A die bonder

Abstract

The present application relates to the technical field of die bonder, and particularly discloses a die bonder, which is provided with a cooling module for reducing the temperature in the second conveying channel, the cooling module comprises a plurality of first heating devices arranged at the lower end of the second track and distributed along the x direction, the heating temperature of each first heating device can be individually set, the second conveying channel is arranged, the cooling track is lengthened, the cooling distance is prolonged, and the independent temperature control of the first heating devices is utilized to form a cooling interval with a certain gradient in the second conveying channel, so that the rapid cooling of the wafer is avoided, the uniformity of the impurity distribution of the boron doped area of the silicon wafer is ensured, and the electrical performance and stability of the wafer are ensured. In addition, the relatively stable cooling can also reduce the risk of wafer cracking.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of die bonder, in particular to a die bonder. BACKGROUND

[0002] In the packaging process of semiconductor devices such as IGBT or module, the wafer fixing (referred to as die bonding) is an important process. The process of die bonding is usually divided into three steps: first, the solder mechanism (also known as solder module) draws tin on the frame base island of the tape; second, the die bonder arm takes the wafer from the wafer disc; third, the mechanical arm moves the taken wafer to the die bonding station with tin. Therefore, the strength, heating time and heating frequency of die bonding are important conditions to ensure the quality of power devices, which is an important indicator to measure the die bonding efficiency of the die bonder.

[0003] In the die bonding process of the die bonder, the temperature needs to be raised from 25℃ to 390℃, so that the wafer is fixed on the frame base island of the tape. After the die bonding is completed, the temperature needs to be reduced to 260℃. The conventional die bonder cooling structure usually sets up a shorter track for cooling, and the cooling speed is faster.

[0004] On the one hand, for boron-doped silicon wafers, high-temperature diffusion and ion implantation are two main boron doping technologies. High-temperature diffusion is that impurity atoms diffuse or deposit on the surface of the silicon wafer through a gas source or doped oxide, while ion implantation is that the doping ions are injected into the semiconductor in the form of ion beam. Fast cooling may cause uneven distribution of impurities in the boron-doped region, affecting the electrical properties and stability of the wafer.

[0005] On the other hand, using the conventional die bonder conveying structure, the silicon wafer is exposed to the air for a long time during die bonding, and high temperature will accelerate the oxidation of the silicon wafer.

[0006] Therefore, the prior art still needs to be improved and developed. SUMMARY

[0007] In view of the shortcomings of the prior art, the purpose of the present application is to provide a die bonder to solve the problems of uneven distribution of impurities in the boron-doped region of the silicon wafer and oxidation of the silicon wafer during die bonding caused by the fast cooling speed of the die bonder.

[0008] A die bonder, comprising:

[0009] The feeding conveying mechanism comprises a first track extending along the x direction, at least one first cover plate fixed on the first track, a first conveying channel formed between the first track and the first cover plate for conveying along the x direction, and a plurality of first air holes on the lower end surface of the first cover plate facing the first conveying channel;

[0010] A temperature increasing module is arranged in the first track to increase the temperature in the first conveying channel;

[0011] A soldering mechanism includes a soldering head movable along the z direction, which can extend into the first conveying channel to apply solder on the frame base island of the material belt conveyed in the first conveying channel;

[0012] A die bonding table is arranged below the first track, and the upper end is used to place a wafer;

[0013] A die bonding mechanism is arranged above the first track to transfer the wafer on the die bonding table to the solder on the frame base island;

[0014] An output cooling mechanism includes a second track extending along the x direction, at least one second cover plate fixed on the second track, a second conveying channel formed between the second track and the second cover plate for conveying along the x direction, the second conveying channel is communicated with the first conveying channel, and the lower end surface of the second cover plate is provided with a plurality of second air holes facing the second conveying channel;

[0015] A temperature decreasing module is arranged in the second conveying channel to decrease the temperature in the second conveying channel, and includes a plurality of first heating devices arranged at the lower end of the second track and distributed along the x direction, and the heating temperature of each first heating device can be individually set.

[0016] Specifically, the temperature in the second conveying channel gradually decreases along the conveying direction thereof.

[0017] Specifically, the temperature increasing module includes a plurality of second heating devices arranged at the lower end of the first track and distributed along the x direction, and the heating temperature of each second heating device can be individually set.

[0018] The temperature in the first conveying channel gradually increases along the conveying direction thereof.

[0019] Specifically, the first heating device and the second heating device are both electric heating columns.

[0020] Specifically, a plurality of first air channels are arranged side by side along the y direction in the first cover plate, the first air holes are communicated with the first air channels, and a first air connector is arranged on the first cover plate and communicated with the first air channels.

[0021] A plurality of second air channels are arranged side by side along the y direction in the second cover plate, the second air holes are communicated with the second air channels, and a second air connector is arranged on the second cover plate and communicated with the second air channels.

[0022] Specifically, the soldering mechanism further comprises a first support, a first lifting device fixed on the first support and driven in the z direction, a first mounting plate connected to the output end of the first lifting device, and a soldering head fixed to the first mounting plate, wherein the nozzle of the soldering head is in communication with the solder supply device.

[0023] Specifically, the die bonding mechanism comprises a second support, a rotary driving device fixed on the second support, a turntable connected to the output shaft of the rotary driving device, a round rod fixed on the turntable and coaxial with the turntable, a swing arm rotatably arranged on the second support, a connecting rod hingedly connected to the swing arm and the round rod at two ends, a swing rod connected to the other end of the swing arm, a second lifting device fixed to one end of the swing rod and driven in the z direction, and a suction nozzle fixed to the output end of the second lifting device.

[0024] Specifically, the second support is further hingedly connected with a pulling arm, and the pulling arm is further hingedly connected with the swing rod.

[0025] Specifically, the die bonding mechanism comprises a second support, a rotary driving device fixed on the second support, a turntable connected to the output shaft of the rotary driving device, a round rod fixed on the turntable and coaxial with the turntable, a swing arm rotatably arranged on the second support, a connecting rod hingedly connected to the swing arm and the round rod at two ends, a swing rod connected to the other end of the swing arm, a second lifting device fixed to one end of the swing rod and driven in the z direction, and a suction nozzle fixed to the output end of the second lifting device.

[0026] The beneficial effects of the present application are as follows:

[0027] The die bonding machine of the present application transports the material belt to below the soldering mechanism through the first conveying channel, applies solder to the frame base island point of the material belt conveyed in the first conveying channel through the soldering head of the soldering mechanism, then transports the material belt to below the die bonding mechanism through the first conveying channel, and transfers the die from the die bonding table to the solder of the frame base island through the die bonding mechanism, and then transports the material belt to the discharge cooling mechanism for cooling.

[0028] Moreover, a cooling module for reducing the temperature in the second conveying channel is arranged, the cooling module comprises a plurality of first heating devices arranged at the lower end of the second track and distributed in the x direction, the heating temperature of each first heating device can be individually set, the second conveying channel is arranged, the cooling track is lengthened, the cooling distance is prolonged, and the independent temperature control of the first heating devices forms a certain gradient cooling interval in the second conveying channel, so as to avoid rapid cooling of the die, ensure the uniformity of the impurity distribution of the boron-doped region of the silicon die, and thus ensure the electrical performance and stability of the die. In addition, the relatively stable cooling can also reduce the risk of die cracking. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a perspective view of the die bonder of the present application;

[0030] Figure 2 is a top view of the die bonder of the present application;

[0031] Figure 3 is Figure 2 is a sectional view along line A-A;

[0032] Figure 4 is Figure 3 is an enlarged view of part C;

[0033] Figure 5 is Figure 3 is an enlarged view of part D;

[0034] Figure 6 is Figure 2 is a sectional view along line B-B;

[0035] Figure 7 is a perspective view of the die bonder mechanism of the present application;

[0036] Figure 8 is a perspective view of the second cover plate of the present application;

[0037] Figure 9 is a perspective sectional view of the second cover plate of the present application.

[0038] The reference signs are: feeding conveying mechanism 10, first track 11, first cover plate 12, first conveying passage 101, first air hole 121, solder mechanism 20, solder head 21, die bonding table 30, die bonder mechanism 40, discharging cooling mechanism 50, second track 51, second cover plate 52, second conveying passage 501, second air hole 521, first heating device 61, second heating device 62, first air passage 122, first air joint 123, second air passage 522, second air joint 523, first support 22, first lifting device 23, first mounting plate 24, second support 41, rotary driving device 42, rotating disc 43, round rod 44, swing arm 45, connecting rod 46, swing rod 47, second lifting device 48, suction nozzle 49, pulling arm 410, base 31, x-axis driving device 32, first carrier plate 33, y-axis driving device 34, second carrier plate 35, annular frame 36, diaphragm 37, thimble 38. DETAILED DESCRIPTION

[0039] The present application provides a die bonder, in order to make the purpose, technical scheme and effect of the present application more clear and definite, the present application is further described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application.

[0040] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right and the like, is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0041] As Figures 1 to 9 The embodiment discloses a die bonder, comprising:

[0042] The feeding conveying mechanism 10 comprises a first track 11 extending along the x direction, at least one first cover plate 12 fixed on the first track 11, a first conveying channel 101 formed between the first track 11 and the first cover plate 12 for conveying along the x direction, and a plurality of first air holes 121 provided on the lower end surface of the first cover plate 12 and facing the first conveying channel 101;

[0043] The temperature rising module is arranged on the first track 11 and is used for rising the temperature in the first conveying channel 101;

[0044] The solder mechanism 20 comprises a solder head 21 movable along the z direction, and the solder head 21 can extend into the first conveying channel 101 to apply solder on the frame base island of the material belt conveyed in the first conveying channel 101;

[0045] The die bonding table 30 is arranged below the first track 11, and the upper end is used for placing a wafer;

[0046] The die bonding mechanism 40 is arranged above the first track 11 and is used for transferring the wafer on the die bonding table 30 to the solder on the frame base island;

[0047] The discharging and cooling mechanism 50 comprises a second track 51 extending along the x direction, at least one second cover plate 52 fixed on the second track 51, a second conveying channel 501 formed between the second track 51 and the second cover plate 52 for conveying along the x direction, the second conveying channel 501 being communicated with the first conveying channel 101, and a plurality of second air holes 521 provided on the lower end surface of the second cover plate 52 and facing the second conveying channel 501;

[0048] The temperature lowering module is used for lowering the temperature in the second conveying channel 501 and comprises a plurality of first heating devices 61 arranged on the lower end of the second track 51 and distributed along the x direction, and the heating temperature of each first heating device 61 can be set individually.

[0049] The die bonder of the embodiment transports the tape to below the solder mechanism 20 through the first conveying channel 101, applies solder on the frame base island points of the tape conveyed in the first conveying channel 101 through the solder head 21 of the solder mechanism 20, then transports the tape to below the die bonder mechanism 40 through the first conveying channel 101, and transfers the die 30 on the die bonder mechanism 40 to the solder on the frame base island, and then transports the tape to the discharge cooling mechanism 50 for cooling through the first conveying channel 101.

[0050] Moreover, the embodiment is provided with a cooling module for reducing the temperature in the second conveying channel 501, which comprises a plurality of first heating devices 61 arranged at the lower end of the second track 51 and distributed along the x direction, and the heating temperature of each first heating device 61 can be set individually. The cooling track is lengthened by setting the second conveying channel 501, and the cooling distance is prolonged. Moreover, the independent temperature control of the first heating device 61 forms a cooling interval with a certain gradient in the second conveying channel 501, which avoids rapid cooling of the die, ensures the uniformity of the impurity distribution of the boron-doped region of the silicon die, and thus guarantees the electrical performance and stability of the die. Moreover, the relatively stable cooling also reduces the risk of die cracking.

[0051] In addition, the first cover plate 12 is arranged on the first track 11, and a plurality of first air holes 121 are arranged on the lower end surface of the first cover plate 12 and face the first conveying channel 101. The second cover plate 52 is arranged on the second track 51, and a plurality of second air holes 521 are arranged on the lower end surface of the second cover plate 52 and face the second conveying channel 501. Nitrogen, argon or other inert gas can be introduced into the first conveying channel 101 through the first air holes 121, and nitrogen, argon or other inert gas can be introduced into the second conveying channel 501 through the second air holes 521. The die is protected by the inert gas to avoid oxidation of the die.

[0052] Further, the heating module of the embodiment comprises a plurality of second heating devices 62 arranged at the lower end of the first track 11 and distributed along the x direction, and the heating temperature of each second heating device 62 can be set individually. The temperature in the first conveying channel 101 gradually increases along the conveying direction thereof, and the temperature in the second conveying channel 501 gradually decreases along the conveying direction thereof. In specific applications, the temperature in the first conveying channel 101 can be increased from 25℃ to 390℃ along the conveying direction thereof through the heating control of the second heating device 62, and the temperature in the second conveying channel 501 can be decreased from 390℃ to 260℃ along the conveying direction thereof through the heating control of the first heating device 61.

[0053] Further, the first heating device 61 and the second heating device 62 are both electric heating columns, the electric heating column has a fast heating speed, the electric heating column can directly generate heat in the interior of the heated object, and heat loss is avoided, and therefore the heat efficiency is high. In addition, the electric heating column has a fast heating speed, the temperature can be rapidly increased, and the electric heating column is suitable for occasions requiring rapid heating.

[0054] Please refer to Figure 3 and Figure 4 , the first cover plate 12 is provided with a plurality of first gas channels 122 arranged side by side along the y direction, the first gas holes 121 are communicated with the first gas channels 122, and the first cover plate 12 is provided with a first gas joint 123 communicated with the first gas channels 122; the first gas joint 123 is connected with the exhaust port of the gas supply device through a pipeline, and the inert gas such as nitrogen and argon is introduced into the first gas channels 122 through the gas supply device, and the inert gas enters the first conveying channel 101 through the first gas holes 121, so that the wafer in the first conveying channel 101 is protected from oxidation.

[0055] Please refer to Figure 3 , Figure 5 , Figure 8 and Figure 9 , the second cover plate 52 is provided with a plurality of second gas channels 522 arranged side by side along the y direction, the second gas holes 521 are communicated with the second gas channels 522, and the second cover plate 52 is provided with a second gas joint 523 communicated with the second gas channels 522; the second gas joint 523 is connected with the exhaust port of the gas supply device through a pipeline, and the inert gas such as nitrogen and argon is introduced into the second gas channels 522 through the gas supply device, and the inert gas enters the second conveying channel 501 through the second gas holes 521, so that the wafer in the second conveying channel 501 is protected from oxidation.

[0056] Please refer to Figure 1 , the solder mechanism 20 further comprises a first support 22, a first lifting device 23 fixed on the first support 22 and driven in the z direction, a first mounting plate 24 connected to the output end of the first lifting device 23, the first lifting device 23 can adopt a pneumatic cylinder or an electric cylinder, the solder head 21 is fixed to the first mounting plate 24, the nozzle of the solder head 21 is communicated with the solder supply device, when the material belt is conveyed below the solder mechanism 20, the first mounting plate 24 is driven to move downward in the z direction through the first lifting device 23, so as to drive the solder head 21 to move downward, and the solder on the frame base island point of the material belt conveyed in the first conveying channel 101 is soldered through the solder head 21.

[0057] Please refer to Figure 7The sticking piece mechanism 40 comprises a second support 41, a rotary driving device 42 fixed on the second support 41, a rotating disc 43 connected to an output shaft of the rotary driving device 42, a round rod 44 fixed on the rotating disc 43 and coaxial with the rotating disc 43, a swing arm 45 rotatably arranged on the second support 41, a connecting rod 46 having two ends respectively hingedly connected with the swing arm 45 and the round rod 44, a swing rod 47 connected to the other end of the swing arm 45, a second lifting device 48 fixed on one end of the swing rod 47 and driven in the z direction, and a suction nozzle 49 fixed on an output end of the second lifting device 48. The rotary driving device 42 can be a motor. When the sticking piece action is performed, the rotating disc 43 is driven to rotate by the rotary driving device 42, the connecting rod 46 is driven to swing by the rotating disc 43, the swing arm 45 is driven to swing by the connecting rod 46, and the swing rod 47 is driven to swing by the swing arm 45. Since the round rod 44 is coaxial with the rotating disc 43, the reciprocating action of the swing rod 47 can be realized. The second lifting device 48 can be a pneumatic cylinder or an electric cylinder. When the swing rod 47 swings the suction nozzle 49 to the diaphragm 37 of the die bonding table 30, the second lifting device 48 drives the suction nozzle 49 to move downward, so that the suction nozzle 49 sucks one die from the diaphragm 37. The rotary driving device 42 continues to drive the rotating disc 43 to rotate, and the swing rod 47 swings the suction nozzle 49 to a reserved groove position on the first cover plate 12. The groove is communicated with the first conveying channel 101, so that the suction nozzle 49 can place the die on the solder of the frame base island in the first conveying channel 101.

[0058] Further, in order to limit the angle of the swing rod 47 when moving, the second support 41 is further hingedly connected with a pulling arm 410, and the pulling arm 410 is further hingedly connected with the swing rod 47.

[0059] Please refer to Figure 6 The die bonding table 30 of the embodiment comprises a base 31, an x-axis driving device 32 arranged on the base 31, a first carrier plate 33 connected to an output end of the x-axis driving device 32, a y-axis driving device 34 arranged on the first carrier plate 33, a second carrier plate 35 connected to an output end of the y-axis driving device 34, a ring-shaped frame 36 arranged on the second carrier plate 35, a diaphragm 37 arranged on the inner side of the ring-shaped frame 36, a thimble 38 arranged on the second carrier plate 35 and capable of lifting the diaphragm 37 in the z direction, and the thimble 38 is movable below the suction nozzle 49. When the suction nozzle 49 sucks the die, the thimble 38 can lift the die separated from the diaphragm 37, so that the die is more easily separated from the diaphragm 37.

[0060] It should be noted that the x-axis driving device 32 and the y-axis driving device 34 can both be a lead screw module, which has high precision and is beneficial to precise movement in a small stroke.

[0061] The preferred embodiments of the present application have been disclosed with specific reference to a preferred embodiment. A person with ordinary skill in the art understands that variations in, or modifications to, the preferred embodiments can be made without departing from the spirit and scope of the present application, which is defined by the following claims.

Claims

1. A die bonder characterized by comprising: The application relates to a soldering and die-bonding device. The device comprises a feeding mechanism (10), a temperature-raising module, a soldering mechanism (20), a die-bonding table (30), a die-bonding mechanism (40) and a discharging and cooling mechanism (50). The feeding mechanism (10) comprises a first track (11) extending along the x direction, at least one first cover plate (12) fixed on the first track (11), a first conveying channel (101) formed between the first track (11) and the first cover plate (12) for conveying along the x direction, and a plurality of first air holes (121) provided on the lower end surface of the first cover plate (12) and facing the first conveying channel (101). The temperature-raising module is arranged on the first track (11) and used for raising the temperature in the first conveying channel (101). The soldering mechanism (20) comprises a soldering head (21) movable along the z direction, the soldering head (21) can extend into the first conveying channel (101) and apply solder on the frame base island of a material belt conveyed in the first conveying channel (101). The die-bonding table (30) is arranged below the first track (11) and used for placing a wafer on the upper end. The die-bonding mechanism (40) is arranged above the first track (11) and used for transferring the wafer on the die-bonding table (30) to the solder on the frame base island. The discharging and cooling mechanism (50) comprises a second track (51) extending along the x direction, at least one second cover plate (52) fixed on the second track (51), a second conveying channel (501) formed between the second track (51) and the second cover plate (52) for conveying along the x direction, the second conveying channel (501) is communicated with the first conveying channel (101), and a plurality of second air holes (521) are provided on the lower end surface of the second cover plate (52) and face the second conveying channel (501). The temperature-lowering module is used for lowering the temperature in the second conveying channel (501) and comprises a plurality of first heating devices (61) arranged on the lower end of the second track (51) and distributed along the x direction, the heating temperature of each first heating device (61) can be individually set. The temperature in the second conveying channel (501) gradually decreases along the conveying direction.

2. The die bonder of claim 1 wherein, The die-bonding mechanism (40) comprises a second support (41), a rotary driving device (42) fixed on the second support (41), a rotating disc (43) connected to the output shaft of the rotary driving device (42), a round rod (44) fixed on the rotating disc (43) and coaxial with the rotating disc (43), a swing arm (45) rotatably arranged on the second support (41), a connecting rod (46) hingedly connected to the swing arm (45) and the round rod (44) at two ends, a swing rod (47) connected to the other end of the swing arm (45), a second lifting device (48) fixed on one end of the swing rod (47) and driven along the z direction, and a suction nozzle (49) fixed on the output end of the second lifting device (48). The temperature-raising module comprises a plurality of second heating devices (62) arranged on the lower end of the first track (11) and distributed along the x direction, the heating temperature of each second heating device (62) can be individually set. The temperature in the first conveying channel (101) gradually increases along the conveying direction.

3. The die bonder of claim 2 wherein, The first heating device (61) and the second heating device (62) are both electric heating columns.

4. The die bonder of claim 1 wherein, The first cover plate (12) is internally provided with a plurality of first air passages (122) arranged side by side along the y direction, the first air holes (121) are communicated with the first air passages (122), and the first cover plate (12) is provided with first air joints (123) communicated with the first air passages (122); The second cover plate (52) is internally provided with a plurality of second air passages (522) arranged side by side along the y direction, the second air holes (521) are communicated with the second air passages (522), and the second cover plate (52) is provided with second air joints (523) communicated with the second air passages (522).

5. The die bonder of claim 1 wherein, The solder mechanism (20) further comprises a first support (22), a first lifting device (23) fixed on the first support (22) and driven in the z direction, a first mounting plate (24) connected to the output end of the first lifting device (23), and the solder head (21) is fixed to the first mounting plate (24), and the nozzle of the solder head (21) is communicated with the solder feeding device.

6. The die bonder of claim 1 wherein, The second support (41) is further hinged with a pulling arm (410), and the pulling arm (410) is further hinged with the swing rod (47).

7. The die bonder of claim 1 wherein, The die bonding table (30) comprises a base (31), an x-axis driving device (32) arranged on the base (31), a first carrier plate (33) connected to the output end of the x-axis driving device (32), a y-axis driving device (34) arranged on the first carrier plate (33), a second carrier plate (35) connected to the output end of the y-axis driving device (34), a ring-shaped frame (36) arranged on the second carrier plate (35), a diaphragm (37) arranged on the inner side of the ring-shaped frame (36), a thimble (38) arranged on the second carrier plate (35) and capable of lifting the diaphragm (37) in the z direction, and the thimble (38) is movable to below the suction nozzle (49).

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