Packaging unit, packaging module and preparation method

Abstract

The invention discloses a packaging unit, a packaging module and a preparation method, the packaging unit comprises a chip, a switching piece and a connecting layer, and the switching piece is connected to one side of the chip through the connecting layer; the switching piece comprises a main body part and a convex part, the convex part is arranged on one side, facing the chip, of the main body part, the connecting layer comprises a first area located between the convex part and the chip and a second area located on the outer side of the first area, and the connecting layer of the first area comprises a sintered material which is subjected to sintering reaction and is connected with the convex part and the chip respectively. And the connecting layer in the second area comprises an unsintered material which is not subjected to sintering reaction and a solvent coating the unsintered material. In the second area, a solvent is reserved in the connecting layer, and the solvent has good oxygen blocking capability and can effectively protect metal on the upper layer of the chip. And on the other hand, the connecting layer which is not subjected to the sintering reaction can play a certain buffering role, so that the problem of chip damage can be improved when the subsequent pressure sintering is carried out.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing technology, and in particular to a packaging unit, a packaging module and a preparation method thereof. Background Art

[0002] For packaging modules that require double-sided heat dissipation, they mainly include the following structures from top to bottom: a top heat dissipation substrate, an adapter, a chip and a bottom heat dissipation substrate, and adjacent structures are sintered by sintering materials. In order to improve efficiency, this type of packaging module is currently prepared by the following process: first, the adapter and the chip are bonded to form a packaging unit, and then the packaging unit is sintered with the top heat dissipation substrate and the bottom heat dissipation substrate to form a packaging module. In the related art, when preparing the packaging unit, the sintering degree of the sintering material between the adapter and the chip is high, and the solvent of the sintering material has completely evaporated. The sintered material after sintering is a porous material at the microscopic level, and its oxygen barrier ability is poor, which can easily cause oxidation of the metal on the upper layer of the chip. On the other hand, the hardness of the sintered material after sintering is high, and its buffering capacity and pressure absorption ability are poor. When the subsequent sintering process is carried out and it is subjected to pressure, there is a possibility of damaging the chip. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a packaging unit that can improve the problems of metal oxidation on the chip and chip damage during pressure sintering.

[0004] The present invention also provides a packaging module using the packaging unit and a method for preparing the packaging unit.

[0005] According to a first embodiment of the present invention, the packaging unit includes a chip, a transfer sheet, and a connection layer, wherein the transfer sheet is connected to one side of the chip through the connection layer; Among them, the adapter includes a main body and a convex portion, the convex portion is arranged on the side of the main body facing the chip, the connecting layer includes a first area located between the convex portion and the chip, and a second area located outside the first area, the connecting layer in the first area includes sintered material that has undergone a sintering reaction and respectively connects the convex portion and the chip, the connecting layer in the second area includes unsintered material that has not undergone a sintering reaction, and a solvent that covers the unsintered material.

[0006] The encapsulation unit according to the first embodiment of the present invention has at least the following beneficial effects: In the first area, the protrusion and the chip are connected and fixed by sintered material, so that the chip and the adapter form an integral structure. In the second area, the connection layer still retains a solvent, which has good oxygen barrier ability and can effectively protect the metal on the upper layer of the chip. On the other hand, the connection layer that has not yet undergone a sintering reaction can play a certain buffering role, and when the subsequent pressure sintering is carried out, it can improve the problem of chip damage.

[0007] In other embodiments of the present invention, the connecting layer also includes a third region located between the first region and the second region, and the connecting layer in the third region includes unsintered material that has not undergone a sintering reaction, wherein the connecting layer in the third region also includes a solvent that coats the unsintered material, and the content of the solvent in the third region is less than the content of the solvent in the second region, or the third region does not contain the solvent.

[0008] In other embodiments of the present invention, a plurality of the protrusions are provided, and the plurality of the protrusions are distributed along a first circumference, and the connection layer includes a plurality of the first regions located between each of the protrusions and the chip.

[0009] In other embodiments of the present invention, the connection layer further includes a fourth region located between the main body and the chip, and the connection layer in the fourth region includes a sintered material that has undergone a sintering reaction to connect the main body and the chip respectively. In other embodiments of the present invention, there are multiple protrusions distributed along the first circumference, the connecting layer includes multiple first regions located between each of the protrusions and the chip, and the fourth region is arranged corresponding to the center of the first circumference.

[0010] In other embodiments of the present invention, the main body further has an exhaust hole extending through the main body along the thickness direction.

[0011] In other embodiments of the present invention, the exhaust hole is provided in plurality, the plurality of exhaust holes are distributed along a first circumference, and the convex portion is provided corresponding to the center of the first circumference.

[0012] In another embodiment of the present invention, the chip has a gate finger, the protrusion is arranged adjacent to the gate finger relative to the exhaust hole, and the exhaust hole is arranged away from the gate finger relative to the protrusion.

[0013] In other embodiments of the present invention, in a space between the chip and the main body and extending in a direction between the chip and the main body, with the outer contour of the protrusion as the boundary line, the volume of the protrusion is greater than or equal to 50% of the volume of the space; And / or, the minimum thickness of the connecting layer in the first region is greater than or equal to 25 micrometers.

[0014] A packaging module according to a second embodiment of the present invention includes: The packaging unit; a first heat dissipation substrate connected to a side of the adapter away from the chip; The second heat dissipation substrate is connected to a side of the chip away from the adapter.

[0015] A method for preparing a packaging unit according to a third embodiment of the present invention includes the following steps: Coating a connecting agent on one side of the chip and placing the adapter on the connecting agent, wherein the connecting agent includes a solvent and an unsintered material coated in the solvent; The local area of ​​the adapter is heated to make the connecting agent form the connecting layer, wherein the unsintered material in the first area undergoes a sintering reaction and is converted into a sintered material, and the unsintered material in the second area remains in an unsintered state encapsulated in the solvent.

[0016] In other embodiments of the present invention, the method of heating the local area of ​​the adapter includes: heating the local area of ​​the adapter using a laser light source.

[0017] In other embodiments of the present invention, the heating time of the laser light source is less than or equal to 60 seconds.

[0018] In other embodiments of the present invention, the method of heating the local area of ​​the adapter plate includes: heating the local area of ​​the adapter plate that is offset relative to the protrusion, so that the unsintered material corresponding to the local area between the main body and the first side undergoes a sintering reaction and is converted into a sintered material.

[0019] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which: Figure 1 A schematic diagram of a packaging module in related art; Figure 2 is a schematic diagram of a packaging unit in an embodiment of the present invention; Figure 3 For Figure 1 Schematic diagram of applying a connecting agent between the adapter and the chip; Figure 4 For Figure 2 Schematic diagram of the connecting layer after sintering of the connecting agent; Figure 5 Schematic diagram of sintering by a heat source that does not overlap with the convex portion; Figure 6 Schematic diagram of sintering by a heat source coinciding with the convex portion; Figure 7 for Figure 2 A top view of the package unit; Figure 8 is a top view of a packaging unit in another embodiment; Figure 9 Schematic diagram of a packaging module in an embodiment of the present invention.

[0021] Reference numerals: Top heat sink 1, top sintered layer 2, middle connecting sheet 3, middle sintered layer 4, chip 5, bottom sintered layer 6, bottom heat sink 7; Encapsulation unit 10; a first heat dissipation substrate 20; A second heat dissipation substrate 30; Heat source 40; Chip 100 , first side 101 , second side 102 , gate finger 110 ; Adapter 200, main body 210, exhaust hole 211, convex portion 220; Connecting layer 300, first region 301, second region 302, third region 303, fourth region 304, sintered material 310, unsintered material 320, silver particles 321, capping agent 322, solvent 330; First circle A; Second circle B; Space C. DETAILED DESCRIPTION

[0022] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0023] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0024] In the description of the present invention, "several" means more than one, "plurality" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0025] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0026] In the description of the present invention, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the exemplary expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0027] Reference Figure 1 , shows a simplified schematic diagram of a conventional packaging module with double-sided heat dissipation function, which includes, from top to bottom, a top heat sink 1, a top sintered layer 2, an intermediate connecting sheet 3, an intermediate sintered layer 4, a chip 5, a bottom sintered layer 6, and a bottom heat sink 7. The top heat sink 1 and the bottom heat sink 7 are both used for heat dissipation, and each sintered layer is used to connect adjacent structures. The intermediate connecting sheet 3 is used to create a certain distance between the top heat sink 1 and the chip 5 so as to connect leads on the upper side of the chip 5. Specifically, the intermediate connecting sheet 3 covers a portion of the upper surface of the chip 5 and exposes another portion of the chip, which can be used to connect leads. The preparation process of this type of packaging module mainly includes the following steps: ① Coating a sintering material such as silver paste on the bottom heat sink 7, placing the chip 5 on the sintering material and performing the first sintering. After sintering, the sintering material forms a bottom sintering layer 6 to connect the chip 5 and the bottom heat sink 7; ② Coating the sintering material on the chip 5, placing the intermediate connecting piece 3 on the sintering material and performing a second sintering. After sintering, the sintering material forms an intermediate sintering layer 4 to connect the chip 5 and the intermediate connecting piece 3; ③ Coat the middle connecting piece 3 with sintered material, place the top heat sink 1 on the sintered material and perform a third sintering. After sintering, the sintered material forms a top sintered layer 2 to connect the middle connecting piece 3 and the top heat sink 1 .

[0028] As can be seen from the above, the preparation of this type of package module requires three sintering steps, which is a complicated process and has low production efficiency. Based on this, there is currently an improved process, which mainly includes the following steps: ① Coating a sintering material on the chip 5, placing the intermediate connecting piece 3 on the sintering material and performing a first sintering to form a package unit. After sintering, the sintering material forms an intermediate sintering layer 4 to connect the chip 5 and the intermediate connecting piece 3; ② Coat sintered material on the bottom heat sink 7 and the middle connecting piece 3 of the packaging unit, place the packaging unit on the sintered material of the bottom heat sink 7, and place the top heat sink 1 on the sintered material of the middle connecting piece 3, and then perform a second sintering. The sintered material between the packaging unit and the bottom heat sink 7 forms a bottom sintered layer 6 after sintering to connect the chip 5 and the bottom heat sink 7, and the sintered material between the middle connecting piece 3 and the top heat sink 1 forms a top sintered layer 2 after sintering to connect the middle connecting piece 3 and the top heat sink 1.

[0029] As can be seen from the above, this type of improved process can first batch-prepare packaging units, and then batch-prepare packaging modules from the packaging units, and reduce the sintering steps, which can significantly improve efficiency. However, this type of improved process still has defects. For example, when preparing the packaging unit, the sintering degree of the sintering material between the adapter and the chip is high, and the solvent of the sintering material has been completely vaporized. The sintered material after sintering is a porous material at the microscopic level, and its oxygen barrier ability is poor, which easily leads to oxidation of the metal on the upper layer of the chip. On the other hand, the hardness of the sintered material after sintering is high, and its buffering capacity and ability to absorb pressure are poor. When the subsequent sintering process is carried out and it is subjected to pressure, there is a possibility of damaging the chip. Based on this, an embodiment of the present invention proposes a packaging unit 10, which can improve the problems of metal oxidation on the chip and damage to the chip during pressurized sintering. The following is an explanation with reference to the embodiments and drawings.

[0030] Reference Figure 2 , shows a schematic diagram of the packaging unit in the first embodiment of the present invention. The packaging unit 10 includes a chip 100, a transfer sheet 200 and a connection layer 300. The chip 100 and the transfer sheet 200 are fixed by the connection layer 300 to form an integral structure. The connection layer 300 is formed by partially and incompletely sintering a connection agent such as silver paste. Before sintering, refer to Figure 3 The connecting agent includes a solvent 330 and an unsintered material 320 coated in the solvent 330. Taking silver paste as an example, the unsintered material 320 includes a capping agent 322 and silver particles 321 coated in the capping agent 322. When sintering, the solvent 330 and the capping agent 322 are heated and vaporized, and metal diffusion occurs between the silver particles 321 under the environment of heating and pressure, so that the unsintered material 320 gradually transforms into Figure 4The sintered material 310 shown can achieve a fixed connection between the chip 100 and the transfer sheet 200 .

[0031] Specifically, the chip 100 has a first side 101 and a second side 102 that are oppositely disposed. Figure 2 Taking the state shown as an example, the first side 101 is the upper side of the chip 100 , and the second side 102 is the lower side of the chip 100 . The connection layer 300 is located on the upper side of the chip 100 , and the transfer sheet 200 is located on the upper side of the connection layer 300 .

[0032] In this embodiment, the adapter plate 200 is made of a material that can conduct heat and electricity, for example, the adapter plate 200 is made of copper. Figure 2 The transfer sheet 200 includes a main body 210 and a protrusion 220. The protrusion 220 is disposed on the side of the main body 210 facing the chip 100. For example, the main body 210 is configured as a sheet, and the protrusion 220 is disposed on the lower side of the main body 210. The main body 210 and the protrusion 220 can be connected to form an integral structure. Based on the above, the area of ​​the transfer sheet 200 where the protrusion 220 is disposed is in contact with the connection layer 300, and the other areas of the transfer sheet 200 that are different from the protrusion 220 are in contact with the connection layer 300. The number of protrusions 220 can be one or more, which will be explained in subsequent embodiments.

[0033] The connection layer 300 includes a first region 301 located between the protrusion 220 and the chip 100, and a second region 302 located outside the first region 301. The connection layer 300 in the first region 301 includes a sintered material 310 that has undergone a sintering reaction and connects the protrusion 220 and the chip 100 respectively. The connection layer 300 in the second region 302 includes an unsintered material 320 that has not undergone a sintering reaction and a solvent 330 that covers the unsintered material 320. In this way, in the first region 301, the protrusion 220 and the chip 100 are connected. The portion 220 and the chip 100 are connected and fixed by the sintered material 310, so that the chip 100 and the adapter 200 form an integral structure. In the second area 302, the connection layer 300 still retains a solvent 330. The solvent 330 has good oxygen barrier ability and can effectively protect the metal on the upper layer of the chip 100. On the other hand, the connection layer 300 that has not yet undergone a sintering reaction can play a certain buffering role, and when the subsequent pressure sintering is carried out, the problem of damage to the chip 100 can be improved.

[0034] To fully understand the concept of the present invention, the following describes the difference between the present invention and related technologies from the perspective of the sintering process. Taking silver paste as an example, the related technology requires a hot pressing mechanism to press the adapter 200 and heat the entire adapter 200, and the heating time is relatively long, so the entire silver paste will sinter. In the present invention, a point light source such as a laser can be used for regional heating, and the heating time is relatively short. Therefore, only a local area of ​​the silver paste is sintered, and most of the silver paste still retains the solvent 330, thus having better oxygen barrier properties.

[0035] In addition, the adapter sheet 200 of this embodiment is provided with a protrusion 220. Since the protrusion 220 occupies part of the space, the volume of the connecting agent at the bottom of the protrusion 220 is smaller than the volume of the connecting agent in other areas where the protrusion 220 is not provided. Therefore, the connecting agent at the bottom of the protrusion 220 is easier to heat up, so that when the connecting agent at the bottom of the protrusion 220 reaches the sintering temperature, the connecting agent in other areas has not yet reached the sintering temperature and can retain the solvent 330. In this way, through local and rapid heating, sintered material 310 can be formed in part of the area of ​​the connecting layer 300, and unsintered material 320 can be retained in most areas.

[0036] It should be noted that, depending on the different heating positions during sintering, the distribution of the first region 301 and the second region 302 are different. Figure 5 When the heating area of ​​the heat source 40 on the adapter sheet 200 is offset from the area where the protrusion 220 is located, the second area 302 at least exists on the side of the first area 301 away from the heating area. Of course, the second area 302 is not limited to this and may also exist in other areas away from the heating area; refer to Figure 6 When the heating area of ​​the heat source 40 on the adapter 200 coincides with the area where the protrusion 220 is located, the second area 302 at least exists outside the first area 301. Figure 4 The scope of the first area 301 and the second area 302 around the protrusion 220 is also roughly shown by dotted lines.

[0037] It should also be noted that the first region 301, the second region 302, and the subsequently mentioned third region 303 and fourth region 304 are primarily used to distinguish between sintered, unsintered, and transitional regions, and do not limit their specific shapes or sizes. Specifically, the first region 301 can be understood as the area directly below the protrusion 220, and the fourth region 304 can be understood as the area directly below the illumination portion of the light source 40.

[0038] On the basis of the first embodiment, in some embodiments of the present invention, referring to Figures 4 to 6The connecting layer 300 also includes a third region 303 located between the first region 301 and the second region 302. The connecting layer 300 in the third region 303 includes an unsintered material 320 that has not undergone a sintering reaction. The connecting layer 300 in the third region 303 also includes a solvent 330 that covers the unsintered material 320, and the content of the solvent 330 in the third region 303 is less than the content of the solvent 330 in the second region 302. That is, the third region 303 is a transition region between the first region 301 and the second region 302. Compared with the first region 301, the third region 303 still retains the unsintered material 320 that has not undergone a sintering reaction and part of the solvent 330. Compared with the second region 302, the third region 303 receives more heat and the amount of solvent 330 vaporized is more. Therefore, the content of solvent 330 is less than the content of solvent 330 in the second region 302.

[0039] In other embodiments, the third region 303 does not contain the solvent 330, that is, the solvent 330 in the third region 303 has been completely vaporized, but the unsintered material 320 therein is still retained. Taking silver paste as an example, the outer side of the silver particles 321 in the third region 303 is still coated with the capping agent 322.

[0040] On the basis of the first embodiment, in some embodiments of the present invention, referring to Figure 7 There are multiple protrusions 220, and the multiple protrusions 220 are distributed along the first circumference A. The connecting layer 300 includes multiple first areas 301 located between each protrusion 220 and the first side 101. In this embodiment, by providing multiple protrusions 220 distributed along the first circumference A, the heat source 40 can heat from the center of the first circumference A. Since the distance from each protrusion 220 to the center of the circle is equal, the heat transferred to each protrusion 220 is roughly uniform, so that sintered material 310 can be formed at the bottom of each protrusion 220. In this way, in addition to the local sintering area formed by direct heating directly below the heat source 40, multiple local sintering areas can be formed in other positions through one heat source 40, thereby reducing the use of heat sources and improving sintering efficiency. Exemplarily, there are two protrusions 220, so that two sintering areas can be formed respectively. Combined with the local sintering areas formed by direct heating by the heat source 40, there are three independent local sintering areas between the chip 100 and the adapter 200, and the connection between the two is more stable.

[0041] On the basis of the first embodiment, in some embodiments of the present invention, referring to Figure 7The connection layer 300 further includes a fourth region 304 located between the main body 210 and the chip 100. The connection layer 300 in the fourth region 304 includes sintered material 310 that has undergone a sintering reaction, connecting the main body 210 and the chip 100. That is, the fourth region 304 is a sintered region similar to the first region 301, and the main body 210 and the chip 100 can be connected through the sintered material 310 therein. The fourth region 304 is formed by direct heating from the heat source 40. Thus, in this embodiment, there is a fourth region 304 formed by direct heating from the heat source 40, as well as a first region 301 formed by the protrusion 220.

[0042] When the connection layer 300 further includes the fourth region 304, in some embodiments of the present invention, Figure 7 There are multiple protrusions 220, and the multiple protrusions 220 are distributed along the first circumference A. The connecting layer 300 includes multiple first areas 301 located between each protrusion 220 and the chip 100, and the fourth area 304 is arranged corresponding to the center of the first circumference A. As mentioned above, this embodiment can use a single heat source 40 to simultaneously form multiple sintering areas.

[0043] It should be noted that the setting of the fourth area 304 corresponding to the center of the first circle A specifically means that the fourth area 304 is located in the center area of ​​the first circle A. More specifically, a second circle B concentric with the first circle A is established, and the radius of the second circle B is much smaller than the radius of the first circle A. The fourth area 304 is located within the range defined by the second circle B.

[0044] It should also be noted that the diameter of the first circle A can be set according to the following principle: on the first circle A, the aforementioned first area 301 can be formed between the protrusion 220 and the chip 100, and the aforementioned second area 302 can be formed between the main body 210 and the chip 100. In other words, the diameter of the first circle A satisfies: in the area without the protrusion 220, the heat transferred by the heat source 40 is not sufficient to cause the unsintered material 320 to undergo a sintering reaction, and in the area with the protrusion 220, the heat transferred by the heat source 40 can completely vaporize the solvent 330 and cause the unsintered material 320 to undergo a sintering reaction and be converted into a sintered material 310.

[0045] On the basis of the first embodiment, in some embodiments of the present invention, referring to Figure 7 The protrusion 220 is distributed in the middle area of ​​the transfer plate 200, which can play a certain supporting role in the middle area of ​​the transfer plate 200 and reduce the deformation of the transfer plate 200 during the pressure sintering process. The chip 100 has a gate finger 110 (through Figure 7 In some embodiments, the gate finger 110 is parallel to the first direction of the chip 100 (eg Figure 7width direction in the middle), and passes through the chip 100 in a second direction (eg Figure 7 ), illustratively, the gate finger 110 is provided with a convex portion 220 and a corresponding first region 301 on opposite sides of the gate finger 110. The convex portion 220 is provided adjacent to the gate finger 110, and the convex portions 220 on both sides can be symmetrically distributed relative to the gate finger 110. In other embodiments, the gate finger 110 is provided at two locations, one of which is parallel to the first direction of the chip 100 (for example, Figure 8 width direction in the middle), and passes through the chip 100 in a second direction (eg Figure 8 The other gate finger 110 is parallel to the second direction of the chip 100 (for example Figure 8 ), and passes through the first direction of the chip 100 (eg Figure 8 The midpoint of the width direction of the two gate fingers 110, that is, the two gate fingers 110 are perpendicular to each other, wherein the partial area separated by the two gate fingers 110 is provided with a protrusion 220 and a corresponding first area 301, and the protrusion 220 is provided adjacent to the gate finger 110.

[0046] As mentioned above, compared with the related art, the present invention adopts a rapid sintering process. In the area directly heated by the heat source 40 and the first area 301 at the bottom of the protrusion 220, the solvent 330 is accelerated to gasify and generate more gas. If the gas needs to be discharged through the connecting layer 300, it is easy to form gas marks on the connecting layer 300. When subsequent sintering is performed, the gas mark area will affect the sintering quality. Based on this, on the basis of the first embodiment, in some embodiments of the present invention, reference is made to Figure 2 、 Figure 7 The main body 210 also has exhaust holes 211 set through the thickness direction. The gas generated during the sintering process can be discharged in time through the exhaust holes 211, reducing the gas marks generated in the connecting layer 300 due to the gas being discharged through the connecting layer 300.

[0047] When the main body 210 further has an exhaust hole 211, in some embodiments of the present invention, Figure 7 A plurality of exhaust holes 211 are provided, and the plurality of exhaust holes 211 are distributed along the first circumference A. The protrusion 220 is provided corresponding to the center of the first circumference A. As previously described, when the center region of the first circumference A (i.e., the aforementioned fourth region 304) is heated by the heat source 40, the solvent in the directly heated region will be vaporized. In this embodiment, by providing a plurality of exhaust holes 211, and distributing the plurality of exhaust holes 211 along the first circumference A, the paths of the gas directly generated by the heat source 40 to reach each exhaust hole 211 can be substantially equal, thereby facilitating uniform exhaust.

[0048] When the main body 210 further has an exhaust hole 211, in some embodiments of the present invention, Figure 7 The exhaust holes 211 and the protrusions 220 are distributed along the first circumference A.

[0049] When the main body 210 further has an exhaust hole 211, in some embodiments of the present invention, Figure 7 The chip 100 has a gate finger 110. The gate finger 110 can be understood with reference to the embodiment. The protrusion 220 is arranged adjacent to the gate finger 110 relative to the exhaust hole 211, and the exhaust hole 211 is arranged away from the gate finger 110 relative to the protrusion 220. In this way, on the one hand, the central area of ​​the adapter 200 can be supported by the protrusion 220. On the other hand, the gate finger 110 area will not be coated with a connecting agent. The gas generated by sintering at the protrusion 220 can be exhausted through the gap between the adapter 200 and the gate finger 110, thereby reducing the setting of the exhaust hole 221. On this basis, the exhaust hole 221 is used to allow the gas to be exhausted in a direction away from the gate finger 110. Figure 7 Taking the example shown in the figure, along the length direction of the chip 100, the protrusions 220 on both sides are roughly located in the middle area and are adjacent to the gate fingers 110, and the exhaust holes 211 on both sides are roughly located at both ends and are far away from the gate fingers 110. Figure 8 As shown in the figure, in the area separated by two gate fingers 110, the protrusion 220 is roughly located at the intersection of the two gate fingers 110 and is arranged adjacent to the gate fingers 110, and the exhaust hole 211 is roughly located at the corresponding corner of the chip 100 and is arranged away from the gate fingers 110.

[0050] In some specific embodiments, a plurality of exhaust holes 211 are provided, and the plurality of exhaust holes 211 are distributed along the first circumference A, and the first circumference A passes through the gate finger 110. When the center area of ​​the first circumference A is heated by the heat source 40, the gas generated in the directly heated area and the adjacent area can be exhausted through the gap between the adapter 200 and the gate finger 110, or through the exhaust holes 211, and the exhaust paths are roughly equal, thereby further achieving uniform exhaust.

[0051] On the basis of the first embodiment, in some embodiments of the present invention, referring to Figure 2 In a space C defined by the outer contour of the protrusion 220 and extending vertically from the chip 100 to the main body 210, the volume of the protrusion 220 is greater than or equal to 50% of the volume of the space C. This ensures that the heat transferred by the heat source 40 does not cause large-scale sintering while also allowing the unsintered material 320 at the bottom of the protrusion 220 to be converted into sintered material 310. For example, when the outer contour of the protrusion 220 is circular, the space C is a cylindrical space, and the diameter of the cylindrical space is equal to the diameter of the protrusion 220.

[0052] Based on the first embodiment, in some embodiments of the present invention, the minimum thickness of the connection layer 300 in the first region 301 is greater than or equal to 25 microns, so that there is a sufficient thickness of sintered material 310 between the protrusion 220 and the chip 100 to achieve a stable connection with the chip 100.

[0053] The second embodiment of the present invention provides a packaging module, referring to Figure 9 The packaging module includes a first heat dissipation substrate 20, a second heat dissipation substrate 30 and the packaging unit 10 in the aforementioned embodiments. The first heat dissipation substrate 20 is connected to the side of the adapter 200 away from the chip 100 through a sintering process using a sintering material such as silver paste. The second heat dissipation substrate 30 is connected to the second side 102 of the chip 100 through a sintering process using a sintering material such as silver paste. Exemplarily, the first heat dissipation substrate 20 is connected to the upper side of the adapter 200, and the second heat dissipation substrate 30 is connected to the lower side of the chip 100.

[0054] Both the first heat sink 20 and the second heat sink 30 can be ceramic heat sinks, specifically comprising a central ceramic layer and metal layers on opposite sides of the ceramic layer. Heat generated by the chip 100 can be dissipated through the first heat sink 20 and the second heat sink 30, respectively, achieving high heat dissipation efficiency.

[0055] A third embodiment of the present invention provides a preparation method for preparing the packaging unit 10 in the aforementioned embodiment, comprising the following steps: S100 applies a connecting agent to the first side 101 of the chip 100 and places the adapter 200 on the connecting agent. In this embodiment, the connecting agent includes a solvent 330 and an unsintered material 320 encapsulated in the solvent 330. Taking silver paste as an example, the unsintered material 320 includes a capping agent 322 and silver particles 321 encapsulated in the capping agent 322.

[0056] S200 heats a local area of ​​the transfer sheet 200 until the unsintered material 320 in the first area 301 undergoes a sintering reaction and is transformed into a sintered material 310, while the unsintered material 320 in the second area 302 remains in an unsintered state encapsulated in the solvent 330, thereby allowing the connector to form a connecting layer 300. It should be noted that the area of ​​the first area 301 is significantly smaller than that of the second area 302. In other words, even after the sintering process, the solvent 330 is still retained in most areas of the connecting layer 300, thereby effectively preventing oxygen from passing through the connecting layer 300 and causing oxidation of the metal layer on the chip 100.

[0057] This embodiment uses local heating to form a local sintering area in the connection layer 300 to connect the chip 100 and the adapter 200, and can also enable the connection layer 300 to retain good oxygen barrier capabilities, which can effectively improve the problem of metal oxidation on the chip 100.

[0058] Based on the third embodiment, in some embodiments of the present invention, the aforementioned "method for heating a local area of ​​the adapter plate 200" specifically refers to using a laser light source to heat a local area of ​​the adapter plate 200. The laser light source can concentrate heat, making it suitable for heating a small area and facilitating adjustment of the heating power.

[0059] In some specific embodiments, the heating time of the laser light source is less than or equal to 60 seconds. Compared to the sintering methods in related arts, the heating time of this embodiment is short. Combined with the heating of the localized area, the solvent 330 can be retained in most areas of the connecting layer 300. It should be noted that because this embodiment uses a rapid sintering process, the sintering degree of the sintered material 310 is less than the sintering degree of the sintered material obtained by a conventional sintering process. For example, the sintering degree of the sintered material 310 in this embodiment is less than or equal to 15%, while the sintering degree of the sintered material obtained by a conventional sintering process is greater than or equal to 80%.

[0060] On the basis of the third embodiment, in some embodiments of the present invention, the aforementioned “method for heating a local area of ​​the adapter sheet 200” specifically refers to: heating a local area of ​​the adapter sheet 200 that is offset from the convex portion 220, so that the unsintered material 320 in the corresponding local area between the main body 210 and the first side 101 undergoes a sintering reaction and is converted into a sintered material 310, that is, Figure 5 、 Figure 7 As shown, in this embodiment, the direct heating area of ​​the heat source 40 does not overlap with the protrusion 220. In this way, multiple local sintering areas can be formed by one heat source 40, thereby reducing the use of heat sources and improving sintering efficiency.

[0061] While the embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to the embodiments described above. Various modifications may be made within the scope of knowledge possessed by a person skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof may be combined with one another unless there is a conflict.

Claims

1. A packaging unit, characterized in that It includes a chip, a transfer sheet and a connection layer, wherein the transfer sheet is connected to one side of the chip through the connection layer; Among them, the adapter includes a main body and a convex portion, the convex portion is arranged on the side of the main body facing the chip, the connecting layer includes a first area located between the convex portion and the chip, and a second area located outside the first area, the connecting layer in the first area includes sintered material that has undergone a sintering reaction and respectively connects the convex portion and the chip, the connecting layer in the second area includes unsintered material that has not undergone a sintering reaction, and a solvent that covers the unsintered material.

2. The packaging unit according to claim 1, characterized in that The connecting layer also includes a third region located between the first region and the second region, and the connecting layer in the third region includes unsintered material that has not undergone a sintering reaction, wherein the connecting layer in the third region also includes a solvent that coats the unsintered material, and the content of the solvent in the third region is less than the content of the solvent in the second region, or the third region does not contain the solvent.

3. The packaging unit according to claim 1, characterized in that There are a plurality of convex portions, and the plurality of convex portions are distributed along a first circumference. The connection layer includes a plurality of first regions located between each of the convex portions and the chip.

4. The packaging unit according to claim 1, characterized in that The connection layer further includes a fourth region located between the main body and the chip. The connection layer in the fourth region includes a sintered material that has undergone a sintering reaction to connect the main body and the chip.

5. The packaging unit according to claim 4, characterized in that There are multiple convex portions distributed along a first circumference. The connection layer includes multiple first regions located between each convex portion and the chip. The fourth region is arranged corresponding to the center of the first circumference.

6. The packaging unit according to claim 1, characterized in that The main body also has an exhaust hole extending through the main body along the thickness direction.

7. The packaging unit according to claim 6, characterized in that There are multiple exhaust holes, which are distributed along a first circumference, and the convex portion is arranged corresponding to the center of the first circumference.

8. The packaging unit according to claim 6, characterized in that The chip has a gate finger. The protrusion is arranged adjacent to the gate finger relative to the exhaust hole. The exhaust hole is arranged away from the gate finger relative to the protrusion.

9. The packaging unit according to claim 1, characterized in that In a space between the chip and the main body and extending in a direction between the chip and the main body, with the outer contour of the protrusion as the boundary line, the volume of the protrusion is greater than or equal to 50% of the volume of the space; And / or, the minimum thickness of the connecting layer in the first region is greater than or equal to 25 micrometers.

10. Encapsulation module, characterized in that include: The packaging unit according to any one of claims 1 to 9; a first heat dissipation substrate connected to a side of the adapter away from the chip; The second heat dissipation substrate is connected to a side of the chip away from the adapter.

11. The method for preparing the package unit according to any one of claims 1 to 9, characterized in that: The following steps are involved: Coating a connecting agent on one side of the chip and placing the adapter on the connecting agent, wherein the connecting agent includes a solvent and an unsintered material coated in the solvent; The local area of ​​the adapter is heated to make the connecting agent form the connecting layer, wherein the unsintered material in the first area undergoes a sintering reaction and is converted into a sintered material, and the unsintered material in the second area remains in an unsintered state encapsulated in the solvent.

12. The preparation method according to claim 11, characterized in that The method for heating the local area of ​​the adapter includes: heating the local area of ​​the adapter using a laser light source.

13. The preparation method according to claim 12, characterized in that The heating time of the laser light source is less than or equal to 60 seconds.

14. The preparation method according to claim 11, characterized in that The method of heating the local area of ​​the adapter plate includes: heating the local area of ​​the adapter plate offset relative to the protrusion, so that the unsintered material corresponding to the local area between the main body and the first side undergoes a sintering reaction and is converted into a sintered material.

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