KR100643169B1 - Film substrate for semiconductor package and semiconductor package having the same - Google Patents

Abstract

The present invention relates to a film substrate for a COF semiconductor package and a semiconductor package having the same, by forming a dummy pattern in a predetermined pattern not connected to the semiconductor die in a central portion of the base film used as a region for bonding the semiconductor die, By reducing the temperature difference between the semiconductor die, the base film, and the bonding medium, it is possible not only to prevent the void space from being formed inside the bonding medium, but also to increase the contact area between the medium and the base film, thereby improving adhesion.

In addition, by additionally forming a reinforcement pad on the back surface of the base film to minimize the sudden heat loss of the curing agent of the bonding medium to suppress the occurrence of bubble phenomenon, while minimizing the remaining amount of the curing agent to further improve the adhesive properties Can be.

COF, Base Film, Lead, Dummy Lead, Void, Adhesive

Description

Film substrate for semiconductor package and semiconductor package having same {FILM SUBSTRATE FOR SEMICONDUCTOR PACKAGE AND SEMICONDUCTOR PACKAGE HAVING THE SAME}

1 is a schematic plan view of a substrate for a COF semiconductor package according to the prior art.

2 is a schematic cross-sectional view of a portion of a semiconductor die according to the prior art.

FIG. 3 is a schematic cross-sectional view illustrating the bonding of a semiconductor die and a film substrate in the direction AA ′ of FIG. 1.

4 is a schematic plan view of a film substrate for a COF semiconductor package according to a preferred embodiment of the present invention.

5 is a diagram illustrating a dummy pattern of various modifications of the present invention.

FIG. 6 is a schematic cross-sectional view illustrating a state in which a semiconductor die and a film substrate are bonded to each other in the direction BB ′ of FIG. 4.

7 is a schematic cross-sectional view of a situation in which a semiconductor die and a film substrate are bonded according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100, 200: film substrate 101, 201: base film

102, 202: lead 111, 211: semiconductor die

112, 212: die pad 113, 213: bump

121, 221: bonding medium 122: empty space

204: dummy pattern 205: reinforcement pad

The present invention relates to a film substrate for a semiconductor package and a semiconductor package having the same, and more particularly, to a film package for a semiconductor package and a semiconductor package having the same for increasing adhesion between the semiconductor die and the film substrate for a package.

In general, a semiconductor package includes a lead frame, a structure for mounting a chip (die) and a pin that can be electrically connected to the outside, a line connecting the lead frame and the bonding pad, pads for mounting the chip, and sealing materials. can do. The semiconductor package is classified into resin sealing package, tape carrier package (TCP), glass sealing package, and metal sealing package according to the sealing material used, and is classified into insert type and surface mounting technology (SMT) according to the mounting method. Are distinguished. Insert-type packages include DIP (Dual-In Line Package), PGA (Pin Grid Array), and surface mount types include QFP (Quad Flat Package), PLCC (Plastic Lead Carrier), CLC (Ceramic Leaded Chip Carrier), Ball Grid Array (BGA).

The development direction of the semiconductor package is directed to the ultra-small chip scale structure in order to reduce the light and small size of the semiconductor package. For example of a recent chip scale semiconductor package, bumps or lands disposed at the bottom of the semiconductor chip instead of lead frames extending out of the conventional package are connected to an external circuit in connection with a predetermined pattern formed on a thin flexible substrate. This has a package structure of wafer size level. That is, by bonding a semiconductor chip on a so-called chip on film (COF), a connection with an external circuit can be realized.

The COF semiconductor package refers to a semiconductor package configured by attaching a semiconductor chip to a predetermined copper foil pattern formed on a flexible base film, for example, and is a semiconductor package mainly used for displays used in LCDs and communication devices.

Hereinafter, a film substrate for a COF semiconductor package according to the prior art will be described with reference to the accompanying drawings. 1 is a schematic plan view of a substrate for a COF semiconductor package according to the prior art.

Referring to FIG. 1, the film substrate 100 of the COF semiconductor package includes a base film 101 and a lead (bonding pad) 102 extending from an edge of the base film 101. Here, the lead 102 is formed in a predetermined pattern on the edge of the upper layer portion of the base film 101, the central portion of the base film 101, the lead 102 is not formed is used as an area for bonding the semiconductor die do.

2 is a schematic cross-sectional view of a portion of a semiconductor die according to the prior art. Referring to FIG. 2, a die pad 112 serving as an electrode is formed on a bottom surface of the semiconductor die 111 in a predetermined pattern, and a bump 113 is formed on the die pad 112. The bump 113 contacts the lead (102 of FIG. 1) when attaching the semiconductor die 111 to the film substrate 100, whereby the die pad 112 and the lead 102 are electrically connected.

3 is a schematic cross-sectional view illustrating a state in which a semiconductor die and a film substrate are bonded to each other in the direction AA ′ of FIG. 1. Referring to FIG. 3, the pad 112 of the semiconductor die 111 may contact the lead 102 formed on the base film 101 through the bump 113. A bonding medium 121 is applied between the semiconductor die 111 and the base film 101 to maintain bonding between them.

However, when the semiconductor die 111 is adhered to the base film 101, in particular, when the base film 101 is a polyimide-based flexible material, the bonding medium 121 may be formed due to temperature difference and humidity between the different materials during bonding. The empty space or the air bubble 122 may be formed in the interior.

The empty space 122 has a problem that may cause a decrease in adhesion and adhesion, cause corrosion due to moisture infiltration and growth of impurities, thereby greatly reducing the reliability.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to reduce the temperature difference between the semiconductor die, the base film, and the bonding medium to prevent the formation of empty space inside the bonding medium. It is to provide a film substrate.

Another object of the present invention is to form a dummy pattern, which is not connected to the semiconductor die, in a predetermined pattern in a central portion of the base film used as an area for bonding the semiconductor die, thereby increasing the contact area between the bonding medium and the base film, thereby improving adhesion. To improve.

Another object of the present invention is to further form a reinforcement pad on the back of the film, to minimize the sudden heat loss of the curing agent of the bonding medium to suppress the occurrence of bubble phenomenon, to minimize the residual amount of the curing agent to improve the adhesive properties will be.

As a technical means for solving the above problems, one side of the present invention is a base film; A plurality of leads formed in a first pattern of the base film in a predetermined pattern and electrically connected to the semiconductor die; And a plurality of dummy patterns formed in a second region of the base film, wherein the first region is an edge of the base film, and the second region is mainly a central region used to bond the semiconductor die to the base film. Provided is a film substrate for a phosphorus semiconductor package.

Preferably, the plurality of dummy patterns have a structure that electrically insulates the plurality of leads from each other.

Preferably, the plurality of dummy patterns have isolated shape shapes and are separated from the plurality of leads.

Preferably, the lead and the dummy pattern are formed of the same material, for example, copper, in one process, and the dummy pattern is formed by repeating a plurality of isolated shapes which are not particularly limited, and may be formed in a triangle or cross shape. .

On the other hand, it may further include a reinforcement pad attached to the back surface of the base film to reduce the heat loss of the curing agent of the bonding medium for attaching the semiconductor die to the base film.

Another aspect of the invention is a semiconductor die; And the above-described film substrate for semiconductor package; And a bonding medium attaching the semiconductor die to the base film.

Preferably, a plurality of pads are formed in the semiconductor die, and bumps are formed on the pads to be electrically connected to the leads through the bumps.

Preferably, the bonding medium is an anisotropic conductive film, an anisotropic conductive paste, nonconductive paste, or nonconductive face, molding compound or epoxy.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various forms, and the scope of the present invention is not limited to the embodiments described below. Only this embodiment is provided to complete the disclosure of the present invention and to fully inform those skilled in the art, the scope of the present invention should be understood by the claims of the present application.

4 is a schematic plan view of a film substrate 200 for a COF semiconductor package according to a preferred embodiment of the present invention.

The film substrate 200 for a semiconductor package includes a base film 201, a plurality of leads (or bonding pads) 202, and a plurality of dummy patterns 204. In addition, the back surface of the base film 201 may be further provided with a reinforcement pad (205 of FIG. 6). The detailed description of each component is as follows.

The base film 201 may be divided into a first region and a second region. A lead 202 is formed in the first region, and a dummy pattern 204 is formed in the second region. Preferably, the first region is an edge of the film substrate 200, and the second region is a center portion of the film substrate 200. The film substrate 200 is provided with a plurality of leads 202 having a stripe shape in a predetermined pattern from the edge of the upper layer of the base film 201. However, when the plurality of leads 202 performs a function of being electrically connected to the die pad 212 of the semiconductor die 211, the plurality of leads 202 is not limited to the stripe-shaped pattern shown in FIG. 4, but may be configured in any other form. It is possible.

The base film 201 may be described using, for example, a COF film carrier tape or a COF FPC (Flexible Print Circuit). However, the base film 201 is not particularly limited as long as it includes a conductive layer and an insulating layer. Can be used. Examples of laminated films include laminated films prepared by sputtering an adhesion reinforcing layer (for example nickel) on a polyimide-based film and plating copper on the adhesion reinforcing layer, and casting borrowing prepared by applying polyimide to a copper foil. Laminated film, a laminated film prepared by thermocompression bonding an insulating film on a copper foil through a thermoplastic or thermosetting sphere, and the like. However, the present inventors have found that the COF FPC employing a soft material of polyimide (polyimide), in particular, causes various defects due to temperature difference or humidity, and thus, there is a lot of problems that the empty space or air bubble is generated. Thus, it has been found that the present invention is more effective when applied thereto.

On the other hand, the second region of the base film 201 where the leads 202 are not formed is mainly used as a region for bonding the semiconductor die. A dummy pattern 204 is formed in this second region. The dummy pattern 204 may be formed in a shape in which a plurality of leads 202 are electrically insulated from each other, that is, not electrically connected to each other. For example, as shown in FIG. Can be formed. 5 is a diagram illustrating a dummy pattern of various modifications of the present invention.

Preferably, the dummy pattern 204 may be formed of the same copper as the lead 202, and in this case, the dummy pattern 204 may be simultaneously formed when the lead 202 is formed. The dummy pattern 204 is configured to be electrically / physically isolated between the semiconductor die (211 of FIG. 6) and the bonding medium (221 of FIG. 6), and attaches the semiconductor die (211 of FIG. 6). It is prevented that the empty space is formed in 221 of FIG.

Meanwhile, a reinforcement pad 205 may be additionally attached to the rear surface of the base film 201. The reinforcement pad 205 of FIG. 6 may be formed of copper, and may be formed of the same area as the semiconductor die or a narrower area thereof. Detailed description of the dummy pattern 204 and the reinforcement pad 205 will be described later.

FIG. 6 is a schematic cross-sectional view of a semiconductor package in which a semiconductor die and a film substrate are bonded to each other in the direction BB ′ of FIG. 4.

The semiconductor package includes a semiconductor die 211, a film substrate for semiconductor package 200, and a bonding medium 221 for attaching the semiconductor die 211 to the base film 201. Referring to FIG. 6, a die pad 212 serving as an electrode is formed on a bottom surface of the semiconductor die 211 in a predetermined pattern, and a bump 213 is formed on the die pad 212. The bump 213 contacts the lead (202 of FIG. 4) when attaching the semiconductor die 211 to the film substrate 200, whereby the die pad 212 and the lead 202 are electrically connected.

A bonding medium 221 is applied between the semiconductor die 211 and the base film 201 to maintain bonding between them. The bonding medium 221 may be an anisotropic conductive film (ACF), anisotropic conductive paste (ACP), non-conductive paste (NCP), or non-conductive paste (NF). , Molding compound, epoxy, etc. may be used. Preferably, the bonding medium is ACF, NCP or NCF.

ACF is composed of a mixture of conductive particles and non-conductive particles with various physical properties in the crystal depending on the direction. When longitudinal thermal pressure is applied to the ACF, the conductive particles are connected in a vertical direction and arranged accordingly. Electrically connect the upper and lower sides of. The conductive particles are characterized in that they are only vertically conductive as they are separated from each other and not connected in the horizontal direction. Preferably, when the widths of the leads 202 and the ACF are of similar sizes, the ACF and the leads 202 are formed on the conductive particles in the direction in which the film substrate 200 and the semiconductor die 300 are compressed when they are compressed by the bumps. By doing so, it is energized with each other and conductivity is improved. On the other hand, when NCP or NCF is used as a bonding medium, when the die pad 212 and the lead 202 are electrically connected by pressing to form a narrow width of the NCP or NCF compared to the width of the lead 202, the connection is performed. The NCP or NCF can be easily pushed out of the connection area, so that the electrical connection can be made easier.

According to the present exemplary embodiment, empty spaces or air bubbles may be formed in the bonding medium 221 by the basic temperature difference and the degree of humidity of different materials. When the dummy pattern 204 is bonded, the semiconductor die 211 and the base may be formed. It reduces the temperature difference between the film 201 and the bonding medium 221, and serves to explode even when air bubbles are generated. Therefore, it is possible to prevent the empty space or air bubbles from occurring inside the bonding medium 221 to prevent the adhesive force from being reduced and to prevent corrosion or harmful crystal growth by the empty space.

In addition, by forming the dummy pattern 204, the contact area of the bonding medium 221 may be increased to further improve the adhesive force.

As the bump 213, a conductor such as copper may be used, for example, to electrically connect the die pad 212 and the lead 202 with energy generated by heat, ultrasonic waves, or pressure. For example, the compression temperature is 180 to 200 degrees.

Hereinafter, the effect of the embodiment of the present invention will be described in detail with reference to FIG. 7. 7 is a schematic cross-sectional view of a situation in which a semiconductor die and a film substrate are bonded according to an embodiment of the present invention.

Referring to Figure 7, according to the present invention, by forming a dummy pattern on the base film, it can be seen that a step corresponding to the dummy pattern is generated on the lower surface of the bonding medium to increase the surface area. This increases adhesion.

Moreover, a reinforcement pad can be attached to the back surface of a base film. When adopting a soft polyimide series as the base film, bouncing effect can occur. By attaching a reinforcement pad, the bouncing effect can be suppressed and the abrupt heat loss of the curing agent of the bonding medium is minimized. The bubble phenomenon can be further suppressed.

In addition, the hardener residue between the bumps and the leads of the semiconductor die can be minimized to induce stable bonding.

Although the technical spirit of the present invention described above has been described in detail in a preferred embodiment, it should be noted that the above-described embodiment is for the purpose of description and not of limitation. In addition, the present invention will be understood by those skilled in the art that various embodiments are possible within the scope of the technical idea of the present invention.

As described above, the present invention forms a dummy pattern that is not connected to the semiconductor die in a predetermined pattern in a central portion of the base film used as an area for bonding the semiconductor die, thereby reducing the temperature difference between the semiconductor die / base film / bonding medium. In addition to reducing the space between the bonding medium and the formation of the empty space, the adhesion between the bond medium and the base film may be increased.

In addition, by additionally forming a reinforcement pad on the rear surface of the base film, it is possible to minimize the sudden heat loss of the curing agent of the bonding medium to suppress the occurrence of bubble phenomenon and to minimize the residual amount of the curing agent to further improve the adhesive properties. Can be.

Claims (9)

Base film; A plurality of leads formed in a first pattern of the base film in a predetermined pattern and electrically connected to the semiconductor die; And Including a plurality of dummy patterns formed in the second region of the base film, Wherein the first region is an edge of the base film and the second region is a central region mainly used to adhere the semiconductor die to the base film. The method of claim 1, The plurality of dummy patterns has a structure that electrically insulates the plurality of leads from each other. The method of claim 1, The plurality of dummy patterns may have isolated shape shapes and have a structure separated from the plurality of leads. The method of claim 1, A film substrate for semiconductor package, wherein the lead and the dummy pattern are made of copper. The method of claim 1, The dummy pattern is a film substrate for a semiconductor package made of copper. The method of claim 1, And a reinforcement pad attached to a rear surface of the base film to reduce heat loss of a curing agent of a bonding medium for attaching the semiconductor die to the base film. Semiconductor die; And The film substrate for semiconductor packages according to any one of claims 1 to 6; And And a bonding medium attaching the semiconductor die to the base film. The method of claim 7, wherein A plurality of pads are formed on the semiconductor die, and bumps are formed on the pads to be electrically connected to the leads through the bumps. The method of claim 7, wherein The bonding medium is an anisotropic conductive film, an anisotropic conductive paste, a nonconductive paste, or a nonconductive film.

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