred embodiment of the present invention is characterized in that the first rear section of each first dummy pin is connected to the adjacent second dummy pin The second post-section of the isolating rather than connecting.

Similarly, in a specific embodiment, according to another preferred specific embodiment of the present invention, the flexible substrate, the first front section of each first dummy pin on it and the adjacent second dummy pin The second front section is joined.

Likewise, in an embodiment, according to another preferred embodiment of the flexible substrate of the present invention, the die mounting area thereon presents an opening.

According to the flexible substrate for semiconductor die packaging of the present invention, by improving the connection mode between the pins in different directions, the pins at the corners of the flexible substrate are eliminated from being pulled by stress during the process. This prevents the pins at the corners of the flexible substrate from interfering with each other due to the difference in thermal expansion and contraction in the horizontal direction and the vertical direction, thereby preventing the flexible substrate from being broken, thereby improving the reliability of the package.

Through the detailed description of the preferred specific embodiments above, it is hoped that the features and spirit of the present invention can be described more clearly, rather than limiting the scope of the present invention by the preferred specific embodiments disclosed above. On the contrary, the intention is to cover various modifications and equivalent arrangements within the scope of the appended claims of the present invention.

Claims (6)

1. A flexible substrate for semiconductor die packaging, the flexible substrate comprising: a flexible insulating film having a die mounting area thereon, the die mounting area defining a first edge, a second edge perpendicular to the first edge, and the first edge and the second edge corners where edges meet; a plurality of first functional pins, the plurality of first functional pins are formed at the first edge of the flexible insulating film, and the first functional pins are used to provide the electrical connection of the semiconductor die ; First dummy pins formed at the corners of the die mounting area on the flexible insulating film and disposed adjacent to the first dummy pins Functional pins, the first dummy pins are used to support the semiconductor die, the first dummy pins are divided into a first front section and a first rear section; a plurality of second functional pins, the plurality of second functional pins are formed at the second edge of the flexible insulating film, and the second functional pins are used to provide electrical connection to the semiconductor die; as well as A second dummy pin is formed at the corner of the die mounting area on the flexible insulating film, and the second dummy pin is disposed adjacent to the first dummy pins and the second functional pins, the second dummy pins are used to support the semiconductor die, the second dummy pins are divided into a second front section and a second rear section; Wherein it is characterized in that the first front section of the first dummy pin located outside the die mounting area and the second front section of the second dummy pin are isolated rather than connected . 2. The flexible substrate as claimed in claim 1, wherein the first rear section of the first dummy pin is connected to the second rear section of the second dummy pin. 3. The flexible substrate of claim 1, wherein the die mounting area presents an opening. 4. A flexible substrate for semiconductor die packaging, the flexible substrate comprising: A flexible insulating film having thereon a semiconductor die mounting region defining a first edge, a second edge perpendicular to the first edge, and a distance between the first edge and the the corner where the second edge meets; a plurality of first functional pins, the plurality of first functional pins are formed at the first edge of the flexible insulating film, and the first functional pins are used to provide the electrical connection of the semiconductor die ; First dummy pins formed at the corners of the die mounting area on the flexible insulating film and disposed adjacent to the first dummy pins Functional pins, the first virtual pins are used to support the semiconductor die, the first virtual pins are divided into a first front section and a first rear section, and only the first virtual pins A portion of the first front section extends into the die mounting area, and the first front section and the first rear section form a bend shape; a plurality of second functional pins, the plurality of second functional pins are formed at the second edge of the flexible insulating film, and the second functional pins are used to provide electrical connection to the semiconductor die; as well as A second dummy pin is formed at the corner of the die mounting area on the flexible insulating film, and the second dummy pin is disposed adjacent to the first dummy pins and the second functional pins, the second dummy pins are used to support the semiconductor die, the second dummy pins are divided into a second front section and a second rear section, so Only a part of the second front section of the second dummy pin extends into the die mounting area, and the second front section and the second rear section form a bent shape; Wherein, it is characterized in that the first rear section of the first dummy pin and the second rear section of the second dummy pin are isolated instead of connected. 5. The flexible substrate as claimed in claim 4, wherein the first front section of the first dummy lead is joined to the second front section of the second dummy lead. 6. The flexible substrate of claim 4, wherein the die mounting area presents an opening.

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