JPWO2016125763A1 - Mounting apparatus and mounting method - Google Patents

Abstract

When a semiconductor chip having electrodes on both upper and lower surfaces is thermocompression bonded to a bonded object having an electrode on the upper surface with a thermosetting adhesive disposed on the lower surface of the semiconductor chip, an adverse effect due to outgas And providing a mounting apparatus and a mounting method that also ensure bonding quality. Specifically, using a temporary pressure-bonding head that sucks and holds the semiconductor chip, a temporary pressure-bonding portion that temporarily pressure-bonds onto the object to be bonded at a temperature at which no outgas is generated from the adhesive, Using the main pressure bonding head having a heating function and a pressure function, the temporarily bonded semiconductor chip is bonded to the electrode on the lower surface of the semiconductor chip and the electrode on the upper surface of the object to be bonded, and the adhesive is thermally cured. Provided are a mounting apparatus and a mounting method provided with a main press-bonding portion that is thermocompression bonded to the object to be bonded.

Description

  The present invention relates to a mounting apparatus and a mounting method. Specifically, the present invention relates to a mounting apparatus and a mounting method in which a semiconductor chip having electrodes on both upper and lower surfaces is thermocompression bonded to an object to be bonded having an electrode on the upper surface with an adhesive interposed therebetween.

  A flip chip method is known as a method for mounting a semiconductor chip on a substrate. In the flip chip method, the bump electrode of the semiconductor chip and the electrode of the substrate are bonded by thermocompression bonding using a flip chip bonder 50 as shown in FIG. The flip chip bonder 50 shown in FIG. 14 has a thermocompression bonding head 57 having a structure as shown in FIG. 15, and the semiconductor chip C sucked and held by reducing the pressure inside the suction hole 590 of the attachment 59 is heated by the heater 58. And has a function of thermocompression bonding to the substrate S0.

  In the flip chip method, the gap between the semiconductor chip and the substrate is sealed with resin in order to ensure the reliability of the joint. As a method of resin sealing, conventionally, a method of injecting a liquid resin into a gap after bonding and thermosetting was generally used, but an adhesive resin was disposed between the semiconductor chip and the substrate in an uncured state. Many methods for thermocompression bonding in the state have been proposed (for example, Patent Document 1).

  In the flip chip method performed in a state where an uncured resin as an adhesive is disposed between the semiconductor chip and the substrate, the electrodes can be bonded to each other and the resin can be sealed simultaneously. For this reason, it is also a method suitable for three-dimensional mounting in which semiconductor chips having electrodes on both upper and lower surfaces such as through electrodes are stacked.

JP 2004-315688 A

  Unlike a general semiconductor chip, a semiconductor chip having electrodes on both upper and lower surfaces such as a through electrode has a protrusion due to the electrode ET on the upper surface of the semiconductor chip C as shown in FIG. For this reason, when attracting and holding by the thermocompression bonding head 57 of the flip chip bonder 50, a gap is generated between the attachment 59 of the thermocompression bonding head 57 and the upper surface of the semiconductor chip C. Since this gap is small, it is possible to hold the semiconductor chip C having electrodes (ET, EB) on the upper and lower surfaces of the attachment. However, the air around the semiconductor chip C continues to enter the suction hole 590 in a reduced pressure state (FIG. 17).

  For this reason, when the semiconductor chip C having electrodes on both upper and lower surfaces is thermocompression-bonded to an object to be bonded S (wiring substrate or a semiconductor having electrodes on both upper and lower surfaces stacked on the wiring substrate) via the uncured resin R. Then, outgas G is generated from the resin by heating and is sucked into the inside 590 of the suction hole. The outgas G contains organic components and the like, and the outgas component adheres to the suction surface of the attachment 59 and the inside of the suction hole 590 in the process of entering the inside of the suction hole 590. The adhesion of the outgas component to the suction surface of the attachment 59 and the inside of the suction hole 590 is gradually accumulated by repeated thermocompression bonding, which contaminates the suction surface of the attachment 59 or clogs the suction hole 590, resulting in poor suction. Sometimes.

  Further, by repeating the heating, the attached outgas component becomes a carbide, and there is a concern that the carbide may fall onto the semiconductor chip C from the suction hole and cause a quality defect.

  Therefore, as shown in FIG. 18, in order to eliminate a gap between the upper surface of the semiconductor chip C and the suction surface of the attachment 59, a recess 592 that accommodates the electrode ET on the upper surface of the semiconductor chip C is formed on the suction surface of the attachment 59. It is conceivable to provide it.

However, if an attempt is made to provide a recess 592 that accommodates the electrode ET on the upper surface of the semiconductor chip C, the recess 592 becomes larger in volume than the electrode ET, so that a gap is formed between the recess 592 and the electrode ET. When such a gap is generated, heat transfer from the attachment 59 to the semiconductor chip C is obstructed in the concave portion 592, and the heating of the semiconductor chip C becomes insufficient. In particular, in a semiconductor chip using penetrating electrodes for both upper and lower electrodes, heating of the lower electrode becomes insufficient, which causes a bonding failure. In addition, when the pressure is large, a shear stress TA (FIG. 19) is generated around the recess 592 to damage the semiconductor chip, which is not preferable.

  On the other hand, if the attachment surface of the attachment 59 is flat, heat and load are applied only to the electrode ET protruding from the upper surface of the semiconductor chip C, so that the fluidity of the uncured resin R below the semiconductor chip C decreases, and the semiconductor Resin bites between the electrodes of the chip C and the object to be bonded S, or voids are generated, causing a bonding failure.

  In addition, a method of heating after stopping the adsorption before reaching the temperature at which the outgas G is generated and preventing the outgas component from flowing into the adsorption hole 590 is conceivable, but the differential pressure between the inside and the outside of the adsorption hole 590 is also conceivable. Therefore, there is a concern that the position of the semiconductor chip C may be shifted due to the flow of the resin during heating. Further, if the heating start is delayed, the tact time becomes longer and the productivity is lowered.

  The present invention has been made in view of the above problems. A semiconductor chip having electrodes on both upper and lower surfaces is disposed on the lower side of the semiconductor chip, and an adhesive is interposed in an object to be bonded having electrodes on the upper surface. The present invention provides a mounting apparatus and a mounting method that are free from the adverse effects of outgassing and ensure bonding quality when thermocompression bonding is performed.

In order to solve the above problems, the invention described in claim 1
A mounting device for thermocompression bonding a semiconductor chip having electrodes on both upper and lower surfaces to a bonded object having an electrode on an upper surface thereof via a thermosetting adhesive, which is disposed on the lower side of the semiconductor chip,
Using a temporary pressure-bonding head that sucks and holds the semiconductor chip, a temporary pressure-bonding portion that temporarily pressure-bonds onto the object to be bonded at a temperature at which no outgas is generated from the adhesive;
The semiconductor chip temporarily bonded onto the object to be bonded is bonded to the electrode on the lower surface of the semiconductor chip and the electrode on the upper surface of the object to be bonded using a main pressure bonding head having a heating function and a pressure function. It is characterized by comprising a main press-bonding portion for heat-curing the agent and finally press-bonding to the object to be joined.

The invention described in claim 2
The mounting apparatus according to claim 1,
A resin sheet supply mechanism is provided for supplying a resin sheet between the main pressure bonding head and the semiconductor chip temporarily bonded to the workpiece.

The invention according to claim 3
The mounting apparatus according to claim 2,
The electrode on the upper surface of the temporarily bonded semiconductor chip is embedded in the resin sheet and then finally bonded.

The invention according to claim 4
The mounting apparatus according to claim 2 or 3, wherein
In the state where the resin sheet is brought into close contact with the surface of the main press-bonding head after the main press-bonding, the invention according to claim 5,
The mounting apparatus according to claim 4,
A moving means for separating the main pressure-bonding head and the resin sheet is provided.

The invention described in claim 6
The mounting apparatus according to any one of claims 1 to 5,
The surface of the temporary crimping head for sucking and holding the semiconductor chip has a recess for accommodating the electrode on the upper surface of the semiconductor chip.

The invention described in claim 7
The mounting apparatus according to any one of claims 1 to 6,
As a temperature at which no outgas is generated from the adhesive, a temperature lower than a curing start temperature of the adhesive is set.

The invention according to claim 8 provides:
A mounting method in which a semiconductor chip having electrodes on both upper and lower surfaces is thermocompression bonded to a bonded object having an electrode on an upper surface thereof via a thermosetting adhesive, disposed on the lower side of the semiconductor chip,
Using a temporary pressure bonding head for adsorbing and holding the semiconductor chip, a temporary pressure bonding step of temporarily pressure bonding on the object to be bonded at a temperature at which no outgas is generated from the adhesive;
The semiconductor chip temporarily bonded onto the object to be bonded is bonded to the electrode on the lower surface of the semiconductor chip and the electrode on the upper surface of the object to be bonded using a main pressure bonding head having a heating function and a pressure function. It is characterized by comprising a main press-bonding step of thermosetting the agent and thermocompression-bonding to the object to be joined.

The invention according to claim 9 is:
The mounting method according to claim 8,
It has the process of supplying a resin sheet between the said semiconductor chip temporarily crimped | bonded to the said crimping | compression-bonding head and the said to-be-joined object.

The invention according to claim 10 is:
The mounting method according to claim 9, comprising:
Before the final press-bonding step, the electrode on the upper surface of the semiconductor chip that has been temporarily press-bonded is embedded in the resin sheet and then subjected to the main press-bonding.

The invention according to claim 11
The mounting method according to claim 9 or 10, wherein:
After the main press bonding step, the resin sheet is separated from the semiconductor chip in a state where the resin sheet is in close contact with the surface of the main press bonding head.

The invention according to claim 12
The mounting method according to claim 11,
The resin sheet is separated from the main pressure bonding head after the resin sheet is separated from the semiconductor chip.

The invention according to claim 13
The mounting method according to any one of claims 8 to 12,
A temporary pressure bonding is performed in a state in which the electrodes on the upper surface of the semiconductor chip are accommodated using a temporary pressure bonding head in which a recess for accommodating the electrodes on the upper surface of the semiconductor chip is formed on the surface for sucking and holding the semiconductor chip. To do.

The invention according to claim 14
The mounting method according to any one of claims 8 to 13,
As a temperature at which no outgas is generated from the adhesive, a temperature lower than a curing start temperature of the adhesive is set.

  According to the present invention, outgassing occurs when a semiconductor chip having electrodes on both upper and lower surfaces is thermocompression bonded to an object to be bonded having an electrode on the upper surface with an adhesive interposed therebetween. In this state, the semiconductor chip is temporarily fixed on the object to be bonded and then heated to a temperature above which the outgas is generated without the need to hold the semiconductor chip by adsorption. .

It is a figure which shows the whole structure of the mounting apparatus which concerns on 1st embodiment of this invention. It is a figure explaining the semiconductor chip and to-be-joined object made into object by this invention. It is a figure which shows the structure of the temporary crimping | compression-bonding head of the mounting apparatus which concerns on 1st embodiment of this invention. (A) It is a figure explaining the state which the temporary crimping | compression-bonding head of the mounting apparatus which concerns on 1st embodiment of this invention adsorb | sucks a semiconductor chip. (B) Temporary crimping | compression-bonding of the mounting apparatus which concerns on 1st embodiment of this invention. It is a figure which shows the state which has adsorb | sucked the semiconductor chip with the modification of a head. It is a figure which shows the structure of this crimping | compression-bonding head of the mounting apparatus which concerns on 1st embodiment of this invention. It is a figure which shows the control structure of the mounting apparatus which concerns on 1st embodiment of this invention. It is a figure which shows the relationship between the temperature of NCF used for the mounting process which concerns on 1st embodiment of this invention, and a viscosity with a graph. (A) It is a figure which shows the state by which a semiconductor chip is adjoined to a to-be-joined object in the temporary crimping process of the mounting apparatus which concerns on 1st embodiment of this invention. (B) Similarly, the lower surface electrode of a semiconductor chip is covered in a temporary crimping process. It is a figure which shows the state which contacted NCF provided in the to-be-joined object (C). It is a figure which shows the state which temporarily fixed the semiconductor chip to the to-be-joined object in the same temporary crimping process. (A) It is a figure which shows the state which the attachment for main crimping | compression-bonding of this crimping | compression-bonding head and a resin sheet approach the semiconductor chip temporarily fixed on the to-be-joined object in the final crimping | compression-bonding process of the mounting apparatus which concerns on 1st embodiment of this invention. FIG. 5B is a diagram showing a state in which the main crimping attachment and the resin sheet are in contact with the semiconductor chip in the final crimping step. FIG. 8C is a diagram in which the electrode on the upper surface of the semiconductor chip is embedded in the resin sheet in the final crimping step. (D) It is a figure which similarly shows the state by which the semiconductor chip was heat-pressed in this crimping | compression-bonding process. (A) It is a figure which shows the state by which the thermocompression bonding was completed in the main press-bonding process of the mounting apparatus which concerns on 1st embodiment of this invention. (B) Similarly, after the main press-bonding process, the main press-fit attachment and the resin sheet are above the semiconductor chip. It is a figure which shows the state which moved to (c) It is a figure which shows the state which spaced apart the resin sheet from the attachment for final press bonding similarly after a final press bonding process. (A) It is an image figure where the electrode of the semiconductor chip was buried in the resin sheet. (B) It is a figure showing an example where the electrode of the semiconductor chip is buried in the resin sheet. It is a figure which shows the whole structure of the mounting apparatus which concerns on 2nd embodiment of this invention. (A) It is a figure which shows the state which the attachment for main press-bonding of this press-fit head approaches the semiconductor chip temporarily fixed on the to-be-joined object in the main press-bonding process of the mounting apparatus which concerns on 2nd embodiment of this invention. ) Similarly, in the final crimping step, the final crimping attachment is in contact with the semiconductor chip. It is a figure which shows the structure of the conventional flip chip bonder. It is a figure which shows the state which the thermocompression-bonding head of the conventional flip chip bonder hold | maintains the semiconductor chip which has an electrode only in the lower surface. It is a figure which shows the state which the thermocompression-bonding head of the conventional flip chip bonder hold | maintains the semiconductor chip which has an electrode on both upper and lower surfaces. It is a figure explaining the outgas generate | occur | produced when the semiconductor chip which has an electrode on both upper and lower surfaces is thermocompression-bonded with the conventional flip chip bonder. It is a figure which shows the state which provided the recessed part in the attachment of a thermocompression-bonding head with the conventional flip chip bonder, and hold | maintained the semiconductor chip which has an electrode on both upper and lower surfaces. It is a figure explaining the problem which arises when providing the recessed part in the attachment of the conventional flip chip bonder thermocompression bonding head, and carrying out the thermocompression bonding of the semiconductor chip which has an electrode on both upper and lower surfaces.

Embodiments of the present invention will be described with reference to the drawings.
First, the mounting apparatus 1 which is one embodiment according to the present invention shown in FIG. 1 will be described. In the following description, the direction in which the workpiece S is transported from the temporary crimping portion 2 to the final crimping portion 12 is the X-axis direction, the Y-axis direction orthogonal thereto, The movement direction perpendicular to S will be described as the Z-axis direction, and the direction of rotation about the Z-axis will be described as the θ direction.

  The semiconductor chip C mounted by the mounting apparatus 1 has electrodes on both upper and lower surfaces by through electrodes as shown in FIG. 2, and the lower electrode EB is a solder bump having a solder BS at the tip. The electrode ET also protrudes from the upper surface by about several μm. The object to be bonded S is obtained by stacking a semiconductor chip C on a substrate S0 as shown in FIG. 2A or a wiring substrate S0 as shown in FIG. In the present embodiment, a non-conductive film (hereinafter referred to as “NCF”) mainly composed of a thermosetting resin is used as an adhesive for bonding the semiconductor chip C and the article S to be bonded. The NCF is attached to the surface of the article to be bonded S, but is not limited to this, and may be attached to the lower surface of the semiconductor chip C. Further, a non-conductive paste (hereinafter referred to as “NCP”) mainly composed of a thermosetting resin may be used as an adhesive.

  A mounting apparatus 1 shown in FIG. 1 mounts a semiconductor chip C on a workpiece S. The mounting apparatus 1 includes a provisional pressure bonding unit 2, a main pressure bonding unit 12, a transport mechanism 21 (see FIG. 6), and a control unit 23 (see FIG. 6).

  The temporary press-bonding portion 2 is for temporarily fixing the semiconductor chip C by temporarily press-bonding the semiconductor chip C to the article S to be bonded using NCF as an adhesive. The temporary pressure bonding unit 2 includes a temporary pressure bonding base 3, a temporary pressure bonding stage 4, a support frame 5, a temporary pressure bonding unit 6, a temporary pressure bonding head 7, and a temporary pressure bonding image recognition device 10.

  The temporary press bonding base 3 is a main structure constituting the temporary press bonding portion 2. The temporary pressure bonding base 3 supports a temporary pressure bonding stage 4 and a support frame 5.

  The temporary press-bonding stage 4 is to be moved to an arbitrary position while holding the workpiece S. The temporary press-bonding stage 4 is configured by attaching a suction table 4b capable of sucking and holding the workpiece S to the drive unit 4a. The temporary press-bonding stage 4 is attached to the temporary press-bonding base 3, and is configured so that the suction table 4b can be moved in the X-axis direction and the Y-axis direction by the drive unit 4a. That is, the temporary press-bonding stage 4 is configured to be able to move the workpiece S sucked by the suction table 4b on the temporary press-bonding base 3 in the X-axis direction and the Y-axis direction. In the present embodiment, the temporary press-bonding stage 4 holds the workpiece S by suction, but is not limited thereto.

  The support frame 5 supports the temporary pressure bonding unit 6. The support frame 5 is configured to extend in the Z-axis direction from the vicinity of the temporary pressure bonding stage 4 of the temporary pressure bonding base 3.

  The temporary pressure bonding unit 6 which is a temporary pressure unit moves the temporary pressure bonding head 7 in the Z-axis direction and the θ direction. The temporary pressure bonding unit 6 includes a servo motor and a ball screw (not shown). The temporary pressure bonding unit 6 is configured to generate a driving force in the axial direction of the ball screw by rotating the ball screw by a servo motor. The temporary press-bonding unit 6 is configured to generate a driving force (pressing force) in the Z-axis direction in which the axial direction of the ball screw is perpendicular to the workpiece S. The temporary press-bonding unit 6 is configured such that a temporary pressure load Ft that is a pressurizing force in the Z-axis direction can be arbitrarily set by controlling the output of the servo motor. In the present embodiment, the provisional pressure bonding unit 6 has a configuration of a servo motor and a ball screw, but is not limited to this, and may be configured of a pneumatic actuator, a hydraulic actuator, or a voice coil motor. .

  The temporary pressure bonding head 7 sucks and holds the semiconductor chip C and transmits the driving force of the temporary pressure bonding unit 6 to the semiconductor chip C. The temporary pressure bonding head 7 is attached to a ball screw nut (not shown) that constitutes the temporary pressure bonding unit 6. Further, the temporary pressure bonding unit 6 is disposed so as to face the temporary pressure bonding stage 4. The temporary press-bonding head 7 is moved in the Z direction by the temporary press-bonding unit 6 so as to be close to the temporary press-bonding stage 4. The structure of the temporary pressure bonding head 7 is shown in FIG. 3, and the temporary pressure bonding head 7 is provided with a temporary pressure bonding heater 8 and a temporary pressure bonding attachment 9.

  The provisional pressure bonding heater 8 shown in FIG. 3 is for heating the semiconductor chip C, and is composed of a cartridge heater. However, the present invention is not limited to the cartridge heater, and any material that can heat the semiconductor chip C, such as a rubber heater, may be used. In addition, the temporary pressure bonding heater 8 is incorporated in the temporary pressure bonding head 7, but is not limited to this. The temporary pressure bonding heater 8 is incorporated in the temporary pressure bonding stage 4, and is connected to the object S from the temporary pressure bonding stage 4 side. The NCF may be heated. Furthermore, it is good also as a structure which incorporated the heater in both the temporary crimping head 7 and the stage 4 for temporary crimping.

  The temporary crimping attachment 9 holds the semiconductor chip C. The temporary crimping attachment 9 is provided on the temporary crimping head 7 so as to face the temporary crimping stage 4. The temporary crimping attachment 9 is configured to be able to suck and hold the semiconductor chip C while positioning it. The temporary crimping attachment 9 is configured to be heated by the temporary crimping heater 8. That is, the temporary crimping attachment 9 is configured to position and hold the semiconductor chip C and to heat the semiconductor chip C by heat transfer from the temporary crimping heater 8. The temporary pressure bonding attachment 9 is provided with a suction hole 90 for sucking the semiconductor chip C, and the suction hole 90 communicates with the decompression system 91. By operating the decompression system 91, the inside of the suction hole 90 is decompressed, and the temporary crimping attachment 9 sucks and holds the semiconductor chip C. Here, although only one suction hole 90 is shown in FIG. 3, the present invention is not limited to this, and there may be a plurality of suction holes 90, which may be increased according to the size of the semiconductor chip C to be sucked.

  Since the suction hole 90 is provided at a position avoiding the electrode ET protruding from the upper surface of the semiconductor chip C, it is possible to apply a load to the entire top of the head of the electrode ET, so that a sufficient force is applied to the electrode EB on the lower surface of the semiconductor chip C. be able to.

  Note that the planar shape of the portion other than the suction hole 90 of the temporary crimping attachment 9 is held by a pressure difference generated between the upper surface and the lower surface of the semiconductor chip C as shown in FIG. However, as shown in FIG. 4B, a recess 92 that accommodates the electrode ET on the upper surface of the semiconductor chip C may be formed. When the concave portion 92 is formed as shown in FIG. 4B, the upper surface of the semiconductor chip C is brought into close contact with the surface of the temporary press-bonding attachment 9, so that the possibility of the lateral displacement of the adsorbed semiconductor chip C is reduced. In addition, since the high temperature required for solder melting and NCF curing and the pressure exceeding the viscosity at the time of NCF curing are not required in the temporary crimping process, even if the recess 92 is provided in the temporary crimping attachment 9, the semiconductor chip C There is no problem of insufficient heating or damage due to shear stress.

  By the way, even if NCF protrudes from between the semiconductor chip C and the article to be bonded S by making the outer peripheral size of the surface for adsorbing the semiconductor chip C of the temporary crimping attachment 9 smaller than the size of the semiconductor chip C, The problem of adhering to the temporary crimping attachment 9 does not occur. Each side of the temporary crimping attachment 9 is desirably about 0.1 mm to 0.5 mm smaller than each side of the semiconductor chip C.

  The temporary press-bonding image recognition apparatus 10 acquires position information of the semiconductor chip C and the article S to be bonded by using an image. The temporary pressure bonding image recognition apparatus 10 includes an alignment mark on the upper surface of the workpiece S held on the temporary pressure bonding stage 4 and an alignment mark on the lower surface of the semiconductor chip C held on the temporary pressure bonding attachment 9. It is configured to recognize the image and acquire positional information of the object to be bonded S and the semiconductor chip C. The alignment mark of the object to be bonded S is the alignment mark written on the wiring substrate S0 when the object to be bonded S is only the wiring substrate S0, and the object to be bonded S is a semiconductor chip on the wiring substrate S0. When C is stacked, the alignment mark written on the wiring board S0 or the alignment mark of the stacked uppermost semiconductor chip C is used.

  The main crimping portion 12 shown in FIG. 1 joins the electrode on the lower surface of the semiconductor chip C and the electrode on the upper surface of the workpiece S by welding of solder and thermally cures the NCF to place the semiconductor chip C on the workpiece S. It is to be fixed. The main crimping portion 12 includes a main crimping base 13, a main crimping stage 14, a support frame 15, a main crimping unit 16, a main crimping head 17, and a main crimping image recognition device 20.

  The main press bonding base 13 is a main structure constituting the main press bonding portion 12. The base for pressure bonding 13 is configured to have sufficient rigidity. The main press bonding base 13 supports a main press bonding stage 14 and a support frame 15.

  The main crimping stage 14 is to move the workpiece S to an arbitrary position while holding the workpiece S. The main crimping stage 14 is configured by attaching a suction table 14b capable of sucking and holding the workpiece S to the drive unit 14a. The main press-bonding stage 14 is attached to the main press-bonding base 13 and is configured so that the suction table 14b can be moved in the X-axis direction, the Y-axis direction, and the θ-direction by the drive unit 14a. That is, the main press-bonding stage 14 is configured to be able to move the workpiece S sucked by the suction table 14b on the main press-bonding base 13 in the X-axis direction, the Y-axis direction, and the θ-axis direction. In the present embodiment, the final press-bonding stage 14 holds the workpiece S by suction, but is not limited to this.

  The support frame 15 supports the main crimping unit 16. The support frame 15 is configured to extend in the Z-axis direction from the vicinity of the main pressure bonding stage 14 of the main pressure bonding base 13.

  The main pressure bonding unit 16 that is a pressure unit moves the main pressure bonding head 17. The main crimping unit 16 includes a servo motor and a ball screw (not shown). The main crimping unit 16 is configured to generate a driving force in the axial direction of the ball screw by rotating the ball screw with a servo motor. The main crimping unit 16 is attached to the support frame 15 so that the axial direction of the ball screw is in the Z-axis direction perpendicular to the workpiece S. That is, the main crimping unit 16 is configured to generate a driving force (pressing force) in the Z-axis direction. The main crimping unit 16 is configured such that a main pressure load Fp, which is a pressing force in the Z-axis direction, can be arbitrarily set by controlling the output of the servo motor. In the present embodiment, the main pressure bonding unit 16 has a servo motor and a ball screw. However, the present invention is not limited thereto, and may be a pneumatic actuator, a hydraulic actuator, or a voice coil motor. . The pressurizing force of the main crimping unit 16 is controlled so as to be variable according to the number of electrodes of the semiconductor chip C and the contact area between the electrodes with the workpiece S.

  The main pressure bonding head 17 transmits the driving force of the main pressure bonding unit 16 to the semiconductor chip C. The main crimping head 17 is attached to a ball screw nut (not shown) constituting the main crimping unit 16. That is, the main crimping unit 16 is disposed so as to face the final crimping stage. That is, the main press-bonding head 17 is moved in the Z-axis direction by the main press-bonding unit 16 and thereby comes close to the main press-bonding stage 14. The configuration of the main pressure bonding head 17 is shown in FIG. 5, and the main pressure bonding head 17 is provided with a main pressure bonding heater 18 and a main pressure bonding attachment 19.

  The resin sheet supply mechanism 22 includes the resin sheet unwinding portion 22S and the resin sheet unwinding portion 22R as components, and the tape-shaped resin sheet P wound around the resin sheet unwinding portion 22S is attached to the main pressure bonding attachment 19 and the semiconductor chip. After being supplied during C, it is taken up by the resin sheet take-up portion 22R. In addition to the resin sheet unwinding part 22S and the resin sheet winding part 22R, the resin sheet supply mechanism 22 may include a guide roll for stably transporting the resin sheet P. Here, as the resin sheet P, a material having flexibility, excellent heat resistance, and excellent adhesion to a semiconductor chip is preferable. Polytetrafluoroethylene (PTFE) is used as a material having this characteristic. ), A fluororesin such as tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA) is preferred. The thickness is preferably about 20 to 50 μm considering the thermal conductivity to the semiconductor chip while maintaining the mechanical strength.

  The main press heater 18 shown in FIG. 5 is for heating the semiconductor chip C. The main crimping heater 18 is composed of a cartridge heater and is incorporated in the main crimping head 17. In the present embodiment, the main crimping heater 18 is composed of a cartridge heater, but is not limited to this, and can heat the semiconductor chip C to a predetermined temperature, such as a ceramic heater or a rubber heater. I just need it.

  The main pressure bonding attachment 19 presses the semiconductor chip C through the resin sheet P. The main pressure bonding attachment 19 is provided on the main pressure bonding head 17 so as to face the main pressure bonding stage 14. Further, the main crimping attachment 19 is configured to be heated by the main crimping heater 18. That is, the main crimping attachment 19 is configured to be heated by heat transfer from the main crimping heater 18 at the same time as the semiconductor chip C is pressurized. Unlike the provisional pressure bonding attachment 9, the main pressure bonding attachment 19 does not need to suck and hold the semiconductor chip C, and therefore may not have a suction hole.

  Since the resin sheet P prevents the NCF from sticking out of the semiconductor chip C during the main bonding, it does not adhere to the main bonding attachment 19, so that the main bonding attachment 19 has a larger outer peripheral size than the semiconductor chip C. Can do. Therefore, heat can be transmitted to the entire surface of the semiconductor chip C, the NCF fillet shape protruding from the outer periphery of the semiconductor chip C can be stabilized, and the bonding strength can be increased. Further, by making the outer peripheral size of the surface to which the semiconductor chip C is pressure-bonded smaller than the mounting pitch size, it is possible to perform the main pressure bonding while suppressing interference between adjacent semiconductor chips C. In addition, it is preferable to use a material having a thermal conductivity of 50 W / mK or more for the main body attachment 19 for efficiently transferring heat.

  The main crimp attachment 19 is preferably inexpensive if it is separated from the main crimp heater 18 and can be attached to and detached from it.

  The main image-recognition apparatus 20 for pressure bonding acquires position information between the semiconductor chip C and the object S to be bonded by an image. The image bonding apparatus 20 for press bonding recognizes an image of the alignment mark on the upper surface of the wiring board S0 constituting the object to be bonded S and the alignment mark on the upper surface of the semiconductor chip C temporarily fixed to the object to be bonded S, The position information of the article to be bonded S and the semiconductor chip C is obtained.

  The transport mechanism 21 delivers the workpiece S between the temporary press-bonding portion 2 and the main press-bonding portion 12. The transport mechanism 21 is configured to be able to transport the article S to which the semiconductor chip C is temporarily press-bonded by the pre-bonding stage 4 of the temporary press-bonding section 2 to the final press-bonding stage 14 of the main press-bonding section 12.

  The transport mechanism 21 may have a function of rotating the workpiece S in the θ direction. By doing so, a mechanism for rotating the main crimping portion 12 in the θ direction becomes unnecessary, and by making a mechanism that moves only in the X direction and the Y-axis direction, a highly rigid main crimping stage 14 can be obtained. It can receive a high load and can be used for mounting a semiconductor chip C having a large number of electrodes.

  As shown in FIG. 6, the control unit 23 controls the temporary crimping unit 2, the final crimping unit 12, the transport mechanism 21, and the like. Specifically, the control unit 23 may have a configuration in which a CPU, a ROM, a RAM, an HDD, and the like are connected by a bus, or may be configured by a one-chip LSI or the like. The control unit 23 stores various programs and data for controlling the temporary crimping unit 2, the main crimping unit 12, the transport mechanism 21, and the like.

  The control unit 23 is connected to the temporary crimping stage 4 and the final crimping stage 14 and controls the movement amounts of the temporary crimping stage 4 and the final crimping stage 14 in the X-axis direction, the Y-axis direction, and the θ-axis direction, respectively. can do.

  The control unit 23 is connected to the resin sheet supply mechanism 22 and can control the conveyance of the resin sheet P immediately below the main pressure bonding attachment 19.

  The control unit 23 is connected to the temporary pressure bonding heater 8 and the main pressure bonding heater 18, and can control the temperatures of the temporary pressure bonding heater 8 and the main pressure bonding heater 18, respectively. In particular, the control unit 23 can maintain the average temperature at the time of pressurization of the main pressure bonding head 17 within a certain range including a temperature not lower than the NCF curing start temperature (reference temperature Ts described later) and not lower than the melting point of the solder. .

  The control unit 23 is connected to the temporary pressure bonding unit 6 and the main pressure bonding unit 16 and can control the applied pressure in the Z-axis direction of the temporary pressure bonding unit 6 and the main pressure bonding unit 16.

  The control unit 23 is connected to a decompression system 91 that communicates with the suction hole 90 of the temporary crimping attachment 9, and can control the suction state of the temporary crimping attachment 9.

  The control unit 23 is connected to the temporary pressure-bonding image recognition device 10 and the main pressure-bonding image recognition device 20, and controls the temporary pressure-bonding image recognition device 10 and the main pressure-bonding image recognition device 20, respectively. Position information with the bonded object S can be acquired.

  The control unit 23 is connected to the transport mechanism 21 and can control the transport mechanism 21.

  Hereinafter, the temporary crimping process and the final crimping process of the mounting apparatus 1 according to the present invention will be described with reference to FIGS. 7 to 9. First, the characteristics of the NCF will be described.

  As shown in FIG. 7, the viscosity of NCF varies depending on its temperature. Specifically, NCF composed mainly of a thermosetting resin does not cure in the temperature range below the reference temperature Ts, which is the curing start temperature determined from the resin characteristics, and reversibly increases with temperature. The viscosity is lowered. On the other hand, NCF is hardened in a temperature range equal to or higher than the reference temperature Ts, and irreversibly exhibits a property that its viscosity increases as the temperature rises. Further, outgas is hardly generated at a temperature lower than the reference temperature Ts, but outgas is easily generated when the temperature is higher than the reference temperature Ts.

  The mounting apparatus 1 heats the semiconductor chip C sucked and held on the temporary pressure bonding attachment 9 of the temporary pressure bonding portion 2 to a predetermined temporary pressure temperature Tt by the temporary pressure bonding heater 8 in the temporary pressure bonding process. Here, the temporary pressure temperature Tt is set lower than the reference temperature Ts in order not to cure the NCF and to generate no outgas. On the other hand, if the temporary pressure temperature Tt is too low, the viscosity of the NCF is high, so that it is difficult to temporarily fix the semiconductor chip C to the workpiece S. For this reason, it is not preferable that the difference between the reference temperature Ts and the temporary pressure temperature Tt exceeds 40 ° C. That is, the difference between the reference temperature Ts and the preliminary pressure temperature Tt is preferably greater than 0 ° C. and less than 40 ° C., and more preferably set to 10 ° C. or more and 30 ° C. or less. The specific set value varies depending on the NCF composition, but if Tt is 120 ° C. or less, almost no outgas is generated, and more preferably 100 ° C. or less.

  As shown in FIG. 8A, the mounting apparatus 1 moves the semiconductor chip C heated to the temporary pressure temperature Tt toward the article to be bonded S in the Z-axis direction by the temporary pressure bonding unit 6. As shown in FIG. 8B, the electrode on the lower surface of the semiconductor chip C moved toward the workpiece S comes into contact with the NCF attached to the workpiece S. In the semiconductor chip C, the provisional pressure load Ft is applied in the Z-axis direction from the provisional pressure bonding unit 6 because the lower surface electrode EB is in contact with the NCF.

  The semiconductor chip C is heated by the temporary pressure bonding heater 8, so that the viscosity of the NCF in contact with the electrode EB on the lower surface of the semiconductor chip C (and the lower surface of the semiconductor chip C) is lowered. Pressurized. Then, the NCF is deformed by the pressurizing load Ft. At this time, a reaction force due to the viscous resistance of NCF is generated in the semiconductor chip C against the temporary pressure load Ft. The reaction force due to the viscous resistance of the NCF generated in the semiconductor chip C increases according to the deformation amount of the NCF sandwiched between the workpiece S and the semiconductor chip C. For this reason, when the semiconductor chip C pressurized with the temporary pressure load Ft reaches the deformation amount of the NCF that generates a reaction force due to the viscous resistance balanced with the temporary pressure load Ft, the position in the Z-axis direction is determined (FIG. 8C )).

  That is, the position of the semiconductor chip C in the Z-axis direction in the temporary pressure bonding step is determined by the temporary pressure load Ft and the viscosity of the NCF. Therefore, the mounting apparatus 1 uses the provisional pressure bonding unit 2 to adjust the electrode ES of the workpiece S and the semiconductor chip C according to the provisional pressure load Ft by the provisional pressure bonding unit 6 and the temperature of the provisional pressure bonding heater 8 for setting the viscosity of NCF. The distance from the lower surface electrode EB can be adjusted to a predetermined range.

  In this process, the temporary pressure temperature Tt is lower than the reference temperature Ts in FIG. For this reason, an outgas component does not adhere to the surface of the attachment 9 for temporary pressure bonding or the inside of the suction hole 90.

  Next, the main crimping process of the mounting apparatus 1 according to the present invention will be described. As shown in FIG. 9, the mounting apparatus 1 is used for the main crimping via the resin sheet P by the main crimping unit 16 in the final crimping process. The attachment 19 is brought into contact with the top of the electrode ET protruding from the upper surface of the semiconductor chip C temporarily fixed to the workpiece S (FIGS. 9A and 9B). Next, the electrode ET is pushed in until it is buried in the resin sheet P (FIG. 9C). The semiconductor chip C is heated to a predetermined main pressure temperature Tp over the entire surface of the semiconductor chip C by the main pressing heater 18 via the main pressing attachment 19 and the resin sheet P. As a result, the heat of the heated semiconductor chip C is transmitted to the electrodes EB and NCF on the lower surface of the semiconductor chip C, and is heated to substantially the same main pressure temperature TP as the semiconductor chip C, including the solder BS at the tip of the electrode EB. The Here, the main pressure temperature Tp is set within a certain range not less than the reference temperature Ts and not less than the melting point of the solder BS. That is, the mounting apparatus 1 controls the temperature of the main crimping heater 18 so that the NCF becomes a predetermined main pressure viscosity (hardness) in the temperature range where the NCF is cured, and the solder BS is melted.

  The mounting apparatus 1 pressurizes the semiconductor chip C heated to the main pressure temperature Tp by the main pressure bonding unit 16 with the main pressure load Fp in the Z-axis direction. The semiconductor chip C is pressed toward the object to be bonded S by the main pressure bonding unit 16 so as to be close to each other so as to eliminate a gap between the electrode EB on the lower surface of the semiconductor chip C and the electrode ES on the upper surface of the object to be bonded S ( FIG. 9 (d)).

  At this time, since the NCF is heated to the reference temperature TS or higher, curing begins and outgas is generated. However, the main-bonding attachment 19 does not need to adsorb the semiconductor chip C. Therefore, the outgas is not drawn into the gap between the upper surface of the semiconductor chip C and the main-bonding attachment 19, and the outgas is not absorbed into the semiconductor chip. It hardly adheres to the upper surface of C or the surface of the main-bonding attachment 19.

  When the thermocompression bonding in the main pressure bonding step is completed (FIG. 10A), the main pressure bonding attachment 19 rises together with the resin sheet P (FIG. 10B). Since the resin sheet P is in a state in which the protruding electrode ET on the upper surface of the semiconductor chip C is buried after the main pressure bonding, when only the main pressure bonding attachment 19 is raised, the resin sheet P is cooled and cannot be separated from the electrode ET due to shrinkage. Therefore, it is desirable to raise it in close contact with the main crimp attachment 19. Thereafter, the resin sheet P is separated from the surface of the main pressure bonding attachment 19 (FIG. 10C). By separating the resin sheet P from the surface of the main press attachment 19, the resin sheet supply mechanism 22 can easily carry the resin sheet P. The main crimping section 12 includes a moving means (not shown) that moves the relative distance in the Z-axis direction between the main crimping unit 16 and the resin sheet supply mechanism 22, and the resin sheet P and the main crimp attachment 19 are moved by the moving means. The approach and the separation are performed.

  9C, 9D, and 10A, the state in which the electrode ET is buried in the resin sheet P is shown in an image diagram as shown in FIG. As shown in FIG. 11B, a gap PV is formed around the electrode ET. However, since the resin sheet P is in close contact with the upper surface of the semiconductor chip C around the gap PV, the heat of the crimp heater 18 is transmitted to the semiconductor chip C through the attachment 19 and the resin sheet P.

  Below, the mounting apparatus 30 which concerns on 2nd embodiment of this invention is demonstrated using FIG. In the following embodiments, the same points as those of the above-described embodiments will not be specifically described, and different portions will be mainly described.

  The mounting apparatus 30 in FIG. 12 is the same as the mounting apparatus 1 in that the semiconductor chip C is temporarily fixed to the object to be bonded S one by one in the temporary pressure bonding part 2, but the object to be bonded S in the main pressure bonding part 32. And a plurality of semiconductor chips C temporarily fixed to each other. The main crimping section 32 of the mounting device 30 includes a main crimping base 33, a main crimping stage 34, a support frame 35, a main crimping unit 36, a main crimping head 37, and a main crimping image recognition device 40. It has the same configuration and function as the main crimping part 12 of the mounting apparatus 1. In addition, the main pressure bonding head 37 is provided with a main pressure bonding heater 38 and a main pressure bonding attachment 39. Further, although not shown, a resin sheet supply mechanism for supplying the resin sheet P between the pressure bonding surface of the main pressure bonding attachment 39 and the semiconductor chip C is also included as a constituent element. As shown in FIG. 13A, the main pressure bonding attachment 39 is configured to be divided in units of the semiconductor chip C. Further, even if there are variations in the thickness of the object to be bonded S and the semiconductor chip C, the elastic body 39a is provided between the main pressure bonding heater 38 and the main pressure bonding attachment 39 in order to equalize the pressure applied to the plurality of semiconductor chips C. Is sandwiched.

  The main press bonding part 32 may have a configuration in which a plurality of main press bonding heads that perform main press bonding for each chip are arranged as long as a plurality of temporarily bonded semiconductor chips C are subjected to thermocompression bonding at the same timing.

  In the final crimping of the semiconductor chip C at the final crimping portion 32 of the mounting apparatus 30, the final crimping attachment 39 is temporarily attached to the workpiece S via the resin sheet P in the same manner as the main crimping section 12 of the mounting apparatus 1. It is made to contact | abut to the top part of the electrode ET which protruded on the upper surface of the fixed semiconductor chip C (FIG. 13 (a), FIG.13 (b)). Next, the electrode ET is pushed in until it is buried in the resin sheet P (FIG. 13C), and then heated to the main pressure temperature Tp.

  Generally, the time required for the main pressure bonding process is longer than that for the temporary pressure bonding process. For this reason, in the mounting apparatus 30 of FIG. 12, since the effect similar to the mounting apparatus 1 of 1st embodiment is acquired, since several semiconductor chips can be finally crimped | bonded collectively, the effect of a tact shortening is also acquired. It is done.

DESCRIPTION OF SYMBOLS 1 Mounting apparatus 2 Temporary pressure bonding part 3 Temporary pressure bonding base 4 Temporary pressure bonding stage 5 Support frame 6 Temporary pressure bonding unit 7 Temporary pressure bonding head 8 Temporary pressure bonding heater 10 Temporary pressure bonding attachment 10 Temporary pressure bonding image recognition apparatus 12 Main pressure bonding part 13 Main pressure bonding base 14 Final pressure bonding stage 15 Support frame 16 Maximum pressure bonding unit 17 Maximum pressure bonding head 18 Maximum pressure bonding heater 19 Maximum pressure bonding attachment 20 Maximum pressure bonding image recognition device 22 Resin sheet supply mechanism 22S Resin sheet unwinding portion 22R Resin Sheet take-up unit 23 Control unit 90 Suction hole 91 Depressurization system 92 Recess C Semiconductor chip P Resin sheet S Bonded object EB Electrode on the lower surface of the semiconductor chip ET Electrode on the upper surface of the semiconductor chip ES Electrode on the upper surface of the bonded object NCF Non-conductive film ( adhesive)

Claims (14)

A mounting device for thermocompression bonding a semiconductor chip having electrodes on both upper and lower surfaces to a bonded object having an electrode on an upper surface thereof via a thermosetting adhesive, which is disposed on the lower side of the semiconductor chip,
Using a temporary pressure-bonding head that sucks and holds the semiconductor chip, a temporary pressure-bonding portion that temporarily pressure-bonds onto the object to be bonded at a temperature at which no outgas is generated from the adhesive;
The semiconductor chip temporarily bonded onto the object to be bonded is bonded to the electrode on the lower surface of the semiconductor chip and the electrode on the upper surface of the object to be bonded using a main pressure bonding head having a heating function and a pressure function. A mounting apparatus, comprising: a thermocompression bonding agent, and a main press-bonding portion that performs a main press-bonding to the object to be bonded. The mounting apparatus according to claim 1,
A mounting apparatus comprising a resin sheet supply mechanism that supplies a resin sheet between the main pressure bonding head and the semiconductor chip temporarily bonded to the object to be bonded. The mounting apparatus according to claim 2,
A mounting apparatus, wherein the electrode on the upper surface of the temporarily bonded semiconductor chip is embedded in the resin sheet and then finally bonded. The mounting apparatus according to claim 2 or 3, wherein
A mounting apparatus having a function of separating the resin sheet from the semiconductor chip in a state where the resin sheet is in close contact with the surface of the main pressure bonding head after the main pressure bonding. The mounting apparatus according to claim 4,
A mounting apparatus comprising a moving means for separating the main pressure bonding head from the resin sheet. The mounting apparatus according to any one of claims 1 to 5,
A mounting apparatus comprising a recess for accommodating an electrode on an upper surface of the semiconductor chip on a surface of the temporary pressure-bonding head that holds the semiconductor chip by suction. The mounting apparatus according to any one of claims 1 to 6,
The mounting apparatus, wherein a temperature lower than a curing start temperature of the adhesive is set as a temperature at which no outgas is generated from the adhesive. A mounting method in which a semiconductor chip having electrodes on both upper and lower surfaces is thermocompression bonded to a bonded object having an electrode on an upper surface thereof via a thermosetting adhesive, disposed on the lower side of the semiconductor chip,
Using a temporary pressure bonding head for adsorbing and holding the semiconductor chip, a temporary pressure bonding step of temporarily pressure bonding on the object to be bonded at a temperature at which no outgas is generated from the adhesive;
The semiconductor chip temporarily bonded onto the object to be bonded is bonded to the electrode on the lower surface of the semiconductor chip and the electrode on the upper surface of the object to be bonded using a main pressure bonding head having a heating function and a pressure function. A mounting method comprising: a main press-bonding step in which an agent is thermally cured and thermocompression-bonded to the object to be bonded. The mounting method according to claim 8,
A mounting method comprising a step of supplying a resin sheet between the main pressure bonding head and the semiconductor chip temporarily bonded to the object to be bonded. The mounting method according to claim 9, comprising:
A mounting method comprising: pre-crimping the electrode on the upper surface of the semiconductor chip, which has been pre-crimped before the main crimping step, after embedding it in the resin sheet. The mounting method according to claim 9 or 10, wherein:
A mounting method comprising: separating the resin sheet from the semiconductor chip in a state where the resin sheet is in close contact with the surface of the main pressure bonding head after the main pressure bonding step. The mounting method according to claim 11,
A mounting method comprising: separating the resin sheet from the main pressure-bonding head after separating the resin sheet from the semiconductor chip. The mounting method according to any one of claims 8 to 12,
A temporary pressure bonding is performed in a state in which the electrodes on the upper surface of the semiconductor chip are accommodated using a temporary pressure bonding head in which a recess for accommodating the electrodes on the upper surface of the semiconductor chip is formed on the surface for sucking and holding the semiconductor chip. How to implement. The mounting method according to any one of claims 8 to 13,
A mounting method, wherein a temperature lower than a curing start temperature of the adhesive is set as a temperature at which no outgas is generated from the adhesive.

Images