TWI654725B - Package with a film adhered on a die for reducing stress borne by the die - Google Patents

Abstract

A package structure includes a first die, a first film, a second die, a second film, a conductive bump, and an adhesive layer. The first die may include a first face, a second face, and a conductive pin formed on the second face of the first die. The first film is coupled to the first surface of the first die to reduce the stress on the first die. The second die may include a first face, a second face, and a conductive pin formed on the first face of the second die. The second film is coupled to the second surface of the second die. The conductive bumps may be disposed between the conductive pads of the first die and the conductive pins of the second die. The sealant layer is formed to cover the first die, the first film, the second die, the second film, and the conductive bump.

Description

A package structure in which a film is adhered to a grain to reduce stress on the grain

The present invention relates to a package structure, and more particularly to a package structure in which a film is adhered to a film to reduce stress on the grain.

In the packaging process, molding is a widely used procedure for fixing and protecting components of the package structure, such as die, wires, bumps, and the like. The sealant material can be, for example, a resin or a plasticizer that can be initially heated to a liquid state and then poured into the package structure until it surrounds the component and finally solidifies to form a sealant layer. Although the sealant layer can achieve the protective effect by coating the component, reliability is still a problem to be solved. For example, thermal stress will result in a decrease in the reliability of the package structure. Since the coefficient of thermal expansion (CTE) of the crystal grain is different from the thermal expansion coefficient of the sealant layer surrounding the crystal grain, when the temperature changes, the contact surface of the crystal grain and the sealant layer generates thermal stress. When this thermal stress is greater than the strength that the wafer can withstand, the die may be damaged. Therefore, there is a need in the art for a solution to improve the reliability of the package structure.

Embodiments of the present invention provide a package structure including a first die, a first film, a second die, a second film, a conductive bump, and an adhesive layer. The first die may include a first face, a second face, and a conductive pin. The conductive pin of the first die is formed on the second face of the first die. The first film is physically coupled to the first surface of the first die to reduce stress on the first die. The second die may include a first surface, a second surface, and a first conductive pin. The first conductive pin of the second die is formed on the first surface of the second die. The second film is physically coupled to the second side of the second die. The conductive bumps may be disposed between the conductive pads of the first die and the first conductive pin of the second die. The sealant layer can be used to coat the first die, the first film, the second die, the second film, and the conductive bump.

Another embodiment of the present invention provides a package structure including a die, a film, a substrate, a conductive bump, and an adhesive layer. The die may include a first surface, a second surface, and a conductive pin. The conductive pin of the die is formed on the second side of the die. The film is physically coupled to the first side of the die to reduce stress on the die. The substrate may include a first surface and a second surface opposite to the first surface of the substrate, and a circuit structure formed between the first surface of the substrate and the second surface of the substrate. And a conductive interface formed on the first surface of the substrate and electrically connected to the circuit structure of the substrate. The conductive bumps may be disposed between the conductive pads of the die and the conductive interface of the substrate. The sealant layer may be formed on the first side of the substrate to cover the die, the film and the conductive bump.

1 is a schematic view of a package structure 100 in accordance with an embodiment of the present invention. The package structure 100 can include a first die 110, a first film 115, a second die 120, a second film 125, a first conductive bump 155, and a sealant layer 188. The first die 110 may include a first face 110a, a second face 110b, and a conductive pin 1101. The conductive pin 1101 is formed on the second face 110b of the first die 110. The first film 115 is physically coupled to the first surface 110a of the first die 110 to reduce the stress on the first die 110. The second die 120 may include a first surface 120a, a second surface 120b, and a first conductive pin 1201. The first conductive pin 1201 may be formed on the first surface 120a of the second die 120. The second film 125 can be physically bonded to the second surface 120b of the second die 120. The conductive pin 1101 can be an input/output interface for accessing the first die 110. The conductive pin 1201 can be an input/output (I/O) interface for accessing the second die 120. The first conductive bump 155 can be disposed between the conductive pin 1101 of the first die 110 and the first conductive pin 1201 of the second die 120 to electrically connect the first die 110 to the second die 120. . The sealant layer 188 can be used to coat the first die 110, the first film 115, the second die 120, the second film 125, and the first conductive bumps 155. As the material of the sealant layer 188, an epoxy molding compound (EMC) or other suitable resin, plastic compound, or a synthetic material of a resin and/or a plastic compound may be used.

As shown in FIG. 1 , when the first film 115 is adhered to the first surface 110 a of the first die 110 , the first film 115 may be located between the first die 110 and the sealant layer 188 . The first film 115 serves as a buffer layer and absorbs thermal stresses that are not to be generated between the first die 110 and the sealant layer 188. Therefore, the thermal stress generated by the temperature change between the first die 110 and the sealant layer 188 can be reduced. The degree of deformation of the first die 115 different from the sealant layer 188 can be absorbed by the first film 115. The stress may be generated by the difference in thermal expansion coefficient and/or Young's modulus of the first die 110 and the sealant layer 188, and the stress may be absorbed and slowed down. Therefore, the first die 110 can be better protected while avoiding defects that do not occur.

As shown in FIG. 1 , in the package structure 100 , the second die 120 may further include a second conductive pin 1202 . The second conductive pin 1202 can be formed on the first face 120a of the second die 120. Similar to the first conductive pin 1201, the second conductive pin 1202 can be an input/output interface for accessing the second die 120. The package structure 100 can further include a substrate 130, a second conductive bump 156, and a wire 166. The substrate 130 can include a first surface 130a, a second surface 130b, a circuit structure 130c, a first conductive interface 1301, and a second conductive interface 1302. The second film 125 can be located on the first side 130a of the substrate 130. In other words, the second die 120 electrically connected to the first die 110 through the first conductive bump 155 may be disposed on the first face 130a. The circuit structure 130c may be formed on the substrate 130. For example, when the substrate 130 is a four-layer substrate, the circuit structure 130c may be formed in a four-layer structure of the substrate 130. At least one of the conductive layers of the substrate 130 may be laid on the surface of the substrate 130. The first conductive interface 1301 can be formed on the first surface 130a of the substrate 130 and electrically connected to the circuit structure 130c to serve as an input/output interface of the access circuit structure 130c. Each of the wires 166 can connect a second conductive pin 1202 of the second die 120 and a first conductive interface 1301 of the substrate 130 to form a communication path between the second die 120 and the substrate 130. The second conductive interface 1302 can be formed on the second surface 130b of the substrate 130 and electrically connected to the circuit structure 130c. The second conductive bump 156 can be soldered to the second conductive interface 1302. The solder resist layer 130sr can be used to protect the substrate 130 from oxidation of the substrate 130, and can prevent the undesired solder bridge structure from being formed between the plurality of second conductive interfaces 1302, resulting in an erroneous electrical connection path.

The second conductive bump 150 can be used to electrically connect the external device, so that the external device accesses the first die 110, the second die 120, and the circuit structure 130c through the second conductive bump 150.

According to an embodiment of the present disclosure, a second conductive interface 1302 may correspond to a first conductive interface 1301. A pair of mutually corresponding first conductive interfaces 1301 and second conductive interfaces 1302 are electrically connectable to each other. According to another embodiment, a second conductive interface 1302 can be electrically connected to the plurality of first conductive interfaces 1301. This may depend on the architecture of the substrate 130.

The conductive pin 1101, the first conductive pin 1201, the second conductive pin 1202, the first conductive interface 1301 and the second conductive interface 1302 are shown as protruding from the first crystal in FIG. The surface of the pellet 110, the second die 120, and the substrate 130. However, this is merely an example diagram to explain the architecture of the package structure 100, and is not intended to limit the scope of the invention. According to an embodiment of the invention, the conductive pin 1101, the first conductive pin 1201, the second conductive pin 1202, the first conductive interface 1301 and the second conductive interface 1302 can also be fabricated as a flat conductive portion, exposed to the first The surface of the die 110, the second die 120, and the substrate 130.

According to an embodiment of the invention, the thickness of the first film 115 may range from 5 micrometers to 50 micrometers. The first film 115 may employ a die attach film (DAF). Because the first film 115 serves as a buffer layer, the first film 115 can be softer and/or more elastic than the sealant layer 188 and the first die 110. Therefore, the first film 115 can have a first crystal. The pellets 110 and the sealant layer 188 have a lower Young's modulus. In addition, the first film 115 may have a lower coefficient of thermal expansion than the first die 110 and the sealant layer 188. The first film 115 can thereby reduce the stress caused by the degree of thermal expansion or the degree of thermal contraction between the first die 110 and the sealant layer 188. Since the undesired stress experienced by the first die 110 is reduced, the reliability of the package structure 100 can be improved.

2 is a schematic view of a package structure 200 in accordance with another embodiment of the present invention. The package structure 200 can include a die 210, a film 215, a substrate 230, a conductive bump 255, and a sealant layer 288. The die 210 may be similar to the first die 110 of FIG. 1, and the substrate 230 may be similar to the substrate 130 of FIG. Therefore, the relevant details are not repeated. Different from the package structure 100 of FIG. 1, the package structure 200 of FIG. 2 may comprise a single die instead of a plurality of die. The conductive bump 255 can be disposed between the conductive pin 2101 of the die 210 and the first conductive interface 2301 of the substrate 230 to form an electrical connection path between the die 210 and the substrate 230. The first conductive interface 2301 formed on the first surface 230a of the substrate 230 can be electrically connected to the circuit structure 230c of the substrate 230. The substrate 230 can include a second conductive interface 2302. The second conductive interface 1302 can be formed on the second surface 230b of the substrate 230 and electrically connected to the circuit structure 230c. The package structure 200 may further include a second conductive bump 256, for example, soldered to the second conductive interface 2302, and electrically connected to the external device. The solder resist layer 230sr can be used to protect the substrate 230 from oxidation of the substrate 230, and prevents the undesired solder bridge structure from being formed between the plurality of second conductive interfaces 2302, resulting in an erroneous electrical connection path. In the same manner as the package structure 100, the die 210 of the package structure 200 may be damaged by undesired stress due to the difference in thermal expansion coefficient and/or Young's modulus of the die 210 and the sealant layer 288. The film 215 acts as a buffer layer to absorb stress and protect the die 210 from damage. Similar to the first film 115, the film 215 can be a die attach film having a lower Young's modulus and/or thermal expansion coefficient than the die 210 and the sealant layer 288.

FIG. 3 is a flow chart of a packaging method 300 of an embodiment of the present invention. Packaging method 300 can be used to form package structure 100. Figures 4-11 may correspond to the process steps of forming package structure 100. The encapsulation method 300 can include:

Step 305: soldering the first conductive bump 155 to the conductive pin 1101 of the first die 110;

Step 307: pasting the first film 115 to the first surface 110a of the first die 110, proceeds to step 340;

Step 310: Adhering the second film 125 to the second surface 120b of the second die 120;

Step 320: The second die 120 is disposed on the first surface 130a of the substrate 130;

Step 330: wire 166 is connected between the second conductive pin 1202 and the first conductive interface 1301;

Step 340: The first conductive bump 155 is soldered to the first conductive pin 1201 of the second die 120, thereby electrically connecting the first die 110 to the second die 120;

Step 350: Injecting a sealing material to form a sealing layer 188, the sealing layer 188 may cover the first film 115, the first die 110, the first conductive bumps 155, the second die 120, and the wires 166;

Step 360: Solder the second conductive bump 156 to the second conductive interface 1302 of the substrate 130.

Steps 305 and 307 may correspond to Figures 4-5. Steps 310-360 may correspond to Figures 6-11. The order of FIG. 3 is merely an example, and other sequences of suitable process steps for fabricating the package structure 100 are also within the scope of the present invention.

Figure 12 is a flow diagram of a packaging method 1200 in accordance with an embodiment of the present invention. Packaging method 1200 can be used to form package structure 200. Referring to Figures 2 and 12, the packaging method 1200 can include:

Step 1210: soldering the first conductive bump 255 to the conductive pin 2101 of the die 220;

Step 1220: Adhesive film 215 on the first side 210a of the die 210;

Step 1230: The first conductive bump 255 is soldered to the first conductive interface 2301 of the substrate 230, thereby electrically connecting the die 220 and the substrate 230;

Step 1240: Injecting a sealing material to form a sealing layer 288, the sealing layer 288 can cover the film 215, the die 210, and the first conductive bump 255;

Step 1250: Solder the second conductive bump 256 to the second conductive interface 2302 of the substrate 230.

In summary, by using the package structure and the packaging method provided by the embodiments of the present invention, the film can be adhered to the die, and the film can be located between the die and the sealant layer.多余 Excessive stress due to different physical properties such as coefficient of thermal expansion and/or Young's modulus can be effectively reduced. The die can be better protected from stress damage and the reliability and yield of the package structure can be improved. The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

100,200‧‧‧Package structure

110‧‧‧First grain

120‧‧‧Second grain

130, 230‧‧‧ substrate

110a, 120a, 130a, 210a, 230a‧‧‧ first side

110b, 120b, 130b, 230b‧‧‧ second side

1101, 2101‧‧‧ conductive feet

1201‧‧‧First conductive pin

1202‧‧‧Second conductive pin

166‧‧‧ wire

130c, 230c‧‧‧ circuit structure

115‧‧‧First film

125‧‧‧Second film

188, 288‧‧ ‧ sealant layer

1301, 2301‧‧‧ first conductive interface

1302, 2302‧‧‧ second conductive interface

155, 255‧‧‧ first conductive bump

156, 256‧‧‧ second conductive bump

130sr, 230sr‧‧‧ solder mask

215‧‧‧film

210‧‧‧ grain

300, 1200‧‧‧Packing method

305-360, 1210-1250‧‧‧ steps

1 is a schematic view showing a package structure of an embodiment of the present invention. Figure 2 is a schematic illustration of a package structure in accordance with another embodiment of the present invention. Fig. 3 is a flow chart showing a method of packaging the package structure of Fig. 1 in the embodiment of the present invention. 4-11 are schematic views of a process corresponding to the package structure forming the first figure. Figure 12 is a flow chart showing a method of packaging the package structure of Figure 2 in the embodiment of the present invention.

Claims (8)

A package structure includes: a first die, a first surface, a second surface, and a conductive pin, wherein the conductive pin of the first die is formed on the first die a first film, physically coupled to the first surface of the first die, thereby reducing stress on the first die, wherein the first film is a die attach film; The second die includes a first surface, a second surface, and a first conductive pin. The first conductive pin of the second die is formed on the first surface of the second die; The second conductive film is physically coupled to the second surface of the second die; a first conductive bump disposed on the conductive pin of the first die and the first conductive leg of the second die And a glue layer for covering the first die, the first film, the second die, the second film, and the first conductive bump. The package structure of claim 1, wherein the second die further comprises a second conductive pin formed on the first side of the second die, and the package structure further comprises: a substrate comprising: a first surface, wherein the second film is disposed on the first surface of the substrate; a second surface is located opposite the first surface of the substrate; a circuit structure is formed on the substrate; a first conductive interface formed on the first surface of the substrate and electrically connected to the circuit structure; and a wire electrically connected to the second conductive pin of the second die and the first conductive interface of the substrate . The package structure according to claim 1, wherein the Young's coefficient of the first film is smaller than the first The Young's modulus of a grain is less than the Young's modulus of the sealant layer. The package structure of claim 1, wherein the first film has a coefficient of thermal expansion that is less than a coefficient of thermal expansion of the first die and less than a coefficient of thermal expansion of the sealant layer. A package structure comprising: a die comprising a first surface, a second surface, and a conductive pin, the conductive pin of the die being formed on the second side of the die; a film, physics Is coupled to the first surface of the die, thereby reducing stress on the die; a substrate comprising: a first surface; a second surface located at an opposite position of the first surface of the substrate; a circuit structure formed between the first surface of the substrate and the second surface of the substrate; and a first conductive interface formed on the first surface of the substrate, the circuit structure electrically connected to the substrate a first conductive bump disposed between the conductive pin of the die and the first conductive interface of the substrate; and an adhesive layer formed on the first side of the substrate for coating The die, the first film and the first conductive bump, wherein a Young's modulus of the film is less than a Young's modulus of the die, and less than a Young's modulus of the sealant layer, and a thermal expansion coefficient of the film It is smaller than the thermal expansion coefficient of the crystal grain and smaller than the thermal expansion coefficient of the sealant layer. The package structure of claim 2 or 5, wherein the substrate further comprises a second conductive medium The surface is formed on the second surface of the substrate, and the circuit structure is electrically connected to the substrate, and the package structure further includes a second conductive bump disposed on the second conductive interface of the substrate. The package structure of claim 5, wherein the film is a die attach film. The package structure of claim 1 or 5, wherein the sealant layer is formed using an epoxy molding compound.