JP6817658B2 - Adsorption stage - Google Patents

Description

The present invention relates to the structure of a suction stage that sucks and holds a semiconductor die.

A die bonding apparatus that bonds a semiconductor die picked up from a wafer to a substrate is often used. In the die bonding apparatus, a semiconductor die picked up from a wafer is temporarily placed on an intermediate stage, the position of the semiconductor die is detected by a camera, and then the semiconductor die is picked up from the intermediate stage by a bonding head to determine a predetermined substrate. Bonding is performed at the position (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2013-65711

In order to detect the position of the semiconductor die by the camera on the intermediate stage, it is necessary to place the semiconductor die flat on the surface of the intermediate stage. Since the semiconductor die is thin and often warped upward, in order to place the semiconductor die flat on the surface of the intermediate stage, the intermediate stage is composed of a suction stage, and the semiconductor die is sucked and held on the surface by vacuum. Is being done.

At this time, in order to adsorb the semiconductor die flatly on the surface of the adsorption stage, it is necessary to adsorb the entire semiconductor die in a well-balanced manner. Further, if there is a suction hole around the semiconductor die that does not adsorb the semiconductor die, air enters from the suction hole and the adsorption force is lowered, so that the adsorption holding of the semiconductor die may not be detected. For this reason, it is necessary to prepare several types of suction stages with different placement of suction holes according to the size of the semiconductor die placed on the surface, and replace the suction stages according to the size of the semiconductor die. there were. Therefore, there is a problem that the tact time of bonding becomes long.

Therefore, an object of the present invention is to provide an adsorption stage capable of suitably adsorbing and holding semiconductor dies of a plurality of sizes.

The suction stage of the present invention is a suction stage that sucks and holds semiconductor dies of different sizes, and the upper plate provided with a plurality of suction holes and the plurality of suction holes provided on the upper plate are made into the size of the semiconductor die. The check valve includes a plurality of vacuum passages connected to the vacuum apparatus for each of a plurality of corresponding groups, and a check valve provided in at least one of the plurality of vacuum flow paths. It closes when the suction hole is open to the atmosphere, and opens when the suction hole is closed by a semiconductor die. The check valve has a rough valve seat surface, and in the closed state, the valve body and the valve seat surface The valve is characterized in that a minute leak of air is generated between the valves.

In the suction stage of the present invention, the valve seat surface is an arcuate surface provided with a hole through which air can pass, and the valve body is a strip-shaped body composed of an elastic body attached to one end of the valve seat surface. Yes, the check valve may be a valve in which the valve body opens and closes the hole. Further, in the suction stage of the present invention, the suction holes may be evenly arranged.

The present invention can provide an adsorption stage capable of suitably adsorbing and holding semiconductor dies of a plurality of sizes.

It is explanatory drawing which shows the structure of the die bonding apparatus which incorporated the suction stage of embodiment. It is a perspective view of the suction stage of an embodiment. It is sectional drawing of the adsorption stage of embodiment. It is a genealogy which shows the arrangement of the suction hole on the surface of the suction stage of embodiment and the structure of a vacuum flow path. It is an exploded perspective view of the valve part of the suction stage of an embodiment. It is a perspective view of the check valve incorporated in the suction stage of an embodiment. It is explanatory drawing which shows the state before mounting the semiconductor die on the suction stage of an embodiment. It is explanatory drawing which shows the suction holding operation at the time of placing the small-sized semiconductor die which closes a suction hole included in 1st group on the suction stage of an embodiment. It is explanatory drawing which shows the suction holding operation when the medium-sized semiconductor die which closes a suction hole included in a 1st and 2nd group is placed on the suction stage of embodiment. It is explanatory drawing which shows the adsorption holding operation at the time of placing the large-sized semiconductor die which closes the adsorption hole included in the 1st, 2nd, and 3rd groups on the adsorption stage of an embodiment.

Hereinafter, the adsorption stage 20 of the present embodiment will be described with reference to the drawings. First, the die bonding apparatus 100 incorporating the suction stage 20 of the present embodiment will be described with reference to FIG.

As shown in FIG. 1, the die bonding device 100 includes a pickup unit 10, an intermediate positioning unit 18, and a bonding unit 70.

The pickup unit 10 is a portion that picks up the semiconductor die 13 from the surface of the wafer 12 and conveys it to the intermediate positioning unit 18. As shown in FIG. 1, the pickup unit 10 includes a wafer holder 11 that holds the wafer 12, a push-up mechanism 16 that pushes up the semiconductor die 13 from below, and a collet 15 that picks up the semiconductor die 13 pushed up by the push-up mechanism 16. It includes a pickup head 14. After the semiconductor die 13 is attracted to the collet 15, the pickup head 14 transfers the semiconductor die 13 from the pickup unit 10 to the intermediate positioning unit 18 and places the semiconductor die 13 on the surface 21a of the adsorption stage 20.

The intermediate positioning unit 18 is a suction stage 20 that temporarily sucks and holds the semiconductor die 13 on the surface 21a, and a camera that is arranged above the surface 21a of the suction stage 20 and captures the semiconductor die 13 that is sucked and held on the surface 21a. It has 48 and. The suction stage 20 is composed of an upper plate 21 and a valve portion 50.

The bonding portion 70 includes a bonding stage 71 that vacuum-adsorbs the substrate 17 on the surface, and a bonding head 72 that includes a bonding tool 73 that picks up the semiconductor die 13 from the surface 21a of the adsorption stage 20 and bonds it onto the substrate 17. There is.

Next, the configuration of the adsorption stage 20 will be described with reference to FIGS. 2 to 6. As shown in FIG. 2, the suction stage 20 includes an upper plate 21 in which a large number of suction holes 22 are uniformly provided on the surface 21a, and the first and second check valves 61 and 62 shown in FIGS. It has a valve portion 50 for accommodating. As shown in FIG. 1, the suction holes 22 are the first group A1 composed of the suction holes 22 in the central portion, the third group A3 composed of the suction holes 22 on the outermost circumference, the first group A1 and the first group. It is divided into three groups of the second group A2 composed of the suction holes 22 located in the middle of the three groups A3. The grouping of the suction holes 22 will be described in detail later.

As shown in FIG. 3, a recess 23 and steps 29 and 31 following the recess 23 are provided on the lower surface 21b side, which is the opposite surface of the surface 21a of the upper plate 21. As shown by the broken line in FIG. 2, the recess 23 has a size that surrounds the outside of the arrangement of the suction holes 22. Two annular protrusions 24 and 25 project from the bottom surface 23a of the recess 23. The annular convex portion 24 constitutes an annular third cavity 28 surrounded by the side surface of the concave portion 23 and the bottom surface 23a. Further, the convex portions 24 and 25 form an annular second cavity 27 surrounded by the inner peripheral surface of the annular convex portion 24 and the outer peripheral surface of the convex portion 25. The inner peripheral surface of the convex portion 25 constitutes the first cavity 26.

As shown in FIGS. 2 to 4, the suction holes 22 included in the first group A1 communicate with the first cavity 26, and the suction holes 22 included in the second group A2 communicate with the second cavity 27, and the third group The suction hole 22 included in A3 communicates with the third cavity 28. Therefore, the convex portions 24 and 25 are also walls that partition the suction holes 22 into the first, second, and third groups A1, A2, and A3.

An upper packing 29a is fitted in the step portion 29 following the recess 23, and a spacer 30a and a lower packing 31a are fitted in the step portion 30 following the step portion 29. The upper surface of the upper packing 29a constitutes the lower surfaces of the first, second, and third cavities 26, 27, and 28. Further, the upper packing 29a, the spacer 30a, and the lower packing 31a are provided with through holes 33, 36, 39 at the first position, through holes 34, 37, 39 at the second position, and through at the third position. Holes 32, 35, 38 are provided. Through holes 33, 36, 39 provided at the first position form a first vacuum flow path 41 communicating with the first cavity 26, and through holes 34, 37, 40 provided at the second position form a second cavity. The second vacuum flow path 42 communicating with the 27 is formed, and the through holes 32, 35, 38 provided at the third position form the third vacuum flow path 43 communicating with the third cavity 28.

As shown in FIG. 3, the first vacuum flow path 41 is connected to a through hole 52 provided in the base 51 of the valve portion 50. Further, the second and third vacuum flow paths 42 and 43 communicate with the first and second valve accommodating recesses 55a and 55b of the base 51. As shown in FIG. 5, through holes 53a and 53b are provided on the bottom surfaces of the first and second valve accommodating recesses 55a and 55b, respectively. The through holes 52, 53a, 53b are connected to the vacuum device 45 via the pipe 54. The pipe 54 is provided with a pressure sensor 46 that detects the pressure of the pipe.

As shown in FIGS. 3 to 5, the first check valve 61 is housed in the first valve accommodating recess 55a communicating with the second vacuum flow path 42 and the through hole 53a, and the third vacuum flow path 43. The second check valve 62 is accommodated in the second valve accommodating recess 55b communicating with the through hole 53b. As shown in FIG. 4, the first check valve 61 is arranged so as to block the flow of air from the suction hole 22 included in the second group A2 toward the vacuum device 45, and the second check valve 62. Is arranged so as to block the flow of air from the suction hole 22 included in the third group A3 toward the vacuum device 45.

Next, the configurations of the first and second check valves 61 and 62 will be described with reference to FIG. The first check valve 61 and the second check valve 62 have the same structure. As shown in FIG. 6, the first and second check valves 61 and 62 have a substantially rectangular parallelepiped main body 63 having an arcuate valve seat surface 64 provided with a hole 66 through which air passes, and a valve seat. A band-shaped valve body 65 made of an elastic body attached to one end of the surface 64 is included. The valve seat surface 64 is a rough surface, and for example, the arithmetic average roughness Ra may be about 1.6. The valve body 65 is a metal plate having a smooth surface. The holes 66 communicate with the holes 69 provided on the side surface of the main body 63 by the flow paths 67 and 68 provided inside the main body. As shown in FIG. 5, when the first and second check valves 61 and 62 are assembled into the first and second valve accommodating recesses 55a and 55b, the holes 69 provided on the side surfaces of the main body 63 have through holes 53a. , 53b communicates with the vacuum device 45. Further, the gap D between the tip of the valve body 65 on the hole 66 side and the wall surfaces of the first and second valve accommodating recesses 55a and 55b communicates with the second and third vacuum flow paths 42 and 43.

When the hole 69 is evacuated by the vacuum device 45 connected to the hole 69, the valve body 65 is attracted to the valve seat surface 64 in the hole 66 to seal the hole 66, as shown by an arrow 95 in FIG. As a result, the first and second check valves 61 and 62 are closed. Further, when the hole 69 reaches the atmospheric pressure, the valve body 65 separates from the valve seat surface 64 by its own elastic force to open the hole 66, and the first and second check valves 61 and 62 are closed. However, since the valve seat surface 64 is a rough surface, even if the first and second check valves 61 and 62 are closed, a minute air leak occurs between the valve seat surface 64 and the valve body 65. Occur.

Next, with reference to FIGS. 7 to 10, the operation of each part when the semiconductor die 13 is sucked onto the suction stage 20 will be described.

First, with reference to FIG. 7, a state in which the vacuum device 45 is activated before the semiconductor die 13 is adsorbed will be described. In this state, since the surface 21a of the upper plate 21 of the suction stage 20 is at atmospheric pressure, when the vacuum device 45 is started, the holes 69 of the first and second check valves 61 and 62 communicating with the vacuum device 45 The flow paths 67 and 68 communicating with the holes 69 are evacuated, the valve body 65 is attracted to the valve seat surface 64, and the holes 66 of the valve seat surface 64 are sealed. Therefore, the first and second check valves 61 and 62 are closed, and the second and third vacuum flow paths 42 and 43 are also closed. On the other hand, since the first vacuum flow path 41 communicating with the suction hole 22 included in the first group A1 is open to the atmosphere, air is sucked into the vacuum device 45 from the first vacuum flow path 41. At this time, the pressure sensor 46 at the inlet of the vacuum device 45 has a pressure higher than -60 to -70 Pa, which is the ultimate pressure when the semiconductor die 13 is adsorbed on the surface 21a, for example, about -10 Pa. ..

Next, as shown in FIG. 8, a case where a small-sized semiconductor die 13a is placed on the surface 21a will be described. The small-sized semiconductor die 13a has the same size as the broken line showing the outer circumference of the first group A1 shown in FIG. 4 and covers the surface of the suction holes 22 included in the first group A1, and the second and third groups A2. , A3 has a size that does not hang on the suction hole 22.

As shown in FIG. 8, when a small-sized semiconductor die 13a is placed on the surface 21a, the surface of the suction holes 22 included in the first group A1 is covered. As a result, the first vacuum flow path 41 becomes a vacuum and the semiconductor die 13a is adsorbed on the surface 21a. Since the suction holes 22 are evenly arranged, the entire semiconductor die 13a is vacuum-held on the surface 21a in a well-balanced manner. Since the second and third vacuum flow paths 42 and 43 are closed by the first and second check valves 61 and 62, the air contained in the first vacuum flow path 41 is sucked by the vacuum device 45. Then, the pressure of the first vacuum flow path 41 reaches −60 to −70 Pa, which is the ultimate pressure when the semiconductor die 13 is adsorbed on the surface 21a. As a result, the pressure sensor 46 provided at the inlet pressure of the vacuum device 45 also detects the pressure of −60 to −70 Pa, and the control device (not shown) detects that the semiconductor die 13a is sucked and held. Then, the control device acquires an image of the semiconductor die 13a by the camera 48 and performs position detection.

Next, a case where a medium-sized semiconductor die 13b is placed on the surface 21a will be described with reference to FIG. The medium-sized semiconductor die 13b has the same size as the broken line showing the outer circumference of the second group A2 shown in FIG. 4, and has a size that covers the surface of the suction holes 22 included in the first and second groups A1 and A2. is there. However, the size does not cover the suction holes 22 included in the region of the third group A3.

As described above with reference to FIG. 7, in the state where the vacuum device 45 is activated before the semiconductor die 13 is sucked, the first and second check valves 61 and 62 are closed and the first and second check valves 61 and 62 are closed. 2. The third vacuum flow paths 42 and 43 are closed, the first vacuum flow path 41 is open to the atmosphere, and air is flowing from the first vacuum flow path 41 toward the vacuum device 45. At this time, the inlet pressure of the vacuum device 45 is, for example, about −10 Pa.

Next, as shown in FIG. 9, when the medium-sized semiconductor die 13b is placed on the surface 21a, the semiconductor die 13b covers the surface of the suction holes 22 included in the first and second groups A1 and A2. As a result, first, the first vacuum flow path 41 becomes a vacuum, and the central portion of the semiconductor die 13b is adsorbed on the surface 21a. Since the first check valve 61 has a minute leak of air in the closed state, when the second vacuum flow path 42 is covered with the semiconductor die 13b, the air contained in the second vacuum flow path 42 is shown in the figure. As shown by the arrow 92 of 9, the air flows to the vacuum device 45 through the first check valve 61. Therefore, the pressure in the second vacuum flow path 42 gradually decreases toward the vacuum. Then, when the differential pressure between the pressure in the second vacuum flow path 42 and the pressures in the flow paths 67 and 68 inside the main body 63 becomes small, the valve body 65 is pressed against the valve seat surface 64 rather than the valve body. Since the elastic force that tends to move away from the valve seat surface 64 of 65 becomes larger, the valve body 65 moves upward as shown by the arrow 91 shown in FIG. 9, and the first check valve 61 is opened. ..

As a result, the second vacuum flow path 42 is in the same vacuum state as the first vacuum flow path 41, and the peripheral portion of the semiconductor die 13b is adsorbed on the surface 21a. Since the suction holes 22 are evenly arranged, the entire semiconductor die 13b is vacuum-held on the surface 21a in a well-balanced manner by the suction holes 22 included in the first group A1 and the suction holes 22 included in the second group A2. To.

As described above with reference to FIG. 8, since the third vacuum flow path 43 is closed by the second check valve 62, it is inside the first and second vacuum flow paths 41 and 42. When air is sucked by the vacuum device 45, the pressures of the first and second vacuum flow paths 41 and 42 reach −60 to −70 Pa, which is the ultimate pressure when the semiconductor die 13b is adsorbed on the surface 21a. As a result, the pressure sensor 46 provided at the inlet pressure of the vacuum device 45 also detects the pressure of −60 to −70 Pa, and the control device (not shown) detects that the semiconductor die 13b is sucked and held. Then, the control device acquires an image of the semiconductor die 13b by the camera 48 and performs position detection.

Next, a case where a large-sized semiconductor die 13c is placed on the surface 21a will be described with reference to FIG. The large-sized semiconductor die 13c has a size that covers all the suction holes 22 shown in FIG.

As shown in FIG. 10, when a large-sized semiconductor die 13c is placed on the surface 21a, the semiconductor die 13c covers the surfaces of all the suction holes 22. As a result, first, the first vacuum flow path 41 becomes a vacuum and the semiconductor die 13c is adsorbed on the surface 21a. Since the first and second check valves 61 and 62 have minute air leaks in the closed state, the second and third vacuum flow paths 42 and 43 are covered with the semiconductor die 13c as described above. , The first and second check valves 61 and 62 are opened.

As a result, the second and third vacuum flow paths 42 and 43 are in the same vacuum state as the first vacuum flow path 41, and the peripheral portion of the semiconductor die 13c is adsorbed on the surface 21a. Since the suction holes 22 are evenly arranged, the entire semiconductor die 13c is vacuum-held on the surface 21a in a well-balanced manner by the suction holes 22 included in the first to third groups A1 to A3.

When the air contained in the first, second and third vacuum passages 41, 42 and 43 is sucked by the vacuum device 45, the pressures of the first, second and third vacuum passages 41, 42 and 43 Reaches the ultimate pressure of -60 to -70 Pa when the semiconductor die 13c is adsorbed on the surface 21a. As a result, the pressure sensor 46 provided at the inlet pressure of the vacuum device 45 also detects the pressure of −60 to −70 Pa, and the control device (not shown) detects that the semiconductor die 13c is adsorbed and fixed. Then, the control device acquires an image of the semiconductor die 13c by the camera 48 and performs position detection.

As described above, in the suction stage 20 of the embodiment, the plurality of suction holes 22 are divided into first to third groups A1 to A3 according to the size of the semiconductor die 13, and the first to third groups A1 to A When the first to third vacuum flow paths 41 to 43 for connecting a plurality of suction holes 22 to the vacuum device 45 are provided for each, and the suction holes 22 are open to the atmosphere in the second and third vacuum flow paths 42 and 43. The first and second check valves 61 and 62 are provided, which are closed and opened when the suction hole 22 is closed by the semiconductor die 13. Further, the suction holes 22 are evenly arranged. As a result, regardless of the size of the semiconductor die 13, the suction holes 22 can suck and hold the semiconductor die 13 in a well-balanced and flat manner as a whole. Then, the position of the semiconductor die 13 can be suitably detected by using the camera 48.

Further, in the suction stage 20 of the present embodiment, according to the above configuration, the suction holes 22 blocked by the semiconductor die 13 are evacuated according to the size of the semiconductor die 13, and the other suction holes 22 are blocked from the vacuum device 45. Therefore, regardless of the size of the semiconductor die 13, the vacuum pressure when the semiconductor die 13 is vacuum-sucked can be set to a pressure at which the suction holding of the semiconductor die 13 can be determined, and the semiconductor die 13 can be determined by the control device. It is possible to confirm the adsorption retention.

As described above, the suction stage 20 of the embodiment can suitably suck and hold the semiconductor dies 13 of a plurality of sizes with one suction stage 20 without exchanging the suction stage 20 according to the size of the semiconductor die. The tact time of bonding can be shortened, and efficient bonding can be performed.

In the embodiment, it has been described that the first vacuum flow path 41 is not provided with a check valve, but the present invention is not limited to this, and a check valve having the same structure as the first check valve 61 is provided. May be good. Further, the check valve may not be incorporated in the suction stage 20 but may be provided outside. In this case, other types of check valves, such as swing check valves, may be used.

10 Pickup part, 11 Wafer holder, 12 Wafer, 13, 13a, 13b, 13c Semiconductor die, 14 Pickup head, 15 Collet, 16 Push-up mechanism, 17 Substrate, 18 Intermediate positioning part, 20 Suction stage, 21 Top plate, 21a Surface , 21b lower surface, 22 suction hole, 23 concave part, 23a bottom surface, 24, 25 convex part, 26 first cavity, 27 second cavity, 28 third cavity, 29, 30 steps, 29a upper packing, 30a spacer, 31a lower Packing, 32-40, 52, 53a, 53b through hole, 41 1st vacuum flow path, 42 2nd vacuum flow path, 43 3rd vacuum flow path, 45 vacuum device, 46 pressure sensor, 48 camera, 50 valve section, 51 base, 54 piping, 55a, 55b valve accommodating recess, 61 first check valve, 62 second check valve, 63 main body, 64 valve seat surface, 65 valve body, 66, 69 holes, 67, 68 flow paths, 70 bonding section, 71 bonding stage, 72 bonding head, 73 bonding tool, 100 die bonding device.

Claims (3)

A suction stage that sucks and holds semiconductor dies of different sizes.
An upper plate with multiple suction holes and
A plurality of vacuum channels for connecting the plurality of suction holes provided on the upper plate to the vacuum apparatus for each of a plurality of groups according to the size of the semiconductor die.
A check valve provided in at least one of the plurality of vacuum flow paths is included.
The check valve closes when the suction hole is open to the atmosphere, and opens when the suction hole is closed by a semiconductor die.
The check valve is a valve in which the valve seat surface is rough and a minute leak of air is generated between the valve body and the valve seat surface in the closed state.
Adsorption stage featuring. The adsorption stage according to claim 1.
The valve seat surface is an arcuate surface provided with a hole through which air can pass, and the valve body is a band-shaped body composed of an elastic body attached to one end of the valve seat surface, and the reverse of the above. The check valve is a valve in which the valve body opens and closes the hole.
Adsorption stage featuring. The adsorption stage according to claim 1 or 3.
The suction holes are evenly arranged,
Adsorption stage featuring.