TWI810845B - Fixing device - Google Patents

Abstract

A fixing device includes a circuit board, a first cover, a reinforcing piece, and a double-layer chip. The circuit board has a first surface and a second surface opposite to each other. The first cover is disposed adjacent to the first surface. The first cover has a first bump. The first bump has a first abutting surface facing the first surface. The reinforcing piece is disposed on the first surface and adjacent to the first bump. The double-layer chip has an upper layer and a lower layer. The upper layer and the lower layer are electrically connected. An upper surface of the upper layer and a lower surface of the lower layer are respectively located on opposite sides of the double-layer chip, and an area of the upper surface is smaller than an area of the lower surface. The lower layer of the double-layer chip is electrically connected to the second surface of the circuit board.

Description

Fixtures

The present disclosure relates to a fixing device.

The realization of the automatic driving technology of electric vehicles in the future can be realized through 5G network technology. The artificial intelligence box (AI Box) of 5G network is systematically set up in the environment, so that it can freely interact with electric vehicles and transmit signals . The CPU used in the 5G AI Box needs to cooperate with double-sided cooling to maintain its working state during work. Generally speaking, a heat sink is provided on the casing of the CPU, and the CPU is dissipated in the form of heat conduction by directly contacting the casing with the CPU.

However, the upper and lower surface areas of this type of CPU are different, if the shell directly touches both sides of the CPU, it will cause uneven force on both sides of the CPU, causing it to break or deform.

Therefore, how to propose a fixing device that can solve the above-mentioned problems is one of the problems that the industry is eager to invest in research and development resources to solve.

In view of this, one purpose of the present disclosure is to provide a fixing device that can effectively solve the above problems.

The present disclosure relates to a fixing device including a circuit board, a first cover, a reinforcement and a double-layer chip. The circuit board has opposite first and second surfaces. The first cover is disposed adjacent to the first surface. The first cover has a first bump. The first protrusion has a first abutting surface facing the first surface. The reinforcement is disposed on the first surface and adjacent to the first bump. A bilayer wafer has an upper layer and a lower layer. The upper layer is electrically connected to the lower layer. The upper surface of the upper layer and the lower surface of the lower layer are respectively located on opposite sides of the double-layer wafer, and the area of the upper surface is smaller than that of the lower surface. The lower layer of the bilayer wafer is electrically connected to the second surface of the circuit board.

In some current embodiments, the reinforcement is completely attached to the first surface.

In some current embodiments, the reinforcing member further includes two fixing parts contacting and being fixed to the first surface, wherein the first protrusion is located between the two fixing parts of the reinforcing member.

In some current embodiments, the circuit board further includes an opening passing through the first surface and the second surface, and the first bump is opposite to the opening, and the upper layer of the double-layer chip is embedded in the opening.

In some current embodiments, the reinforcement is a closed frame surrounding the opening.

In some current embodiments, the projection of the first abutting surface in a direction perpendicular to the first surface passes through the opening and is located within the inner edge of the opening.

In some current embodiments, the first abutment surface partially protrudes into the opening and contacts the upper layer of the double-layer wafer.

In some current embodiments, the fixing device further includes a second cover, the circuit board is located between the first cover and the second cover, the second cover includes a second protrusion, and the second protrusion has a second abutment The face is opposite the opening and contacts the lower layer of the bilayer wafer.

In some current embodiments, the reinforcing member further includes fixing locations, at least one of the fixing locations is fixed to the first cover, and at least another of the fixing locations is fixed to the second cover.

In some current embodiments, the first bump and the second bump include thermally conductive material.

To sum up, in the fixing device of the present disclosure, the circuit board located between the first cover and the second cover evenly distributes the stress from different directions through the reinforcing member disposed on its surface. The reinforcing piece further strengthens the force strength around the opening of the circuit board, and disperses the stress around the opening, and together with the first bump and the second bump, the force applied by the first cover and the second cover is evenly applied to the opening The opposite sides of the middle chip are evenly stressed, thus further preventing the circuit board or the components or chips arranged on the circuit board from being broken or deformed due to the extrusion of the covers on both sides. In addition, the fixing device not only utilizes the reinforcing member to average the stress of the area around the opening, but also conducts heat to the heat dissipation fins through the first bump and the second bump, thereby solving the heat dissipation problem of the circuit board.

The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. Of course, these are examples only, and are not intended to be limiting. For example, in the following description a first feature is formed on or on a second feature may include embodiments where the first feature is formed in direct contact with the second feature, and may also include embodiments where additional features may be An embodiment formed between a first feature and a second feature such that the first feature and the second feature may not be in direct contact. In addition, the present disclosure may repeat element symbols and/or letters in various examples. This repetition is for simplicity and clarity and does not in itself indicate a relationship between the various embodiments and/or configurations discussed.

Additionally, for simplicity of description, spatially relative terms such as "below," "beneath," "lower," "above," "upper," and similar terms may be used herein to describe Describes the relationship of one element or feature to another (further) element or feature as shown in the figures. Such spatially relative terms are intended to encompass different orientations of the elements in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

As used herein, "approximately", "approximately", "approximately" or "substantially" means falling within twenty percent, or within ten percent, or within one hundred percent of a given value or range Five out of five. Numerical quantities given herein are approximations, meaning that terms such as "about," "about," "approximately," or "substantially" can be inferred when not expressly stated otherwise.

FIG. 1 is a schematic diagram of a fixation device 100 according to some embodiments of the present disclosure. FIG. 2A is an exploded view of a fixation device 100 according to some embodiments of the present disclosure. FIG. 2B is an exploded view from another perspective of the fixation device 100 according to some embodiments of the present disclosure. FIG. 2C is a schematic diagram of a bilayer wafer 200 of the fixture 100 according to some embodiments of the present disclosure. Please refer to FIG. 1 , FIG. 2A , FIG. 2B and FIG. 2C at the same time. The fixing device 100 of the present disclosure includes a circuit board 110 , a first cover 120 , a reinforcing member 130 and a double-layer chip 200 . The circuit board 110 has a first surface 112 and a second surface 114 opposite to each other. The first cover 120 is disposed adjacent to the first surface 112 . The first cover 120 has a first protrusion 122 . The first protrusion 122 has a first abutting surface 122 a facing the first surface 112 . The reinforcing piece 130 is disposed on the first surface 112 and adjacent to the first bump 122 . The double-layer wafer 200 is disposed on the circuit board 110 . The bilayer wafer 200 has an upper layer 210 and a lower layer 220 . The upper surface 210 a of the upper layer 210 and the lower surface 220 a of the lower layer 220 are respectively located on opposite sides of the double-layer wafer 200 , and the area of the upper surface 210 a is smaller than that of the lower surface 220 a. The upper layer 210 and the lower layer 220 of the double-layer chip 200 are electrically connected through solder balls (not shown).

The first surface 112 of the circuit board 110 is provided with a plurality of circuit elements and chips (for example, a CPU chip with a ball grid array (BGA) package, and the BGA chip will be used as an implementation of the double-layer chip 200 below. example) and is covered by the first cover 120 . In some embodiments, the circuit board 110 further includes an opening 116 passing through the first surface 112 and the second surface 114 , and the first bump 122 is opposite to the opening 116 , and the upper layer 210 of the double-layer chip 200 is embedded in the opening 116 . Further, in some embodiments, the opening 116 may accommodate a circuit element or die, such as the bilayer die 200 . The double-layer wafer 200 has a double-layer structure with upper and lower layers. The upper layer and the lower layer are soldered by BGA. The upper layer 210 has a smaller surface area than the lower layer 220 . For example, the upper layer 210 has a rectangular surface area (that is, the area of the upper surface 210a) when viewed in a direction perpendicular to the first surface 112, and the lower layer 220 has a rectangular surface area (that is, the area of the lower surface 220a). The rectangular surface area is larger than the rectangular surface area of the upper layer 210 . Furthermore, the lower layer 220 of the double-layer chip 200 is connected to the upper layer 210 through the bonding surface, and the exposed area of the lower layer 220 in the bonding surface has a plurality of solder balls arranged in an array. Referring to the embodiment shown in Figure 2A and Figure 2B, the size of the opening 116 will allow the upper layer 210 of the double-layer wafer 200 to protrude therein, but the lower layer 220 of the double-layer wafer 200 will be limited to one side of the circuit board 110 (eg, confined to the second surface 114 of the circuit board 110 ), and the double-layer chip 200 can electrically connect the chip 200 to the second surface 114 of the circuit board 110 through the solder balls of the lower layer 220 .

The first cover 120 is disposed on a side adjacent to the first surface 112 . In some embodiments, a side of the first cover 120 away from the first surface 112 may have multiple heat dissipation structures, for example, heat dissipation fins. These heat dissipation structures can improve the heat dissipation efficiency of the circuit board 110 to maintain the normal operation of the circuit. The first cover 120 can conduct heat to the heat dissipation fins by contacting a heat source (for example, a heating element or chip on the circuit board 110 ) and dissipate the heat through the heat dissipation fins.

The first bump 122 protrudes from the first cover 120 toward the first surface 112 . The position of the first bump 122 may correspond to the position of the circuit elements or chips on the circuit board 110 and be in contact with at least one of these circuit elements or chips. Specifically, the projection of the first abutting surface 122 a in a direction perpendicular to the first surface 112 passes through the opening 116 and is located within the inner edge of the opening 116 . Inheriting the above-mentioned embodiment of using a BGA chip as the double-layer chip 200, the first abutting surface 122a of the first bump 122 can correspond to the position of the opening 116 of the circuit board 110, and the first bump 122 is in the position of the opening 116 of the circuit board 110 The area projected in a direction perpendicular to the first surface 112 will be smaller than the area of the opening 116 . Therefore, in some embodiments, the first abutting surface 122 a partially protrudes into the opening 116 and contacts the upper layer 210 of the bilayer wafer 200 . Specifically, the first bump 122 can extend into the opening 116 and touch the upper surface 210 a of the double-layer chip 200 through the first abutting surface 122 a, but the disclosure is not limited thereto.

FIG. 3 is a partially enlarged view of the fixing device 100 according to some embodiments of the present disclosure. Referring to Figure 2A, Figure 2B and Figure 3, the reinforcing member 130 is disposed adjacent to the first bump 122. In some embodiments, the reinforcing member 130 is completely attached to the first surface 112, but this disclosure does not mean that limit. Specifically, in Fig. 3, the reinforcing member 130 is arranged around the opening 116 to average the stress on the area around the opening 116, and further prevent the circuit board 110 from being bent or deformed, and further prevent the circuit board 110 from The component or wafer is broken due to the extrusion of the outer cover (eg, the first cover 120 ). In detail, due to the board bending problem of the circuit board 110, the BGA solder joint (solder ball) between the upper layer 210 and the lower layer 220 and the BGA solder joint (solder ball) between the lower layer 220 and the back of the circuit board 110 are cracked under pressure can be effectively avoided. The reinforcing member 130 that is fully attached (for example, by bonding or locking) to the first surface 112 can maximize the contact area between the two, so as to achieve the effect of optimizing stress distribution and avoid circuit board 110 bent or deformed. In some embodiments, the reinforcing member 130 is a closed frame surrounding the opening 116 , but the present disclosure is not limited thereto. Specifically, in FIG. 3 , the reinforcing member 130 is a frame with an approximately rectangular opening, and the rectangular opening surrounds and fully exposes the opening 116 . However, in other embodiments, the reinforcing member 130 may also be a closed frame with other shapes. In addition, in some other embodiments, the reinforcing member 130 may also be composed of a plurality of separated or connected parts with the same or different shapes.

In some embodiments, the reinforcing member 130 further includes at least two fixing portions 132 contacting and being fixed to the first surface 112 , wherein the first protrusion 122 is located between the two fixing portions 132 of the reinforcing member 130 . The fixing method of the fixing part 132 may be, for example, screw locking, welding, welding and the like. Specifically, the fixing portion 132 of the reinforcement 130 can be located at any two ends of the reinforcement 130 , so that the reinforcement 130 can evenly distribute the stress to the area it covers. In FIG. 3 , the reinforcing member 130 is a frame with a rectangular opening, and has two sets of opposite fixing parts 132 , and the first protrusion 122 is located at the center of the two sets of fixing parts 132 to optimize stress distribution.

Continuing to refer to FIG. 1, FIG. 2A, FIG. 2B and FIG. 2C, in some embodiments, the fixing device 100 further includes a second cover 140, and the circuit board 110 is located between the first cover 120 and the second cover 140 Between them, the second cover 140 includes a second bump 142 , and the second bump 142 has a second abutting surface 142 a opposite to the opening 116 and contacts the lower layer 220 of the double-layer wafer 200 . Specifically, there is an accommodating space between the first cover 120 and the second cover 140 for accommodating the circuit board 110 or other devices and components. The first cover 120 and the second cover 140 can be fixed to each other by suitable methods such as screw locking, welding, snapping and the like. In some embodiments, the second protrusion 142 of the second cover 140 protrudes toward the second surface 114, and the area of the second abutting surface 142a of the second protrusion 142 is larger than the area of the opening 116, so that the second protrusion 142 may completely cover opening 116 . In the embodiment of Figure 2A and Figure 2B, the area of the second abutment surface 142a is equal to or greater than the lower surface 220a of the lower layer 220 of the double-layer wafer 200, and the second abutment surface 142a can be formed by the lower surface of the double-layer wafer 200. 220a exerts an average force on the double-layer chip 200 to stabilize the electrical connection between the double-layer chip 200 and the circuit board 110 .

In some embodiments, the second cover 140 may also have a plurality of heat dissipation structures similar or identical to the first cover 120 , such as heat dissipation fins, so as to improve the heat dissipation efficiency of the circuit board 110 and maintain the normal operation of the circuit. Furthermore, in some embodiments, the first bump 122 and the second bump 142 include thermally conductive material. For example, the first cover 120 and the second cover 140 can be good conductors of heat as a whole, and the first cover 120 and the second cover 140 can be contacted by the first bump 122 and the second bump 142 respectively. A heat source (for example, a double-layer wafer 200), and conducts the heat to the heat dissipation fins for heat dissipation. However, the present disclosure is not limited thereto. In other embodiments, the first bump 122 and the second bump 142 may only have heat conduction properties in specific areas, so as to conduct heat from the heat source and pass through the first cover 120 And the second cover 140 escapes.

Figure 4A is a perspective cross-sectional view along line 4-4 of Figure 1, according to some embodiments of the present disclosure. Figure 4B is an enlarged partial cross-sectional view of Figure 4A. In the embodiments of Fig. 3, Fig. 4A and Fig. 4B, the circuit board 110 is located between the first cover 120 and the second cover 140, and the double-layer wafer 200 (for example, the upper layer 210 of the double-layer wafer 200 ) is partially accommodated in the opening 116 . A reinforcing member 130 is disposed on the first surface 112 of the circuit board 110 between the first cover 120 and the circuit board 110 . The first abutment surface 122a passes through the reinforcing member 130 and partially protrudes to the opening 116 to contact the upper surface 210a of the double-layer wafer 200, and the second abutment surface 142a contacts the lower surface 220a of the double-layer wafer 200, and the double-layer wafer The lower layer 220 of the 200 is also electrically connected to the circuit board 110 through solder balls. Thermal paste may be coated between the double-layer chip 200 and the first bump 122 and the second bump 142 to help conduct heat to the first bump 122 and the second bump 142 . In this way, the double-layer chip 200 can not only overcome the problem of cracking or deformation caused by uneven stress distribution, but also enable the double-layer chip 200 to have a good heat dissipation effect to maintain the operation of the double-layer chip 200 .

In some embodiments, the reinforcing member 130 further includes fixing parts 132 , at least one of the fixing parts 132 is fixed to the first cover 120 , and at least another one of the fixing parts 132 is fixed to the second cover 140 . Specifically, the reinforcing piece 130 in FIG. 3 has four fixing parts 132, which are respectively located at the four corners of the reinforcing piece 130 (a rectangular frame in this embodiment), and the fixing parts 132 are divided according to two diagonal lines. There are two groups, the two fixing parts 132 on the same diagonal line are the same group, one group of fixing parts 132 is fixed on the first cover body 120, and the other group of fixing parts 132 is fixed on the second cover body 140 Above all, the purpose is to use the first cover 120 and the second cover 140 to evenly distribute the force of the reinforcing member 130 . Compared with fixing the fixing portions 132 of the reinforcing member 130 on one of the first cover 120 or the second cover 140 , such a fixing method can increase the stress distribution effect of the reinforcing member 130 .

From the above detailed description of the specific implementation of the present disclosure, it can be clearly seen that in the fixing device of the present disclosure, the circuit board located between the first cover and the second cover, through the reinforcing member arranged on its surface Evenly distributes the stress from different directions. The reinforcing piece further strengthens the force strength around the opening of the circuit board, and disperses the stress around the opening, and together with the first bump and the second bump, the force applied by the first cover and the second cover is evenly applied to the opening The opposite sides of the middle chip are evenly stressed, thus further preventing the circuit board or the components or chips arranged on the circuit board from being broken or deformed due to the extrusion of the covers on both sides. In addition, the fixing device not only utilizes the reinforcing member to average the stress of the area around the opening, but also conducts heat to the heat dissipation fins through the first bump and the second bump, thereby solving the heat dissipation problem of the circuit board.

In an embodiment of the present invention, the server of the present invention can be used for artificial intelligence (English: Artificial Intelligence, referred to as AI) computing, edge computing (edge computing), and can also be used as a 5G server, cloud server or vehicle Internet server use.

The foregoing outlines features of several embodiments so that those skilled in the art may better understand aspects of the disclosure. Those skilled in the art should appreciate that they can readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments described herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions and substitutions herein without departing from the spirit and scope of the present disclosure.

100: Fixtures

110: circuit board

112: first surface

114: second surface

116: opening

120: the first cover

122: The first bump

122a: the first abutment surface

130: reinforcement

132: fixed part

140: the second cover

142: Second bump

142a: second abutment surface

200: chip

210: upper floor

210a: upper surface

220: lower layer

220a: lower surface

4-4: Line

Aspects of the present disclosure are best understood from the following Detailed Description when read in conjunction with the accompanying drawings. It should be noted that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion. FIG. 1 is a schematic diagram of a fixation device according to some embodiments of the present disclosure. Figure 2A is an exploded view of a fixture according to some embodiments of the present disclosure. FIG. 2B is an exploded view from another perspective of a fixation device according to some embodiments of the present disclosure. FIG. 2C is a schematic diagram of a two-layer wafer of a fixture according to some embodiments of the present disclosure. FIG. 3 is a partially enlarged view of a fixing device according to some embodiments of the present disclosure. Figure 4A is a perspective cross-sectional view along line 4-4 of Figure 1, according to some embodiments of the present disclosure. Figure 4B is an enlarged partial cross-sectional view of Figure 4A.

100: Fixtures

110: circuit board

114: second surface

116: opening

120: the first cover

122: The first bump

122a: the first abutment surface

130: reinforcement

132: fixed part

140: the second cover

Claims (9)

A fixing device, comprising: a circuit board, comprising an opening, a first surface opposite to a second surface, the opening passing through the first surface and the second surface; a first cover, adjacent to the first surface Set, the first cover has a first bump, the first bump has a first abutting surface facing the first surface, the first bump is opposite to the opening; a reinforcing piece is arranged on the The first surface is adjacent to the first bump; and a double-layer chip has an upper layer and a lower layer, the upper layer and the lower layer are electrically connected, wherein an upper surface of the upper layer and a lower surface of the lower layer are respectively located on the double-layer opposite sides of the wafer, and the area of the upper surface is smaller than the area of the lower surface, the lower layer of the double-layer wafer is electrically connected to the second surface of the circuit board, wherein the upper layer of the double-layer wafer is embedded in the opening. The fixing device as claimed in claim 1, wherein the reinforcing member is completely attached to the first surface. The fixing device according to claim 1, wherein the reinforcing member further includes two fixing parts contacting and being fixed to the first surface, wherein the first protrusion is located between the two fixing parts of the reinforcing member. The fixing device as claimed in claim 1, wherein the reinforcing member is a closed frame surrounding the opening. The fixing device according to claim 1, wherein the projection of the first abutting surface in a direction perpendicular to the first surface passes through the opening and is located within the inner edge of the opening. The fixing device as claimed in claim 5, wherein the first abutting surface partially protrudes into the opening and contacts the upper layer of the double-layer wafer. The fixing device according to claim 1, further comprising a second cover, the circuit board is located between the first cover and the second cover, the second cover includes a second protrusion, the first The two bumps have a second abutting surface opposite to the opening and contacting the lower layer of the double-layer chip. The fixing device according to claim 7, wherein the reinforcement further includes a plurality of fixing parts, at least one of the fixing parts is fixed on the first cover, and at least another of the fixing parts is fixed on the the second cover. The fixing device as claimed in claim 7, wherein the first bump and the second bump include thermally conductive material.

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