Double-layer thermocompression bonding device and method

Abstract

The invention provides a double-layer thermocompression bonding device and method, and relates to the technical field of semiconductor manufacturing. The double-layer hot pressing bonding device comprises a bearing plate, a lower disc assembly, a heat conduction plate, an upper disc assembly and a driving assembly, and the lower disc assembly is fixedly arranged on the upper surface of the bearing plate and comprises a lower chuck and a lower heating disc which are arranged in a stacked mode in the vertical direction; the heat conducting plate is arranged above the lower disc assembly; the upper disc assembly is arranged above the heat conducting plate and comprises an upper heating disc and an upper chuck which are stacked in the vertical direction, and the upper disc assembly can ascend and descend and apply bonding pressure under the driving of the bonding driving part; the driving assembly comprises an ascending driving part, and the ascending driving part can make the heat conduction plate ascend in the state that the upper disc assembly moves upwards and is separated from the heat conduction plate. By using the device and the method provided by the invention, the two wafer pairs can be subjected to thermocompression bonding at the same time, so that the thermocompression bonding efficiency of the wafer pairs can be improved. In addition, the device is simple in structure and convenient to assemble, adjust and maintain.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and in particular to a double-layer thermal compression bonding device and method. Background Art

[0002] Wafer bonding technology refers to the process of tightly bonding two mirror-polished homogeneous or heterogeneous wafers together through chemical and physical effects. After the wafers are bonded, the atoms on the interface react under the action of external forces to form covalent bonds to form a whole, and the bonding interface reaches a specific bonding strength.

[0003] As a bonding method based on bonding layers, thermocompression bonding is a bonding method that presses two bonding surface metals together under the simultaneous action of pressure and temperature to complete bonding. It has been widely used in chip stacking welding and wafer-level packaging. Due to the importance of thermocompression bonding, the market demand for thermocompression bonding equipment continues to increase. However, the thermocompression bonding equipment in the prior art can usually only perform thermocompression bonding operations on one pair of wafers at a time, and the efficiency of thermocompression bonding is relatively low. Summary of the invention

[0004] The first object of the present invention is to provide a double-layer thermocompression bonding device to solve the technical problem of low thermocompression bonding efficiency of wafer pairs in the prior art.

[0005] The double-layer hot pressing bonding device provided by the present invention comprises a supporting plate, a lower disk assembly, a heat conducting plate, an upper disk assembly and a driving assembly, wherein the lower disk assembly is fixedly arranged on the upper surface of the supporting plate, and comprises a lower chuck and a lower heating disk stacked in an up-and-down direction; the heat conducting plate is arranged above the lower disk assembly; the upper disk assembly is arranged above the heat conducting plate, and comprises an upper heating disk and an upper chuck stacked in an up-and-down direction, and under the drive of a bonding driving member, the upper disk assembly can be raised and lowered and apply bonding pressure; the driving assembly comprises an ascending driving member, and when the upper disk assembly moves upward and is separated from the heat conducting plate, the ascending driving member can cause the heat conducting plate to rise.

[0006] Furthermore, the bearing plate is provided with a plurality of vertical guide pins, and the heat conducting plate is slidably inserted into each of the guide pins along the up-down direction.

[0007] Furthermore, the number of the guide pins is four, the heat conducting plate is rectangular, and the four guide pins are respectively arranged at four corners of the heat conducting plate.

[0008] Furthermore, the driving assembly further comprises a mounting frame, the mounting frame is fixedly arranged on the lower surface of the bearing plate, and the ascending driving member is fixedly mounted on the mounting frame;

[0009] The power output end of the rising drive member is fixedly connected to at least one support column, the support column is movably inserted into the through hole of the supporting plate, and a telescopic member is outerly disposed on the support column, the upper end of the telescopic member is sealed to the lower surface of the supporting plate, and the lower end is sealed to the power output end.

[0010] Furthermore, the telescopic member is a bellows.

[0011] Furthermore, the power output end of the ascending driving member is vertically fixed with a support plate; the number of the support columns is two, and the two support columns are respectively vertically fixed at the two ends of the support plate to jointly lift the heat conducting plate; the lower end of the telescopic member is sealed and connected to the upper surface of the support plate.

[0012] Furthermore, an upper cold plate is stacked above the upper heating plate, and a lower cold plate is stacked below the lower heating plate. Cooling water channels are provided in both the upper cold plate and the lower cold plate.

[0013] Furthermore, the upper heating plate is provided with a plurality of upper heating tubes, the lower heating plate is provided with a plurality of lower heating tubes, and both the upper heating tubes and the lower heating tubes are quartz heating tubes.

[0014] Furthermore, the upper heating tube is of a bottom heating type, and / or the lower heating tube is of a top heating type.

[0015] Further, both ends of the upper heating tube extend out of the upper heating plate, and the end of the upper heating tube is supported by a first positioning block, and the end connected to the power line is supported by a cushion block, and the first positioning block and the cushion block are both fixedly arranged on the lower surface of the upper cold plate;

[0016] Both ends of the lower heating tube extend out of the lower heating plate, and the end of the lower heating tube is supported by a second positioning block, and the end connected to the power line is supported by a pad, and the second positioning block and the pad are both fixedly arranged on the upper surface of the lower cold plate.

[0017] Furthermore, a first graphite pad is sandwiched between the upper heating plate and the upper chuck, and a second graphite pad is stacked below the upper chuck;

[0018] A third graphite pad is sandwiched between the lower chuck and the lower heating plate.

[0019] Further, the upper cold plate is fixedly provided with a limit plate, the limit plate includes a fixedly connected horizontal portion and a connecting portion, the connecting portion is fixedly connected to the upper cold plate; the horizontal portion is provided with an avoidance hole for avoiding the wafer pair, and is stacked with the second graphite pad, and the second graphite pad, the upper chuck, the first graphite pad, and the upper heating plate are pressed and fixed to the upper cold plate;

[0020] The lower cold plate is fixed with a plurality of fixing blocks, and the plurality of fixing blocks press the lower chuck, the third graphite pad, and the lower heating plate onto the lower cold plate.

[0021] Furthermore, an upper surface of the heat conducting plate is provided with a receiving groove, and the receiving groove is used to receive the wafer pair.

[0022] The double-layer hot-pressing bonding device provided by the present invention can produce the following beneficial effects:

[0023] The double-layer hot-compression bonding device provided by the present invention, when used to perform hot-compression bonding on two pairs of wafers at the same time, mainly includes the steps of placing the wafer pairs to be bonded, performing hot-compression bonding on the two pairs of wafers at the same time, and taking out the wafer pairs that have completed bonding. Specifically, placing the wafer pairs to be bonded: driving the upper disk assembly to rise by the bonding drive to separate it from the heat-conducting plate, and placing the first wafer pair to be bonded on the heat-conducting plate; lifting the heat-conducting plate by the rising drive to separate it from the lower disk assembly, and placing the second wafer pair to be bonded on the lower chuck of the lower disk assembly. Hot-compression bonding: retracting the power output end of the rising drive to press the heat-conducting plate onto the second pair of wafers; driving the upper disk assembly to press down at a preset pressure by the bonding drive, and heating the first pair of wafers and the second pair of wafers at a preset temperature by the upper heating disk and the lower heating disk respectively. Take out the wafer pair that has completed bonding: After heating the two pairs of wafers at a preset temperature for a preset time, the upper plate assembly is raised again by the bonding drive, and then the first pair of wafers that have completed bonding are taken out; the heat conduction plate is raised again by the lifting drive, and then the second pair of wafers that have completed bonding are taken out. At this point, the thermal compression bonding of the two pairs of wafers is completed.

[0024] If you want to continue to perform thermocompression bonding on a new pair of wafers to be bonded, you can place a new pair of wafers to be bonded into the lower plate assembly, then drop the heat transfer plate, and place another pair of wafers to be bonded on the heat transfer plate. Repeat the steps of thermocompression bonding and removing the bonded wafer pairs until thermocompression bonding of all wafer pairs is completed.

[0025] In summary, the double-layer hot-compression bonding device provided by the present invention can perform hot-compression bonding on two pairs of wafers at the same time, thereby improving the hot-compression bonding efficiency of the wafers. In addition, the double-layer hot-compression bonding device provided by the present invention has a simple structure, so it is easy to install and repair. Of course, the heat conducting plate is always in the fall-back position, that is, located on the lower plate assembly, or the heat conducting plate is removed, and hot-compression bonding can be performed on only one pair of wafers at a time.

[0026] The second object of the present invention is to provide a double-layer thermocompression bonding method to solve the technical problem of low thermocompression bonding efficiency of wafer pairs in the prior art.

[0027] The double-layer thermocompression bonding method provided by the present invention uses the above-mentioned double-layer thermocompression bonding device to simultaneously perform thermocompression bonding on two pairs of wafers, and the method comprises the following steps:

[0028] S100, driving the upper plate assembly to rise by the bonding driving member to separate it from the heat conducting plate, and placing the first wafer to be bonded on the heat conducting plate;

[0029] S200, lifting the heat conducting plate by the lifting driving member to separate it from the lower plate assembly, and placing the second wafer to be bonded on the lower chuck of the lower plate assembly;

[0030] S300, retracting the power output end of the ascending driving member to press the heat conducting plate onto the second pair of wafers;

[0031] S400, driving the upper plate assembly downward at a preset pressure by the bonding drive, and heating the first pair of wafers and the second pair of wafers at a preset temperature by the upper heating plate and the lower heating plate respectively;

[0032] S500, after heating the two pairs of wafers at the preset temperature for a preset time, the upper plate assembly is raised again by the bonding drive component, and then the first pair of wafers that have completed bonding are taken out;

[0033] S600, raising the heat conducting plate again by the raising driving member, and then taking out the second pair of wafers that have completed bonding;

[0034] S700, placing a new pair of wafers to be bonded into the lower plate assembly, then dropping the heat conducting plate, and placing another pair of wafers to be bonded on the heat conducting plate, and repeating steps S400 to S600 until the thermocompression bonding of all wafer pairs is completed.

[0035] The double-layer thermocompression bonding method provided by the present invention uses the above-mentioned double-layer thermocompression bonding device to perform thermocompression bonding on two pairs of wafers at the same time, so the thermocompression bonding efficiency of the wafer pairs can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0037] Figure 1A schematic front view of the structure of a double-layer hot-pressing bonding device provided in an embodiment of the present invention in a working state, wherein the upper plate assembly, the heat conducting plate and the lower plate assembly are in a pressed state;

[0038] Figure 2 A schematic diagram of the structure of a double-layer thermal compression bonding device provided by an embodiment of the present invention in a working state, wherein the upper plate assembly, the heat conducting plate and the lower plate assembly are separated from each other;

[0039] Figure 3 A schematic structural diagram of an upper plate assembly of a double-layer thermal compression bonding device provided in an embodiment of the present invention;

[0040] Figure 4 A schematic structural diagram of a lower plate assembly of a double-layer thermal compression bonding device provided in an embodiment of the present invention;

[0041] Figure 5 One of the partial structural schematic diagrams of a double-layer thermal compression bonding device provided in an embodiment of the present invention;

[0042] Figure 6 The second partial structural schematic diagram of the double-layer thermal compression bonding device provided in an embodiment of the present invention.

[0043] Description of reference numerals:

[0044] 100-upper plate assembly; 110-upper cold plate; 111-water inlet pipe; 112-water outlet pipe; 120-upper heating plate; 121-upper heating tube; 122-first positioning block; 123-pad; 130-first graphite pad; 140-upper chuck; 150-second graphite pad; 160-limiting plate; 161-avoidance hole; 162-long round hole;

[0045] 200-heat conducting plate; 210-accommodating tank;

[0046] 300-lower plate assembly; 310-lower cold plate; 320-lower heating plate; 321-lower heating tube; 322-second positioning block; 323-pad; 330-third graphite pad; 340-lower chuck; 350-fixed block;

[0047] 400-carrying plate; 410-guide pin;

[0048] 500 - driving assembly; 510 - mounting frame; 520 - rising driving member; 530 - supporting plate; 540 - supporting column; 550 - telescopic member. DETAILED DESCRIPTION

[0049] In order to make the above-mentioned objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0050] This embodiment provides a double-layer thermal compression bonding device, such as Figures 1 to 6 As shown, the double-layer hot pressing bonding device includes a carrier plate 400, a lower disk assembly 300, a heat conductive plate 200, an upper disk assembly 100 and a driving assembly 500. The lower disk assembly 300 is fixedly arranged on the upper surface of the carrier plate 400, and includes a lower chuck 340 and a lower heating disk 320 stacked in an up-and-down direction; the heat conductive plate 200 is arranged above the lower disk assembly 300; the upper disk assembly 100 is arranged above the heat conductive plate 200, and includes an upper heating disk 120 and an upper chuck 140 stacked in an up-and-down direction. Driven by a bonding driving member (not shown in the figure), the upper disk assembly 100 can be raised and lowered and a bonding pressure can be applied; the driving assembly 500 includes an ascending driving member 520. When the upper disk assembly 100 moves upward and is separated from the heat conductive plate 200, the ascending driving member 520 can cause the heat conductive plate 200 to rise. The bonding drive member may be an electric cylinder or a hydraulic cylinder, etc., which is used to drive the upper plate assembly 100 to rise and fall and output pressure during hot pressing.

[0051] The double-layer hot compression bonding device provided in this embodiment, when used to perform hot compression bonding on two pairs of wafer pairs at the same time, mainly includes the steps of placing the wafer pairs to be bonded, performing hot compression bonding on the two pairs of wafer pairs at the same time, and taking out the wafer pairs that have completed bonding. Specifically, the wafer pairs to be bonded are placed: the upper disk assembly 100 is driven to rise (for example, to the upper limit position) by the bonding drive member to separate it from the heat transfer plate 200, and the first wafer pair to be bonded is placed on the heat transfer plate 200; the heat transfer plate 200 is lifted up by the rising drive member 520 to separate it from the lower disk assembly 300, and the second wafer pair to be bonded is placed on the lower chuck 340 of the lower disk assembly 300. Thermal compression bonding: retract the power output end of the ascending drive 520 to press the heat conducting plate 200 onto the second pair of wafers; drive the upper disk assembly 100 to press down at a preset pressure, i.e., process pressure (detected by a pressure sensor, not shown in the figure) through the bonding drive, and heat the first pair of wafers and the second pair of wafers at a preset temperature, i.e., process temperature (detected by a thermocouple sensor, not shown in the figure) through the upper heating disk 120 and the lower heating disk 320. Take out the bonded wafer pairs: after heating the two pairs of wafers at a preset temperature for a preset time, raise the upper disk assembly 100 again through the bonding drive, and then take out the first pair of wafers that have been bonded; raise the heat conducting plate 200 again through the ascending drive 520, and then take out the second pair of wafers that have been bonded. At this point, the thermal compression bonding of the two pairs of wafers is completed.

[0052] If it is desired to continue to perform thermocompression bonding on a new pair of wafers to be bonded, a new pair of wafers to be bonded can be placed into the lower plate assembly 300, and then the heat conducting plate 200 can be lowered, and another pair of wafers to be bonded can be placed on the heat conducting plate 200, and the steps of thermocompression bonding and removing the bonded wafer pairs can be repeated until thermocompression bonding of all wafer pairs is completed.

[0053] In summary, the double-layer hot compression bonding device provided in this embodiment can perform hot compression bonding on two pairs of wafer pairs at the same time, thereby improving the hot compression bonding efficiency of the wafer pairs. In addition, the double-layer hot compression bonding device provided in this embodiment has a simple structure, so it is easy to install and repair. Of course, by making the heat conducting plate 200 always in the fallen position, that is, located on the lower plate assembly 300, or removing the heat conducting plate 200, it is also possible to perform hot compression bonding on only one pair of wafer pairs at a time. Moreover, the double-layer hot compression bonding device provided in this embodiment can be compatible with hot compression bonding of wafer pairs of various specifications (4 inches, 6 inches and 8 inches, etc.) by replacing the lower chuck 340 and the heat conducting plate 200 of different sizes.

[0054] Specifically, in this embodiment, the material of the heat conducting plate 200 is graphite, and in other embodiments of the present application, the heat conducting plate 200 is not limited to a plate shape, as long as it can carry wafers, conduct heat, and carry and transfer bonding pressure, the heat conducting plate 200 can also be other shapes, such as a block.

[0055] Specifically, in this embodiment, Figure 5 and Figure 6 As shown, combined with Figure 2 As shown, the carrier plate 400 is provided with a plurality of vertical guide pins 410, and the heat conducting plate 200 is slidably inserted in each guide pin 410 along the up and down direction. In this way, the guide pins 410 can limit the position of the heat conducting plate 200 and can guide the heat conducting plate 200 to rise and fall stably and accurately, that is, they play the role of limiting and guiding the heat conducting plate 200.

[0056] More specifically, in this embodiment, the number of guide pins 410 is four, the heat conducting plate 200 is rectangular, and the four guide pins 410 are respectively arranged at the four corners of the heat conducting plate 200. In this arrangement, the four guide pins 410 are relatively far from each other, and different parts of the heat conducting plate 200 are taken into consideration, so that the heat conducting plate 200 can be raised and lowered smoothly, stably and accurately as a whole. Of course, in other embodiments of the present application, the number of guide pins 410 is not limited to four, but can also be three, five, etc., as long as the position of the heat conducting plate 200 can be limited and the heat conducting plate 200 can be guided to be raised and lowered smoothly, stably and accurately.

[0057] Specifically, in this embodiment, Figure 5As shown, the drive assembly 500 also includes a mounting frame 510, which is fixedly arranged on the lower surface of the carrier plate 400, and the rising drive member 520 is fixedly installed on the mounting frame 510; the power output end of the rising drive member 520 is fixedly connected with at least one support column 540, the support column 540 is movably inserted in the through hole of the carrier plate 400, and the support column 540 is provided with a telescopic member 550, the upper end of the telescopic member 550 is sealed and connected to the lower surface of the carrier plate 400, and the lower end is sealed and connected to the power output end. In this way, the telescopic member 550 can not only protect the support column 540 inside it from pollution and damage, but also ensure the vacuum state above the carrier plate 400 under the premise that the support column 540 passes through the carrier plate 400, so that the wafer pair is bonded in a vacuum environment (other components surrounding the vacuum chamber are not shown in the figure). Furthermore, in the present embodiment, the telescopic member 550 is a bellows. However, it should be noted that in other embodiments of the present application, the telescopic member 550 may also be other telescopic flexible tubes as long as the telescopic and sealing requirements can be met.

[0058] It should also be noted here that, although the mounting frame 510 and the rising drive component 520 of the driving component 500 in this embodiment are all arranged below the supporting plate 400, in other embodiments of the present application, the rising drive component 520 may also be arranged at other positions, such as on the side or above the supporting plate 400. As long as it can make the heat conducting plate 200 rise and fall, the present application may not impose specific restrictions on the setting position of the driving component 500.

[0059] Specifically, in this embodiment, the power output end of the ascending driving member 520 is vertically fixed with the support plate 530; the number of the support columns 540 is two, and the two support columns 540 are respectively vertically fixed at the two ends of the support plate 530 to jointly lift the heat conducting plate 200; the lower end of the telescopic member 550 is sealed and connected to the upper surface of the support plate 530. In this way, the two support columns 540 jointly lift the heat conducting plate 200, and the lifting force received by the heat conducting plate 200 is more balanced, so that the heat conducting plate 200 will be more stable during the ascending process. Of course, in other embodiments of the present application, the number of the support columns 540 is not limited to two, for example: it can also be one or three, etc.

[0060] Specifically, in this embodiment, the lifting drive member 520 is a lifting cylinder, the cylinder body of the lifting cylinder is fixedly mounted on the mounting frame 510, and the gas rod of the lifting cylinder is fixedly connected to the support plate 530. It should be noted that in other embodiments of the present application, the lifting drive member 520 can also be an electric cylinder or a hydraulic cylinder, etc., as long as it can provide power for the heat conducting plate 200 to rise.

[0061] Specifically, in this embodiment, Figure 3 and Figure 4As shown, an upper cold plate 110 is stacked above the upper heating plate 120, and a lower cold plate 310 is stacked below the lower heating plate 320, and cooling water channels are provided in both the upper cold plate 110 and the lower cold plate 310. During the hot pressing bonding process, PCW (Plant Cooling Water / Process Cooling Water, process cooling water system / process cooling water system) (not shown in the figure) can be used to continuously introduce and circulate cooling water into the cooling water channel of the upper cold plate 110 through the water inlet pipe 111 and the water outlet pipe 112 to adjust the temperature of components other than the upper heating plate 120 and the upper chuck 140 so that the temperature is not too high and damaged. PCW can also be used to continuously introduce and circulate cooling water into the cooling water channel of the lower cold plate 310 to adjust the temperature of components other than the lower heating plate 320 and the lower chuck 340 so that the temperature is not too high and damaged. The water inlet pipe 111 and the water outlet pipe 112 of the upper cold plate 110 can be directly adapters of the cooling water circulation pipeline. Of course, corresponding adapters can also be provided on the pipe body to facilitate connection with the cooling water circulation pipeline.

[0062] Moreover, after the wafer pair is heated at a preset temperature for a preset time, that is, after the heating of the wafer pair is stopped, the circulating cooling water in the upper cold plate 110 and the lower cold plate 310 can take away the heat of the upper heating plate 120 and the lower heating plate 320, so that the temperature of the overall structure quickly drops to room temperature, thereby improving the bonding efficiency. Compared with the setting of the heat insulation block structure, the present embodiment sets the upper cold plate 110 and the lower cold plate 310 and directly stacks and bonds with the upper heating plate 120 and the lower heating plate 320 respectively, whether it is blocking the heat transfer to the heating plate and the components outside the chuck, or cooling the heating plate and the components outside the chuck, and cooling the heating plate, it is faster.

[0063] Specifically, in this embodiment, continue as Figure 3 and Figure 4 As shown, the upper heating plate 120 is provided with a plurality of upper heating tubes 121, and the lower heating plate 320 is provided with a plurality of lower heating tubes 321. Both the upper heating tubes 121 and the lower heating tubes 321 are quartz heating tubes, which not only have a simple structure but also are easy to control the heating state, which is beneficial to improving the heating uniformity, thereby improving the heating effect.

[0064] Specifically, in this embodiment, the upper heating tube 121 is a bottom heating type, and the lower heating tube 321 is a top heating type. Both the upper heating tube 121 and the lower heating tube 321 use a quartz heating tube single-side infrared radiation heating method, which only heats the side that needs to be heated, and can effectively improve the utilization rate of the heat source.

[0065] Specifically, in this embodiment, Figure 3As shown, both ends of the upper heating tube 121 extend out of the upper heating plate 120, and the end of the upper heating tube 121 is supported by the first positioning block 122, and the end connected to the power line is supported by the cushion block 123, and the first positioning block 122 and the cushion block 123 are both fixedly arranged on the lower surface of the upper cold plate 110. In this arrangement, the upper heating plate 120 provides a support space for the upper heating tube 121 to avoid crushing the upper heating tube 121 when pressurized, and plays a role in transferring the heat generated by the upper heating tube 121 to the upper chuck 140; the first positioning block 122 plays a role in positioning and supporting the end of the upper heating tube 121; the cushion block 123 plays a role in supporting and limiting the other end of the upper heating tube 121 extending out of the upper heating plate 120.

[0066] Specifically, in this embodiment, Figure 4 As shown, both ends of the lower heating tube 321 extend out of the lower heating plate 320, and the end of the lower heating tube 321 is supported by the second positioning block 322, and the end connected to the power line is supported by the pad 323, and the second positioning block 322 and the pad 323 are both fixedly arranged on the upper surface of the lower cold plate 310. In this arrangement, the lower heating plate 320 provides a supporting space for the lower heating tube 321 to avoid crushing the lower heating tube 321 when pressurized, and plays a role in transferring the heat generated by the lower heating tube 321 to the lower chuck 340; the second positioning block 322 plays a role in positioning and supporting the end of the lower heating tube 321; the pad 323 plays a role in supporting and limiting the other end of the lower heating tube 321 extending out of the lower heating plate 320.

[0067] Specifically, in this embodiment, Figure 3 As shown, a first graphite pad 130 is sandwiched between the upper heating plate 120 and the upper chuck 140, and a second graphite pad 150 is stacked below the upper chuck 140. In this embodiment, the material of the upper chuck 140 can be SiC, which mainly plays the role of heat conduction and bearing and transmitting bonding pressure. Since the first graphite pad 130 and the second graphite pad 150 are relatively soft in material, they can absorb the non-parallelism between the planes of each part during the pressurization process, and can also play a certain buffering role, thereby reducing the possibility of wafer breakage.

[0068] like Figure 4 As shown, a third graphite pad 330 is sandwiched between the lower chuck 340 and the lower heating plate 320. The main function of the lower chuck 340 is to conduct heat, bear the wafer and pressure, and its material can also be SiC. The wafer is not easy to stick when heated here, which is convenient for wafer handling; a circular groove can be provided on the top of the lower chuck 340 to position the wafer and prevent the wafer from sliding and losing its position. As for the third graphite pad 330, its material is relatively soft, so it can absorb the non-parallelism between the planes of each part and buffer during the pressurization process, thereby reducing the possibility of wafer breakage.

[0069] Specifically, in this embodiment, Figure 3 As shown, the upper cold plate 110 is fixedly provided with a limit plate 160, and the limit plate 160 includes a fixedly connected horizontal portion and a connecting portion, and the connecting portion is fixedly connected to the upper cold plate 110; the horizontal portion is provided with an avoidance hole 161 for avoiding the wafer pair, and is stacked with the second graphite pad 150, and the second graphite pad 150, the upper chuck 140, the first graphite pad 130, and the upper heating plate 120 are pressed and fixed to the upper cold plate 110. In this arrangement, when two pairs of wafer pairs are simultaneously subjected to thermal compression bonding, the avoidance hole 161 avoids the wafer pair on the heat conducting plate 200, and the wafer pair on the heat conducting plate 200 contacts the second graphite pad 150; when the heat conducting plate 200 is removed and only one pair of wafer pairs is subjected to thermal compression bonding, the avoidance hole 161 avoids the wafer pair on the lower plate assembly 300.

[0070] More specifically, if Figure 3 As shown, combined with Figure 1 and Figure 2 As shown, the two opposite sides of the horizontal part of the limiting plate 160 are provided with connecting parts, that is, the limiting plate 160 has two connecting parts, and the two connecting parts are fixedly connected to the water cooling plate 110. With such a configuration, the limiting plate 160 has a simple structure, and can firmly press the second graphite pad 150, the upper chuck 140, the first graphite pad 130, and the upper heating plate 120 onto the upper cooling plate 110 from both sides. Further, the connecting part of the limiting plate 160 is provided with an oblong hole 162, and the oblong hole 162 extends in the vertical direction. With such a configuration, it is convenient to adjust the position of the horizontal part of the limiting plate 160 up and down, so as to facilitate placing the second graphite pad 150, the upper chuck 140, the first graphite pad 130 and the upper heating plate 120 between the horizontal part of the limiting plate 160 and the upper cooling plate 110.

[0071] like Figure 4 As shown, the lower cold plate 310 is fixedly provided with a plurality of fixing blocks 350, and the plurality of fixing blocks 350 press the lower chuck 340, the third graphite pad 330, and the lower heating plate 320 onto the lower cold plate 310. More specifically, the number of the fixing blocks 350 may be four, and the four fixing blocks 350 are distributed in groups of two on opposite sides of the lower chuck 340, and the two fixing blocks 350 in the same group may be respectively arranged at the two ends of the lower chuck 340, so that the four fixing blocks 350 firmly press the lower chuck 340 and the third graphite pad 330 and the lower heating plate 320 thereunder onto the lower cold plate 310.

[0072] Specifically, in this embodiment, Figure 6 As shown, the upper surface of the heat conducting plate 200 is provided with a receiving groove 210, and the receiving groove 210 is used to receive the wafer pair.

[0073] Specifically, Figure 1As shown, the overall size of the entire double-layer hot pressing bonding device in the working state is: length * width * height = 280mm * 180mm * 550mm, wherein the length and width do not take into account the size of the heat conducting plate 200, and the length is Figure 1 The width is the dimension in the left-right direction under the viewing angle, and the width is the dimension perpendicular to the front-back direction of the paper. It can be seen that the double-layer hot pressing bonding device provided in this embodiment has a relatively simple and compact structure, so the overall size is relatively small and the space occupied is relatively small.

[0074] This embodiment also provides a double-layer thermocompression bonding method, using the above-mentioned double-layer thermocompression bonding device to simultaneously perform thermocompression bonding on two pairs of wafers, the method comprising the following steps:

[0075] S100, driving the upper plate assembly 100 to rise by a bonding driving member to separate it from the heat conducting plate 200, and placing a first wafer to be bonded on the heat conducting plate 200;

[0076] S200, lifting the heat conducting plate 200 by the lifting driving member 520 to separate it from the lower plate assembly 300, and placing the second wafer to be bonded on the lower chuck 340 of the lower plate assembly 300;

[0077] S300, retracting the power output end of the ascending driving member 520 to press the heat conducting plate 200 onto the second pair of wafers;

[0078] S400, driving the upper plate assembly 100 downward at a preset pressure through the bonding drive, and heating the first pair of wafers and the second pair of wafers at a preset temperature through the upper heating plate 120 and the lower heating plate 320 respectively;

[0079] S500, after heating the two pairs of wafers at a preset temperature for a preset time, the upper plate assembly 100 is raised again by the bonding drive component, and then the first pair of wafers that have completed bonding are taken out;

[0080] S600, the heat conducting plate 200 is raised again by the raising driving member 520, and then the second pair of wafers that have been bonded are taken out;

[0081] S700, a new pair of wafers to be bonded is placed into the lower plate assembly 300, and then the heat conducting plate 200 is dropped, and another pair of wafers to be bonded is placed on the heat conducting plate 200, and steps S400 to S600 are repeated until the thermocompression bonding of all wafer pairs is completed.

[0082] The double-layer thermocompression bonding method provided in this embodiment uses the above-mentioned double-layer thermocompression bonding device to perform thermocompression bonding on two pairs of wafers at the same time, thereby improving the thermocompression bonding efficiency of the wafer pairs.

[0083] Finally, it should be noted that, in this article, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0084] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to the embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A double-layer thermal compression bonding device, characterized in that: include: A carrier plate (400); A lower plate assembly (300) is fixedly arranged on the upper surface of the carrying plate (400), comprising a lower chuck (340) and a lower heating plate (320) stacked in an up-down direction; A heat conducting plate (200) is disposed above the lower plate assembly (300); An upper plate assembly (100) is arranged above the heat conducting plate (200), comprising an upper heating plate (120) and an upper chuck (140) stacked in an up-down direction. When driven by a bonding drive member, the upper plate assembly (100) can be raised and lowered and can apply bonding pressure. as well as The driving assembly (500) includes an ascending driving member (520), and when the upper disk assembly (100) moves upward and is separated from the heat conducting plate (200), the ascending driving member (520) can cause the heat conducting plate (200) to ascend.

2. The double-layer thermal compression bonding device according to claim 1, characterized in that: The supporting plate (400) is provided with a plurality of vertical guide pins (410), and the heat conducting plate (200) is slidably inserted into each of the guide pins (410) in an up-down direction.

3. The double-layer thermal compression bonding device according to claim 2, characterized in that: The driving assembly (500) further comprises a mounting frame (510), wherein the mounting frame (510) is fixedly arranged on the lower surface of the carrying plate (400), and the ascending driving member (520) is fixedly mounted on the mounting frame (510); The power output end of the ascending driving member (520) is fixedly connected to at least one supporting column (540), and the supporting column (540) is movably inserted into the through hole of the supporting plate (400), and the outer sleeve of the supporting column (540) is provided with a telescopic member (550), and the upper end of the telescopic member (550) is sealedly connected to the lower surface of the supporting plate (400), and the lower end is sealedly connected to the power output end.

4. The double-layer thermal compression bonding device according to claim 3, characterized in that: The power output end of the ascending driving member (520) is vertically fixed to a support plate (530); there are two support columns (540), which are respectively vertically fixed to the two ends of the support plate (530) to jointly lift the heat conducting plate (200); the lower end of the telescopic member (550) is sealed and connected to the upper surface of the support plate (530).

5. The double-layer thermal compression bonding device according to any one of claims 1 to 4, characterized in that: An upper cold plate (110) is stacked above the upper heating plate (120), and a lower cold plate (310) is stacked below the lower heating plate (320). Cooling water channels are provided in both the upper cold plate (110) and the lower cold plate (310).

6. The double-layer thermal compression bonding device according to claim 5, characterized in that: The upper heating plate (120) is provided with a plurality of upper heating tubes (121), and the lower heating plate (320) is provided with a plurality of lower heating tubes (321), and both the upper heating tubes (121) and the lower heating tubes (321) are quartz heating tubes; The upper heating tube (121) is of a bottom heating type, and / or the lower heating tube (321) is of a top heating type.

7. The double-layer thermal compression bonding device according to claim 6, characterized in that: Both ends of the upper heating tube (121) extend out of the upper heating plate (120), and the end of the upper heating tube (121) is supported by a first positioning block (122), and the end connected to the power line is supported by a cushion block (123), and the first positioning block (122) and the cushion block (123) are both fixedly arranged on the lower surface of the upper cold plate (110); Both ends of the lower heating tube (321) extend out of the lower heating plate (320), and the end of the lower heating tube (321) is supported by a second positioning block (322), and the end connected to the power line is supported by a pad (323), and the second positioning block (322) and the pad (323) are both fixedly arranged on the upper surface of the lower cold plate (310).

8. The double-layer thermal compression bonding device according to claim 5, characterized in that: A first graphite pad (130) is sandwiched between the upper heating plate (120) and the upper chuck (140), and a second graphite pad (150) is stacked below the upper chuck (140); A third graphite pad (330) is sandwiched between the lower chuck (340) and the lower heating plate (320).

9. The double-layer thermal compression bonding device according to claim 8, characterized in that: The upper cold plate (110) is fixedly provided with a limit plate (160), the limit plate (160) comprising a fixedly connected horizontal portion and a connecting portion, the connecting portion being fixedly connected to the upper cold plate (110); the horizontal portion is provided with an avoidance hole (161) for avoiding the wafer pair, and is stacked with the second graphite pad (150), and the second graphite pad (150), the upper chuck (140), the first graphite pad (130), and the upper heating plate (120) are pressed and fixed to the upper cold plate (110); The lower cold plate (310) is fixedly provided with a plurality of fixing blocks (350), and the plurality of fixing blocks (350) press the lower chuck (340), the third graphite pad (330), and the lower heating plate (320) onto the lower cold plate (310).

10. A double-layer thermal compression bonding method, characterized in that: Using the double-layer thermocompression bonding device according to any one of claims 1 to 9 to simultaneously perform thermocompression bonding on two pairs of wafers, the method comprising the following steps: S100, driving the upper plate assembly (100) to rise by the bonding drive component so as to separate it from the heat conducting plate (200), and placing a first wafer to be bonded on the heat conducting plate (200); S200, lifting the heat conducting plate (200) by the lifting driving member (520) to separate it from the lower plate assembly (300), and placing the second wafer to be bonded on the lower chuck (340) of the lower plate assembly (300); S300, retracting the power output end of the ascending driving member (520) so that the heat conducting plate (200) is pressed onto the second pair of wafers; S400, driving the upper disk assembly (100) to press downward at a preset pressure through the bonding drive component, and heating the first pair of wafers and the second pair of wafers at a preset temperature through the upper heating disk (120) and the lower heating disk (320); S500, after heating the two pairs of wafers at the preset temperature for a preset time, the upper plate assembly (100) is raised again by the bonding drive component, and then the first pair of wafers that have completed bonding are taken out; S600, raising the heat conducting plate (200) again through the raising driving member (520), and then taking out the second pair of wafers that have been bonded; S700, placing a new pair of wafers to be bonded into the lower plate assembly (300), then causing the heat conducting plate (200) to fall, and placing another pair of wafers to be bonded on the heat conducting plate (200), and repeating steps S400 to S600 until the thermocompression bonding of all wafer pairs is completed.

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