TW477044B - Structure and method to provide highly thermally conductive interface between semiconductor chip devices and lid structures - Google Patents

Abstract

In order to provide a high thermal conductivity path between one or more semiconductor chips and an overlying lid structure, a wettable wicking material is employed. In particular, wicking material is disposed between one or more chips and an overlying lid structure. One or more apertures in the lid provide a flow path for a meltable infiltrant such as solder which, upon heating, flows through an aperture in the lid and uniformly wets the wicking material. The process is thermally consistent with concomitant thermal processes which are meant to provide curing of materials designed to seal the lid structure to an underlying substrate.

Description

477044 V. Description of the invention (1) Background of the invention The present invention is generally directed to providing an interface between a semiconductor wafer and a cover thereon and / or sealing such a wafer. More particularly, the present invention is directed to a system in which a low melting point permeate, such as solder, is disposed throughout a dipping material, which is then disposed on a wafer and a lid or cap structure. Even more particularly, the present invention is directed to a method in which a low melting point permeate is disposed on an opening of a packaging lid to cause melting and flow into the wafer. A compactable body member is prevented from directing the guide element. The degree is approaching from the semi-sub-type inclination, and then there is a power cut. It is also equipped with a defense that must be integrated. It must be reloaded. The limit of the package must be more moderate and the build of the trust is a dense film. Crystals and hot-drive materials are available at the time of installation. The surface energy can be charged with hot energy. The high level of heat generation and heat dissipation in the bulk makes the removal and removal of the installation, and the installation is the addition of the half-shifted road. CLP does not need to increase the quasi-assembly. The electric heating industry continues to download bit mold accumulation. In addition to the temporary retention rate, the frequency of the material's transfer from the energy of the paste can be increased from half to medium in the paste, which is often higher than that of the hot tin. The species and the existence and the face seal must be connected to the ground to form a crystal.

477044 V. Description of the invention (2) A mechanism for thermally bridging the gap between the die and a cover and / or under the radiator. However, even with the use of solder materials, where they do provide a high degree of thermal conductivity, there are still some issues to consider. For example, solder mediators typically use a metal-to-metal contact, which involves both the backside of the semiconductor wafer and the underside of the cover. In particular, wetting the backside of the die is generally an important aspect of a solder thermal interface. Furthermore, when solder is used, the metal itself's contamination at the required interface is an important consideration. In addition, whatever processing is used to configure the chip and the heat sink and the solder between the covers should be reasonably compliant with standard processing and involve space tolerances in the semiconductor package. In addition, any configuration method used for the heat-conducting layer should also take into account reasonable measurements for controlling the stresses on the die and the cover without causing breakage and detachment at the interface. Finally, and most importantly, the materials used should be highly thermally conductive so that heat is quickly removed and / or dissipated from the die to a cover or heat sink structure. SUMMARY OF THE INVENTION According to one embodiment of the present invention, a method is provided for forming a pair of thermal interfaces useful for cooling a semiconductor device. In particular, the method includes a single step of heating a low melting point permeate, such as solder, when the permeate is disposed in or on an opening of a package lid of a semiconductor wafer. This heating step is performed to a compressible immersion tin material sufficient to cause a solder-like flow through the opening and wet a configuration configured to contact both the wafer and the die. According to another embodiment of the present invention, a semiconductor package having a high thermal conductivity interface is provided and includes an insulating substrate having electrical conductors and a substrate disposed face down on the substrate such that the wafer system and at least some of the substrates

477044 Description of the invention (3) Semiconductor crystal with conductors electrically connected. One piece between the cover. The cover is disposed on the crystal I, and the material is disposed on the crystal and is attached to the substrate. Just like a solder ^ You Gu = not in contact with it and the most penetrant is actually filled in the hollow g of the immersion tin material, the low melting point of the conductivity, a high thermal conduction path exists in the chip and the pu. In this way, fgj 〇 According to this, the purpose of the present invention is to make the feature space small, and where Qiu Zixin = Nutun Road Daily Film, its origin day 3 i 一 purpose # # m /,, clothing, high degree. It is not clear that it is known to be used for circuit chips for six years, < ^ l These chips are operated at an increasing frequency. The cold heading system makes the present invention compatible in the same way when the module is packaged. The present invention minimizes or reduces the present invention, or the radiator of the present invention does not reverse the media arranged in these positions. The present invention also provides a backing force for the conductor chip encapsulating the conductor die, providing the present invention to provide a-* of the electronic i%-* on the z 9 of the influence of the method surface material / target surface 0-used for One-eye heat-conducting step-eye circuit, crystal-step configuration, < Tλ lifting circuit operation, and its < material (τ ') provides an interface, regardless of the system from which it is removed, and the interface provided. The thermal system provides a system of soldering, soldering, or soldering to make the heat from ordinary crystals // days / 1 pens. The traditional semiconductor packaging method is used for thermal and mechanical stress interface. The method of covering a sheet and a cover. Similar to those methods in which the solder or permeate solder permeate can be configured in the sheet operation interface-a method for using solder material as a material without metallization The 4

$ 7 pages 477044 V. Description of the invention (4) Yet another object of the present invention is to provide a system and method for using solder and similar materials of solder in a semiconductor chip package.

Finally, but not limited to this, it is an object of the present invention to improve the thermal path between a semiconductor die and a structure on a cover or heat sink to improve removal from the wafer device or from a multi-wafer mold. Thermal energy of many wafer devices in the group. Schematic description

Matters related to the subject matter of the present invention are particularly pointed out and distinguished in the conclusions of this specification. However, regarding the practical structure and method combined with its further purposes and advantages, the present invention can be best understood by referring to the following descriptions of the attached drawings, in which: Figure 1 shows the use of thermal paste in a semiconductor package Sectional perspective view of the material, FIG. 2 is a sectional perspective view showing a specific embodiment of the present invention and particularly showing the position and configuration of a wettable immersion tin material; Sectional perspective view of the initial stage;

Fig. 4 is a sectional perspective view of the method of the present invention in a stage subsequent to the initial permeate heating stage; Fig. 5a is a sectional perspective view of a process stage of a completed process; Fig. 5b is similar to Fig. 5a; A sectional perspective view of the final processing steps of the method; and Figure 6 is an isometric drawing of a window pad that can be used in conjunction with the present invention to ensure that the solder or penetrant configuration is controlled at its final positioning position.

Page 8 477044 V. Description of the invention (5) ^ _____ Description of preferred embodiments Figure 1 (unmeasured) shows-used to provide-different structures in the conduction path of wafer 2. Especially in the case shown, ^ 24 of 30 敎 1 is arranged between the wafer 20 and 盍 30. Cover 30 is attached to the: p thermal junction. In addition, as shown in the figure, the structure 25 also represents a moving radiator and includes an active cooling device 一 ^; one is only filled with the agent 32 on the substrate surface to fill = 10. In FIG. I, no electrical conductive pads or solder balls arranged on the wafer 20 and the substrate are seen. These 塾 or spheres m face down on the insulating substrate 10 and are typically within the insulating substrate = =, connected to FIG. 2 shows a specific embodiment of the present invention. Especially broad. Holes for liquid metal permeate used to introduce solder 3 2 0 now contain 2 also shown appearing on the back of the wafer 2 0 and bu 'note that the drawing dipped material 50 0. The compressible S 3, ·, and 示 between the faces are used to introduce too dry tin or similar materials to the initial stage of storage. In particular, Fig. 3 shows the emergence of:-a conductive material in the lower area, which can immerse the solder material 50. —The heat of the plug 55: an example is applied to the paper shown in FIG. 3: The preferred and specific flow through the hole 34 and completely wet the dipping tin material is to melt the plug 55 into 4, and its special description appears to represent because Complete ~ Produced structure is shown in the figure and then flows through the bumps 56 of too much tin dip material through the hole 34. ~, ^ Sn material 50 but not tin material is indicated by reference number 51. In Fig. 4, the wet immersion "=" top in the preferred embodiment of the invention. This helps to match the cover 3. And-heat dissipation 5. Description of the invention (6) Any of the moving cooling devices. Convex In the direction shown in block 56, the knife or chisel: 5a shows the use of moving to remove: not in Figure 5b. Based on focus and setting 100. The rest of the structure in the resulting product. Figure 5a for clarity And 5b ignore Figure 4 in a combination of the surname shown in Figure 4

The 20 series is electrically connected to the "integrated processing, integrated circuit chip

Material to provide mechanical support for unfilled, such as epoxide 22, thermal paste, thermal compound 24 series: to improve reliability. The present invention allows the grains to be replaced during the capping, which is attached to the part. Sponge 50 is formed by sponges in the area between easy to spot and 20 grains through the hole 34 in the cover + = f After the cover is attached and processed, it is borrowed. Typically, the material provided by the metal is wetted by the material _ as from D0 ... a § company can be compressible; however :: sword 32? To the substrate 10. The sponge material 50 is best ^ t 1, not enough demand, especially in the cover 30

: In the case where the adhesive 32 is in close proximity to the substrate 10 during application. In fact, a class k operation is made to more precisely control the gap between the chip and the cover. Sponge 3 y wet sub-tin material 50 is preferably made of copper, beryllium copper, nickel or aluminum metal, and any one can also include a plating surface to improve the use of a metal winter Wetability of sponge material. Sponge 50 may also contain polymers that have been metallized. In addition, sponge 50 is made of carbon that is forged with metal using a metal infiltrate to improve wettability. The sponge material is preferably in the form of carbon fibers, but also includes carbon particles or other forms. Sponge 50 is also configured as a foam fiber pad or lining or other lightly porous structure. Sponge 50 provides a conduit and a stock for supplying molten metal permeate, which is used to

Page 10 V. Description of the invention (7) Wet and thermally connect the underside of the cover and the die, the term " sponge " is used to refer to all this, as here the cover is attached to the substrate After 10, a second Kabuki 'Palladium case. The one used in Sylgarf) was used to treat the permeate into the sponge5. . A small solid solder is stored with, for example, the lid 3 for the penetration of tin. Middle hole 34. If required, the outer surface of the top of the cover shown in Fig. 3 is used to prevent money from being applied to the area of the hole or hole 34. This is true; tin; ::; permeate more than surrounds the infiltration and remains attached to the outer surface of the cover 30. ： ； ： ； :: The two materials are not randomly distributed and the material is polyimide or any conventional welding # I The material of the masking material is a supply of heat to promote the]] = the structure shown in Figure 3, let it flow The hole 34 enters the temperature of the permeate 55, and therefore, the back of the crystal 2 2 and the cover _ show the result of this processing step. . As shown above, Fig. 4 shows that both the 3 'cover and the 2 ° chip in the column 3 are required. In the present invention :: real = volume application, this is not-the main solder. More specifically, it is better, Tan ^, Meng Tuancai 55 preferably includes some, which have the ability to wet both: from the low melting point alloys, these alloys have the ability to sentence and non-oxide surfaces. You 2 90 (can be from # · 0 I ^ to the bottom of those, such as alloy 1 E4 and UIU can be obtained from Wu Guo lndiUm company, Qi ^ factory. These alloys have less than about 15 ° =, Ge pure indium And ^ silver production is considered to be suitable for exposure to the melting or liquid core / dish temperature of the seedlings, and the state temperature to accommodate the higher energy of approximately 80 degrees with the group having a fixed surface exceeding 100 ° c. Device / 1144

, Can = fine working temperature. Indium-based thermal expansion: such as l makes this type of solder quite suitable ^ _ # tin 70 completely wet the back of the silicon grains because this type of surface system is almost #: = ㈣ oxygen "layer" However, this thickness in the heat There is a negligible effect on the attack. The area that surrounds and extends outward from the lower edge of crystal 1 or crystal 20 is covered with a female, the oxide is not filled with material. As such, there is no wettable path from the die to the substrate 10 surface, which typically includes a ceramic material. Note that this substrate material is not a limitation of the invention. In the event that the cap or cap 3 () includes a material such as aluminum, it is found that it is also almost always covered with a thin layer of alumina, and therefore f is easily wetted by the alloy that wets the grain 20. In some examples In the case where an oxide layer is deliberately formed under the cover 30, it can be expected that the electric chip system is electrically isolated from the conditions in the cover. Under the cap or the cover 30, the thickness of the oxide layer is, for example, one The plating deposition method is further added. The infiltrated sponge material 50 provides heat distributed to the cover 30 by providing a path for the molten infiltrate to wet the surface across the lower surface of the cover 30. The amount of permeate or solder is preferably selected to slightly exceed the amount needed to wet the surface of the stone 20 grain ^ that is used to completely penetrate the sponge 50 and wet the cover 30 below and fill in 盍 30 In the hole 34. In particular, it is used for a solar chip or solar chip with a size of 32 mm on each side, and there is a gap of about 10 mils (mi 1 S) between the grain and the crystal grains. The useful amount of solder is Less than about 0.2 cubic centimeters. The flux from solder to sponge 50 is completely made by the solder in the sponge Abort This limits the number of its occurrence or wetting may occur down along the inside of the lid 3 and the square

/ U44

If required, the surface of the δH3O3 is a compound that has, for example, a wet-enhancing compound that is tin-plated in advance with the solder used for penetration. For example, indium I 4 can simply wet the surface by rubbing the solder on the surface of the solder. Same as J: With solder storage related to the 盍, a non-wettable cover can be optionally used on the inner vertical surface of the cover to prevent them from being covered by the solder or the substrate cleaning system. Very small cover '-not to be soldered or penetrated Objects: ίτ 4 Ϊ fill! ^ Layer to use. Such filler layers may include-for example, carbon sV dry :: seed or film material. This type of filler layer is best-as shown in Figure V7H, which shows a 7 ° outer surface of a filler layer with an open profile window format, which is formulated to match the internal dimensions of the cover and has a The size of the die opening is attached to or fixed before adhering to the substrate. For example, if the gap is very small, it is expected on the back of the die and there is an example of the present invention in a multi-chip module. Type: In the sub-module, after the crystal grains are not filled, the module is chemically modified: and all the crystal grains are fixed to a coplanar surface from the surface of the substrate. In order to help control the distance between the crystal grains and the cover (CTE ^ coefficient, the sponge material 50 is chosen to have a thermal expansion sponge combination with a -bad tin "surface, so the CTE of the sponge is reduced.-Low CTE material 2 丨: Carbon or stone I of solder penetrating wet recording material I. Solder solder has-high lit: system; f can be used to win f, they are

Page 13 477044 V. Description of the invention (10) Excellent connection with f and materials with large CTE error combination. "Inch" pure steel has been shown to be unfavorable for cooling. If the soldering department 捭 ± evening double order / dish and outer space conditions. Excess solder can be left on the i-side 3 :: solder. However, the planar structure shown in the figure. In order to provide a direct thermal path as described above and as described in Sections 5a and 5b, it should also be noted that excess solder can be used to provide a tin. In this method, "use," said particles, which use a heat sink soldering-a third reflow step, to connect the heat sink with a fine X tick tin, for example the remaining use from the above, it should be understood that this solder A connection is attached to the heat sink. Method and structure. In particular, the purpose of Wu Mingming has been fully provided in accordance with the compatible processing described herein—seeing that the method and structure of the present invention provides an economical soldering interface that provides a semiconductor wafer and a structure overlying a cover path. In particular, it is to be noted that ^ is used to provide the heat path after removing the heat circuit board from the wafer. It is clear that the process is particularly unique when the cover has been attached to the base. In this case, many modifications are made here. The preferred embodiment is described in detail herein. Accordingly, it is intended that those skilled in the art will invent the true spirit and scope of the patent application 2 to cover all such modifications and changes that fall within this specification.

Claims (1)

N application for patent scope I A method for providing a right grip, the method Red T is added to a thermal interface for cooling a semiconductor device, and the following steps are included: ..., the block is arranged on a for-: Low-melting-point metal permeate: + Wetting or sub-wetting in the hole of the package cover of the conductor chip is sufficient to cause the permeate to contact the chip through the hole. The temperature between the wafers is related to the cover and the cover, wherein the cover is pre-treated 0, and further includes from the cover, 'where the solder block is shaped, so that the solder system is maintained in the tube', where the The immersion tin material is selected, in which the immersion tin material includes 2. The method by which the patent application scope item > The method under which it is applied, "m neodymium power supply 3, such as the patent application shovel μ 、 、 彖 material month Look for the first step in removing the excess solder in Method 1. Method 4 · If you apply for the item in the scope of the patent application, you must have a $ method that can be inserted into the hole during the operation. Large out 'Copper 6 · 5 · As in the scope of the patent application, the group method of beryllium copper, nickel, or aluminum is as in the scope of the patent application: Carbon. N 7 · As in the scope of the patent application, ^ is set-selected from Posh纤维, fiber pads, where the tin-impregnated material is matched 8. As in the second patent application scope; cloth: group family; medium structure. Carbon that has been plated with a metal to improve wettability. / And tin materials include 9. If the law of the scope of the first application of the patent, the further package Containing—The filler layer is under the cover and an area occupied by the immersion tin material is arranged around the die. V. Tin Six /, τ, π and Ibtria, the flow of steps around the die is restricted To the area occupied by the immersion tin material 477044 6. Scope of applying for patent 10. The method according to item 1 of the scope of applying for patent, wherein the immersion tin material is compressible. 11. The method according to item 1 of the patent application range, wherein the tin immersion material is a metal. ”12. The method according to item 1 of the scope of patent application, wherein the tin-impregnated material is a metallized polymer.” 1 3. The method according to item 1 of the scope of patent application, wherein the wafer and the two are both Λ I 14. An integrated package with a thermal interface that helps to cool a semiconductor device, the package includes: a semiconducting insulating substrate with an electrical conductor; a substrate disposed on the delta substrate and facing downward A semiconductor wafer that is connected to at least some of the electrical conductors; ^ sexually connected to a seedling, a board disposed on the wafer but not in contact with it; I 忒 盍 is attached to the base of the dip material disposed between the wafer and the cover; The low-dazzle point with high thermal conductivity is filled in the cavity of the immersion tin material. 'The permeate system is actually filled between the wafer and the cover. 3 ^ A highly thermally conductive path forms the cover. It is pre-made where the permeate is as described in the patent application No. 14 $ Misplaced to provide an electric milk seal under it 16. * The patent application No. 14 Erhao is also equipped with a small amount of material in the cover P package In the immersion tin-based material 1 ?. For example, the scope of patent application: Item 14: Package 477044 6. The scope of patent application From the copper, Lu or I Lusuo group. 18. The encapsulation as in item 14 of the patent application includes carbon. The tin-impregnated material package 19. The package according to item 14 of the scope of patent application is configured to be selected from a foam pad, a fiber pad and a fiber structure. Among them, the material in the ethnic group of the dipping tin cloth is 2 0. The encapsulation of item 4 in the scope of patent application includes carbon that has been mined with a metal to improve wettability. 21 · If the filling material layer encapsulating under the cover in item 14 of the patent application and surrounding the die is limited to the area occupied by the immersion tin material 22. Such as stepping solder in the application item 14 . / 、 Zhong 5 Hai dipping tin package, one step includes a configuration straw to ensure the permeate, where the permeate system / Page 17