JP5762185B2 - Die bonding equipment - Google Patents

Description

  The present invention relates to a structure of a die bonding apparatus.

  A semiconductor chip is bonded to a substrate such as a lead frame, and in a post-process of manufacturing a semiconductor device that connects each electrode of the semiconductor chip and the electrode of the substrate or the lead of the lead frame, the semiconductor chip is bonded to the substrate or the like. A die bonding apparatus or a bonding apparatus such as a wire bonding apparatus that connects the electrodes of a semiconductor chip bonded to a substrate or the like and the leads of the lead frame with wires is used (see, for example, Patent Document 1). Further, in the manufacture of μGBA · IC, a single point bonding apparatus or the like that presses an inner lead of a TAB tape to a semiconductor electrode is used (for example, see Patent Document 2).

  In such a wire bonding apparatus or a single point bonding apparatus, a capillary or a single point bonding tool, which is a bonding tool, is moved in a direction to be in contact with or separated from the electrode of the semiconductor chip, and the wire or inner lead is moved to the semiconductor chip. The wire or the inner lead is bonded to the electrode of the semiconductor chip by ultrasonic contact with the electrode. For this reason, it is necessary for each bonding apparatus to move the bonding tool in a direction perpendicular to the surface of the semiconductor chip. In such a conventional bonding apparatus, for example, as shown in FIG. 7 of Patent Document 1, the arm to which the bonding tool is attached is rotated, and the bonding tool attached to the tip of the arm is used as the semiconductor chip. A structure in which the electrode surface is contacted and separated substantially perpendicularly is used.

  However, in this structure, even if the arm length is increased, the tip of the bonding tool moves in an arc shape, so that it is difficult to always move the bonding tool in a direction perpendicular to the electrodes of the semiconductor chip.

  Therefore, as shown in FIG. 3 of Patent Document 1, instead of attaching the bonding tool to the tip of the rotating arm, the bonding tool is supported by two parallel springs and the capillary is perpendicular to the semiconductor chip. It has been proposed to make contact and separation. In addition, as shown in FIG. 7 of Patent Document 2, two plates are arranged in parallel, and the rigidity is increased by sandwiching the central portion between the two plates, one at each end of each of the two plates, There has been proposed a parallel link structure in which a total of four rotary hinges are formed and a single point bonding tool is moved in a direction perpendicular to the electrode surface of the semiconductor chip by the four rotary hinges.

JP 2001-127097 A JP 2000-323522 A

  By the way, a die bonding apparatus for bonding a semiconductor chip to a substrate or the like picks up a semiconductor chip from a diced wafer and bonds the picked semiconductor chip on a substrate or a lead for bonding. This die bonding apparatus uses a slider that moves in the vertical direction in order to move the bonding head attached with a collet, which is a tool for picking up and picking up the semiconductor chip, in a direction perpendicular to the surface of the semiconductor chip. Many. When picking up a semiconductor chip or bonding the semiconductor chip onto a substrate or the like, it is necessary to press the collet against the semiconductor chip with a certain pressing load. However, if a large pressing force is applied to the semiconductor chip, the semiconductor chip is damaged, so that the pressing force of the collet to the semiconductor chip can be adjusted between the collet and the bonding head by the descending distance of the bonding head. Many load springs are attached so that an excessive pressing force is not applied to the semiconductor chip when the semiconductor chip is bonded to a pickup or a substrate.

  On the other hand, in recent years, the thickness of a semiconductor chip is very thin, and its strength is decreasing. In addition, a semiconductor chip using a brittle material such as gallium arsenide has also been widely used. For this reason, there has been a problem that such a thin or fragile semiconductor chip may be damaged when a conventional pickup load is applied. However, if the load spring is weakened to reduce the pick-up load of the semiconductor, an appropriate pressing load cannot be applied due to the frictional force of the Z-direction guide that slides the collet up and down with respect to the bonding head. There has been a problem in that an excessive pressing load is temporarily applied due to the hooking of the direction guide. Further, instead of this Z direction guide, for example, when a parallel spring or parallel link as described in Patent Documents 1 and 2 is used, the bending stiffness of the parallel spring or the parallel link itself is large. When the pressure falls, the reaction force of the load spring and the deformation reaction force of the parallel link or the like are applied as the pressing force of the collet to the semiconductor chip. For this reason, the pressing force on the semiconductor chip cannot be properly adjusted depending on the descending distance of the bonding head, and a small pressing load necessary for bonding a thin or fragile semiconductor chip on a pickup or a substrate cannot be applied. However, there is a problem that it is difficult to appropriately pick up a thin or fragile semiconductor chip and bond it onto a substrate or the like.

  An object of the present invention is to appropriately pick up and bond a thin or fragile semiconductor chip in a die bonding apparatus.

The die bonding apparatus according to the present invention includes a shaft on which a bonding tool for picking up and bonding a semiconductor chip is attached to the tip, and a shaft that is attached via at least one flat plate link and moves linearly along the extending direction of the shaft. A flat plate link extending along a surface intersecting with the direction in which the shaft extends, and an annular plate fixed to the bonding head at two opposing fixed points on the outer edge, and the annular plate They are arranged on the same plane as, Ri pass the hollow portion of extending in a direction perpendicular to the direction connecting the fixed point of the annular plate to the inside of the annular plate includes a footplate that the shaft is mounted in the center thereof, a circular The plate is composed of two semi-annular plates facing each other with a jumper plate, and each fixing point is at the center of each semi-annular plate. That it is location, characterized by.

A die bonding apparatus of the present invention, passed Riita is the width becomes smaller toward both ends connected to the annular plate from the center of the connection sheet Yafuto, and also to be suitable, the annular plate, It is also preferable that the width is reduced from each fixed point toward both ends connected to the jumper plate, and the annular plate is a substantially quadrangular ring and arranged at the center of the two sides where each fixed point faces each other. This is also suitable.

  In the die bonding apparatus of the present invention, it is also preferable that the shaft is attached to the bonding head by two flat plate links spaced apart in parallel.

  The die bonding apparatus of the present invention includes a lever that is rotatably attached to the bonding head by a rotation guide, one end is connected to the shaft, and the other end is connected to a spring that applies a pressing load that presses the bonding tool against the semiconductor chip. The rotation guide is also preferably a cross leaf spring in which two leaf springs are crossed in a cross shape, and the cross leaf spring has four end points, and one of the end points is: It is also preferable that the other three end points connected to the lever are respectively attached to the bonding head.

  The present invention has an effect that a thin or fragile semiconductor chip can be appropriately picked up and bonded in a die bonding apparatus.

It is a perspective view which shows the structure of the die-bonding apparatus in embodiment of this invention. It is a perspective view which shows the flat plate link of the die bonding apparatus in embodiment of this invention. It is sectional drawing which shows the state before picking up the semiconductor chip of the die bonding apparatus in embodiment of this invention. It is sectional drawing which shows the state which picks up the semiconductor chip of the die-bonding apparatus in embodiment of this invention. It is a perspective view which shows the deformation | transformation state of the flat link of the die-bonding apparatus in embodiment of this invention. It is a side view which shows the deformation | transformation state of the flat link of the die-bonding apparatus in embodiment of this invention. It is a graph which shows the change of the press load with respect to the sinking amount of the bonding head of the die-bonding apparatus in embodiment of this invention. It is a top view which shows the flat plate link of the die bonding apparatus in other embodiment of this invention. It is a top view which shows the flat plate link of the die bonding apparatus in other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the die bonding apparatus 100 of the present embodiment includes a linear guide 62 attached to an XY-direction moving device (not shown), a slider 61 that moves in the Z direction along the linear guide 62, and a slider A bonding head 50 that is fixed to 61 and moves in the Z direction together with the slider 61 is provided. The bonding head 50 is fixed to the main body 51 fixed to the slider 61, a pair of lower arms 52 extending in the Y direction from the main body 51, a pair of upper arms 53, and the lower arms 52 with bolts 54 via bushes 55. The lower flat plate link 20, the upper flat plate link 30 fixed to the upper arm 53 by a bolt 54 via a bush 55, the shaft 12 fixed to the lower flat plate link 20 and the upper flat plate link 30, respectively, And a bonding tool 11 for adsorbing a semiconductor chip attached to the tip on the side. The lower flat link 20 and the upper flat link 30 are arranged in parallel. An end block 13 having an outer diameter larger than that of the shaft 12 is attached to the upper end of the shaft 12. The lower surface of the end block 13 on the main body 51 side is an inverted U-shaped stopper fixed to the upper arm 53 with a bolt 54. It is comprised so that it may hit 56 upper surfaces. In FIG. 1, the Z direction is a vertical direction, and the XY direction is a horizontal plane orthogonal to each other. The same applies to other drawings described below.

  A lever 40 is rotatably attached to the bonding head 50 via a cross leaf spring 45 that is a rotation guide. The distal end portion 41 (the shaft 12 side or the Y direction plus side) of the lever 40 and the end block 13 of the shaft 12 are connected by a connecting plate 49. A balance weight 48 is fixed to the rear end portion of the lever 40 (on the slider 61 side or the Y direction minus side) by bolts 42. A spring 58 for applying a pressing load for pressing the bonding tool 11 against the semiconductor chip is attached to a hole 57 provided in the lower main body 51 of the balance weight 48. The upper end of the spring 58 is in contact with the balance weight 48.

  The cross leaf spring 45 is a combination of a horizontal spring plate 46 and a vertical spring plate 47 in a cross shape, and the rear end (the slider 61 side or the Y direction minus side) of the horizontal spring plate 46 is connected to the main body 51 of the bonding head 50. The front end (the shaft 12 side or the Y direction plus side) is fixed by a bolt 42, and is fixed to the lower surface of the central block 44 of the lever 40 by the bolt 42. The lower end of the vertical spring plate 47 is fixed to the upper portion of the main body 51 of the bonding head 50 by a bolt 42, and the upper end is fixed to the vertical surface of the central block 44 of the lever 40 by the bolt 42. As described above, the cross leaf spring 45 has four ends, that is, a front end and a rear end of the horizontal spring plate 46 and an upper end and a lower end of the vertical spring plate 47, and is perpendicular to the rear end of the adjacent horizontal spring plate 46. The lower end of the spring plate 47 is fixed to the main body 51 of the bonding head 50, and the tip of the horizontal spring plate 46 and the upper end of the vertical spring plate 47 are fixed to the central block 44 of the lever 40. A line extending in the X direction intersecting the horizontal spring plate 46 and the vertical spring plate 47 serves as a rotation axis, and the cross plate spring 45 supports the lever 40 rotatably around the X axis.

  Details of the structure of the upper flat plate link 30 will be described with reference to FIG. As shown in FIG. 2, the upper flat link 30 is obtained by processing thin stainless steel, spring steel, or the like, and extends along the XY plane perpendicular to the Z direction in which the shaft 12 extends. The upper flat plate link 30 includes an annular plate 31 and a transition plate 32 that crosses the hollow portion 34 inside the annular plate 31 in the Y direction. The annular plate 31 and the crossing plate 32 are arranged in the same plane. The annular plate 31 is a substantially square ring, and each side extends in the X direction and the Y direction. The center in the longitudinal direction of the pair of first sides 31 a extending in the Y direction is fixed to the upper surface of the upper arm 53 by a bolt 54 via a bush 55. The portions of the first side 31a fixed to the upper arm 53 by the bolts 54 are fixing points 33 of the upper flat plate link 30, respectively. Further, the centers of the pair of second sides 31 b extending in the X direction of the annular plate 31 are connected in the Y direction by the crossing plate 32. The shaft 12 is fixed at the center of the transition plate 32. As shown in FIG. 2, the center line 72 of the crossover plate 32 is a line passing through the center line 71 of the shaft 12. The portion where the shaft 12 is attached to the bridge plate 32 is reinforced by the ring 14. As shown in FIG. 2, the bridge plate 32 extends in the Y direction through the center line 71 of the shaft 12, and the central portion to which the shaft 12 is fixed has a wide width toward the end connected to the annular plate 31. The taper has a smaller width. The pair of first sides 31a extending in the Y direction is such that the portion of the fixing point 33 fixed by the bolt 54 is wide, and the width of the first side 31a becomes smaller toward the second side 31b. It is configured. The two fixed points 33 and the shaft 12 are arranged on one straight line 73 and are arranged in a line in the X direction. The structure of the upper flat link 30 has been described above, but the structure of the lower flat link 20 is the same as that of the upper flat link 30.

  An operation when picking up a semiconductor chip by the die bonding apparatus 100 of the present embodiment configured as described above will be described. The parts described with reference to FIGS. 1 and 2 are denoted by the same reference numerals, and the description thereof is omitted. As shown in FIG. 3, the semiconductor chip 90 to be picked up is adsorbed and fixed on the pick-up stage 81 with a dicing tape 83 attached to the back surface. In the state where the dicing tape 83 is pulled toward the periphery, minute gaps are formed between the semiconductor chips 90. The die bonding apparatus 100 moves the bonding head 50 by means of an XY moving apparatus (not shown) so that the position of the bonding tool 11 attached to the lower end of the shaft 12 is directly above the semiconductor chip 90 to be picked up.

Next, as shown in FIG. 4, the die bonding apparatus 100 lowers the slider 61 to which the bonding head 50 is attached downward in the Z direction according to a command from a control unit (not shown). The control unit further lowers the slider 61 and the bonding head 50 by the height ΔZ _{0 after} the tip of the bonding tool 11 contacts the surface of the semiconductor chip 90. Then, as shown in FIG. 4, the shaft 12 is guided by the two flat plate links 20 and 30 and moves upward by a height ΔZ _{0 with} respect to the bonding head 50, and the end block 13 at the upper end of the shaft 12 is also high. Move upward by ΔZ ₀ . Then, only the tip portion 41 height ΔZ also ₀ of lever 40 connected by a connecting plate 49 to the end block 13 moves upward. Lever 40 is rotated around the X-axis along a line that intersects with the horizontal spring plate 46 of the cross plate spring 45 and the vertical spring plate 47, the rear end portion 43 of the lever 40 is moved by a height [Delta] Z ₅ downwards . Then, the spring 58 contracts in the Z direction by a length ΔZ ₅ , the reaction force pushes up the rear end portion 43 of the lever 40, and the end block 13 connected to the front end portion 41 of the lever 40 via the connecting plate 49, A force F ₀ is applied downward with respect to the shaft 12. Since the inside of the bonding tool 11 is evacuated by a vacuum device (not shown), when the bonding tool 11 is pressed against the surface of the semiconductor chip 90 by this force F ₀ , the bonding tool 11 sucks the semiconductor chip 90. Thereafter, when the slider 61 is raised by a control unit (not shown), the bonding tool 11 picks up the semiconductor chip 90.

5 and 6, after the bonding tool 11 contacts the surface of the semiconductor chip 90, the deformation of the upper plate link 30 and the movement of the shaft 12 when the bonding head 50 is further lowered by the height ΔZ _0. This will be described in detail. After the bonding tool 11 is in contact with the surface of the semiconductor chip 90, the bonding head 50 is lowered further by the height [Delta] Z _0, as shown in FIG. 5, even the upper arms 53 that hold the upper flat link 30 bonding tool 11 Is lowered by a height ΔZ ₀ from the height when contacting the surface of the semiconductor chip 90, so that the fixing point 33 of the upper flat plate link 30 is also higher than the height when the bonding tool 11 contacts the surface of the semiconductor chip 90. is ΔZ ₀ only drops. On the other hand, since the bonding tool 11 at the tip of the shaft 12 is in contact with the surface of the semiconductor chip 90, the shaft 12 does not descend any further, so that the center of the transition plate 32 that fixes the shaft 12 of the upper plate link 30 and two fixing points. A difference in height from that of 33 can be obtained by ΔZ ₀ . As shown in FIGS. 5 and 6A, each first side 31a whose center is fixed to the upper arm 53 by the fixing point 33 of the upper flat plate link 30 extends from the fixing point 33 to the second side 31b. It curves upwards. Moreover, as shown in FIG. 5 and FIG. 6B, the crossing plate 32 that extends between the second sides 31 b is located upward so that the central portion to which the shaft 12 is attached rises from the second side 31 b. Deforms toward Furthermore, as shown in FIG. 5 and FIG. 6B, the second side 31b faces upward so that the central part to which the crossover plate 32 is connected rises from both ends connected to the first side 31a. Deform. As shown in FIG. 6 (a), the curvature of the upper first side 31a, between the fixed point 33 and the ends or the second side 31b of the first side 31a is, [Delta] Z ₁ only high You can make a difference. Further, as shown in FIG. 6 (b), between the central portion of the opposite ends and the second side 31b of the first side 31a by swelling deformation of the second side 31b, the height difference [Delta] Z ₂ Can do. Furthermore, as shown in FIG. 6 (b), between the central transfer plates 32 mounted with the second side 31b center the shaft 12 of the raised deformation of the footplate 32, only a height of [Delta] Z ₃ There is a difference. The sum of the height differences ΔZ ₁ , ΔZ ₂ , ΔZ ₃ is the height ΔZ ₀ . That is, ΔZ ₁ + ΔZ ₂ + ΔZ ₃ = ΔZ ₀ .

Thus, the upper flat plate link 30 is formed by the bending plate 32 passed between the bending deformation of the first side 31a extending from the fixed point 33, the rising deformation of the second side 31b, and the second side 31b. The shaft 12 is moved in the Z direction by a height ΔZ _{0 with} respect to the bonding head 50 by the rising deformation. In addition, since the width of the end connected to the first side 31a and the second side 31b of the jumper plate 32 is small, links are formed at both ends of the second side 31b and both ends of the jumper plate 32, respectively. The shaft 12 is moved in the Z direction by the rotation of each link.
For this reason, the resistance with respect to the movement of the shaft 12 in the Z direction hardly occurs. Moreover, the die bonding apparatus 100 of this embodiment arrange | positions two flat plate links, the lower flat plate link 20 and the upper flat plate link 30, in parallel, and, thereby, the shaft 12 supports so that a movement to a Z direction is possible. The semiconductor chip 90 can move smoothly in a direction perpendicular to the surface. Further, as shown in FIG. 4, since the lever 40 is rotatably supported by the cross leaf spring 45, there is no frictional resistance as in the case of a rotary bearing, and almost no resistance to rotation is generated.

  Therefore, after the bonding tool 11 comes into contact with the surface of the semiconductor chip 90, the force applied to the surface of the semiconductor chip 90 when the bonding head 50 sinks by the height ΔZ is, as shown in FIG. Is directly proportional to ΔZ. That is, F = K × ΔZ. Accordingly, the control unit can accurately control the pressing load applied to the semiconductor chip 90 by controlling the sinking amount ΔZ of the bonding head 50. For this reason, when picking up a thin or fragile semiconductor chip 90, a smaller pressing load can be accurately controlled, and the thin and low strength or fragile semiconductor chip 90 can be picked up appropriately without damaging it. In addition, the die bonding apparatus 100 according to the present embodiment is worn out because there is no sliding part such as a part that slides the shaft 12 in the Z direction or supports the lever 40 in a rotational manner as in the conventional bonding apparatus. It has a long life and does not change the pressing load due to a change in frictional resistance, and can operate stably over a long period of time.

  The operation when picking up the semiconductor chip 90 by the die bonding apparatus 100 of the present embodiment has been described above. However, the operation when the semiconductor chip 90 is bonded onto a substrate or a lead frame is the same. Since the small pressing force applied can be accurately controlled, the thin, low-strength or brittle semiconductor chip 90 can be appropriately bonded onto the substrate or the lead frame without damaging it. Similarly, when further bonding a semiconductor chip on the semiconductor chip, the bonding can be appropriately performed without damaging the semiconductor chip 90.

  Another embodiment of the present invention will be described with reference to FIGS. The parts described with reference to FIG. 1 to FIG. An upper flat plate link 130 shown in FIG. 8 is formed by replacing the substantially square annular plate 31 of the upper flat plate link 30 of the embodiment described with reference to FIGS. A point 133 is provided, and a jumper plate 132 is provided so as to cross the opposing short circle. In the embodiment shown in FIG. 9, a lug 35 is provided outside the center of the first side 31 a of the embodiment described with reference to FIGS. 1 to 7, and the lug 35 is fixed to the upper arm 53. It is configured. Each of the embodiments shown in FIGS. 8 and 9 has the same effect as the embodiment described with reference to FIGS. 1 to 7.

  11 Bonding tool, 12 Shaft, 13 End block, 14 Ring, 20 Lower plate link, 21, 31, 131 Ring plate, 22, 32, 132 Cross plate, 24, 34 Hollow part, 30, 130 Upper plate link, 31a First Side, 31b second side, 33, 133 fixing point, 35 lug, 40 lever, 41 tip, 42 bolt, 43 rear end, 44 center block, 45 cross leaf spring, 46 horizontal spring plate, 47 vertical spring Plate, 48 Balance weight, 49 Connecting plate, 50 Bonding head, 51 Main body, 52 Lower arm, 53 Upper arm, 54 Bolt, 55 Bush, 56 Stopper, 57 Hole, 58 Spring, 61 Slider, 62 Linear guide, 71, 72 Center line, 73 straight lines, 81 pickup stage, 83 dies Thing tape, 90 semiconductor chips, 100 die bonding equipment.

Claims (7)

A die bonding apparatus,
A shaft on which a bonding tool for picking up and bonding a semiconductor chip is attached to the tip;
A bonding head that is attached to the shaft via at least one flat plate link and moves linearly along the direction in which the shaft extends;
The flat plate link extends along a plane that intersects the direction in which the shaft extends, and an annular plate that is fixed to the bonding head at two opposing fixing points on the outer edge ;
Is disposed in the annular plate in the same plane, Ri hollow portion of extending in a direction perpendicular to the direction connecting the respective fixing points of the annular plate to the inside of the annular plate pass, that the shaft is mounted in the center A transition board, and
The annular plate is composed of two semi-annular plates facing each other with the connecting plate interposed therebetween, and the fixing points are respectively arranged at the centers of the semi-annular plates;
A die bonding apparatus characterized by the above. The die bonding apparatus according to claim 1 ,
The footplate is the width from the center of pre-Symbol shaft is connected toward both ends connected to the annular plate is reduced,
A die bonding apparatus characterized by the above. The die bonding apparatus according to claim 1 or 2,
The annular plate has a width that decreases from each fixed point toward both ends connected to the crossover plate,
A die bonding apparatus characterized by the above. The die bonding apparatus according to any one of claims 1 to 3,
The annular plate is a substantially rectangular ring, and each of the fixed points is disposed at the center of two sides facing each other;
A die bonding apparatus characterized by the above. The die bonding apparatus according to any one of claims 1 to 4,
The shaft is attached to the bonding head by two flat link links spaced apart in parallel;
A die bonding apparatus characterized by the above. The die bonding apparatus according to any one of claims 1 to 5,
A lever that is rotatably attached to the bonding head by a rotation guide, one end is connected to the shaft, and the other end is connected to a spring that applies a pressing load that presses the bonding tool against the semiconductor chip;
The rotation guide is a cross leaf spring in which two leaf springs are crossed in a cross shape;
A die bonding apparatus characterized by the above. The die bonding apparatus according to claim 6, wherein
The cross leaf spring has four end points, of which two adjacent end points are connected to the lever, and the other two end points are respectively attached to the bonding head;
A die bonding apparatus characterized by the above.

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