KR20000041231A - Semiconductor package - Google Patents

Abstract

PURPOSE: A semiconductor package is to enhance the heat radiation capability and the chip protection capability of the stiffner attached on the rear surface of the semiconductor chip. CONSTITUTION: A semiconductor package(100) comprises: a substrate(20) having a bonding pad(22); a semiconductor chip(10) whose one surface is in contact with the bonding pad to electrically connect with the substrate; and a stiffner(40) attached on the other surface of the semiconductor chip, for radiating heat generated from the semiconductor chip and protecting the semiconductor chip from external force, the stiffner being first bent to form an upper plate(41) and a side wall(42), the upper plate covering the semiconductor chip and the bent side walls of the stiffner encircling the both edges of the semiconductor chip.

Description

Semiconductor package

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor package, such as a flip-type semiconductor package, and more particularly, to first bend the edge of a stiffener so that the stiffener holds the top plate and the side plate, whereby the upper and side portions of the semiconductor chip The present invention relates to a semiconductor package which allows the stiffener to perform more stable "heat dissipation" and "chip protection" by being covered by the top and side plates.

In recent years, as the information processing speed of electronic devices and information devices has increased, the semiconductor chips used therein have also increased in speed, and in response to this trend, semiconductor packages have become increasingly multi-pinned. In accordance with the trend of multi-pinning of the semiconductor package, a flip chip type semiconductor package in which wires have been removed has been developed and widely received.

However, in recent years, as information processing speeds of electronic devices and information devices are increased, driving speeds of semiconductor packages, for example, flip-type semiconductor packages, which are used therein, have also been very fast. Various methods for smoothly dissipating heat generated in the field have been studied in depth.

In general, in a conventional flip-type semiconductor package, a semiconductor chip is inverted so that the active surface faces the substrate, unlike a general semiconductor chip, and the surface of the chip is in contact with the substrate through a conductive medium such as solder bumps. In addition, the back surface of the chip is exposed in the opposite direction of the substrate.

At this time, a plate-shaped stiffner is mounted on the rear surface of the semiconductor chip in a state parallel to the semiconductor chip. The stiffener serves to discharge heat generated from the semiconductor chip to the outside and during the process, When an impact is applied to the semiconductor chip at, by blocking the impact, it serves to prevent damage to the semiconductor chip in advance.

The flip chip type semiconductor package in which the stiffener mounting is completed, then performs a high speed operation in a state of being in contact with a substrate through solder bumps or the like, thereby quickly performing a role given to the self.

Such a conventional structure of solder bumps is, for example, US Patent No. 4950623 "Method of building solder bumps", US Patent No. 5162257 "Solder bump fabrication method" and the like. It is presented in detail.

At this time, the heat generated by the high-speed operation of the semiconductor chip is quickly released to the outside through, for example, a heat sink through the stiffener, the semiconductor chip performs a stable operation without unnecessary deterioration.

However, there are some serious problems with these conventional semiconductor packages.

As described above, a plate-shaped stiffener is mounted on the rear surface of the semiconductor chip to release heat generated from the semiconductor chip to the outside and to protect the semiconductor chip from external shocks. In order to increase the "heat dissipation ability" and "chip protection ability", additional measures such as increasing the size of the stiffener or increasing the thickness of the stiffener are required.

However, when the size of the stiffer is increased or the thickness is increased, the occupied space of the stiffener is greatly increased, and as a result, the overall size of the semiconductor package employing the stiffener is increased, whereby the semiconductor package can be densely mounted on the main board. Unavoidable problems are caused.

As a result of these problems, despite the advantages of increasing the "heat dissipation ability" and "chip protection ability" in the production line, it is not possible to significantly increase the size and thickness of the stiffener.

As a result, when the "heat dissipation ability" and "chip protection ability" of the stiffeners are maintained at a flat level, "deterioration failure of semiconductor chips" and "damage of semiconductor chips" frequently occur, and as a result, the overall process of the product The problem that efficiency falls significantly is caused.

Therefore, an object of the present invention is to improve the "heat dissipation ability" and "chip protection ability" of the stiffener while maintaining the size and thickness of the stiffener at an appropriate level.

Another object of the present invention is to improve the "heat dissipation ability" and "chip protection ability" of the stiffener, thereby preventing the frequent "deterioration failure", "damage by external impact", etc. of the semiconductor chip in advance.

Still another object of the present invention is to prevent the "deterioration failure", "damage caused by external shock", etc. of the semiconductor chip in advance, thereby significantly improving the overall process efficiency.

Still other objects of the present invention will become more apparent from the following detailed description and the accompanying drawings.

1 is an exemplary view showing a semiconductor package according to an embodiment of the present invention.

2 is an exemplary view showing a semiconductor chip employed in the present invention.

3 is an exemplary view showing a semiconductor package according to another embodiment of the present invention.

In order to achieve the above object, in the present invention, the structure of the stiffener is changed to an appropriate shape, and the edge of the stepper is firstly bent to form upper and side plates at adjacent portions of the semiconductor chip. At this time, the top plate is in contact with one surface of the semiconductor chip in a state covering the semiconductor chip, the side plate is placed on the edge side of the semiconductor chip.

When the present invention achieves such a configuration, the stiffeners have more side plates than the conventional ones, and thus, their overall size is increased, and as a result, their "heat dissipation ability" and "chip protection ability" are appropriate. As a result, the semiconductor chip can be prevented in advance from "deterioration failure", "damage by external shock", etc. by the action of the stiffener. In the case of the present invention, since the side plate has a shape bent adjacent to the edge of the semiconductor chip, while the stiffener exhibits the effect of increasing its size, the stiffener occupies an appropriate level of occupied space, so that the overall size of the package does not increase. Can be suppressed.

As a result, the semiconductor package employing the present invention can be mounted on the main board with high density while maintaining excellent size of heat dissipation and chip protection.

When the present invention is achieved, the semiconductor chip can be prevented in advance from "deterioration failure", "damage by external shock", etc. by the action of the stiffener of the present invention, which has been improved in shape, and finally, the overall process of the production line The efficiency can be significantly improved.

Hereinafter, a semiconductor package according to the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, in the semiconductor package 100 according to the present invention, the surface of the substrate 20 may be electrically connected with circuit patterns of the substrate 20 and internal electrical components such as the semiconductor chip 10. Bonding pads 22 are provided to provide a conductive path, and a signal terminal 21 is provided on the rear surface of the substrate 20 to provide an electrical conductive path between the substrate 20 and an external circuit block. The signal terminal may have various shapes such as BGA, PGA, and LGA. 1 illustrates a signal terminal having a PGA shape as an example.

In this case, a semiconductor chip 10 electrically connected to circuit patterns of the substrate 20 is disposed on the bonding pad 22 by contacting one surface thereof, for example, the surface with the bonding pad 22. On both sides of the semiconductor chip 10 including the upper portion of the bonding pad 22, an underfilling portion for alleviating the difference in thermal expansion coefficient between the bonding pad 22, the conductive bumps 16, and the semiconductor chip 10 ( 50) is further formed.

In this case, as shown in FIG. 2, the semiconductor chip 10 includes, for example, a chip body 11 made of silicon, a pad metal 12 disposed on the chip body 11, and a pad metal 12. Laminated structure of the passivation film 13 surrounding both sides of the pedmetal 12 so as to expose the center of the metal film, and the polyimide film 15 disposed on the passivation film 13 so that the center of the pad metal 12 is exposed Is made of.

Here, for example, a ball-shaped conductive bump 16 is formed on the polyimide film 15 to be in contact with the pad metal 12. The conductive bump 16 is inverted by the semiconductor chip 10. When the surface is mounted on the substrate 20 with the surface exposed in the direction of the substrate 20, the chip body 12 receives electrical signals output from circuit patterns of the substrate 20 by contacting the bonding pads 22. To be delivered quickly.

Here, as shown in the drawing, at the interface between the conductive bump 16, the polyimide film 15, and the pad metal 12, for example, an under bump metallurgy (UBM) film made of Cr, Cr / Cu, or Cu ( 17) is further formed.

Meanwhile, as shown in FIG. 1, the stiffener 40 is attached to the upper portion of the semiconductor chip 10 with the adhesive layer interposed therebetween, and the stiffener 40 is generated from the semiconductor chip 10. In addition to dissipating heat to the outside, during the process, when the external force is applied to the semiconductor chip 10, by buffering it to its front surface, so that the semiconductor chip 10 can be stably protected from the external force It plays a role.

At this time, the stiffener 40 is made of a material such as synthetic resin or metal, for example, one surface of the stiffener 40 is further formed with a heat radiation fin 43 to maximize the heat dissipation effect.

As shown in the figure, the stiffener 40 of the present invention forms a structure in which the edge is bent primarily to form the upper plate 41 and the side plate 42. At this time, the upper plate 41 is in contact with the semiconductor chip 10 while covering the semiconductor chip 10, the side plate 42 is the edge of the semiconductor chip 10 in a state separated from the semiconductor chip 10 by a predetermined distance It is placed in the immediate vicinity.

Such a stiffener 40 is a constituent forming the gist of the present invention, of course, the stiffener 40 of the present invention forms a completely different structure from the conventional stiffener.

When the present invention achieves such a configuration, the stiffener 40 has a side plate 42 more than the conventional structure. In this case, the stiffener 40 is capable of dissipating heat generated from the semiconductor chip 10 not only through its top plate 41 but also through the side plate 42, so that the " heat dissipation ability " It shows a remarkable improvement over the prior art. In addition, the stiffener 40 of the present invention can protect not only the upper part of the semiconductor chip 40 but also the side part by using both the upper plate 41 and the side plate 42, so that the " chip " Protection capability "represents a significant improvement over the prior art.

At this time, although the stiffener 40 of the present invention further has a side plate, instead of extending in parallel with the semiconductor chip, the side plate 40 is bent at a right angle, for example, adjacent to the edge of the semiconductor chip 10. Because of the shape, even if the stiffener 40 of the present invention further has the side plate 42, the stiffener 40 can maintain a proper level of occupied space in the entire semiconductor package.

As a result, the stiffener 40 of the present invention exhibits the effect of increasing its size by the formation of the side plate 42, while occupying an appropriate level of occupied space, thereby suppressing the overall size of the semiconductor package from increasing. Can be done.

In the conventional case, the production line could not do this, knowing that increasing the size of the stiffeners or increasing the thickness could increase the "heat dissipation" and "chip protection" of the stiffeners. When the size of the stiffener is increased or the thickness is increased, the occupied space of the stiffener is greatly increased, and the overall size of the semiconductor package employing the stiffener is increased, so that the semiconductor package cannot be mounted on the main board with high density. Because it was caused.

However, in the present invention, in the production line, the side plate 42 is further formed on the stiffener 40, and the side plate 42 is bent toward the edge of the semiconductor chip, whereby the stiffener 40 is formed on the side plate 42. While forming the effect of increasing its size by forming, it is possible to maintain an appropriate level of occupied space in the semiconductor package. Of course, in this case, since the semiconductor package can maintain an appropriate size, in the production line, the semiconductor package can be mounted on the main board with high density.

At this time, in the present invention, the thermal conductivity between the stiffener 40 and the semiconductor chip 10 is excellent, for example, a binder layer 30 made of grease, epoxy, and solder metal is formed therebetween. Let's do it. Since the binder layer 30 of such a material is generally known to be very excellent in thermal conductivity and excellent in adhesion to the bonding interface, the bonding agent layer 30 is interposed between the semiconductor chip 10 and the stiffener 40. In this case, the stiffener 40 may be firmly disposed on the upper portion of the semiconductor chip, and the semiconductor chip 10 may transmit heat generated by its high-speed operation through the adhesive layer 30 and the stiffener 40. It can be released quickly.

At this time, as shown in the figure, the upper surface of the semiconductor chip 10, for example, VNi / Au, Ti / VNi / Au, Cr / Au, Ti / Pt / Au, Cr / CrCu / (Cu) / Au, Metal layer with TiW / (Cu) / Au, VNi / Pd, Ti / VNi / Pd, Cr / Pd, Ti / Pt / Pd, Cr / CrCu / (Cu) / Pd, TiW / (Cu) / Pd 14 is further formed. The metal layer 14 is interposed between the semiconductor chip 10 and the bonding layer 30, thereby performing a function to greatly improve the contact between the semiconductor chip 10 and the bonding layer 30.

At this time, as shown in the figure, the stiffener 40 of the present invention, for example, forms a structure in which the thickness of the upper plate 41 and the side plate 42 are different. In this case, for example, the top plate 41 maintains a thicker thickness than the side plate 42.

In general, heat dissipation of the semiconductor chip is mainly performed via the top plate 41 of the stiffener 40. In the present invention, the top plate 41 of the stiffener 40 is formed to be thicker than the side plate 42. . On the contrary, in the semiconductor chip 10, the amount of heat released toward the side plate 42 is weaker than that of the top plate 41. In the present invention, in view of this, the side plate 42 of the stiffener 40 is lower than the top plate 41. Form thinner.

In addition, since the external force applied to the semiconductor chip mainly acts on the upper part of the semiconductor chip 10, in view of the present invention, the upper plate 41 of the stiffener 40 positioned on the upper side of the semiconductor chip 10 is provided with a side plate ( 42) thicker than that. On the contrary, since a relatively weak external force acts on the side of the semiconductor chip 10 compared to the upper side, in view of the present invention, the side plate 42 of the stiffener 40 located on the side of the semiconductor chip 10 has a top plate ( 41) thinner than that.

When the present invention is achieved, the stiffener 40 can occupy a minimum occupied space in the entire semiconductor package while maximizing its "heat dissipation capability" and "chip protection capability". As a result, the semiconductor package employing the present invention can be mounted on the main board with high density while maintaining excellent size of heat dissipation and chip protection.

Of course, in contrast to the above-described case, the side plate 42 of the stiffener 40 may have a thickness thicker than that of the top plate 41. Each structure of the stiffener 40 can be freely selected according to the actual situation of the production line.

Meanwhile, as shown in FIG. 3, according to another embodiment of the present invention, the stiffener 40 may have a structure in which the thicknesses of the upper plate 41 and the side plate 42 are the same. In this case, for example, both the upper plate 41 and the side plate 42 may maintain a thick thickness, or both may maintain a thin thickness. As an example, FIG. 3 shows a shape in which both the top plate 41 and the side plate 42 maintain a thick thickness.

As described above, the heat dissipation of the semiconductor chip 10 is performed through both the upper plate 61 and the side plate 62 of the stiffener 60. If the upper plate 61 and the side plate 62 are both thick, In the case of maintaining the semiconductor chip 10, the semiconductor chip 10 may be provided with more smooth heat dissipation in proportion to the thicknesses of the upper plate 61 and the side plate 62.

In addition, as described above, the external force applied to the semiconductor chip 10 simultaneously acts on the upper side and the side portion of the semiconductor chip 10. If the top plate 61 and the side plate 62 of the stiffener 60 are both In the case of maintaining a thick thickness, the semiconductor chip 10 may be more stably protected in proportion to the thicknesses of the upper plate 61 and the side plate 62.

As another example, according to another embodiment of the present invention, if both the top plate 61 and the side plate 62 of the stiffener 60 maintains a thin thickness, the stiffener 60 may not achieve smooth heat dissipation although By minimizing the total size thereof, the area of the semiconductor package can be minimized. In this case, the semiconductor package employing the stiffener 60 according to another embodiment of the present invention Because of its compact size, it can be easily mounted on the main board.

Further, according to another embodiment of the present invention, when both the top plate 61 and the side plate 62 of the stiffener 60 maintains a thin thickness, the stiffener 60 may not perform a stable chip protection function, As described above, by minimizing the total size thereof, it is possible to minimize the occupied area of the semiconductor package. In this case, as described above, according to another embodiment of the present invention Since the semiconductor package employing the stiffener 60 can maintain a more compact size, the semiconductor package employing the stiffener 60 according to another embodiment of the present invention can be more easily and densely mounted on the main board.

On the other hand, in the semiconductor package according to another embodiment of the present invention constituting such a structure, as in the case of the above-described embodiment, since the stiffener 60 has more side plates 62 than the conventional structure, Since the heat generated from the semiconductor chip can be released not only through the top plate 61 but also through the side plate 62, in the end, when the present invention is implemented, the "heat dissipation capacity" of the stiffener 60 is remarkably improved compared with the prior art. Will be displayed. In addition, the stiffener 60 according to another embodiment of the present invention is able to protect not only the upper part of the semiconductor chip 10 but also the side part by using both its upper plate 61 and the side plate 62, and thus, When the present invention is practiced, the "chip protection capability" of the stiffener 60 will show a significant improvement over the prior art.

As described above, in the present invention, the edge of the stiffener is firstly bent so that the stiffener retains the top plate and the side plate, and thereby the upper and side portions of the semiconductor chip are covered by the top plate and the side plate of the stiffener, thereby providing a stiffener. It enables more stable "heat dissipation" and "chip protection".

As described above, the stiffener of the present invention may be directly assembled by a semiconductor package manufacturer. Alternatively, the stiffener of the present invention may be assembled by a mounting company and then supplied to a semiconductor package manufacturer. Of course, considering factors such as mass production and cost control, it is natural that semiconductor package manufacturers are more advantageous in assembling stiffeners directly.

This invention shows the overall useful effect in the semiconductor package of all varieties produced in the production line.

And while certain embodiments of the invention have been described and illustrated, it will be apparent that the invention may be embodied in various modifications by those skilled in the art.

Such modified embodiments should not be understood individually from the technical spirit or point of view of the present invention and such modified embodiments should fall within the scope of the appended claims of the present invention.

As described in detail above, in the semiconductor package according to the present invention, the structure of the stiffener is changed to an appropriate shape, and the edges of the stiffener are bent primarily to arrange the top plate and the side plate in the vicinity of the semiconductor chip. In this case, the upper plate is in contact with one surface of the semiconductor chip while covering the semiconductor chip, and the side plate is placed on the edge side of the semiconductor chip.

When the present invention is achieved, the stiffener can maintain an appropriate level of occupied space in the semiconductor package while expressing the effect of increasing its size by forming the side plates. Accordingly, the semiconductor package incorporating the stiffener can maintain an appropriate size, and as a result, in the production line, the semiconductor package can be mounted on the main board with high density.

Claims (9)

A substrate having a bonding pad; A semiconductor chip electrically connected to the substrate by contacting one surface with the bonding pad; It is attached to the other surface of the semiconductor chip via a bonding agent layer, and includes a stiffener for releasing heat generated from the semiconductor chip, and protects the semiconductor chip from an external force, The stiffener has a primary edge bent to form a top plate and a side plate, and the top plate is in contact with the semiconductor chip in a state covering the semiconductor chip, the side plate is placed in the vicinity of the edge of the semiconductor chip Semiconductor package. The semiconductor package of claim 1, wherein the top plate and the side plate have different thicknesses. The semiconductor package of claim 2, wherein the upper plate has a thickness thicker than that of the side plate. The semiconductor package of claim 1, wherein the top plate and the side plate have the same thickness. The semiconductor package of claim 1, wherein the top plate and the side plate are made of metal or synthetic resin. The semiconductor package of claim 1, wherein the top plate further includes a plurality of heat dissipation fins for rapidly dissipating heat generated from the semiconductor chip. The semiconductor package of claim 1, wherein a metal layer is further formed on the other surface of the semiconductor chip to improve contact with the stiffener. The method of claim 7, wherein the metal layer is made of VNi / Au, Ti / VNi / Au, Cr / Au, Ti / Pt / Au, Cr / CrCu / (Cu) / Au, TiW / (Cu) / Au, A semiconductor, characterized in that any one selected from the group consisting of VNi / Pd, Ti / VNi / Pd, Cr / Pd, Ti / Pt / Pd, Cr / CrCu / (Cu) / Pd, TiW / (Cu) / Pd package. The semiconductor package of claim 1, wherein the binder layer is any one selected from the group consisting of grease, epoxy, and solder metal.