1. Technical Field
The present disclosure generally relates to semiconductor package technology, and particularly to a package on package structure and a method for manufacturing the package on package structure.
2. Description of Related Art
Among the existing package structures for semiconductor, a package on package structure is one of the well-known package structures.
A typical package on package structure includes an upper package device, a lower package device, and a number of solder balls sandwiched between the upper package and the lower package device for electrically connecting the upper package device and the lower package device. However, because the pitch of the conventional solder ball is between 200 micrometers and 300 micrometers, highness of the package on package structure is higher. In addition, the temperature of the conventional package on package structure rises during thermal cycling test or actual operation, thermal stresses would easily induce in the package on package structure due to the differences of coefficient of thermal expansion (CTE) in different materials in the package on package structure, especially easily inducing warpage to the lower package device and the upper package device caused poor joints such as missing solder or cold soldering or breaking of solder balls leading to poor reliability of the package on package structure.
What is needed, therefore, is a package on package structure and a method for manufacturing the package on package structure to overcome the above-described problems.
Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, all the views are schematic, and like reference numerals designate corresponding parts throughout the several views.
A package on package structure and a method for manufacturing a package on package structure and a according to embodiments will be described with reference to the drawings.
A method of manufacturing a package on package structure according to an exemplary embodiment includes the steps as follows.
The first package device 11 includes a first circuit substrate 14, a first semiconductor chip 15, a third semiconductor chip 16, and a first package adhesive 17. The first semiconductor chip 15 and the third semiconductor chip 16 are arranged on the first circuit substrate 14. The first package adhesive 17 is arranged on the first circuit substrate 14, and covers the first semiconductor chip 15 and the third semiconductor chip 16.
The connection substrate 13 includes a substrate main body 131, a plurality of first electrically conductive posts 133, and a plurality of second electrically conductive posts 135. The first electrically conductive posts 133 and the second electrically conductive posts 135 are arranged in the substrate main body 131. The first electrically conductive posts 133 and the second electrically conductive posts 135 have the same length.
In the present embodiment, the package body 10 may be manufactured by the following steps.
First, as
The first electrically conductive pattern 143 includes a plurality of first solder pads 1431, a plurality of third solder pads 1432, and a plurality of electrically conductive traces 1433. Each of first solder pads 1431 is arranged between the third solder pads 1432. That is, the first solder pads 1431 are surrounded by the third solder pads 1432. The first solder pads 1431 spatially correspond to the first electrically conductive posts 133, and each first solder pad 1431 is aligned with the corresponding first electrically conductive post 133. The third solder pads 1432 spatially correspond to the second electrically conductive posts 135, and each third solder pad 1432 is aligned with the corresponding second electrically conductive post 135.
The second electrically conductive pattern 145 includes a plurality of first electrical contact pads 1451, a plurality of second electrical contact pads 1453, and a plurality of electrically conductive traces 1455. Each first electrical contact pad 1451 is located between the second electrical contact pads 1453. That is, the second electrical contact pads 1453 surround the first electrical contact pad 1451. The first electrical contact pads 1451 are electrically connected to the first semiconductor chip 15. That is, the first semiconductor chip 15 is arranged on the first circuit substrate 14, and is electrically connected to the first electrical contact pads 1451 using a wire bonding process, or using a surface mounted process, or using a flip chip process, thereby electrically connecting the first semiconductor chip 15 to the first circuit substrate 14. The first electrical contact pads 1451 correspond to the first solder pads 1431, and each first electrical contact pad 1451 is aligned with the corresponding first solder pad 1431. Each first electrical contact pad 1451 is electrically connected to the corresponding first solder pad 1431 using a first plated hole 142. The second electrical contact pads 1453 are electrically connected to the second semiconductor chip 16. That is, the second semiconductor chip 16 is arranged on the first circuit substrate 14, and is electrically connected to the second electrical contact pads 1453 using a wire bonding process, or using a surface mounted process, or using a flip chip process, thereby electrically connecting the second semiconductor chip 16 to the first circuit substrate 14. The second electrical contact pads 1453 corresponds to the third solder pads 1432, and each second electrical contact pad 1453 is aligned with the corresponding third solder pad 1432. Each second electrical contact pad 1453 is electrically connected to the corresponding third solder pad 1432 using a second plated hole 144. In the present embodiment, the first semiconductor chip 15 is electrically connected to the first circuit substrate 14 using a wire bonding process, and the second semiconductor chip 16 is electrically connected to the first circuit substrate 14 using a wire bonding process.
The first solder mask 147 covers at least part of first electrically conductive pattern 143, and the upper surface 141a which is exposed at the first electrically conductive pattern 143. The first solder mask 147 protects the electrically conductive traces 1433 of the first electrically conductive pattern 143 from damage. At least part of each of the first solder pads 1431 and the third solder pads 1433 is exposed at the first solder mask 147. The second solder mask 149 covers at least part of the second electrically conductive pattern 145, and the lower surface 141b which is exposed at the second electrically conductive pattern 145. The second solder mask 149 protects the electrically conductive traces of the first electrically conductive pattern 143 from damage. At least part of each of the first electrical contact pads 1451 and the second electrical contact pads 1453 are exposed at the first solder mask 147.
Second, as
In the present embodiment, the first electrically conductive posts 133 and the second electrically conductive posts 135 are manufactured by the following steps.
First, as
Second, as
Third, as
Finally, as
Third, as
In the present embodiment, the molding compound layer 13a defines a receiving hole 1311. The receiving hole 1311 passes through the first surface 131a and the second surface 131b. The first electrically conductive posts 133 surround the receiving hole 1311. The second electrically conductive posts 135 surround the first electrically conductive posts 133. In the present embedment, a material of the molding compound layer 13a is sheet molding compound, and the first surface 131a is parallel with the upper surface 141a.
Four, as
Five, as
Finally, as
Preferably, in order to prevent signal interference between the first and second semiconductor chips 15, 16, a separation sheet 12 is sandwiched between the first and second semiconductor chips 15, 16. That is, the separation sheet 12 is arranged in the second insulation adhesive layer 19. In other embodiments, the separation sheet 12 may be omitted. Then, the first package adhesive 17 is arranged on the side of the circuit substrate 14 furthest from the connection substrate 13 to obtain the package body 10. The first circuit substrate 14, the first semiconductor chip 15, the third semiconductor chip 16 and the first package adhesive 17 cooperatively constitute the first package device 11. The first package adhesive 17 covers the first semiconductor chip 15, the third semiconductor chip 16, and the surface of the first circuit substrate 14 exposed at the first and third semiconductor chips 15, 16, thereby protecting the first and third semiconductor chips 15, 16 from damage. A material of the first package adhesive 17 is epoxy molding compound. In the present embodiment, an area of a cross-section of the first package adhesive 17 taken in a plane parallel with the upper surface 141a of the first circuit substrate 14 is the same as an area of a cross-section of the first circuit substrate 14 taken in a plane parallel with the upper surface 141a of the first circuit substrate 14.
The second package device 30 includes a second circuit substrate 31, a second semiconductor chip 33 arranged on the second circuit substrate 31, and a second package adhesive 35 arranged on the second circuit substrate 31 and covering the second semiconductor chip 33.
The second circuit substrate 31 may be a single-sided circuit board, a double-sided circuit board, or a multi-layered circuit board. The second circuit substrate 31 includes a second base 311, a third electrically conductive pattern 312, a fourth electrically conductive pattern 313, a third solder mask 314, and a fourth solder mask 315. In the present embodiment, the second circuit substrate 31 is a four-layer circuit board, and there are two electrically conductive pattern layers in the second base 311.
The second base 311 includes a first insulation layer 3111, a first electrically conductive pattern layer 3112, a second insulation layer 3113, a second electrically conductive pattern layer 3114, and a third insulation layer 3115. The first electrically conductive pattern layer 3112 and the second electrically conductive pattern layer 3114 are formed on the opposite surfaces of the second insulation layer 3113. The first electrically conductive pattern layer 3112 is electrically connected to the second electrically conductive pattern layer 3114 using at least one third plated hole 317. The first insulation layer 3111 covers the first electrically conductive pattern layer 3112. A surface of the first insulation layer 3111 furthest from the second insulation layer 3113 is considered as the upper surface 311a of the second base 311. The third insulation layer 3115 covers the second electrically conductive pattern layer 3114. A surface of the third insulation layer 3115 furthest from the second electrically conductive pattern layer 3114 is considered as the lower surface 311b of the second base 311.
The third electrically conductive pattern 312 is formed on the upper surface 311a of the second circuit substrate 311, and is electrically connected to the first electrically conductive pattern layer 3112 using at least one fourth plated hole 318. The third electrically conductive pattern 312 includes a plurality of second solder pads 3121, a plurality of fourth solder pads 3122, a plurality of fifth solder pads 3123, and a plurality of electrically conductive traces (not shown). Each of the second solder pads 3121 is arranged between the fourth solder pads 3122. That is, the fourth solder pads 3122 surround the second solder pads 3121. Each of the fifth solder pads 3123 is arranged between the second solder pads 3121. That is, the second solder pads 3121 surround the fifth solder pads 3123. The second solder pads 3121 spatially correspond to the first electrically conductive posts 133, and each second solder pad 3121 is nearest the solder paste 137 on the corresponding first electrically conductive post 133, such that the first semiconductor chip 15 is electrically connected to the second circuit substrate 31 using the first electrically conductive posts 133 and the solder paste 137 on the first electrically conductive posts 133. The fourth solder pads 3122 spatially correspond to the second electrically conductive posts 135, and each fourth solder pad 3122 is nearest the solder paste 137 on the corresponding second electrically conductive post 135, such that the third semiconductor chip 16 is electrically connected to the second circuit substrate 31 using the second electrically conductive posts 135 and the solder paste 137 which is on the second electrically conductive posts 135. The third solder mask 314 covers at least part of the electrically conductive traces of the third electrically conductive pattern 312 and the upper surface 311a exposed at the third electrically conductive pattern 312, and itself exposes the second solder pads 3121, the fourth solder pads 3122, and the fifth solder pads 3123. The third solder mask 314 protects the electrically conductive traces of the third electrically conductive pattern 312 from damage.
The fourth electrically conductive pattern 313 is formed on the lower surface 211b of the second circuit substrate 311, and is electrically connected to the second electrically conductive pattern layer 3114 using at least one seventh plated hole 319 in the third insulation layer 3115. The fourth electrically conductive pattern 313 includes a plurality of sixth solder pads 3131. The fourth solder mask 315 covers at least part of the fourth electrically conductive pattern 313 and the lower surface 311b exposed at the fourth electrically conductive pattern 313, and itself exposes the sixth solder pads 3131. A plurality of solder balls 37 are formed on the exposed solder pads 3131. The solder balls 37 on the exposed solder pads 3131 are configured for electrically connecting the second circuit substrate 31 to another circuit board or other electronic elements.
The second semiconductor chip 33 may be a memory chip, a logic chip, or a digital chip. In the present embodiment, the second semiconductor chip 33 is a logic chip. The second semiconductor chip 33 is adhered to the surface of the third solder mask 314 using a third insulation adhesive layer 38, and is electrically connected to the fifth solder pads 3123 using a wire bonding process, using a surface mounted process, or using a flip chip process. In the present embodiment, the second semiconductor chip 33 is packaged on the second circuit substrate 31 using a flip chip process. The second semiconductor chip 33 is electrically connected to the fifth solder pads 3123 using solder bumps 331.
The second package adhesive 35 is attached on the third solder mask 314 of the second circuit substrate 31, and covers the second semiconductor chip 33 to protect the second semiconductor chip 33 from damage. The second package adhesive 35 may be attached on the third solder mask 314 using a printing process or using a molding process. An area of a cross-section of the second package adhesive 35 taken in a plane parallel with the upper surface 311a is larger than an area of a cross-section of the second semiconductor chip 33 taken in a plane parallel with the upper surface 311a, and is smaller than an area of a cross-section of the receiving hole 1311 taken in a plane parallel with the upper surface 141a, thereby covering the second semiconductor chip 33 with the second package adhesive 35 received in the receiving hole 1311. A material of the second package adhesive 35 may be epoxy molding compound.
The package on package structure 100 includes the connection substrate 10, the first package device 21 being arranged on one side of the connection substrate 10, and the second package device 30 being arranged on the other side of the connection substrate 10. The first package device 11 includes the first circuit substrate 14, the first semiconductor chip 15, and the third semiconductor chip 16. The first semiconductor chip 15 and the third semiconductor chip 16 are arranged on the first circuit substrate 14. The first circuit substrate 14 includes the first solder pads 1431 and the third solder pads 1432. The first solder pads 1431 and the third solder pads 1432 are arranged at the same side of the first circuit substrate 14, and the third solder pads 1432 surround the first solder pads 1431. The first solder pads 1431 are electrically connected to the first semiconductor chip 15, and the third solder pads 1432 are electrically connected to the third semiconductor chip 16. The connection substrate 13 includes a substrate main body 131, the first electrically conductive posts 133, and the second electrically conductive posts 135. The first electrically conductive posts 133 and the second electrically conductive posts 135 are arranged in the substrate main body 131. The substrate main body 131 has the first surface 131a and the second surface 131c. The first surface 131a is adhered to the surface of the first circuit substrate 14 on which the first solder pads 1431 are formed. The second electrically conductive posts 135 surround the first electrically conductive posts 133, and each of the first electrically conductive posts 133 and the second electrically conductive posts 135 passes through the first surface 131a and the second surface 131b. The first electrically conductive posts 133 spatially correspond to the first solder pads 1431, and an end of each first electrically conductive post 133 nearest to the first surface 131a is in contact with and electrically connected to the corresponding first solder pad 1431. A solder paste 137 is printed on the distal end surface of each first electrically conductive post 133 nearest to the second surface 131b. The second electrically conductive posts 135 spatially correspond to the third solder pads 1432, and an end of each second electrically conductive post 135 nearest to the first surface 131a is in contact with and electrically connected to the corresponding third solder pad 1432. A solder paste 137 is printed on an end surface of each second electrically conductive post 135 nearest to the second surface 131b. The second package device 30 includes the second circuit substrate 31 and the second semiconductor chip 33 arranged on the second circuit substrate 31. The second circuit substrate 31 includes the second solder pads 3121 and the fourth solder pads 3122. The second solder pads 3122 and the fourth solder pads 3122 are exposed at the same side of the second circuit substrate 31. The second solder pads 3121 spatially correspond to the first electrically conductive posts 133, and each second solder pad 3121 is soldered to an end of the corresponding first electrically conductive post 133 nearest to the second surface 131b using a solder paste 137 printed on the corresponding first electrically conductive post 133. The fourth solder pads 3122 spatially correspond to the second electrically conductive posts 135, and each fourth solder pad 3122 is soldered to an end of the corresponding second electrically conductive post 135 nearest to the second surface 131b using a solder paste 137 printed on the corresponding second electrically conductive post 133, such that the second package device 30 is soldered to the second surface 131c of the connection substrate 13.
In the package on package structure 100, the connection substrate 13 is laminated onto the first package device 11, and the connection substrate 13 is attached to the second package device 30 using solder paste 137 on the first and second electrically conductive posts 133, 135 in the connection substrate 13. Accordingly, the first package device 11 is connected to the second package device 30 using the connection substrate 13, not using the solder balls. The rate of finished product of the package on package structure 100 is thus significantly improved. In addition, the method for manufacturing the package on package structure 100 is very simple, and the cost of the method is much lower.
In other embodiments, there may be another package device arranged on the surface of the first package adhesive 17 furthest from the connection substrate 13, and there may be another package device arranged on the surface of the second package device 30 furthest from the connection substrate 13, thereby obtaining a package on package structure having three package devices, four package devices, or more than four package devices.
While certain embodiments have been described and exemplified above, various other embodiments will be apparent from the foregoing disclosure to those skilled in the art. The disclosure is not limited to the particular embodiments described and exemplified but is capable of considerable variation and modification without departure from the scope and spirit of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012103179936 | Aug 2012 | CN | national |