JP6200737B2 - Die bonder dipping mechanism and flip chip bonder - Google Patents

Description

  The present invention relates to a die bonder dipping mechanism and a flip chip bonder, and more particularly to a die bonder dipping mechanism capable of reliably supplying a flux and a highly reliable flip chip bonder using the same.

  A part of the process of assembling a package by mounting a semiconductor die having bumps (hereinafter simply referred to as a die) on a work such as a wiring board, and a process of dividing the die from a semiconductor wafer (hereinafter simply referred to as a wafer) There is a boarding process in which a bumped die is picked up from a wafer, the die is inverted, flux is applied to the bump, and bonding is performed to solder on the substrate.

In the bonding process, there is a dipping process in which flux is applied to the bump surface having the bumps of the die. In the dipping process, the bonding head is moved up and down, and the bump surface of the die is immersed in a concave cavity in which flux is stored. There is also a dipping mechanism to replenish the void flux lost by application. The dipping mechanism is performed by moving a container having a bottom opened and containing a flux on a hollow plate.
There exists patent document 1 as such a dipping mechanism.
In the dipping mechanism of Patent Document 1, the container moves on the plate by engaging a pin provided on the lower part of the container with a recess of a slide running on a guide rail provided on the lower part of the base plate.

JP 2010-504633 A

  In the dipping mechanism, it is necessary to make the immersion height of the flux into the bump uniform. Therefore, for example, tilt adjustment of the dipping plate is performed in order to maintain the parallelism between the bonding head and the base plate (dipping plate). As a result, the dipping plate and the container (squeegee) are not parallel, and the flux supply to the cavity by the squeegee is not uniform. If the flux supply is not uniform, the height of the flux immersed in the bumps is not uniform. Although it is conceivable to provide a squeegee with a parallelism adjusting mechanism, it takes time to adjust the squeegee.

  The dipping mechanism of Patent Document 1 can cope with the right and left tilt (inclination) to some extent with springs provided on the left and right pins, but cannot cope with it when it exceeds a predetermined value. In particular, as shown in FIG. 8, since the distance to the guide rail G is not changed, it is not possible to cope with front and rear tilts.

  Therefore, an object of the present invention is to provide a dipping mechanism that can automatically maintain the parallelism of the squeegee with respect to the dipping plate, and a flip chip bonder having a high reliability or high operating rate.

In order to achieve the above object, the present invention has at least the following features.
The present invention relates to a die bonder that moves a dipping plate having a squeegee having a bottom opened and containing a flux and a dipping plate having a containing portion for containing the flux by a driving means, and supplying the flux from the bottom to the containing portion. A dipping mechanism for tracking the squeegee to follow the plane of the dipping plate, a tracking means having a biaxial inclined tracking axis, and the squeegee to the dipping plate side via a rotation axis of the biaxial inclined tracking axis And pressing means for pressing.

Further, the following means has a structure in which a first axis having a rotation axis in the moving direction and a second axis having a rotation axis perpendicular to the first axis and parallel to the plane of the dipping plate are connected in series. You may have.
Furthermore, the following means includes a first axis having a rotation axis in the moving direction and a second axis having a second axis orthogonal to the first axis and parallel to the plane of the dipping plate. It may be.

The pressing means has one end connected to the two-axis tilt following shaft and the other end connected to a third shaft that rotates the two-axis tilt following shaft up and down; A frame drive source that presses the squeegee toward the dipping plate with the three axes as axes, and the pressing means may be fixed to the pressing means fixing portion via the third axis.
Further, the pressing means includes a frame having one end connected to the biaxial inclined tracking axis, and a frame drive source that moves the frame up and down and presses the biaxial inclined tracking axis toward the dipping plate. And the pressing means may be fixed to the pressing portion fixing portion via the frame driving source.

In addition, the frame may have a square shape (a quadrangle enclosure).
Further, the driving means includes a pressing portion base that supports the pressing means, a pulley provided below each of the dipping base that supports the dipping plate, a belt disposed between the two pulleys, one end May be connected to the belt and the other end connected to one of the pressing means and the dipping plate, and a pulley drive source that drives one of the two pulleys. .

  Further, the present invention picks up a die having bumps from a wafer with a pickup head, reverses the picked-up die, receives the die with a bonding head, and bonds the bumps coated with flux to a solder part of a workpiece. It is a flip chip bonder, Comprising: The said bonding head applies the said flux to the said bump by the said accommodating part of the dipping mechanism in any one of Claim 1 thru | or 9.

  Therefore, according to the present invention, it is possible to provide a flip chip bonder having a dipping mechanism capable of automatically maintaining parallelism of the squeegee with respect to the dipping plate and a dipping mechanism thereof, and having high reliability or high operating rate.

It is a schematic top view of the flip chip bonder which is one Embodiment of this invention. It is a figure explaining operation | movement of a pick-up head and a bonding head when it sees from the arrow A direction in FIG. It is a schematic sectional drawing which shows the principal part of the die | dye supply part which is one Embodiment of this invention. 2 is a bird's-eye view of the dipping mechanism as viewed from the front side of the page as indicated by an arrow B. FIG. It is the side view which looked at FIG. 4 from the Y direction, and is a figure which shows a state when a squeegee is on the leftmost side. FIG. 6 is a side view of FIG. 4 as viewed from the Y direction, similar to FIG. 5, and shows a state where the squeegee has moved from the right side to the leftmost side. It is a figure explaining the effect in the Example of this invention. It is a figure which shows the subject of a prior art.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic top view of a flip chip bonder 10 according to an embodiment of the present invention. FIG. 2 is a diagram for explaining the operation of the pickup head 21 and the bonding head 41 when viewed from the direction of arrow A in FIG.
The die bonder 10 is roughly divided into a die supply unit 1, a pickup unit 2, a reversing mechanism unit 3, a bonding unit 4, a transport unit 5, a substrate supply unit 6K, a substrate carry-out unit 6H, a dipping mechanism 8, and each unit. And a control unit 7 for monitoring and controlling the operation of

  First, the die supply unit 1 supplies a die D to be mounted on a work such as a substrate P. The die supply unit 1 includes a wafer holding table 12 that holds the wafer 11 and a push-up unit 13 indicated by a dotted line that pushes up the die D from the wafer 11. The die supply unit 1 is moved in the XY directions by a driving unit (not shown), and moves the die D to be picked up to the position of the push-up unit 13.

  The pickup unit 2 includes a collet unit 22 that attracts the die D from the die supply unit 1, a pickup head 21 that includes the collet unit 22 at the tip and picks up the die, and a Y drive unit 23 that moves the pickup head 21 in the Y direction. And a reversing mechanism 24 for reversing the die D. The pickup head 21 has driving units (not shown) that move the collet unit 22 up and down, rotate, and move in the X direction.

  As shown by a broken line in FIG. 2, the reversing mechanism unit 24 rotates the pickup head 21 by 180 degrees, reverses the pump of the die D, faces the lower surface, and passes the die D to the bonding head 41.

  The bonding unit 4 receives the inverted die D from the pickup head 21, applies a flux F by a dipping mechanism, and bonds it to the solder portion of the workpiece that has been conveyed. Similar to the pickup head 21, the bonding unit 4 includes a bonding head 41 having a collet unit 42 that sucks and holds the die D at the tip, a Y driving unit 43 that moves the bonding head 41 in the Y direction, and a workpiece position recognition mark ( And a substrate recognition camera 44 for recognizing the bonding position.

  With such a configuration, the bonding head 41 corrects the pickup position / orientation based on imaging data of a stage recognition camera (not shown), receives the inverted die D from the pickup head, and based on the imaging data of the substrate recognition camera 44. A die D is bonded to the substrate P. During the above operation, the bonding head 41 moves to the dipping mechanism 8 described later and applies the flux F to the bumps Db.

  The transport unit 5 includes a substrate transport pallet 51 on which one or more substrates P (four in FIG. 1) are placed and a pallet rail 52 on which the substrate transport pallet 51 moves, and is provided in parallel. And the first and second transfer units having the same structure. The substrate transfer pallet 51 is moved by driving a nut (not shown) provided on the substrate transfer pallet 51 with a ball screw (not shown) provided along the pallet rail 52.

  With such a configuration, the substrate transport pallet 51 places the substrate P on the substrate supply unit 6K, moves to the bonding position along the pallet rail 52, and moves to the post-bonding substrate unloading unit 6H. Pass the substrate P to 6H. The first and second transfer units are driven independently of each other, and while the die D is being bonded to the substrate P placed on one substrate transfer pallet 51, the other substrate transfer pallet 51 carries out the substrate P. Returning to the substrate supply unit 6K, preparations such as placing a new substrate P are made.

  FIG. 3 is a schematic cross-sectional view showing the main part of the die supply unit 1. As shown in FIG. 3, the die supply unit 1 includes an expand ring 15 that holds the wafer ring 14, and a support ring 17 that horizontally positions the dicing tape 16 that is held by the wafer ring 14 and to which a plurality of dies D are adhered. And a push-up unit 13 for pushing up the die D upward. In order to pick up a predetermined die D, the push-up unit 13 is moved up and down by a drive mechanism (not shown), and the die supply unit 1 is moved in the horizontal direction.

  The die supply unit 1 lowers the expanding ring 15 holding the wafer ring 14 when the die D is pushed up. As a result, the dicing tape 16 held on the wafer ring 14 is stretched, and the distance between the dies D is increased. In such a state, the die supply unit 1 improves the pickup property of the die D by pushing up the die D from below the die by the push-up unit 13.

  As the die D is made thinner, the adhesive used to bond the die D to the substrate P is often used from a liquid to a film, and a film called a die attach film DAF is used. In some cases, it is provided between the die D and the dicing tape 16. The die attach film DAF is attached with a film-like adhesive material and holds a plurality of dies D. In the wafer 11 having the die attach film DAF, dicing is performed on the wafer and the die attach film DAF.

Hereinafter, the configuration and operation of the dipping mechanism 8, which is a feature of the embodiment of the present invention, will be described.
An embodiment of the dipping mechanism 8 will be described with reference to FIGS. FIG. 4 is a bird's-eye view of the dipping mechanism 8 as seen from the front side of the page, as indicated by an arrow B in FIG. FIG. 5 is a side view of FIG. 4 as viewed from the Y direction, and shows a state when the squeegee 81 is on the leftmost side. FIG. 6 is a side view of FIG. 4 as viewed from the Y direction in the same way as FIG.

  The dipping mechanism 8 roughly includes a squeegee 81, a dipping portion 82 on which the squeegee 81 slides, a follower 83 for moving the squeegee 81 while following the surface of the dipping plate 82p, and a drive portion 84 for moving the squeegee 81. . Since the squeegee and the dipping plate slide on each other, it is desirable that at least one of the sliding surfaces is made of a material with low friction.

  The squeegee 81 is uniformly filled with the flux F, and replenishes the flux F uniformly into the accommodating portion 82d from the opening provided at the bottom. The opening at the bottom has a long side that is greater than or equal to the width W in the Y direction of the accommodating portion 82d. The flux F has a sufficient viscosity and does not fall from the opening.

  The accommodating portion 82d is provided on the dipping plate 82p on which the squeegee 81 slides, and has a concave shape. The bonding head 41 descends to the accommodating portion 82d and immerses the bump Db of the die D. In FIG. 4, the accommodation portion 82 d is provided only at one place, but a plurality of accommodation portions 82 d may be provided. The depth of the accommodating portion 82d is about 1/2 to 2/3 of the thickness t of the bump Db. For example, if t = 60 μm, the depth of the accommodating portion 82d is approximately 30 μm to 40 μm.

  In addition, the dipping portion 82 includes a raising plate 82k that raises the dipping plate 82p and a dipping base 82f that fixes the dipping portion 82 to the mechanism portion of the flip chip bonder 10 so that the squeegee 81 can be moved by the follower 83 described later. Have.

  The follower 83 has three rotation axes. The first is an X inclination tracking axis 83x that follows the inclination of the dipping plate 82p in the X direction, the second is a Y inclination tracking axis 83y that follows the inclination of the dipping plate 82p in the Y direction, and the third is an X inclination tracking axis. And the Y-inclination following axis are pressing shafts 83p that press both axes against the dipping plate 82d so that the following axes can follow the respective inclinations.

  The X-inclined occasional shaft 83x has a U-shaped frame 83xf having a U-shaped shape and has a rotation axis 83xj on upper and lower sides parallel to the U-shape, and the squeegee 81 is supported by the rotation axis. . The Y tilt following shaft 83y has a rotation shaft 83yj at the center of the vertical side of the U-shaped frame 83xf. The pressing shaft 83p has a rotary shaft 83pj on a side 83pm away from the squeegee 81 side and a Y-direction side 83ps on the squeegee side of the Y-direction side of the mouth-shaped frame 83pf having a square shape (quadrangle enclosure). , And a rotation axis 83yj of the Y tilt following axis 83y. The pressing shaft 83p is fixed to the pressing portion fixing plate 83pk via the side 83pm. The pressing portion fixing plate 83pk is fixed to a slide 84s of the driving portion 84, which will be described later, and the entire mouth-shaped frame 83pf is movable in the X direction.

  The pressing shaft 83p has a spring portion 83pb that presses the mouth frame 83pf downward in the drawing in order to press the squeegee 81 against the dipping plate 82p. The spring portion 83pb is composed of a lower fixing portion 83pd extending to the squeegee 81 whose bottom is fixed to the pressing portion fixing plate 83pk, and an upper fixing plate 83pu connecting two sides in the X direction of the mouth-shaped frame 83pf. It is fixed. Further, the spring portion 83pb has a compression spring 83pa (mouth-shaped frame drive source) between the head and the upper fixing plate 83pu, and presses the upper fixing plate 83pu downward.

  With this configuration, the square frame 83pf is always pressed downward through the upper fixing plate 83pu. As a result, the rotary shafts 83yj and 83xj are pressed downward, and the squeegee 81 can follow the surface of the dipping plate 82p. For example, even if the dipping plate 82p moves up and down, the squeegee 81 can follow the surface of the dipping plate 82p.

  The drive unit 84 moves the squeegee 81 in the X direction by moving the slide 84s fixed to the pressing unit fixing plate 83pk and the guide rails 84r provided on both sides of the pressing unit base 84b. The slide 84s is fixed to the drive belt 84v via the connecting plate 84t. The drive belt 84v is moved by a drive motor 84m between pulleys 84pm and 84pf provided on a rotary shaft at a drive shaft of the drive motor 84m and a lower portion of the dipping base 82f.

  FIG. 6 shows a state in which the squeegee 81 has moved from the state of FIG. 5 to the right end of the flux F accommodating portion 82d. The length in the X direction of the guide rail 84r and the square frame 83pf needs to be a length that allows at least the squeegee 81 to cover the length in the X direction of the accommodating portion 82d. Of course, when there are a plurality of accommodating portions 82d, a length that covers the plurality of accommodating portions 82d is required.

  Even if the dipping plate 82p is inclined with respect to the XY plane or displaced in the Z direction by the follower 83 and the drive unit 84 described above, the squeegee 81 slides along the surface of the dipping plate 82. be able to. FIG. 8 shows the effect of this embodiment by paying attention to the easy-to-understand inclination in the X direction. In this embodiment, there is a pressing shaft 83p for rotating the square frame 83pf, and the pressing shaft absorbs fluctuations in the distance between the guide rail 84r and the squeegee 81, so that the squeegee 81 always has a dipping plate. Since it can slide according to 82p, it can supply only to the accommodating part 82d, without discharging | emitting excess flux. As a result, the reliability of the apparatus can be improved.

  Furthermore, since the squeegee 81 can always slide along the dipping plate 82p, it is not necessary to adjust the inclination of the squeegee 81 and the operating rate of the apparatus can be improved.

  In the embodiment described above, the two axes are separated as the two-axis tilt following axis that enables the squeegee to follow the inclination of the dipping plate 82p with respect to the XY plane, and the X tilt occasional axis 83x is provided on the squeegee 81 side. , Y tilt following shaft 83y may be provided. Further, as the biaxial inclined follow-up axis, a biaxial universal joint such as a universal joint may be used without separating the two axes.

  In the embodiment described above, the squeegee 81 can follow the inclination of the surface of the dipping plate 82p by the two-axis inclination following axis, and the mouth-shaped frame 83pf is rotated as the rotation axis 83pj of the pressing shaft 83p so that The squeegee was pressed against the dipping plate via the rotation axes 83xj and 83yj of the tilt arbitrary axis 83x and the Y tilt arbitrary axis 83y. In short, it is sufficient if there is a means for pressing the squeegee to the dipping plate side via the rotation shafts 83xj and 83yj of the X-tilt optional shaft 83x, the Y-tilt optional shaft 83y, or the rotary shaft of the biaxial universal joint.

  For example, a mouth-shaped frame driving source that pushes the mouth-shaped frame 83pf in parallel without rotating it may be used. In that case, for example, the frame 83pm on which the rotation shaft 83pj exists is not fixed to the pressing portion fixing plate 83pk, and the mouth-shaped frame 83pf is provided between the lower fixing portion 83pd and the upper fixing plate 83pu. It is fixed to the pressing part fixing plate 83pk through the tension spring (mouth-shaped frame drive source).

  As described above, the dipping mechanism according to the present embodiment is configured so that the squeegee can follow the plane of the dipping plate, and the squeegee is moved to the dipping plate side via the rotation axis of the two-axis inclined tracking axis. It has a pressing means for pressing.

  In the embodiment described above, the squeegee 81 is moved, but the dipping plate 82p may be moved. For example, as a configuration, a dipping plate that is directly or indirectly connected to the connecting plate 84t by fixing the square frame 83pf to the pressing portion base and extending the guide rail 84 to the dipping base 82f as a guide. It is configured to run on rails.

  Furthermore, in the embodiment described above, a compression spring or a tension spring may be used instead of a spring, such as an air cylinder, as a square frame driving source.

  Although the embodiments of the present invention have been described above, various alternatives, modifications, and variations can be made by those skilled in the art based on the above description, and the present invention is not limited to the various embodiments described above without departing from the spirit of the present invention. It encompasses alternatives, modifications or variations.

1: Die supply unit 2: Pickup unit 24: Reversing mechanism unit 4: Bonding unit 41: Bonding head 42: Collet unit 7: Control unit 8: Dipping mechanism 10: Flip chip bonder 11: Wafer 81: Squeegee 82: Dipping unit 82d : Housing part 82f: Dipping base 82k: Raising plate 82p: Dipping plate 83: Tracking part 83b: Pushing part base 83p: Pushing shaft 83pa: Compression spring 83pb: Spring part 83pd: Lower fixing part 83pf: Round frame 83pk: Pressing portion fixing plate 83 pu: upper fixing plate 83 pm, 83 ps: Y-direction side of mouth-shaped frame 83 x: X-inclined tracking axis 83 xf: U-shaped frame 83 xj: rotation axis 83 y: Y-inclination following axis 83 yj: rotation axis 84: Drive unit 84m: Drive motor 8 pf, 84pm: pulley 84r: guide rails 84s: Slide 84t: connection plate 84v: drive belt D: Die Db: bumps F: Flux P: substrate W: width of the housing portion

Claims (9)

A die bonder dipping mechanism that moves a dipping plate having a squeegee whose bottom is opened and contains the flux and a dipping plate having a containing portion for containing the flux by a driving means, and supplies the flux from the bottom to the containing portion. There,
Tracking means having a two-axis inclined tracking axis that enables the squeegee to follow the plane of the dipping plate; and pressing means for pressing the squeegee to the dipping plate side through the rotation axis of the two-axis inclined tracking axis. And
The following means has a structure in which a first axis having a rotation axis in the moving direction and a second axis having a rotation axis perpendicular to the first axis and parallel to the plane of the dipping plate are connected in series.
Die bonder dipping mechanism. A die bonder dipping mechanism that moves a dipping plate having a squeegee whose bottom is opened and contains the flux and a dipping plate having a containing portion for containing the flux by a driving means, and supplies the flux from the bottom to the containing portion. There,
Tracking means having a two-axis inclined tracking axis that enables the squeegee to follow the plane of the dipping plate; and pressing means for pressing the squeegee to the dipping plate side through the rotation axis of the two-axis inclined tracking axis. And
The following means is a two-axis universal joint including a first axis having a rotation axis in the moving direction and a second axis having a rotation axis perpendicular to the first axis and parallel to the plane of the dipping plate. ,
Die bonder dipping mechanism. A dipping mechanism for a die bonder according to claim 1 or 2 ,
The pressing means has one end connected to the two-axis tilt following shaft and the other end connected to a third shaft that rotates the two-axis tilt following shaft up and down, and the frame is connected to the third shaft. A frame drive source for pressing the squeegee against the dipping plate with the shaft as an axis, and the pressing means is fixed to the pressing means fixing portion via the third shaft.
Die bonder dipping mechanism. A dipping mechanism for a die bonder according to claim 1 or 2 ,
The pressing means includes a frame having one end connected to the biaxial tilt following shaft, and a frame drive source that moves the frame up and down and presses the biaxial tilt following shaft toward the dipping plate. The pressing means is fixed to the pressing portion fixing portion via the frame drive source.
Die bonder dipping mechanism. A die bonder dipping mechanism according to claim 3 or 4 ,
The frame has a square (quadrangle enclosure) shape,
Die bonder dipping mechanism. A die bonder dipping mechanism according to claim 3 or 4 ,
The frame drive source is a spring or an air cylinder. A die bonder dipping mechanism according to claim 3 or 4 ,
The driving means includes a pressing portion base that supports the pressing means, a pulley provided below the dipping base that supports the dipping plate, a belt disposed between the two pulleys, and one end of the pulley. A connecting portion connected to a belt and having the other end connected to one of the pressing means and the dipping plate, and a pulley drive source for driving one of the two pulleys,
Die bonder dipping mechanism. The die bonder dipping mechanism according to claim 7 ,
The pressing means connected to the connecting portion moves along a guide rail provided on the pressing portion base.
Die bonder dipping mechanism. A flip chip bonder that picks up a die having bumps from a wafer with a pick-up head, reverses the picked-up die, receives the die with a bonding head, and bonds the bumps coated with flux to a solder part of a workpiece. ,
The bonding head, the flux is applied to the bump at the receiving portion of the die bonder for dipping mechanism according to any one of claims 1 to 8,
Flip chip bonder characterized by that.

Images