JP3671051B2 - Electronic component bonding apparatus and bonding method - Google Patents

Description

  The present invention relates to an electronic component bonding apparatus and bonding method.

  Conventionally, in a flip chip bonding apparatus for bonding electronic components such as flip chips on a substrate, a substrate coated with flux or cream solder is positioned on the bonding stage, and the bonding point on the substrate is set. On the other hand, the flip chip is bonded via the solder bump.

  In the bonding apparatus described above, a substrate transfer apparatus using a chuck or a roller is provided. In these substrate transport apparatuses, the pair of chucks or rollers is changed from the open state to the closed state, the substrate is sandwiched and lifted from the bonding stage, and then the substrate is moved in the transport direction by one pitch in this state. Thereafter, after the substrate is lowered, the chuck or roller is opened, and after placing the substrate on the bonding stage, the chuck or roller returns to its original position. As such a prior art, it is disclosed by the technical document 1, for example.

JP-A-5-306039

  By the way, when a substrate transfer device using a chuck or a roller that is driven to open and close is used, an impact is generated when the chuck or roller opens or closes when the substrate is sandwiched or opened, and this impact is generated. In some cases, the electronic components already transmitted to the substrate are bonded to the substrate. This degrades the bonding accuracy and leads to a decrease in product yield.

  Usually, the bonding stage is heated. Then, the substrate is intermittently conveyed on the bonding stage by one pitch, but the substrate is separated from the bonding stage at the time of feeding, and is heated in contact with the bonding stage at the time of stopping feeding and at the time of bonding. Therefore, since the substrate is subjected to a periodic heating action from the bonding stage, the substrate is warped due to thermal distortion, and as a result, good bonding cannot be performed.

  Therefore, an object of the present invention is to provide an electronic component bonding apparatus and bonding method that can bond an electronic component to a substrate with good bonding accuracy and improve the yield of the product.

According to the first aspect of the present invention, there is provided a bonding apparatus for bonding an electronic component to a substrate transported in a predetermined direction. The first transport means for transporting the substrate, and the substrate transported by the first transport means. A transfer means having a bonding stage that is received and held immovably and drivable in the substrate transfer direction; and a substrate held immovably on the bonding stage driven in the substrate transfer direction. A bonding head for bonding a plurality of electronic components at a predetermined interval in the conveying direction; and a second conveying means for receiving and unloading the substrate on which the electronic components are bonded by the bonding head from the bonding stage , The substrate positioned at the bonding position by the bonding head is Characterized in the conveying means and second conveying means being positioned upward from the conveying surface level position of each substrate.
According to a second aspect of the present invention, in a bonding apparatus for bonding an electronic component to a substrate transported in a predetermined direction, the first transport means for transporting the substrate, and the first transport means for transporting the substrate. A transfer means having a bonding stage that is received and held immovably and is drivable in the substrate transfer direction, and a substrate held immovably on the bonding stage driven in the substrate transfer direction hand, comprising a bonding head for bonding a plurality of electronic components at predetermined intervals in the conveying direction, the substrate on which the electronic components in the bonding head is bonded and a second conveying means for carrying out by receiving from the bonding stage The first transport unit and the second transport unit intersect with the transport direction of the substrate. Direction comprises a pair of endless belts which are arranged at predetermined intervals, the bonding stage is characterized by being formed on entrance permitted size between the pair of belts.
According to a third aspect of the present invention, the delivery means includes a reciprocating drive means for driving the bonding stage from a position facing the bonding head to an upstream side and a downstream side in the substrate transport direction, and the bonding And a vertical drive means for driving the stage in the vertical direction,
The bonding stage ascends from the lowered position at the substrate receiving position of the first conveying means to receive the substrate, and descends from the elevated position at the substrate delivery position of the second conveying means to deliver the substrate. And
According to a fourth aspect of the present invention, the bonding stage is provided with suction holding means for sucking and holding the substrate received from the first transport means.
The invention according to claim 5 further comprises a detecting means for detecting a transport position of the substrate transported by the first transport means and positioning the substrate at a position where the substrate is delivered to the bonding stage. And
The invention described in claim 6 is characterized in that the bonding stage is provided with a heater for heating the substrate held immovably.
Further, the invention described in claim 7 is characterized in that the bonding head sucks and holds the electronic component that is inverted 180 degrees after being taken out from the electronic component supply device, and bonds the electronic component to the substrate. .
According to an eighth aspect of the present invention, there is provided a bonding method for bonding an electronic component to a substrate transported in a predetermined direction, a loading step for loading the substrate, and the loaded substrate received by a bonding stage. A step of holding the substrate immovably, a step of pitch-moving the bonding stage holding the substrate immovable in the substrate transport direction to sequentially position bonding points on the substrate at a bonding position, and a bonding position A step of sequentially bonding electronic components to the positioned bonding points; and a unloading step of receiving and unloading the substrate on which the electronic components are bonded from the bonding stage, and positioning at a bonding position by the bonding head. Is The substrate is characterized in that it is positioned above the conveying surface level position of each substrate in the loading step and unloading step of unloading the substrate for carrying the substrate.

  According to the present invention, since a plurality of electronic components can be bonded to the substrate without moving the substrate on the bonding stage, the electronic components can be bonded to the substrate with high accuracy.

  According to the present invention, electronic components can be bonded to a substrate with good bonding accuracy, and the yield can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic plan view of a flip-chip bonding apparatus to which the present invention is applied, FIG. 2 is a schematic front view of FIG. 1, FIG. 3 is a schematic plan view of a substrate transfer apparatus used in FIG. FIG.

  The flip chip bonding apparatus 10 shown in FIG. 1 and FIG. 2 is connected to a group of connected terminals (not shown) of a substrate 1 such as a lead frame and a corresponding electrode group (not shown) of a flip chip (hereinafter simply referred to as “chip”) 2. (Shown) are opposed to each other, and both are pressed and bonded.

  The flip chip bonding apparatus 10 includes a chip supply apparatus 11, a reversing unit 12, a substrate transfer apparatus 13, and a bonding head 14.

  The chip supply device 11 includes a wafer holder 20 on which a wafer ring 4 on which a wafer sheet 3 formed by sticking a plurality of chips 2 with the electrode surfaces facing upward is placed, and a wafer ring on which the wafer sheet 3 is stretched. 4 has a wafer transfer 21 for supplying and discharging 4 to / from the wafer holder 20.

  The reversing unit 12 sucks and takes out the chip 2 located on the wafer holder 20 by the suction nozzle 12A, and can rotate the chip 2 sucked by the suction nozzle 12A by 180 degrees by the rotation of the rotary head 12B. That is, the reversing unit 12 can move between the chip take-out position where the chip 2 is taken out from the wafer holder 20 and the chip transfer position where the chip 2 can be delivered to the bonding head 14 by this rotational movement. Has been.

  As shown in FIGS. 3 and 4, the substrate transfer apparatus 13 includes a first transfer unit 22, a second transfer unit 23, and a delivery unit 24. The first transport unit 22 and the second transport unit 23 are configured by a pair of endless belts 26 and 31 that are spaced apart at a predetermined interval in a direction intersecting the transport direction of the substrate 1. Is constituted by a bonding stage 36 to be described later.

  A first transport unit 22 is disposed upstream of the substrate 1 in the transport direction, a second transport unit 23 is disposed downstream, and a transfer unit 24 is disposed between the first and second transport units 22 and 23. The

  The first conveying means 22 activates the first motor 25 to cause the pair of belts 26 to run endlessly and convey the substrate 1 in the conveying direction H. In FIG. 3, reference numeral 22A denotes a guide rail for guiding the substrate 1 to be conveyed. A fixing stopper 27 is provided in the vicinity of the final end of the belt 26. A movable stopper 28 is disposed near the intermediate point of the belt conveyor 26. The movable stopper 28 is driven in the upward direction indicated by the arrow J1 by the operation of an actuator 29 such as a cylinder, and its tip can protrude above the conveyance surface of the substrate 1 conveyed by the belt 26, and the arrow J2 It can also be driven in the downward direction indicated by.

  The second transport unit 23 causes the belt 31 to travel endlessly by starting the second motor 30 and transports the substrate 1 in the transport direction H. In FIG. 3, reference numeral 23A denotes a guide rail for guiding the substrate 1 to be conveyed. Further, the substrate conveyance surface level of the belt 31 is set substantially the same as the conveyance surface level of the substrate 1 of the belt 26 of the first conveyance means 22.

  Incidentally, the transport height of the substrate 1 by the first and second transport means 22 and 23 is set to 900 ± 30 mm from the floor surface.

  As shown in FIG. 4, the delivery means 24 rotates the screw shaft 33 pivotally supported in parallel with the slide guide 32 by the third motor 34 so that the slide plate 35 on the slide guide 32 is moved to the first position. The substrate can be moved from the substrate receiving position of the transfer means 22 to the substrate transfer position of the second transfer means 23. The screw shaft 33 and the third motor 34 constitute reciprocating drive means for reciprocatingly driving the slide plate 35 to the upstream side and the downstream side in the transport direction of the substrate 1.

  Above the slide plate 35, a bonding stage 36 is provided so as to be vertically driven via a vertically driving means. That is, the vertical drive means has a pair of slide guides 37 spaced apart along the transport direction of the substrate 1 on the upper surface of the slide plate 35. A plate cam 38 is slidably provided on the slide guide 37. The plate cam 38 is driven in the horizontal direction along the slide guide 37 by an actuator 39 fixed to the slide plate 35.

  Above the slide plate 35, a bonding stage 36 is provided in which a cam follower 36a provided on the lower surface is slidably brought into contact with the plate cam 38. The bonding stage 36 is guided by the ball slide 40 in the vertical direction.

  Then, the plate cam 38 is moved horizontally by the operation of the actuator 39, so that the bonding stage 36 is driven up and down while being guided by the ball slide 40 and the horizontal surface of the upper surface thereof being kept horizontal. . As will be described later, the ascending limit position of the bonding stage 36 is a receiving level position of the substrate 1, and the descending limit position is a passing level position of the substrate 1.

  The bonding stage 36 is formed to have a size that can enter between the pair of belts 26 and 31 of the first and second conveying means 22 and 23.

  On the upper surface of the bonding stage 36, a plurality of vacuum holes 41 constituting suction holding means that can hold the substrate 1 by vacuum suction are formed at predetermined intervals along the transport direction of the substrate 1. Each vacuum hole 41 is connected to a vacuum pump (not shown) via a switching device (not shown). Therefore, the bonding stage 36 can hold and fix the substrate 1 on the upper surface of the bonding stage 36 so as to be immovable by the suction force generated in the vacuum hole 41. The bonding stage 36 includes a heater 41a so that the substrate 1 held on the bonding stage 36 can be heated.

  First to third substrate detection sensors 42, 43, and 44 that detect the presence or absence of the substrate 1 are disposed in the vicinity of the upstream sides of the first transport unit 22, the movable stopper 28, and the fixed stopper 27. A fourth substrate detection sensor 45 that detects the presence or absence of the substrate 1 is disposed on the downstream side of the second transport unit 23. These sensors 42 to 45 constitute detection means.

  Each of the substrate detection sensors 42 to 45 can be, for example, a reflective optical non-contact sensor. The detection signals of the substrate detection sensors 42 to 45 are sent to a control device (not shown), and the motors 25, 30, 34, actuators 29, 39, etc. described above are processed by the control device in the following procedure. Controlled by.

  Next, the operation of the substrate transfer apparatus 13 described above will be described.

  The substrate 1 is supplied from a supply unit (not shown) by a substrate absence signal from the first substrate detection sensor 42 and is carried in by a belt 26 constituting the first transfer unit 22. At this time, the movable stopper 28 protrudes upward by the operation of the actuator 29. Therefore, the substrate 1 hits the movable stopper 28 and stops.

  Next, based on the AND condition of the substrate presence signal from the second substrate detection sensor 43 and the substrate absence signal from the third substrate detection sensor 44, the movable stopper 28 is lowered in the direction of arrow J2. As a result, the substrate 1 is transported further downstream by the first transport means 22, hits the fixed stopper 27 and stops again. That is, the substrate 1 is positioned at the substrate receiving position.

  Next, based on the substrate presence signal from the third substrate detection sensor 44, the third motor 34 rotates in the reverse direction, and the bonding stage 36 is stopped by the fixed stopper 27 as shown by a chain line in FIG. Position below the substrate 1. At this time, the upper surface of the bonding stage 36 is positioned at a position lower than the lower surface position of the substrate 1 stopped by the fixing stopper 27, that is, a delivery level position of the substrate 1 by the operation of the actuator 39.

  Thereafter, the bonding stage 36 moves up so as to enter between the pair of belts 26 of the first conveying means 22. Due to this rise, the upper surface level of the bonding stage 36 is positioned at a position higher than the transport surface level of the substrate 1 in the first transport means 22, that is, the reception level position of the substrate 1. It is transferred to the bonding stage 36 while being scooped up from the belt 26 of the first conveying means 22. At this time, a vacuum pressure acts on the vacuum hole 41 formed on the upper surface of the bonding stage 36, and the substrate 1 is vacuum-adsorbed on the upper surface of the bonding stage 36 so as not to move.

  The substrate 1 sucked and held by the bonding stage 36 moves to the right as shown by H in FIG. 4 by the forward rotation of the third motor 34, and this movement causes the first bonding point on the substrate 1 on the bonding stage 36 to move. It is positioned at a bonding position by the bonding head 14 as indicated by an arrow B in FIG. Then, the chip 2 is bonded to the bonding point.

  In this chip bonding operation, the wafer ring 4 is carried to the wafer holder 20 by the wafer transfer 21, and the reversing unit 12 takes out one chip 2 affixed to the wafer sheet 3 and reverses it. The chip 2 is held by the suction nozzle 14A of the bonding head 14 and bonded onto the substrate 1.

  Thus, when the bonding operation for the first bonding point on the substrate 1 is completed, the bonding stage 36 is moved downstream by one pitch of the bonding point on the substrate 1 by the operation of the third motor 34. The next bonding point on the substrate 1 is positioned at the bonding position. Then, the chip 2 is bonded to the bonding point.

  Similarly, when the chip 2 is bonded to all bonding points on the substrate 1, the bonding stage 36 moves to the substrate transfer position to the second transfer means 23 indicated by the chain line in FIG. 1 is transferred to the second transport means 23. For this delivery, first, the bonding stage 36 at the substrate receiving level position is driven to a position above the substrate conveying surface level of the belt 31 constituting the second conveying means 23.

  Here, the vacuum hole 41 of the bonding stage 36 is cut off from the vacuum pump (not shown) by the switching of the switching device (not shown) and released to the atmosphere. Thereafter, the bonding stage 36 is lowered to the delivery level position. This delivery level position is a position below the substrate transport surface level of the belt 31 constituting the second transport means 23. Therefore, in this lowering process, the substrate 1 on the bonding stage 36 is transferred onto the bell and 31 of the second transport means 23. Thereafter, the substrate 1 is carried out downstream by the second transfer means 23.

  With respect to the second substrate 1, the movable stopper 28 rises again during the bonding of the necessary chip 2 to the first substrate 1 and is conveyed by the belt 26 to the position of the movable stopper 28. Since the movable stopper 28 descends when the signal from the third substrate detection sensor 44 changes from the substrate presence signal to the substrate absence signal, the movable stopper 28 is conveyed to the fixed stopper 27 by the belt 26. In this way, the third and subsequent substrates 1 are also transported to the fixed stopper 27 of the first transport means 22.

  The movement of the bonding stage 36 to the second transfer means 23 is controlled so as to be permitted by changing from the substrate presence signal to the substrate absence signal of the substrate detection sensor 45 arranged on the downstream side of the second transfer means 23. Is done.

  Therefore, the flip chip bonding apparatus 10 according to the present embodiment has the following effects.

  First, after the substrate 1 transferred by the first transfer unit 22 is received by the bonding stage 36 of the transfer unit 24, the substrate 1 is bonded to all the bonding points on the substrate 1 until the bonding is completed. Bonding was carried out in a state where it was adsorbed and held by 36 and integrated.

  Further, the substrate 1 is transferred to the belt 31 by positioning the bonding stage 36 of the transfer means 24 at a position lower than the upper position of the substrate transfer surface level of the belt 31 constituting the second transfer means 23. Thereby, the bonding to the substrate 1 can be performed without giving an impact to the substrate 1. Moreover, the board | substrate 1 after bonding can be carried out.

  Accordingly, since it is possible to prevent the electronic component already bonded to the substrate 1 from being displaced, it is possible to improve the bonding accuracy and improve the product yield.

  Second, the substrate 1 held on the bonding stage 36 is sucked and held on the bonding stage 36 until the bonding to all bonding points on the substrate 1 is completed, and is integrated so as not to move. Therefore, in the type in which the substrate 1 is heated by the bonding stage 36, the substrate 1 is not subjected to the conventional periodic heating action. Therefore, it is possible to prevent the substrate 1 from warping due to heat distortion, and as a result, good bonding can be performed.

  Further, when the pitch of the substrate 1 is moved, the conventional impact to the substrate 1 is avoided, so that the bonding accuracy can be improved even in a bonding operation that does not require heating of the substrate 1. Product yield can be improved.

  Thirdly, by positioning the bonding stage 36 of the delivery means 24 at a position higher than the position below the substrate transport surface level of the belt 26, the bonding stage 36 receives the substrate 1 carried by the first transport means 22, The bonding stage 36 holds the substrate 1 and conveys it. Further, the bonding stage 36 of the delivery means 24 is positioned below the position above the substrate conveyance surface level of the belt 31, so that the second conveying means 23 The substrate 1 is transferred to the belt 31.

  That is, the movement of the transfer means 24 allows the substrate 1 to be received from the first transfer means 22 to the transfer means 24 and the transfer of the substrate 1 from the transfer means 24 to the second transfer means 23. Can be simplified.

  Further, in the case of such receiving and delivering operations, it is not necessary to accurately match the transport surface level of the substrate 1 between the belts 26 and 31 constituting the first transport unit 22 and the second transport unit 23. Since the level adjustment time becomes unnecessary, the adjustment time can be shortened, and the conveyance trouble due to the mismatch of the conveyance surface level of the substrate 1 can be avoided.

  Fourth, the transport height of the substrate 1 by the first and second transport means 22 and 23 is set to a relatively low height of 900 ± 30 mm from the floor surface. Therefore, for example, when the reversal radius of the reversing unit 12 is 100 mm, the chip surface level in the chip supply device 11 is 700 mm from the floor surface, which is lower than the conveyance height of the substrate 1 by the distance reversed by the reversing unit 12. it can. Since this height is suitable for work from an ergonomic point of view, even if the wafer ring 4 is heavy, it can be easily attached to and detached from the apparatus.

  Although the embodiment of the present invention has been described in detail above, the specific configuration of the present invention is not limited to this embodiment, and the present invention can be changed even if the design is changed without departing from the gist of the present invention. include.

  For example, although the substrate detection sensor described above has been described as a reflective sensor, the substrate may be detected by a transmission sensor.

  Further, the holding of the substrate has been described by vacuum adsorption, but when the substrate is a magnetic body, a magnet may be used for holding.

  In the case where the substrate shape cannot be vacuum-sucked or a bent substrate or the like, a clamping mechanism may be provided on the bonding stage, and the substrate on the bonding stage may be pressed onto the bonding stage by this clamping mechanism.

  In addition, when bonding a plurality of chips to the substrate, the bonding stage is driven at a predetermined pitch in the substrate transport direction. Instead of the bonding stage, the bonding head is driven in the substrate transport direction to drive the plurality of chips. Bonding may be performed.

  Further, the present invention is not limited to the flip chip bonding apparatus described in the embodiment, but can be applied to bonding without reversing electronic components.

1 is a schematic plan view of a flip chip bonding apparatus to which the present invention is applied. The schematic front view of FIG. FIG. 2 is a schematic plan view of a substrate transfer device used in FIG. 1. FIG. 4 is a schematic front view of FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Board | substrate, 2 ... Chip, 3 ... Wafer sheet, 4 ... Wafer ring, 10 ... Flip chip bonding apparatus, 11 ... Chip supply apparatus, 12 ... Reversing unit, 12A ... Adsorption nozzle, 12B ... Rotating head, 13 ... Substrate conveyance 14: Bonding head, 14A: Suction nozzle, 20 ... Wafer holder, 21 ... Wafer transfer, 22 ... First transfer means, 23 ... Second transfer means, 24 ... Delivery means, 25 ... First motor, 26 ... belt, 27 ... fixed stopper, 28 ... movable stopper, 29 ... actuator, 30 ... second motor, 31 ... belt, 32 ... slide guide, 33 ... screw shaft, 34 ... third motor, 35 ... slide plate, 36 ... Bonding stage, 37 ... Slide guide, 38 ... Plate cam, 39 ... Actuator, 40 ... Ball slurry De, 41 ... Vacuum holes, 42 ... first substrate detection sensor, 43 ... second substrate detection sensor, 44 ... third substrate detection sensor, 45 ... fourth substrate detection sensor.

Claims (8)

In a bonding apparatus for bonding electronic components to a substrate conveyed in a predetermined direction,
First conveying means for carrying in the substrate;
A delivery means having a bonding stage provided to receive the substrate carried by the first transport means and hold it immovable and to be driven in the transport direction of the substrate;
A bonding head for bonding a plurality of electronic components at a predetermined interval in the transport direction to the substrate held immovably on the bonding stage driven in the transport direction of the substrate;
And a second transfer means for receiving and carrying out the substrate on which the electronic component is bonded by the bonding head from the bonding stage, and the substrate positioned at the bonding position by the bonding head is the first transfer means. And an electronic component bonding apparatus characterized by being positioned above a transport surface level position of each substrate in the second transport means . In a bonding apparatus for bonding electronic components to a substrate conveyed in a predetermined direction,
First conveying means for carrying in the substrate;
A delivery means having a bonding stage provided to receive the substrate carried by the first transport means and hold it immovable and to be driven in the transport direction of the substrate;
A bonding head for bonding a plurality of electronic components at a predetermined interval in the transport direction to the substrate held immovably on the bonding stage driven in the transport direction of the substrate;
A second transfer means for receiving and carrying out the substrate on which the electronic component is bonded by the bonding head from the bonding stage , wherein the first transfer means and the second transfer means are in the transfer direction of the substrate; An electronic component comprising a pair of endless belts arranged at a predetermined interval in a direction intersecting with each other, wherein the bonding stage is formed in a size capable of entering between the pair of belts Bonding equipment. The transfer means includes a reciprocating drive means for driving the bonding stage from a position facing the bonding head to an upstream side and a downstream side in the substrate transport direction, and a vertical drive means for driving the bonding stage in the vertical direction. With
The bonding stage ascends from the lowered position at the substrate receiving position of the first conveying means to receive the substrate, and descends from the ascending position at the substrate delivery position of the second conveying means to deliver the substrate. The electronic component bonding apparatus according to claim 1 or 2. To the bonding stage, a bonding apparatus for an electronic component according to any of claims 1 to 3, characterized in that the substrate received from the first conveying means suction holding means for holding suction is provided. To any one of claims 1 to 4, characterized in that it comprises a detecting means for positioning the first detector to the substrate transfer position of the substrate transported by the transport means to a position to pass on the bonding stage A bonding apparatus for electronic components as described. To the bonding stage, a bonding apparatus for an electronic component according to any of claims 1 to 5, characterized in that the heater for heating the immovably retained substrate is provided. The bonding head, the electronic component 180 electronic components is inverted after removal from the supply device and held by suction, according to any one of claims 1 to 6, characterized in that the bonding to the substrate Electronic component bonding equipment. In a bonding method for bonding an electronic component to a substrate conveyed in a predetermined direction, a loading step for loading the substrate ,
Receiving the carried substrate by the bonding stage, and holding the immovable substrate on the bonding stage;
Positioning the bonding points on the substrate sequentially at bonding positions by pitch-moving the bonding stage holding the substrate immovable in the transport direction of the substrate;
A step of sequentially bonding electronic components to the bonding point positioned at the bonding position;
An unloading step of receiving and unloading the substrate on which the electronic component is bonded from the bonding stage;
The electronic component positioned at a bonding position by the bonding head is positioned above a transfer surface level position of each substrate in a carry-in process for carrying in the substrate and a carry-out process for carrying out the substrate. Bonding method.

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