TWI311360B - Flip chip package with high performance of heat dissipation - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a flip chip package structure, and more particularly to a high heat dissipation performance flip chip package structure. [Prior Art] In the advanced packaging technology, the flip-chip bonding will replace the wire bonding, which is to flip-bond the wafer to the substrate without electrically connecting the wafer and the substrate with a bonding wire formed by conventional wire bonding. Not only can the electrical transmission path be shortened, but also the size of the package can be reduced. Therefore, it is known that a high-speed operation or a south frequency wafer is bonded to a substrate by flip chip bonding. However, since the wafer generates a large amount of heat during high-speed operation, the conventional flip chip package requires an appropriate heat dissipation mechanism to facilitate heat dissipation of the wafer. Referring to FIG. 1 , a conventional flip-chip package structure mainly includes a substrate 10 , a flip chip 20 , and a heat sink 3 . The flip chip 2 is bonded to the substrate by a plurality of bumps 21 . An upper surface of a substrate is generally provided with a stiffener ring on one of the upper surfaces of the substrate 1A, which is adhered to the upper surface of the substrate 1 by an adhesive layer 41 to prevent the upper surface. The warpage of the substrate 1 is warped. After bonding the flip chip 20, an underfill 50 is usually provided between the flip chip 20 and the substrate 10 to seal and protect the active surfaces of the bumps 21 and the flip chip 20 and to avoid The stress concentration phenomenon causes the bumps 21 to crack. The heat sink is adhered to the reinforcing ring 40 by another adhesive layer 31 and covers the flip chip 20. And a thermal interface material (TIM) is formed between the heat sink 30 and the flip chip 20 to heat

1311360 V. Description of the invention (2) Coupling. The flip chip 20 and the heat sink 3 are so that the flip chip 2 can be dissipated by the heat sink 30. In addition, a plurality of solder balls 70 are disposed on the lower surface of the substrate 1 for external electrical conduction. Since the flip chip 20 is hermetically sealed in a sealed space formed by the substrate 丨〇, the reinforcing ring 40 and the heat sink 30, the heat generated by the flip chip 2 聚集 is concentrated on the flip chip. Inside the package structure, the internal heat transfer effect is not uniform, and the flip chip 2 is placed in a high voltage environment, so that the internal components of the flip chip package structure are easily damaged. In addition, in order to further enhance the heat dissipation effect of the flip chip package structure, an additional heat sink fin and a heat dissipation fan (not shown) are additionally disposed on one outer surface 32 of the heat sink, and the heat sink is additionally mounted. A flip chip having a heat dissipating fin is disclosed in U.S. Patent No. 6,617,683. A conventional flip chip package having a heat dissipating fan is disclosed in the Chinese Patent Publication No. 47872. When a heat dissipating fan is disposed on the heat sink, the overall thickness of the flip chip structure is thickened, which is disadvantageously assembled in the thinned electronic product, and the fan of the heat dissipating fan lacks protection, and the fan noise generated when the fan is running and assembled poorly Cannot be excluded. In addition, the cooling fan is required to be additionally wired to lead to increase the entanglement and wiring. SUMMARY OF THE INVENTION The purpose of the present invention is to provide a high heat dissipation performance of a flip chip package. The main package 3 has a substrate, a flip chip bonded to the substrate, a 7 micro heat sink fan, and a heat sink. Micro heat dissipation wind = base J is used to join the same surface of the flip chip and is covered by the heat sink J to protect the micro heat sink fan, reduce fan noise and reduce

Page 7 1311360 5. Invention Description (4) A board, a flip chip, at least one micro heat sink fan and a heat sink, wherein the substrate has a first surface and a corresponding second surface, the flip chip Bonding to the first surface of the substrate, the micro cooling fan is disposed on the first surface of the substrate, the heat sink is disposed on the first surface of the substrate and covers the flip chip and the micro Cooling fan. [Embodiment] The present invention will be described with reference to the following embodiments. In the first embodiment of the present invention, a high heat dissipation performance flip chip package structure 100 is disclosed. Referring to FIG. 2 , the flip chip package structure 100 mainly includes a substrate 110 , a flip chip, at least one micro heat dissipation fan 130 , and a heat sink 14 , wherein the substrate 11 has a first surface 111 and A corresponding second surface 112, in the present embodiment, the substrate 110 is a multilayer circuit substrate including a BT resin. The flip chip 12 is flip-chip bonded to the first surface ln of the substrate 11A. The micro heat dissipation fan 130 is disposed on the first surface 1U of the substrate 110. The heat sink 140 is disposed on the first surface of the substrate no and covers the flip chip 120 and the micro heat dissipation fan 13A. Preferably, the space between the heat sink 14 〇 and the substrate 110 is in gas communication with the heat sink 14 〇 to facilitate rapid discharge of high temperature gas to prevent heat from collecting inside the flip chip package 100 and The flip chip 12 can be prevented from being in a high voltage environment. The flip chip 120 has an active surface 1 2 1 and a corresponding back surface 1 2 2 and includes a plurality of bumps 23 on the active surface 21, the bumps 123 being tin Wrong bumps, error-free bumps or gold bumps, which are directly soldered, solder bonded or anisotropic conductive films (Anis〇tr〇pic

Page 9 1311360

Conductive Film, ACF) is electrically connected to the substrate. An underfill 150' can typically be formed between the flip chip 120 and the substrate iio to avoid stress concentration. Please refer to FIG. 3 in particular. In the embodiment, the micro-cooling fan 130 is a surface-bonding type micro-cooling fan, and is bonded to a circuit layer of the substrate 11 by using a plurality of guiding ends 134. The micro heat dissipation fan 130 is electrically connected to the micro heat dissipation fan 13 by the substrate 110. Preferably, the micro heat dissipation fan 130 is electrically connected to the substrate through at least one of the substrates 110. A plurality of solder balls on the surface 112 are used in place of the conventional heat-dissipating fan to reduce the entanglement and wiring. The micro cooling fan 130 has a plurality of blades 131 and drives the blades 131 to rotate by a micro motor 132. Preferably, the thermal fan 130 is further provided with a thermal switch 133. When the substrate 11 〇 corresponds to a region under the flip chip 120 or other heat accumulating portion, the thermal switch 133 will be turned on. The micro motor 132 is actuated to dissipate heat; in contrast, when the temperature of the substrate 1 1 〇 corresponding to the area under the flip chip 或 2 或 or other heat accumulating portion is lowered to a predetermined value, the thermal switch 13 3 will stop the operation of the micro motor 1 3 2 to achieve the effect of power saving. In addition to the micro-heating fan 130 of this specific type, other conventional micro-dissipating fans of any shape or power can be disposed on the first surface ini of the substrate 110 for the micro-heating fan 130 of the present invention. Referring to FIG. 2 again, the heat sink 140 has an inner surface 141 and an outer surface 142. The heat sink 140 covers the flip chip j 2 〇 and the micro heat dissipation fan 130 to make the micro Cooling fan 13〇 and the flip chip

Page 10 1311360 V. Description of the Invention (6) The wafer 120 is protected from the space between the inner surface hi of the heat sink and the first surface 111 of the substrate 110 and can reduce fan operation. The noise has the effect of reducing the overall package thickness. Generally, after the heat sink 140 and the substrate 110 are bonded, a thermal conductive interface material 160 having excellent thermal conductivity is formed between the inner surface 141 of the heat sink i 4 and the back surface 122 of the substrate 11 (Thermal) The interface material (TIM) is such that the back surface heat 122 of the flip chip 120 is coupled to the heat sink 140, and the heat generated by the flip chip 120 can be transferred to the heat sink 140. In this embodiment, the heat sink 14 is formed with a plurality of fins 143 on the inner surface for heat conduction. The fins 143 may be disposed around the inner surface of the heat sink 140 to form a space for accommodating the flip chip 120, and by a gas flow channel between the fins 143' or The vent hole is designed to allow gas in the space between the heat sink 140 and the substrate 11 to be externally connected to the heat sink 140 to facilitate rapid discharge of high temperature gas. In addition, a plurality of solder balls 170 or other external guiding elements may be disposed on the second surface 112 of the substrate 110. Preferably, at least one solder ball 170 is electrically connected to the micro heat dissipating fan 130. The present invention is not limited to the shape and shape of the heat sink on the substrate. For the second embodiment of the present invention, please refer to FIG. 4 , and another flip chip package structure 200 mainly includes a substrate 210 and a flip chip. The substrate 22, the at least one micro heat dissipation fan 230, and the heat sink 240, wherein the substrate 210, the flip chip 220 and the micro heat dissipation fan 230 are combined with the substrate 110 of the first embodiment, and the flip chip 12 0 is the same as the micro cooling fan 1 3 0

Page 11 1311360 V. Description of invention (7)

Similarly, the substrate 20 0 has a first surface 211 and a corresponding second surface 212. Preferably, the first surface 211 of the substrate 210 is provided with a stiffener ring 213 to enhance the flexural strength of the substrate 210 so that the substrate 20 0 does not generate during the packaging process or use. Warping. Typically, the reinforcing ring 213 is adhered to the substrate 210 by an adhesive layer 214. The flip chip 250 is bonded to the first surface 211 of the substrate 210 by a plurality of bumps 2 21 , and the micro heat dissipation fan 230 is also disposed on the first surface 211 of the substrate 210 and adjacent thereto. A heat source such as the flip chip 220 is preferable. An underfill 150 may be formed between the flip chip 220 and the substrate 210. A thermally conductive interface material 260 may be formed between the heat sink 240 and the flip chip 220. The heat sink 240 has an inner surface 241 and an outer surface 242. The heat sink 240 is disposed on the reinforcing ring 213 by using another adhesive layer 243, so that the heat sink 240 is located on the substrate 210. The flip chip 220 and the micro cooling fan 23 are covered by the cover on the first surface 2U. Further, a plurality of solder balls 270 may be disposed on the second surface 2 12 of the substrate 21A.

Therefore, the flip chip 220 and the micro heat dissipation fan 23 are disposed in a space between the inner surface 241 of the heat sink 240 and the first surface 211 of the substrate 21 to achieve good protection and concealment, and The problem of heat accumulation inside the conventional flip chip package structure can be solved. Preferably, the reinforcing ring 213 or the heat sink 240 may have a plurality of air holes 215 for gas communication between the heat sink 240 and the substrate 210 to the outside of the heat sink 24, to the south. The discharge of warm gas achieves a good heat dissipation effect. The scope of protection of the present invention is defined by the scope of the appended patent application.

</ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; Ϊ́ϋϊ page 13 1311360 Brief description of the drawing [Simplified description of the drawing] Fig. 1 is a schematic cross-sectional view of a conventional flip chip sealing structure; Fig. 2 is a high heat dissipation performance flip chip according to the first embodiment of the present invention Schematic diagram of the wearing structure of the package structure; FIG. 3 is a schematic cross-sectional view of the micro heat dissipation fan of the high heat dissipation performance flip chip package structure according to the first embodiment of the present invention; and FIG. 4: second embodiment according to the present invention For example, a schematic cross-sectional view of another high heat dissipation performance flip chip package structure. Brief description of component symbol 10 substrate 30 heat sink 4 〇 reinforcement ring 60 thermal interface material 1 〇〇 flip chip package structure 110 substrate 120 flip chip 123 bump 130 micro heat sink fan 133 thermal switch 140 heat sink 143 fin 160 heat Leading interface material 2 〇〇 flip chip package structure 2 〇 flip chip wafer adhesive layer 41 adhesive layer 70 solder ball 111 first surface 121 active surface 131 blade 134 guiding end 141 inner surface 150 bottom filling glue 1 7 0 fresh ball 21 Bump 32 Outer surface 50 Underfill rubber 11 2 Second surface 122 Back side 132 Micro motor 1 4 2 Outer surface

1311360 Schematic description 210 substrate 21 3 reinforcement ring 2 2 0 flip chip 230 micro cooling fan 240 heat sink 243 adhesive layer 250 underfill 211 first surface 214 adhesive layer 221 bump 2 41 inner surface 212 second Surface 21 5 vent 2 4 2 outer surface 260 thermal interface material 270 solder balls

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Claims (1)

1311360 Sixth, the scope of application for patents [Scope of application for patents] 1. A flip chip package structure comprising: a surface; a substrate having a first surface and a corresponding second surface flip chip, which is bonded to the substrate The first surface surface; the finite-micro heat dissipation fan is disposed on the first surface of the substrate, and is disposed on the first surface of the substrate and covers the flip chip and the micro heat dissipation fan. Sergei 2. The flip-chip package structure as described in the scope of claim 2, wherein the micro-cooling fan comprises a thermal switch. , μ 3, : the patented range (9) described in the flip chip package structure, the surface of the heat sink fan is bonded to the flip chip package structure of the first item of the second line of the substrate, wherein the heat sink is hot Coupling one of the back sides of the flip chip. The flip-chip sealing structure according to the above aspect, wherein a thermal interface material is formed between the heat sink and the flip chip, and the flip chip package structure according to the range (i) It also includes a stiffener ring that connects the substrate to the heat sink. The flip chip package structure of claim 1, wherein the plurality of recording sheets are formed on a surface of the substrate. 8. The flip chip package structure of claim 7, wherein the