TWI587461B - Improve thermal efficiency heat sink device - Google Patents

Description

Heat sink device capable of improving heat conduction efficiency

The present invention relates to a heat sink device, and more particularly to a heat sink device that can improve heat conduction efficiency.

With the ever-changing semiconductor manufacturing process, the size of the existing semiconductor components is gradually reduced and the efficiency is gradually improved. The heat generated by the operation of the semiconductor components is increased due to the improvement of the performance. In order to avoid the semiconductor components being burned due to heat, the semiconductor components are burned. Bad, a metal heat sink is adhered to the top of the semiconductor component to improve the heat dissipation of the semiconductor component.

1 is a semiconductor package structure, a flip chip package, and a semiconductor flip chip package forming method. The semiconductor package structure 10 includes a substrate 20 having an upper surface 42 and a substrate 20 a semiconductor wafer 30 on the upper surface 42; and a semiconductor wafer 30 mounted on the semiconductor wafer 30 and bonded to a heat sink 80 by a thermal interface material 52.

The thermal interface material 52 is usually a gel-like material having thermal conductivity, is applied to the upper surface of the semiconductor wafer 30 in a semiconductor packaging process, and the heat sink 80 is pressure-bonded to the thermal interface material 52 to bond the semiconductor. When the wafer 30 operates, heat is generated to the outside, and accumulation of too much heat is prevented to cause the semiconductor wafer 30 to burn.

However, directly placing the thermal interface material directly on the semiconductor wafer and the heat sink will cause the following problems:

First, the contact surface is incomplete

Since the heat sink and the heat interface material are heterogeneous materials, when the two are adhered together, contact defects are generated, resulting in contact of the heat sink with the heat interface material. The face is incomplete.

Second, the thermal conductivity is reduced

When the contact surface of the heat sink and the thermal interface material generates germanium, the heat generated by the semiconductor wafer is not smoothly transmitted to the heat sink, resulting in a decrease in heat transfer efficiency of the heat sink.

Third, affect the service life

The heat sink is stamped from a metal material and has the characteristics of thermal expansion and contraction. When it is adhered to a heterogeneous material, the joint peeling occurs after a period of use, and the heat generated by the semiconductor wafer cannot be dissipated. It affects the service life of semiconductor products.

Therefore, how to effectively improve the contact condition between the heat sink and the thermal interface material in the semiconductor product, improve the heat dissipation effect of the semiconductor product, and maintain the semiconductor wafer operating within a certain temperature range, and protect the service life of the semiconductor product, becomes relevant The industry needs to work hard.

In view of the above, an object of the present invention is to provide a heat sink device capable of improving heat conduction efficiency, which is suitable for transferring heat generated by a wafer on a substrate to a heat sink device by a heat conductive silver paste, the heat sink device A body, a first protective layer, and a thermally conductive bonding layer are included.

The body includes a heat dissipating portion disposed above the wafer and has an upper surface and an opposite lower surface.

The first protective layer is made of nickel metal and is plated on the lower surface of the body.

The thermally conductive bonding layer is made of a silver metal material and is plated on the surface of the first protective layer. When the heat dissipating device is adhered to the wafer by using the thermal conductive silver paste, the thermally conductive bonding layer can be lifted with the thermal conductive silver paste. The adhesion effect is used to improve the heat dissipation effect of the wafer.

Another technical means of the present invention lies in the above heat conduction The surface of the bonding layer is a rough surface.

Another technical means of the present invention is that the thermal conductive bonding layer is plated on the surface shape and position of the first protective layer, and cooperates with the surface shape and position of the wafer.

According to still another aspect of the present invention, the first protective layer is plated on a surface of the body and the body is covered.

According to still another aspect of the present invention, the body further includes a support portion extending from a periphery of the heat dissipation portion toward the substrate.

Another technical means of the present invention is that the body is made of a material selected from the group consisting of a copper alloy and an aluminum alloy.

Still another technical means of the present invention is that the thickness of the above thermally conductive bonding layer is greater than 1 μm.

According to still another aspect of the present invention, the thickness of the first protective layer is 2 μm.

Another technical means of the present invention is that the heat sink device capable of improving heat conduction efficiency further includes a second protective layer made of chrome metal and plated on the surface of the first protective layer.

According to still another aspect of the present invention, the second protective layer is coated with the first protective layer in cooperation with the thermally conductive bonding layer.

The beneficial effect of the invention is that when the conductive silver paste is used as the heat conductive material between the wafer and the heat sink device, the thermal conductive bonding layer made of silver metal can improve the adhesion between the heat sink device and the heat conductive silver paste. The thermal conductive silver paste is completely adhered to the surface of the thermally conductive bonding layer, which not only improves the heat dissipation effect of the wafer, but also prolongs the service life of the semiconductor product using the wafer.

A‧‧‧Substrate

B‧‧‧ wafer

C‧‧‧thermal silver glue

D‧‧‧ring type heat sink

E‧‧‧Epoxy resin

3‧‧‧ Ontology

31‧‧‧ Department of heat dissipation

311‧‧‧ upper surface

312‧‧‧ lower surface

32‧‧‧Support

4‧‧‧First protective layer

5‧‧‧ Thermal bonding layer

51‧‧‧Rough surface

6‧‧‧Second protective layer

1 is a schematic view of a device, illustrating a semiconductor package structure of the Republic of China Patent No. I415228; FIG. 2 is a schematic view of the device, illustrating that the present invention can improve thermal conductivity. FIG. 3 is a partial cross-sectional view showing a cross-sectional view of the first preferred embodiment; FIG. 4 is a schematic view of the device, illustrating a preferred embodiment of the present invention; A second preferred embodiment of the heat sink device for improving heat conduction efficiency; FIG. 5 is a schematic view of the device, illustrating a state in which the second preferred embodiment is adhered to the wafer; FIG. 6 is a schematic view of the device, illustrating the present invention A third preferred embodiment of the heat sink device for improving heat conduction efficiency; FIG. 7 is a schematic view of a device for explaining a fourth preferred embodiment of the heat sink device capable of improving heat conduction efficiency and the wafer; 8 is a cross-sectional view of a device illustrating a fifth preferred embodiment of the heat sink device capable of improving heat conduction efficiency of the present invention; and FIG. 9 is a schematic view of the device, illustrating a sixth embodiment of the heat sink device capable of improving heat conduction efficiency of the present invention. Preferred embodiment.

The details of the related patents and the technical contents of the present invention will be apparent from the following detailed description of the preferred embodiments of the accompanying drawings.

It should be noted that, before the detailed description, similar elements are denoted by the same reference numerals. The semiconductor packaging process mentioned in the manual can be used for Flip Chip Package (FC), Plastic Ball Grid Array Package (PBGA), Ball Grid Array (BGA), Square A variety of semiconductor packaging technologies, such as Quad Flat Package (QFP), Quad Flat No-lead Package (QFN), and Chip Scale Package (CSP).

Referring to FIG. 2 and FIG. 3, a first preferred embodiment of the heat sink device capable of improving heat conduction efficiency according to the present invention is applicable to heat generated by one of the wafers B on a substrate A, which is conducted by a thermally conductive silver paste C. Heat sink And comprising a body 3, a first protective layer 4, and a thermally conductive bonding layer 5.

The thermal conductive silver paste C used in the invention is actually a large amount of silver powder mixed in the epoxy resin, so that the thermal conductive silver paste C has electrical conductivity and thermal conductivity, which is different from the characteristics of the conventional epoxy resin. Although the thermal conductive silver paste C is doped with a large amount of silver powder resin to obtain a high thermal conductivity, the proportion of the epoxy resin is relatively low, resulting in poor strength of the wafer B, which tends to cause instability of product quality. Even so, the cost of manufacturing the thermally conductive silver paste C is relatively low and is widely used in the industry.

The wafer B is a semiconductor product and is placed on the substrate A by a packaging technology to facilitate use in various electronic products. Since the packaging technology is already familiar to the industry, it will not be described in detail here.

The body 3 includes a heat dissipating portion 31 disposed above the wafer B, and has an upper surface 311 and an opposite lower surface 312 for providing heat dissipation of the wafer B, which is usually made of a metal material. The body 3 is made of a material selected from the group consisting of a copper alloy and an aluminum alloy. The actual implementation should not be limited thereto.

The first protective layer 4 is made of nickel metal, and its composition includes one of pure nickel or a nickel alloy, and is plated on the lower surface 312 of the body 3. Among them, nickel metal is a lustrous silver-white metal, and is easy to be polished, and is easy to form an anti-oxidation oxide layer on the surface, which is usually used to isolate air to avoid oxidation of the body 3 in contact with air. However, the first protective layer 4 of the present invention is mainly used for plating the buffer layer between the thermally conductive bonding layers 5, so that the first protective layer 4 can be firmly plated on the surface of the body 3, or The thermally conductive bonding layer 5 is firmly plated on the surface of the first protective layer 4.

The thermally conductive bonding layer 5 is made of a silver metal material, and its composition includes one of pure silver or a silver alloy, and is plated on the surface of the first protective layer 4. Since the thermal conductive bonding layer 5 made of a silver metal material is directly plated on the surface of the body 3, the characteristics of the two materials themselves are too different, and the contact surface often causes flaws to cause the thermally conductive bonding layer 5 to peel off.

The inventors have found through experiments that the material properties of the thermally conductive bonding layer 5 and the nickel material are small and are easily combined. Therefore, in the present invention, before the thermal conductive bonding layer 5 is plated, the first protective layer 4 must be plated first, not only to improve the bonding degree of each layer of the heat sink device, but also to improve the heat sink device by increasing the bonding degree. Thermal conductivity. Further, the thermally conductive bonding layer 5 may be dispersedly plated on the surface of the first protective layer 4 to reduce the amount of silver material used.

Since the heat conductive bonding layer 5 is made of a silver metal material, when the heat sink device is adhered to the wafer B by using the heat conductive silver paste C, the silver metal surface of the heat conductive bonding layer 5 and the heat conductive silver paste C The silver metal material is similar in material, and the heat conductive bonding layer 5 can enhance the adhesion effect with the thermal conductive silver paste C to improve the heat dissipation effect of the wafer B.

Preferably, the surface of the thermally conductive bonding layer 5 is a rough surface 51, which can increase the adhesion effect of the epoxy resin in the thermal conductive silver paste C, so that the effect of the thermal conductive silver paste C to stabilize the wafer B is improved. In addition, the inventors have repeatedly tested that the thickness of the first protective layer 4 is greater than 2 μm, and the thermally conductive bonding layer 5 can be tightly plated on the surface of the first protective layer 4 without being easily peeled off; When the thickness of 5 is greater than 1 μm, the thermally conductive silver paste C can be tightly adhered to the surface of the thermally conductive bonding layer 5 without being easily separated. The invention has the best heat conduction efficiency, so that the heat generated by the wafer B can be conducted to the outside for a first time and achieve the best heat dissipation effect.

In the first preferred embodiment, the body 3 is in the form of a square body. When the semiconductor package is used, a ring-shaped heat sink D must be used on the lower periphery of the heat sink device to provide better adhesion. The epoxy resin E is adhered to the substrate A to seal the wafer B. Since the semiconductor packaging process is already familiar to the industry, it will not be described in detail herein.

Referring to FIG. 4 and FIG. 5, a second preferred embodiment of the heat sink device capable of improving heat conduction efficiency is provided. The second preferred embodiment is substantially the same as the first preferred embodiment, and the same is not described herein. The difference is that the thermal conductive bonding layer 5 is plated on the surface shape of the first protective layer 4 and The position cooperates with the shape and position of the surface contacting the wafer B.

Although silver has good electrical and thermal conductivity properties, silver metal is a relatively expensive precious metal, and a large amount of use will increase manufacturing costs. Therefore, in the second preferred embodiment, the thermally conductive bonding layer 5 will be on the surface of the first protective layer 4 of the plated portion, and the size and position of the thermally conductive bonding layer 5 must conform to the wafer B. The size and position of the surface, when the heat sink device of the present invention is used in the semiconductor packaging process, the thermally conductive bonding layer 5 is just pasted over the wafer B and adhered to the thermally conductive silver paste C to reduce The amount of silver metal used to achieve the best heat dissipation with the best economic results.

In addition, the thermally conductive bonding layer 5 does not need to be plated on the plated surface. In actual implementation, partial plating may be performed on the plated surface, and should not be limited thereto. For example, the thermally conductive bonding layer 5 can form a ring-shaped surface on the surface of the first protective layer 4. The thermally conductive bonding layer 5 of the ring-shaped surface and the surface of the wafer B are pasted with the thermal conductive silver paste C. Together, and achieve electrical and thermal properties.

Referring to FIG. 6 , a third preferred embodiment of the heat sink device capable of improving heat conduction efficiency is provided. The third preferred embodiment is substantially the same as the second preferred embodiment, and the same is not described herein again. The first protective layer 4 is plated on the surface of the body 3 and wraps the body 3.

Although the first protective layer 4 of the present invention is used to increase the plating effect of the thermally conductive bonding layer 5, the thermally conductive bonding layer 5 can be firmly adhered to the heat sink device, but the first protection of the nickel metal material The layer 4 has an effect of preventing oxidation, and therefore, in the third preferred embodiment, the first protective layer 4 covers the body 3 to prevent oxidation of the body 3 in contact with air.

Referring to FIG. 7 , a fourth preferred embodiment of the heat sink device capable of improving heat conduction efficiency of the present invention is substantially the same as the third preferred embodiment, and the same is not described herein again. Where The body 3 further includes a support portion 32 extending from the periphery of the heat dissipation portion 31 in the direction of the substrate A.

The heat dissipation portion 31 and the support portion 32 cooperate with each other to make the heat sink device have a cap shape, and the support portion 32 of the body 3 can replace the ring heat sink D. The packaging step is simplified in the packaging process, and the epoxy resin E is directly adhered to the substrate A, which can reduce the cost of the semiconductor package and surely seal the wafer B.

Referring to FIG. 8 , a fifth preferred embodiment of the heat sink device capable of improving heat conduction efficiency is provided. The fifth preferred embodiment is substantially the same as the fourth preferred embodiment, and the same portions are not described herein again. The heat sink device capable of improving heat conduction efficiency further comprises a second protective layer 6 made of chrome metal, and the composition comprises one of pure chromium or chrome alloy, and is plated on the first protective layer 4 . s surface.

Chromium is a silvery metal with a hard texture, a shiny surface and a high melting point. Therefore, the surface of the first protective layer 4 is further plated with a hardened second protective layer 6 for protecting the heat sink device.

Although the fifth preferred embodiment directly coats the thermally conductive bonding layer 5 on the surface of the second protective layer 6, the surface bonding degree of silver and chromium is lower than that of the nickel metal material, and the quality thereof is acceptable. Accepted, but the heat sink device is simpler to manufacture, can reduce the cost of production, and can be used in low-end electronic products.

Referring to FIG. 9 , a sixth preferred embodiment of the heat sink device capable of improving heat conduction efficiency is provided. The sixth preferred embodiment is substantially the same as the fifth preferred embodiment, and the same portions are not described herein again. The second protective layer 6 is bonded to the thermally conductive bonding layer 5 to wrap the first protective layer 4.

In the sixth preferred embodiment, the first protective layer 4 wraps the body 3 to prevent the body 3 from being exposed to air and oxidizing. The second protective layer 6 is matched with the thermally conductive bonding layer 5 to wrap the first protective layer 4, so that the first protective layer 4 is protected by the hard second protective layer 6, and the thermally conductive bonding layer 5 and the first A protective layer 4 is adhered together, so that the thermally conductive bonding layer 5 is firmly adhered to the heat sink device to improve the heat conduction efficiency of the heat sink device and the life of the product, and is suitable for use in high-order or in harsh environments. Under the electronic products.

As can be seen from the above description, the heat sink device of the present invention which can improve the heat conduction efficiency does have the following advantages:

First, improve the strength of the stable wafer

The surface of the thermally conductive bonding layer 5 is a rough surface 51, which can increase the adhesion effect of the epoxy resin in the thermal conductive silver paste C, so that the effect of the thermal conductive silver paste C to stabilize the wafer B is improved.

Second, increase the service life

The first protective layer 4 wraps the body 3 to prevent the body 3 from being oxidized by contact with air. The second protective layer 6 cooperates with the thermally conductive bonding layer 5 to wrap the first protective layer 4 to The first protective layer 4 and the body 3 are protected by the hard second protective layer 6, which can improve the structural strength of the heat sink device and prolong the service life.

Third, increase the heat dissipation rate of the wafer

The thermal conductive bonding layer 5 and the nickel material have different material characteristics and are easily combined to improve the heat conduction effect of the heat sink device itself; the silver metal surface of the heat conductive bonding layer 5 and the silver metal in the thermal conductive silver paste C The thermal conductive bonding layer 5 can improve the adhesion effect with the thermal conductive silver paste C, and the heat of the wafer B can be conducted to increase the heat dissipation efficiency of the wafer B.

In summary, the present invention uses the heat dissipation of the thermal conductive silver paste C In the sheet, a thermal conductive bonding layer 5 which is perfectly adhered to the thermal conductive silver paste C is plated to improve the heat conduction efficiency on the wafer B. In order to firmly adhere the thermally conductive bonding layer 5 to the heat sink device, a layer of the first protective layer 4 is further plated on the outer layer of the body 3 to reach a buffer layer between the body 3 and the thermally conductive bonding layer 5. The second protective layer 6 is coated on the surface of the first protective layer 4 to improve the structural strength of the heat sink device and prolong the service life. Therefore, the object of the present invention can be achieved.

However, the above is only the six preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent change of the patent application scope and the description of the invention is Modifications are still within the scope of the invention.

3‧‧‧ Ontology

4‧‧‧First protective layer

5‧‧‧ Thermal bonding layer

Claims (10)

A heat sink device capable of improving heat conduction efficiency, wherein heat generated by a wafer on a substrate is conducted to the heat sink device by a conductive silver paste, and includes: a body, including a device disposed above the wafer a heat dissipating portion having an upper surface and an opposite lower surface; a first protective layer made of nickel metal and plated on the lower surface of the body; and a thermally conductive bonding layer made of silver metal and plated Covering the surface of the first protective layer, when the heat sink device is adhered to the wafer by using the conductive silver paste, the heat conductive bonding layer can enhance the adhesion with the conductive silver paste to improve heat dissipation of the wafer. effect. A heat sink device capable of improving heat conduction efficiency according to the first aspect of the invention, wherein the surface of the heat conductive bonding layer is a rough surface. A heat sink device capable of improving heat conduction efficiency according to the second aspect of the invention, wherein the heat conductive bonding layer is plated on a surface shape and a position of the first protective layer to match a surface shape and a position of the surface contacting the wafer. A heat sink device capable of improving heat conduction efficiency according to claim 3, wherein the first protective layer is plated on a surface of the body and wraps the body. A heat sink device capable of improving heat conduction efficiency according to the fourth aspect of the invention, wherein the body further includes a support portion extending from a periphery of the heat radiating portion toward the substrate. A heat sink device capable of improving heat conduction efficiency according to the fifth aspect of the patent application, wherein the body is made of a material selected from the group consisting of a copper alloy and an aluminum alloy. A heat sink device capable of improving heat conduction efficiency according to the sixth aspect of the invention, wherein the heat conductive bonding layer has a thickness greater than 1 μm. A heat sink device capable of improving heat conduction efficiency according to the seventh aspect of the invention, wherein the first protective layer has a thickness greater than 2 μm. The heat sink device capable of improving heat conduction efficiency according to Item 8 of the patent application scope further comprises a second protective layer made of chrome metal and plated on the surface of the first protective layer. A heat sink device capable of improving heat conduction efficiency according to claim 9, wherein the second protective layer and the heat conductive bonding layer cooperate to coat the first protective layer.