JP7433203B2 - Semiconductor manufacturing equipment and semiconductor device manufacturing method - Google Patents

Description

The present disclosure relates to a semiconductor manufacturing apparatus and a method for manufacturing a semiconductor device.

Conventionally, semiconductor devices have been manufactured through two steps: coating a thermosetting resin on a lead frame and mounting a control semiconductor element thereon, curing the thermosetting resin by heating the lead frame, and applying heat to the lead frame. It is manufactured through a process in which solder is applied to a location different from the location where the control semiconductor device is mounted, the power semiconductor device is mounted on top of the solder, and the lead frame is soldered by heating. Because the heating temperature and other conditions for curing thermosetting resin and soldering are different, these processes are performed using different equipment, but from the perspective of improving productivity, it is recommended to perform these processes using one equipment. is desirable.

Patent Document 1 discloses that after the solder joint surface of the circuit assembly has been preheated to a temperature equal to or higher than the melting point of the solder, a terminal-integrated outer resin case is docked from above and stacked on top of the circuit assembly. Technology to assemble the module by applying additional pressure to solder the external terminals to the main circuit block and control circuit block, and bond the outer resin case to the metal base plate in the same process. is disclosed.

Japanese Patent Application Publication No. 10-233484

However, in the technique described in Patent Document 1, solder bonding and adhesion between the outer resin case and the metal base plate are performed at the same heating temperature. Therefore, there is a problem in that when the thermosetting resin is heated at a temperature for performing solder bonding, the bonding strength of the thermosetting resin decreases.

Therefore, an object of the present disclosure is to provide a technique that allows a control semiconductor element and a power semiconductor element to be bonded to a lead frame in the same device using different bonding materials without reducing bonding strength.

A semiconductor manufacturing apparatus according to the present disclosure includes: a chamber; a loader that carries a lead frame, on which a control semiconductor element is mounted at a first mounting location, into the chamber via a thermosetting resin before curing; and an unloader for transporting the lead frame, and the chamber includes a transport rail for transporting the lead frame, and a second mounting location other than the first mounting location on the lead frame for placing solder before hardening. a mounting section on which a power semiconductor element is mounted via a mounting section, and a mounting section provided at a position opposite to the lower surface of the first mounting section of the lead frame on the transport rail, and heating the first mounting section and curing the thermosetting section. a first heater block for curing the adhesive resin, and a second heater block provided at a position opposite to the lower surface of the second mounting location of the lead frame on the conveyance rail, and for heating and soldering the second mounting location. A heater block and a cooling unit that cools the second mounting location of the lead frame and hardens the solder are provided, and the heating temperature of the first heater block is lower than the heating temperature of the second heater block. It is.

According to the present disclosure, the first heater block heats the first mounting location of the lead frame at a temperature suitable for curing the thermosetting resin, and the second heater block heats the first mounting location of the lead frame at a temperature suitable for curing the thermosetting resin. Since the second mounting point of the lead frame can be heated with temperature, the control semiconductor element and the power semiconductor element can be bonded to the lead frame using different bonding materials in the same device without reducing the bonding strength. be able to.

1 is a perspective side view showing the basic configuration of a semiconductor manufacturing apparatus according to Embodiment 1. FIG. FIG. 3 is an explanatory diagram for explaining a process of mounting a control semiconductor element onto a lead frame. FIG. 3 is a top view showing a state in which lead frames are set in first and second heater blocks included in the semiconductor manufacturing apparatus according to the first embodiment. FIG. 3 is a transparent perspective view for explaining loading of a lead frame from a loader included in the semiconductor manufacturing apparatus according to the first embodiment to a chamber. 1 is a cross-sectional view of a semiconductor device manufactured using the semiconductor manufacturing apparatus according to Embodiment 1. FIG. 7 is a cross-sectional view showing a state in which a lead frame is set in a first heater block included in a semiconductor manufacturing apparatus according to a second embodiment. FIG.

<Embodiment 1>
Embodiment 1 will be described below using the drawings. FIG. 1 is a perspective side view showing the basic configuration of a semiconductor manufacturing apparatus according to a first embodiment.

As shown in FIG. 1, the semiconductor manufacturing apparatus includes a chamber 18, a loader 6, an unloader 17, an entrance shutter 20, and an exit shutter 27.

The loader 6 carries the plate-shaped lead frame 1 on which the control semiconductor element 3 is mounted into the chamber 18 via the thermosetting resin 2 before hardening.

Here, the process of mounting the control semiconductor element 3 onto the lead frame 1, which is carried out before being carried into the loader 6, will be described using FIG. FIG. 2 is an explanatory diagram for explaining the process of mounting the control semiconductor element 3 onto the lead frame 1. As shown in FIG.

As shown in FIG. 2, in the step of mounting the control semiconductor element 3 onto the lead frame 1, a thermosetting resin 2 is applied to the upper surface of the lead frame 1, and the control semiconductor element 3 is mounted thereon. The control semiconductor element 3 is mounted using a general resin die bonder. In this case, the lead frame 1 is transported to the resin dispensing area in the atmosphere at room temperature. The resin dispensing area is provided with a dispenser 4 and a syringe 5 connected to the dispenser 4. The syringe 5 is filled with thermosetting resin 2, and the thermosetting resin 2 is applied onto the lead frame 1 by applying pressure to the syringe 5 from the dispenser 4. Thereafter, the lead frame 1 is transported to a semiconductor element mounting area, and the control semiconductor element 3 is mounted on the thermosetting resin 2 coated on the lead frame 1. At this time, the thermosetting resin 2 is in an uncured state.

Returning to the explanation of the semiconductor manufacturing equipment. As shown in FIG. 1, the chamber 18 is connected to the loader 6 and the unloader 17. Inside the chamber 18, a process of applying solder 11 to the lead frame 1, a process of mounting the power semiconductor element 15 on the lead frame 1 via the solder 11, and a process of mounting the control semiconductor element 3 on the lead frame 1 are performed. At the same time, the thermosetting resin 2 is heated to harden the thermosetting resin 2 at the location where the power semiconductor element 15 is mounted (hereinafter referred to as the "second mounting location") in the lead frame 1 (hereinafter referred to as the "second mounting location"). ) and a step of heating and soldering the lead frame 1, and a step of cooling the second mounting portion of the lead frame 1 and hardening the solder 11.

After the above steps are completed, the unloader 17 carries out the lead frame 1 from the chamber 18. The loader 6 and the unloader 17 are housed in a separate chamber from the chamber 18, and the loader 6 and the chamber 18 are separated by an entrance shutter 20, and the chamber 18 and the unloader 17 are separated by an exit shutter 27. There is. Further, the interiors of the loader 6 and the unloader 17 are evacuated to a reduced pressure state. Note that when the inside of the chamber 18 is set to a nitrogen atmosphere, the insides of the loader 6 and the unloader 17 may also be set to a nitrogen atmosphere.

Next, the chamber 18 will be explained in detail. As shown in FIG. 1, inside the chamber 18, a transport rail 9, a supply section 10, a stirring section 12, a mounting section 14, a cooling section 16, a plurality of digital pushers 7, and an elevator 8 are provided. It is being

The conveyor rail 9 chucks the outer circumference of the lead frame 1 and conveys the lead frame 1. The supply unit 10 includes a supply means 10a that supplies and applies uncured solder 11 to the second mounting location of the lead frame 1. The stirring section 12 includes a solder stirring tool 12a that spreads out the applied solder 11. The mounting section 14 includes mounting means (not shown) for mounting the power semiconductor element 15 onto the solder 11 spread out on the upper surface of the lead frame 1 . The cooling unit 16 includes a cooling block (not shown) in which a cooling pipe (not shown) through which air or water circulates is disposed.

Further, the inside of the chamber 18 can be replaced with a reduced pressure state or a nitrogen atmosphere by evacuation in order to reduce solder voids. In order to ensure time for the thermosetting resin 2 applied to the top surface of the lead frame 1 to harden, the transport rail 9 that transports the lead frame 1 is configured in multiple stages, thereby reducing the distance until it reaches the supply section 10. is being made longer. In this way, by configuring the transport rail 9 in multiple stages, it is possible to shorten the width of the semiconductor manufacturing apparatus.

Here, the supply section 10, the stirring section 12, the mounting section 14, and the cooling section 16 are provided adjacent to each other on the uppermost conveyance rail 9 inside the chamber 18. Further, the entrance shutter 20 is provided at the starting end of the lowermost transport rail 9 in the transport direction, and the exit shutter 27 is provided at the terminal end of the uppermost transport rail 9 in the transport direction.

In order to make each process easier to understand, FIG. 1 shows a state in which control semiconductor elements 3 are mounted on the transport rails 9 other than the top stage, and power semiconductor devices are mounted on the top transport rail 9. A state in which the element 15 is mounted is shown.

Next, the configuration of the transport rail 9 will be described using FIGS. 1 and 3. FIG. 3 is a top view showing the lead frame 1 set in the first and second heater blocks 24 and 25 included in the semiconductor manufacturing apparatus according to the first embodiment. Although FIG. 3 shows a state in which the transport rail 9 is removed to make it easier to see the first and second heater blocks 24 and 25, the explanation will be given assuming that the transport rail 9 is present.

As shown in FIG. 1, the transport rail 9 has, for example, a three-stage configuration. Although not shown in FIG. 1, a first heater block 24 is provided at a position in contact with the lower surface of the lead frame 1 on the transport rail 9 of the stages other than the top stage.

Furthermore, as shown in FIG. 3, a first heater block 24 and a second heater block 25 are provided at positions on the uppermost transport rail 9 that contact the lower surface of the lead frame 1. The first heater block 24 is provided at a position facing the lower surface of the first mounting location of the lead frame 1 on the transport rail 9, and heats the first mounting location of the lead frame 1 to harden the thermosetting resin 2. The second heater block 25 is provided at a position facing the lower surface of the second mounting location of the lead frame 1 on the transport rail 9, and heats the second mounting location of the lead frame 1 for soldering.

Here, a plurality of first mounting locations for the lead frame 1 are provided in line in the transport direction of the transport rail 9. Further, a plurality of second mounting locations of the lead frame 1 are provided parallel to the direction in which the plurality of first mounting locations are lined up and lined up in the transport direction of the transport rail 9. Therefore, the first heater block 24 at the uppermost stage is provided at a position facing the lower surface of the plurality of first mounting locations of the lead frame 1 and the portion connecting these locations. Further, the second heater block 25 is provided at a position facing the plurality of second mounting locations of the lead frames 1 on the transport rail 9 and the lower surface of a portion connecting these.

A thermocouple and a temperature controller are attached to each heater block 24, 25, and the heating temperature can be set. In the transport rails 9 of the stages other than the top stage, the first heater block 24 is set at a heating temperature suitable for curing the thermosetting resin 2. Specifically, the heating temperature of the first heater block 24 is set to 150°C or more and 200°C or less. Therefore, by dragging the lead frame 1 on the first heater block 24 during transportation, heat is transferred to the lead frame 1, and the entire lead frame 1 is heated at a heating temperature suitable for curing the thermosetting resin 2. be done.

On the other hand, in the uppermost conveyor rail 9, when the thermosetting resin 2 is heated at the heating temperature for soldering, the bonding strength of the thermosetting resin 2 decreases, etc. Therefore, the heating temperature of the first heater block 24 is set to be lower than the heating temperature of the second heater block 25. Specifically, the heating temperature of the first heater block 24 is set to 150°C or more and 200°C or less, and the heating temperature of the second heater block 25 is set to 250°C or more and 330°C or less, which is a temperature suitable for soldering. There is.

Further, as shown in FIG. 3, on the uppermost conveyance rail 9, the first heater block 24 and the second heater block 25 are arranged in a spaced apart state, and the heating temperature of the first heater block 24 is controlled by the second heater block 25. Since the heating temperature is lower than the heating temperature of the block 25, it is possible to suppress an adverse effect on the bonding strength of the thermosetting resin 2. As a result, it becomes possible to bond two different bonding materials, thermosetting resin 2 and solder 11, with the same device without reducing the bonding strength.

Furthermore, in order to reduce the portion connecting the first mounting location and the second mounting location in the lead frame 1, a slit 21 is formed between the first mounting location and the second mounting location in the lead frame 1. ing. This makes it possible to suppress heat transfer between the first mounting location and the second mounting location on the lead frame 1. The slit 21 is a cavity formed by punching out the plate-shaped lead frame 1, and the shape of the slit 21 may be any shape as long as it does not affect the quality of the product.

Next, the digital pusher 7 and elevator 8 will be explained. As shown in FIG. 1, after the entrance shutter 20 is opened, the digital pusher 7 delivers the lead frame 1 from the loader 6 to the chamber 18. The lead frame 1 is transported by a transport rail 9 from the lowest stage to the highest stage. In addition to the method of transporting the lead frame 1 by chucking the outer periphery of the lead frame 1, the transport method using the transport rail 9 includes a method of pinching the outer periphery of the lead frame 1 with rollers and pushing it out, a method of transporting with pins, A method of pushing out with a pusher may also be used.

Further, after the lead frame 1 reaches the end of the lower transport rail 9, the digital pusher 7 descends and moves forward, thereby ejecting the lead frame 1 to the elevator 8. The elevator 8 moves the lead frame 1 to the transport rail 9 one step above by rising to the transport rail 9 one step above. The digital pusher 7 again discharges the lead frame 1 onto the transport rail 9 located one step above, and the lead frame 1 is transported by the transport rail 9 located one step above. By repeating these operations for the number of stages of the transport rail 9, the lead frame 1 is transported from the lowest stage to the highest stage.

Next, the operation of the semiconductor manufacturing apparatus will be explained using FIGS. 1 to 5. FIG. 4 is a transparent perspective view for explaining the loading of the lead frame 1 from the loader 6 included in the semiconductor manufacturing apparatus according to the first embodiment to the chamber 18. FIG. 5 is a cross-sectional view of a semiconductor device manufactured using the semiconductor manufacturing apparatus according to the first embodiment.

As shown in FIG. 4, the loader 6 has a plurality of dedicated magazines 19 arranged on a pedestal 19a. The dedicated magazine 19 accommodates a plurality of lead frames 1 on which control semiconductor elements 3 are mounted via a thermosetting resin 2 before curing. When the semiconductor manufacturing apparatus is in operation, the entrance shutter 20 between the loader 6 and the chamber 18 is open, and the lead frames 1 are transferred from the loader 6 to the chamber 18 one by one.

When placing the dedicated magazine 19 containing the lead frame 1 in the loader 6, or when taking out the empty dedicated magazine 19 from the loader 6 after transporting the lead frame 1 to the chamber 18, the loader 6 and The entrance shutter 20 between the chamber 18 and the chamber 18 is closed, only the loader 6 is exposed to the atmosphere, and the dedicated magazine 19 is replaced. After replacing the special magazine 19, the loader 6 evacuates again, and after reaching a vacuum state, the entrance shutter 20 between the loader 6 and the chamber 18 is opened, and the lead frame 1 is received from the replaced special magazine 19. hand over.

As shown in FIG. 1, the lead frame 1 is transported from the lowest stage to the highest stage by the transport rail 9, and therefore is heated to a sufficient temperature by the time it reaches the supply section 10. At this time, the first mounting portion of the lead frame 1 is also sufficiently heated and the thermosetting resin 2 is cured. This completes the bonding between the lead frame 1 and the control semiconductor element 3.

The supply unit 10 applies solder 11 to the second mounting location of the lead frame 1 that has been heated. The applied solder 11 melts immediately.

Next, in the stirring section 12, the solder stirring tool 12a heated to the same temperature as the heating temperature of the second heater block 25 is moved up and down by a motor (not shown), and when it descends, the solder 11 is applied. By contacting the lead frame 1, the solder 11 is spread out.

Next, in the mounting section 14, the mounting means grasps the side surface of the diced power semiconductor element 15 and mounts the power semiconductor element 15 onto the solder 11 that has finished the solder agitation. At this time, the second mounting location of the lead frame 1 is heated by the second heater block 25, and the power semiconductor element 15 is soldered. Note that the mounting means is made of a material that does not damage the power semiconductor element 15 when it comes into contact with the power semiconductor element 15.

Further, if suction is possible, there is no problem even if the power semiconductor element 15 is suctioned and mounted. The power semiconductor devices 15 are packed in a tray, and the tray is replaced by opening a shutter (not shown). Note that the power semiconductor elements 15 are not limited to being packed in a tray, and may be supplied in a state stuck on a dicing tape.

Next, in the cooling unit 16, the entire lead frame 1 is cooled, thereby cooling the second mounting location and hardening the solder 11. This completes the bonding between the lead frame 1 and the power semiconductor element 15.

The exit shutter 27 between the unloader 17 and the chamber 18 is open, and the cooled lead frame 1 is carried out from the chamber 18 to the unloader 17. Although not shown in FIG. 1, a plurality of dedicated magazines are arranged in the unloader 17. The dedicated magazine can accommodate a plurality of cooled lead frames 1. Note that the method for replacing the dedicated magazine arranged in the unloader 17 is the same as the method for replacing the dedicated magazine 19 arranged in the loader 6.

The loading of the lead frame 1 from the loader 6 to the chamber 18 and the unloading of the lead frame 1 from the chamber 18 to the unloader 17 are performed after the insides of the loader 6 and unloader 17 are brought into a reduced pressure state, but the atmosphere and reduced pressure are By minimizing the difference in state fluctuations, production efficiency is improved.

After the above steps, as shown in FIG. 5, a wire bonding step for connecting metal wires 29, a transfer molding step for sealing with mold resin 28, etc. are performed to complete the semiconductor device.

As described above, the semiconductor manufacturing apparatus according to the first embodiment connects the lead frame 1 with the control semiconductor element 3 mounted at the first mounting location via the chamber 18 and the thermosetting resin 2 before curing into the chamber. The chamber 18 includes a loader 6 for loading the lead frame 1 into the chamber 18, and an unloader 17 for loading the lead frame 1 from the chamber 18. A mounting section 14 for mounting the power semiconductor element 15 via uncured solder 11 at a second mounting location other than the above, and a mounting section 14 at a position opposite to the lower surface of the first mounting location of the lead frame 1 on the transport rail 9. A first heater block 24 that is provided and heats the first mounting location to harden the thermosetting resin 2; and a first heater block 24 that is provided at a position facing the lower surface of the second mounting location of the lead frame 1 on the transport rail 9; , a second heater block 25 that heats the second mounting location and performs soldering, and a cooling section 16 that cools the second mounting location of the lead frame 1 and hardens the solder 11. The temperature is lower than the heating temperature of the second heater block 25.

Therefore, the first heater block 24 heats the first mounting location of the lead frame 1 at a temperature suitable for curing the thermosetting resin 2, and the second heater block 25 heats the first mounting location of the lead frame 1 at a temperature suitable for curing the thermosetting resin 2. Since the second mounting location of the lead frame 1 can be heated at high temperature, the control semiconductor element 3 and the power semiconductor element 15 can be bonded to the lead frame 1 in different ways within the same device without reducing the bonding strength. Can be joined using materials.

Further, by setting the inside of the chamber 18 to a reduced pressure state or a nitrogen atmosphere, the oxygen concentration inside the chamber 18 can be reduced, so that oxidation of the joint by the solder 11 and reduction of voids can be realized. This makes it possible to stabilize the bonding properties of the solder 11.

As described above, it is possible to reduce energy consumption when manufacturing semiconductor devices and improve the yield of semiconductor devices.

Moreover, since the conveyance rail 9 has a multi-stage structure arranged vertically, the distance from the conveyance start position by the conveyance rail 9 until it reaches the supply unit 10 can be increased. This makes it possible to secure the time necessary for the thermosetting resin 2 applied to the upper surface of the lead frame 1 to harden. Furthermore, by forming the transport rail 9 in multiple stages, it is possible to shorten the width of the semiconductor manufacturing apparatus.

Further, the method for manufacturing a semiconductor device according to the first embodiment includes a step of applying solder 11 to a second mounting location of lead frame 1 on which control semiconductor element 3 is mounted via thermosetting resin 2 before curing. (a), step (b) of mounting the power semiconductor element 15 on the second mounting location of the lead frame 1 via the solder 11, and heating the first mounting location of the lead frame 1 to coat the thermosetting resin 2. The process includes a step (c) of curing the solder 11 and heating the second mounting location of the lead frame 1 to perform soldering, and a step (d) of cooling the second mounting location of the lead frame 1 and hardening the solder 11. .

Therefore, since the control semiconductor element 3 and the power semiconductor element 15 can be bonded to the lead frame 1 using different bonding materials in the same device, the productivity of the semiconductor device including the work time required for manufacturing the semiconductor device can be increased. It becomes possible to improve the

<Embodiment 2>
Next, a semiconductor manufacturing apparatus according to a second embodiment will be described. FIG. 6 is a cross-sectional view showing the lead frame 1 set in the first heater block 24 included in the semiconductor manufacturing apparatus according to the second embodiment. Note that, in the second embodiment, the same components as those described in the first embodiment are given the same reference numerals, and a description thereof will be omitted.

As shown in FIG. 6, in the second embodiment, a plurality of discharge ports 26 are provided below the first heater blocks 24 other than the lowest stage. The plurality of exhaust ports 26 are connected to an intake pipe (not shown) and communicate with the outside of the chamber 18 via the intake pipe. The solvent contained in the thermosetting resin 2 before curing flows out when the thermosetting resin 2 is cured, and the flowing out solvent is discharged to the outside through the plurality of discharge ports 26. In addition, the shape of the discharge port 26 may be circular or rectangular.

Moreover, the discharge port 26 is not provided below the first heater block 24 at the lowest stage. This is because at the lowest stage, the distance from the transport start position by the transport rail 9 is short, so the thermosetting resin 2 is in an uncured state and the solvent of the thermosetting resin 2 does not flow out.

As described above, in the semiconductor manufacturing apparatus according to the second embodiment, the exhaust port 26 communicating with the outside of the chamber 18 is provided on the lower side of the first heater block 24. Therefore, it is possible to prevent the solvent of the thermosetting resin 2 that has flowed out into the chamber 18 from accumulating. Thereby, high quality bonding can be obtained within the semiconductor device.

Note that it is possible to freely combine each embodiment, or to modify or omit each embodiment as appropriate.

1 lead frame, 2 thermosetting resin, 3 control semiconductor element, 6 loader, 9 transport rail, 14 mounting section, 15 power semiconductor element, 16 cooling section, 17 unloader, 18 chamber, 24 first heater block, 25 Second heater block, 26 Discharge port.

Claims (4)

chamber and
a loader that transports a lead frame, on which a control semiconductor element is mounted at a first mounting location, into the chamber via a thermosetting resin before hardening;
an unloader for carrying out the lead frame from the chamber,
Inside the chamber,
a transport rail that transports the lead frame;
a mounting portion for mounting a power semiconductor element on a second mounting location other than the first mounting location on the lead frame via uncured solder;
a first heater block that is provided at a position opposite to the lower surface of the first mounting location of the lead frame on the transport rail, and that heats the first mounting location and hardens the thermosetting resin;
a second heater block that is provided at a position opposite to the lower surface of the second mounting location of the lead frame on the transport rail, and that heats and solders the second mounting location;
a cooling unit that cools the second mounting location of the lead frame and hardens the solder;
In the semiconductor manufacturing apparatus, the heating temperature of the first heater block is lower than the heating temperature of the second heater block. 2. The semiconductor manufacturing apparatus according to claim 1, wherein the transport rail has a multi-stage configuration arranged vertically. 3. The semiconductor manufacturing apparatus according to claim 1, wherein a discharge port communicating with the outside of the chamber is provided on a lower side of the first heater block. A method for manufacturing a semiconductor device using the semiconductor manufacturing apparatus according to any one of claims 1 to 3, comprising:
(a) applying the solder to the second mounting location of the lead frame on which the control semiconductor element is mounted via the thermosetting resin before hardening;
(b) mounting the power semiconductor element on the second mounting location of the lead frame via the solder;
(c) heating the first mounting location of the lead frame to cure the thermosetting resin, and heating and soldering the second mounting location of the lead frame;
(d) cooling the second mounting location of the lead frame to harden the solder;
A method for manufacturing a semiconductor device, comprising:

Images