Disclosure of Invention
The invention aims to provide a heat dissipation type packaging structure and a forming method thereof, which can improve the heat dissipation of a chip.
In order to achieve the above object, the present invention provides a method for forming a heat dissipation package structure, including the steps of:
providing a circuit substrate; providing a plurality of semiconductor dies, flip-chip mounting the plurality of semiconductor dies on the circuit substrate with a gap between adjacent semiconductor dies; providing a heat dissipation plate, wherein the heat dissipation plate is provided with a first surface and a second surface opposite to the first surface; forming a stepped portion, a first annular groove and a second annular groove on a first surface of the heat dissipation plate, wherein the stepped portion is located at the peripheral edge of the first surface and comprises a plurality of continuous steps, and the first annular groove is located between the stepped portion and the second annular groove; arranging a heat conduction bonding layer on the second surface of the heat dissipation plate, and further bonding the heat dissipation plate on the plurality of semiconductor dies by using the heat conduction bonding layer; pressing a separation film on the first surface of the heat dissipation plate, wherein the separation film is directly attached to the bottom surfaces and the side surfaces of the plurality of continuous steps, and covers the top ends of the first annular groove and the second annular groove; injecting a molding compound between the separation film and the circuit substrate, the molding compound supporting the separation film such that the molding compound fills the step portion.
Further preferably, the lower surfaces of the plurality of semiconductor dies are provided with conductive pads, and conductive bumps are provided on the conductive pads before the plurality of semiconductor dies are flip-chip mounted on the circuit substrate.
It is further preferred that an underfill layer is disposed between each of the semiconductor dies and the circuit substrate.
Further preferably, a bottom surface of the first annular groove is higher than a bottom surface of the stepped portion, and a bottom surface of the second annular groove is lower than the bottom surface of the first annular groove.
Further preferably, a projection of the heat dissipation plate on the circuit substrate completely covers a projection of the plurality of semiconductor dies on the circuit substrate.
Further preferably, the plurality of consecutive steps includes a first step and a second step located above the first step, and the height of the first step is smaller than the height of the second step.
Further preferably, the molding compound fills the first step and the second step such that an upper surface of the molding compound is flush with the first surface of the heat dissipation plate.
The invention also provides a heat dissipation type packaging structure which is manufactured by adopting the method.
Compared with the prior art, the heat dissipation type packaging structure and the forming method thereof have the following beneficial effects: in the present invention, the heat dissipation plate is provided on the plurality of semiconductor dies by forming the step portion on the first surface of the heat dissipation plate. During the packaging process, the glue overflow phenomenon can be effectively inhibited while the damage of the semiconductor die is avoided. And the projection of the heat dissipation plate on the circuit substrate completely covers the projection of the plurality of semiconductor dies on the circuit substrate, so that the semiconductor dies are effectively protected. Further, through further in first surface formation first annular groove and second annular groove of heating panel, set up the step includes a plurality of continuous ladders, just first annular groove is located the step with between the second annular groove, further effectively restrain the overflow and glue and produce, and effectively improve heat dissipation type packaging structure's steadiness.
Detailed Description
For better understanding of the technical solutions of the present invention, the following detailed descriptions of the embodiments of the present invention are provided with reference to the accompanying drawings.
It should be understood that the described embodiments are only some embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Please refer to fig. 1 to 4. It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the drawings only show the components related to the present invention rather than being drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of each component in actual implementation may be changed arbitrarily, and the layout of the components may be more complicated.
As shown in fig. 1 to 4, the present embodiment provides a method for forming a heat dissipation package structure, which includes the following steps:
as shown in fig. 1, acircuit substrate 100 is provided. Next, a plurality of semiconductor dies 200 are provided, and the plurality of semiconductor dies 200 are flip-chip mounted on thecircuit substrate 100 with a gap between adjacent semiconductor dies 200.
In a specific embodiment, the lower surfaces of the plurality of semiconductor dies 200 are provided with conductive pads, and before the plurality of semiconductor dies 200 are flip-chip mounted on thecircuit substrate 100,conductive bumps 201 are provided on the conductive pads. Anunderfill layer 300 is disposed between each of the semiconductor dies 200 and thecircuit substrate 100.
In a specific embodiment, thecircuit substrate 100 may be a multilayer printed circuit board, or may be a ceramic substrate or a plastic substrate provided with a metal wiring layer, and the plurality of semiconductor dies 200 may be dies with the same function or dies with different functions.
In a specific embodiment, a conductive pad is disposed on a lower surface of each of the semiconductor dies 200, the conductive pad is a copper pad or an aluminum pad, aconductive bump 201, specifically a solder bump, is disposed on the conductive pad before the plurality of semiconductor dies 200 are flip-chip mounted on thecircuit substrate 100, and then the plurality of semiconductor dies 200 are flip-chip mounted on thecircuit substrate 100 by using the solder bump through a reflow process.
In a specific embodiment, after flip-chip mounting a plurality of semiconductor dies 200 on thecircuit substrate 100, anunderfill layer 300 is disposed between the semiconductor dies 200 and thecircuit substrate 100 to protect the semiconductor dies 200 for subsequent mounting of a heat dissipation plate.
As shown in fig. 2, aheat dissipation plate 400 is provided, theheat dissipation plate 400 having a first surface and a second surface opposite to the first surface.
Astepped portion 401, a firstannular groove 402, and a secondannular groove 403 are formed on a first surface of theheat dissipation plate 400, thestepped portion 401 is located at a peripheral edge of the first surface and includes a plurality of continuous steps, and the firstannular groove 402 is located between thestepped portion 401 and the secondannular groove 403.
In a specific embodiment, the bottom surface of the firstannular groove 402 is higher than the bottom surface of thestep portion 401, and the bottom surface of the secondannular groove 403 is lower than the bottom surface of the firstannular groove 402, and due to the fact that the firstannular groove 402 is close to thestep portion 401, if the depth of the firstannular groove 402 is set too deep, the edge stability of theheat dissipation plate 400 is easily reduced, and the edge of the heat dissipation plate is easily broken. In addition, the firstannular groove 402 is configured such that, in a subsequent packaging process, even if a small portion of the molding compound overflows the first surface of theheat dissipation plate 400, the portion of the molding compound is received by the firstannular groove 402, and even if the firstannular groove 402 is filled, the secondannular groove 403 can be used for receiving the molding compound, so that the molding compound can be effectively prevented from covering the first surface of theheat dissipation plate 400, and the heat dissipation effect of the heat dissipation plate can be prevented from being affected. And the bottom surface of the secondannular groove 403 is lower than the bottom surface of the firstannular groove 402, so that the heat dissipation area of theheat dissipation plate 400 can be increased, and the heat dissipation effect of the heat dissipation type package structure can be improved.
In a specific embodiment, the plurality of continuous steps includes afirst step 4011 and a second step 4012 located above thefirst step 4011, wherein the height of thefirst step 4011 is smaller than the height of the second step 4012, and more specifically, the height of thefirst step 4011 is 100-. By providing a specific structure for each step, it may be convenient for the mold compound to fill thestep 401 during a subsequent injection of the mold compound.
As shown in fig. 3, a heat conductiveadhesive layer 404 is disposed on the second surface of theheat spreader 400, and theheat spreader 400 is bonded to the plurality of semiconductor dies 200 by the heat conductiveadhesive layer 404.
In a specific embodiment, aseparation film 500 is pressed on the first surface of theheat dissipation plate 400, theseparation film 500 is directly attached to the bottom and side surfaces of the plurality of continuous steps, and theseparation film 500 covers the top ends of the firstannular groove 402 and the secondannular groove 403.
In a specific embodiment, the projection of theheat dissipation plate 400 on thecircuit substrate 100 completely covers the projection of the plurality of semiconductor dies 200 on thecircuit substrate 100, so as to effectively protect the semiconductor dies.
In a specific embodiment, therelease film 500 includes a base layer and a low-tack layer, the base layer is made of suitable material such as PET, PI, etc., and therelease film 500 has a thickness of 50-100 μm.
As shown in fig. 4, amold compound 600 is injected between theseparation film 500 and thecircuit substrate 100, and themold compound 600 holds up theseparation film 500 so that themold compound 600 fills thestepped portion 401.
In a specific embodiment, themolding compound 600 fills thefirst step 4011 and the second step 4012 such that an upper surface of themolding compound 600 is flush with the first surface of theheat sink 400.
The invention also provides a heat dissipation type packaging structure which is manufactured by adopting the method.
In another embodiment, the present invention provides a method for forming a heat dissipation package structure, including the following steps:
a circuit substrate is provided.
Providing a plurality of semiconductor dies, flip-chip mounting the plurality of semiconductor dies on the circuit substrate with a gap between adjacent semiconductor dies.
A heat sink plate is provided, the heat sink plate having a first surface and a second surface opposite the first surface.
A stepped portion, a first annular groove, and a second annular groove are formed at a first surface of the heat dissipation plate, the stepped portion being located at a peripheral edge of the first surface and including a plurality of continuous steps, and the first annular groove being located between the stepped portion and the second annular groove.
And arranging a heat conduction adhesive layer on the second surface of the heat dissipation plate, and further adhering the heat dissipation plate on the plurality of semiconductor dies by using the heat conduction adhesive layer.
Pressing a separation film on the first surface of the heat dissipation plate, wherein the separation film is directly attached to the bottom surfaces and the side surfaces of the plurality of continuous steps, and covers the top ends of the first annular groove and the second annular groove.
Injecting a molding compound between the separation film and the circuit substrate, the molding compound supporting the separation film such that the molding compound fills the stepped portion.
According to one embodiment of the present invention, the lower surfaces of the plurality of semiconductor dies are provided with conductive pads on which conductive bumps are provided before the plurality of semiconductor dies are flip-chip mounted on the circuit substrate.
According to one embodiment of the invention, an underfill layer is disposed between each of the semiconductor dies and the circuit substrate.
According to an embodiment of the present invention, a bottom surface of the first annular groove is higher than a bottom surface of the stepped portion, and a bottom surface of the second annular groove is lower than the bottom surface of the first annular groove.
According to one embodiment of the present invention, the projection of the heat dissipation plate on the circuit substrate completely covers the projection of the plurality of semiconductor dies on the circuit substrate.
According to one embodiment of the invention, the plurality of consecutive steps comprises a first step and a second step located above the first step, the first step having a height smaller than the height of the second step.
According to one embodiment of the present invention, the molding compound fills the first step and the second step such that an upper surface of the molding compound is flush with the first surface of the heat dissipation plate.
The invention also provides a heat dissipation type packaging structure which is manufactured by adopting the method.
In the invention, the step part is formed on the first surface of the heat dissipation plate, so that the heat dissipation plate is arranged on the plurality of semiconductor dies, and the glue overflowing phenomenon can be effectively inhibited while the semiconductor dies are prevented from being damaged in the packaging process. And the projection of the heat dissipation plate on the circuit substrate completely covers the projection of the plurality of semiconductor dies on the circuit substrate, so that the semiconductor dies are effectively protected. Further, through further in first surface formation first annular groove and second annular groove of heating panel, set up the step includes a plurality of continuous ladders, just first annular groove is located the step with between the second annular groove, further effectively restrain the overflow and glue and produce, and effectively improve heat dissipation type packaging structure's steadiness.
The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.