JP6385885B2 - Bonding equipment - Google Patents

Description

  The present invention relates to a bonding apparatus for bonding a chip such as a semiconductor chip to a substrate such as a lead frame.

  A bonding apparatus for bonding a chip to a lead frame, for example, as disclosed in Patent Document 1, conveys an island of a lead frame to a paste application position, applies the paste to the island, and further attaches the island to a bonding position. The chip is bonded to the island. At the paste application position and the bonding position, the lead frame is supported from below by a backup plate in order to stabilize the paste application operation and the bonding operation.

  By the way, conventionally, there is a type in which a thermoplastic adhesive is attached in advance to the back surface of a chip, and the substrate is heated and bonded. In such a case, even if an attempt is made to evacuate through the suction hole provided in the backup plate and the substrate is sucked to the backup plate, heating the substrate causes a so-called warpage, that is, a bulging displacement to the substrate. There is a risk of doing so.

  When the substrate is warped, the observation of the island (chip bonding portion) is not stable, and the chip may not be bonded to an accurate position. Therefore, there is a conventional technique in which a substrate is brought into close contact with a backup plate by holding the substrate with a substrate press.

JP 2000-150545 A

  However, the conventional pressing means presses the periphery of each chip bonding portion so that each island (chip bonding portion) does not float from the backup plate. For this reason, if the chip mounting density is large and the chip bonding sites are close to each other, it cannot be pressed.

  SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a bonding apparatus that can attach a substrate to a backup plate even when the chip mounting density is large and can perform a highly accurate bonding operation.

  The bonding apparatus of the present invention includes a conveying means for conveying a substrate onto an adapter plate, an adsorption means for adsorbing the substrate that has been conveyed on the adapter plate by the conveying means, onto the adapter plate, and the substrate to which the adapter plate is attached. A bonding device comprising heating means for bonding a chip disposed at a chip bonding site of the substrate to the chip bonding site, and a substrate pressing unit for pressing the substrate, The substrate pressing means has a pair of pressing pieces that hold both sides parallel to the substrate transport direction, and the pressing force in the direction that separates both sides by pressing the both sides with the pair of holding pieces. Is given.

  According to the bonding apparatus of the present invention, the substrate transported on the adapter plate by the transport means is adsorbed on the adapter plate via the suction means, and the substrate is heated by the heating means. The chip can be bonded to the chip bonding site. In addition, since the pressing force in the direction of separating the side portions is applied by pressing the both side portions of the substrate with the pair of pressing pieces of the substrate pressing device, the suction force of the suction device and the pressing force of the substrate pressing device are applied. In cooperation with pressure, the substrate can be brought into close contact with the adapter plate.

  The pair of pressing pieces of the substrate pressing means is composed of inclined pieces that are sequentially separated from the upper side to the lower side. When the pressing force is applied, the angle formed between the inner surface of the inclined piece and the substrate is reduced, and the pressing force is released. What returns to an initial state with the restoring force is preferable.

  The pair of pressing pieces of the substrate pressing means may be connected by a connecting bar extending in a direction orthogonal to the substrate transport direction. By setting in this way, a pair of pressing pieces can be integrated.

  It is preferable that the lower end surfaces of the pair of pressing pieces of the substrate pressing means and the substrate make surface contact. By setting in this way, the contact area between the lower end surface and the substrate can be increased.

  It is preferable that at least the lower end surfaces of the pair of pressing pieces of the substrate pressing means are provided with high sliding resistance means for reducing relative displacement due to sliding with the substrate. The high sliding resistance means may be constituted by an uneven portion provided on the lower end surface of the pressing piece, or may be constituted by a high friction coefficient material provided on the lower end surface of the pressing piece.

  It is preferable that the substrate pressing means is formed with an observation opening for recognizing the substrate by the recognition means.

  In the present invention, the substrate can be brought into close contact with the adapter plate in cooperation with the adsorption force of the adsorption unit and the pressing force of the substrate holding unit, so that even if the island arrangement density is high, it is stable. Thus, chip bonding work can be performed, the apparatus operating rate can be improved, the substrate pattern can be recognized accurately, and a highly accurate chip mounting function can be exhibited.

  When the pressing force is applied, if the angle formed between the inner surface of the inclined piece and the substrate is small, the application of the pressing force in the direction in which the side portion is separated from the substrate is stable. Moreover, since the pressing force is released and the restoring force returns to the initial state, the function of bringing the substrates sequentially conveyed onto the adapter plate can be stably functioned over a long period of time.

  In the case where the pair of pressing pieces are integrated, the pressing force in the direction of separating the side portions can be equally applied to each side portion, and the substrate can be stably brought into close contact. In the case where the lower end surface of the pressing piece makes surface contact with the substrate, the contact area between the lower end surface and the substrate can be increased, and the application of the pressing force in the direction of separating the side portions is stable.

  If the high sliding resistance means is applied, the application of the pressing force in the direction of separating the side portions is more stable. If the observation opening that can recognize the substrate by the recognition means is formed, the alignment can be surely performed through the observation opening.

It is a simplified block diagram of the bonding apparatus of this invention. It is a simplified top view which shows the relationship between the board | substrate of the said bonding apparatus of FIG. 1, an adapter plate, and a pressing piece. 1A and 1B show a bonding process using the bonding apparatus of FIG. 1, wherein FIG. 1A is a simplified view of a main part before the pressing piece is pressed, and FIG. 1 shows a pressing piece of the bonding apparatus of FIG. 1, (a) is an enlarged cross-sectional view of a pressing piece not provided with high sliding resistance means, and (b) is a pressing piece provided with high sliding resistance means. It is an expanded sectional view. The bonding process using the bonding apparatus of a reference example is shown, (a) is a main part simplified diagram before pressing of the pressing piece, and (b) is a main part simplified diagram of the pressing state by the pressing piece.

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

  1 to 4, the bonding apparatus according to the present invention transports the substrate 1 onto the adapter plate 2 and transports the adapter 1 onto the adapter plate 2 using the transport means 3 as shown in FIGS. 1 and 2. The adsorption means 4 for adsorbing the substrate 1 that has been formed on the adapter plate 2 and the chip disposed on the island (chip bonding portion) 10 of the substrate 1 by heating the substrate 1 through the adapter plate 2. Is provided with a heating means 5 for adhering to the chip bonding portion and a substrate pressing means 6 for pressing the substrate 1.

  As the substrate 1, a plurality of islands (chip bonding portions) 10 are formed at a predetermined pitch along the longitudinal direction (conveying direction) and the width direction (direction orthogonal to the longitudinal direction). In the illustrated example, four island groups 11 arranged at a predetermined pitch along the width direction are arranged at a predetermined pitch in the longitudinal direction. The lead frame is a thin metal used as an internal wiring of a semiconductor package. For this reason, in the present invention, the board 1 includes a board generally called a lead frame and a board (for example, a printed board) on which various electronic components are arranged.

  The transport unit 3 includes, for example, a clamp mechanism that clamps the substrate 1 and a drive mechanism that moves the clamp portion of the clamp mechanism from the upstream side toward the downstream side. For example, a servo motor or the like can be used as the drive mechanism, and the substrate 1 can be sent to the downstream side at an arbitrary pitch (set pitch) under the control of the control means 7 (see FIG. 1). That is, the board | substrate 1 moves along the arrow A direction, and can send one island group 11 on the adapter plate 2 sequentially.

  The conveying means 3 may include a feeder such as a belt feeder including a driving wheel, a driven wheel, and a belt wound around them, and a driving mechanism for driving the feeder. . In this case, if the board | substrate 1 is supplied to a feeder, it will be arrange | positioned on a feeder in the state positioned by the positioning means (For example, the pin etc. which fit in the through-hole formed in a board | substrate). As the driving mechanism, for example, a servo motor or the like can be used, and the driving wheel of the feeder is driven at an arbitrary rotation angle set by the control of the control means 7 so that the substrate 1 can be driven at an arbitrary pitch (set pitch). Can be sent downstream. In addition, when using a feeder, feeders other than a belt feeder may be sufficient.

  The control means 7 is, for example, a microcomputer in which a ROM (Read Only Memory), a RAM (Random Access Memory), and the like are connected to each other via a bus with a central processing unit (CPU) as a center. The control means 7 is provided with a storage device as storage means. The storage device includes an HDD (Hard Disc Drive), a DVD (Digital Versatile Disk) drive, a CD-R (Compact Disc-Recordable) drive, an EEPROM (Electronically Erasable and Programmable Read Only Memory), and the like. The ROM stores programs executed by the CPU and data.

  As shown in FIG. 3, the heating means 5 includes a plate 13 in which a heater wire 12 is housed, and the adapter plate 2 is disposed on the plate 13. The adapter plate 2 is provided with a number of suction holes 15, each suction hole 15 is connected to a connection hole, and a vacuum generator (vacuum source) is connected to the connection hole. For this reason, the suction force which attracts | sucks the board | substrate 1 from each suction hole 15 like the arrow B acts by the drive of this vacuum generator.

  The substrate pressing means 6 for pressing the substrate 1 can be configured by a pair of pressing pieces 16 and 16 for pressing both side portions 1a and 1b parallel to the conveyance direction of the substrate 1. In this case, the pair of pressing pieces 16, 16 are inclined pieces that are sequentially spaced from the upper side to the lower side, and are connected via a pair of connecting bars 17, 17 arranged along the width direction of the substrate 1. ing. The connection bars 17, 17 connect the upper portions of both end portions (end portions in the substrate transport direction) of the pressing pieces 16, 16. For this reason, as shown in FIG. 1, the holding pieces 16 and 16 and the connecting bars 17 and 17 constitute a rectangular frame 20 in plan view.

  For this reason, as the substrate pressing means 6, all the islands 10 of one island group 11 are formed with observation openings 21 that can recognize the substrate by a recognition means (not shown). The recognition means is provided with an observation camera, can move along the width direction of the substrate 1, and can observe all the islands 10 of one island group 11.

  Incidentally, the inclination angle θ (see FIG. 4A) of the pressing pieces 16 and 16 of the substrate pressing means 6 is set to about 70 ° in this embodiment. And as the lower end surfaces 16a and 16a of the pressing pieces 16 and 16, it is set as the horizontal surface shape according to the inclination-angle of this pressing pieces 16 and 16. FIG.

  In this case, depending on the material of the pressing pieces 16 and 16, as shown in FIG. 4B, the high sliding resistance means 18 reduces the relative displacement due to sliding between the lower end surfaces 16a and 16a and the substrate. It may be preferable to apply. As the high sliding resistance means 18, it can comprise by the uneven | corrugated | grooved part provided in the lower end surfaces 16a and 16a of the pressing pieces 16 and 16, for example. Moreover, you may comprise with the high friction coefficient material provided in the lower end surfaces 16a and 16a of the holding | suppressing pieces 16 and 16. The high friction coefficient material can be composed of a rubber material or a resin material.

  The rectangular frame 20 is provided with vertical movement means (not shown). That is, the rectangular frame 20 can be moved up and down as shown by the arrow C in FIG. The vertical movement means can be composed of, for example, a cylinder mechanism in which the rod expands and contracts along the vertical direction, and a rolling body that is connected to the rod of the cylinder mechanism and transmits the vertical movement of the rod to the rectangular frame body 20. At this time, it is necessary to configure the vertical movement means so as not to obstruct the observation of each island by the observation camera and the collet 22 described later. For this reason, the cylinder mechanism needs to be disposed at a position shifted in the lateral direction of the substrate 1 and set so that the rolling element does not enter the inside of the rectangular frame 20 from the cylinder mechanism.

  Further, the chip adsorbed by the collet 22 (see FIG. 3B) is supplied to the island 10 of the substrate 1. The collet 22 is vacuum-sucked through a suction hole opened in its lower end surface, and the chip is adsorbed on the lower end surface of the collet 22. When this vacuum suction (evacuation) is released, the chip is detached from the collet 22.

  The collet 22 is provided with an unillustrated arm, through which horizontal reciprocation and vertical reciprocation are possible. For this reason, after the chip in the chip supply unit is adsorbed by the collet 22, the chip is positioned above the island 10 to be bonded, and then the collet is lowered to release the suction. Chips can be supplied to the power island 10.

  Next, a bonding method using the bonding apparatus configured as described above will be described. In this case, the control means 7 controls the means such as the transport means 3, the suction means 4, the heating means 5, the substrate pressing means 6, the collet operation means, and the confirmation means to perform the following operations. Do. First, the transport unit 3 transports the island group 11 at the most downstream end onto the backup plate 2 as shown in FIG. At this time, the island 10 of the lead frame 1 to be bonded is observed with an observation camera positioned above the observation opening 21 and the collet 22 is positioned on the island.

  Further, the substrate 1 is heated by energizing the heater wire 12 of the plate 13 of the heating means 5. At this time, the rectangular frame 20 of the pressing means 6 is lowered as shown by an arrow C1 in FIG. 1A, and the substrate 1 is moved as shown by an arrow A through the suction holes 15 provided in the adapter plate 2. Suction.

  By the way, when the board | substrate 1 is heated, as shown to Fig.3 (a), curvature will generate | occur | produce so that the board | substrate 1 may swell to the anti-adapter plate side. However, by lowering the rectangular frame body 20 of the pressing means 6, the inclination angle θ of the pair of pressing pieces 16 and 16 of the rectangular frame body 20 becomes smaller as shown in FIG. For this reason, the lower end surface 16a that is in surface contact with the substrate 1 is pressed in the direction of arrow D, whereby the substrate 1 has a pressing force in the direction in which the side portions 1a and 1b are separated from each other (arrow E direction). Is granted.

  As described above, when the both side portions 1a and 1b of the substrate 1 are given a pressing force in the direction of arrow E, tension is applied to the substrate 1 so that the warp is eliminated, and along with this, the suction holes 15 are interposed. As shown in FIG. 3B, the substrate 1 comes into close contact with the adapter plate 2 by the suction.

  In this close contact state, a bonding operation is performed. In other words, the position of the island 10 of the substrate 1 can be confirmed by the image recognition camera that constitutes the confirmation means through the observation opening 21, and the chips adsorbed by the collet 22 can be supplied to the island 10.

  When the bonding of the chip to all the islands 10 in the most downstream island group 11 is completed, the rectangular frame 20 of the pressing means 6 is raised as indicated by an arrow C2 shown in FIG. When the rectangular frame 20 is raised in this way, the holding pieces 16 and 16 return to the original state (free state) as indicated by the phantom line in FIG. That is, the inclination angle θ of the pressing pieces 16, 16 returns to the original 70 °.

  Thereafter, the substrate 1 is transported by one pitch, the next island group 11 is transported onto the adapter plate 2, and a chip is bonded to the island 10 of the island group 11 by performing the same process as described above. be able to. Thereafter, the chip can be bonded to the island 10 of the substrate 1 by sequentially performing the above steps.

  In the present invention, if the substrate 1 conveyed on the adapter plate 2 by the conveying means 3 is adsorbed on the adapter plate 2 via the adsorption means 4, and the substrate 1 is heated by the heating means 5, A chip can be bonded to the chip bonding site 10 of the substrate 1. Moreover, since the pair of pressing pieces 16, 16 of the substrate pressing means 6 presses the side portions 1 a, 1 b of the substrate 1, a pressing force in the direction of separating the side portions 1 a, 1 b is applied. The substrate 1 can be brought into close contact with the adapter plate 2 in cooperation with the suction force of 4 and the pressing force of the substrate pressing means 6. For this reason, even if the arrangement density of the islands 10 is high, the chip bonding operation can be performed stably, and the device operating rate is improved. In addition, the substrate pattern can be accurately recognized, and a highly accurate chip mounting function can be exhibited.

  When the pressing force is applied, the angle θ formed between the inner surface 16b of the inclined piece (the pressing piece 16) and the substrate 1 is reduced, so that the pressing force in the direction of separating the side portions 1a and 1b from the substrate 1 is applied. Stabilize. In addition, since the restoring force returns to the initial state when the pressing force is released, the function of bringing the substrates 1 sequentially conveyed onto the adapter plate 2 can be stably functioned over a long period of time.

  Since the pair of pressing pieces 16 and 16 are integrated, the pressing force in the direction in which the side portions 1a and 1b are separated can be equally applied to the side portions 1a and 1b, and the substrate 1 can be stabilized. Can be in close contact. Since the lower end surfaces 16a and 16a of the pressing pieces 16 and 16 make surface contact with the substrate 1, the contact area between the lower end surfaces 16a and 16a and the substrate 1 can be increased. Applying a pressing force in the direction of separating the side portions 1a and 1b is stable.

  Further, as shown in FIG. 4B, when the high sliding resistance means 18 is applied, the application of the pressing force in the direction in which the side portions 1a and 1b are separated from each other becomes more stable. The rectangular frame 20 is formed with an observation opening 21 that can be recognized by the recognition means of the substrate 1, so that the alignment can be reliably performed through the observation opening 21.

  FIG. 5 shows a reference example. In this case, the pressing pieces 16 </ b> A and 16 </ b> A of the rectangular frame 20 of the pressing means 6 extend along the vertical direction with respect to the adapter plate 2. By the way, when the adhesive to be used is not a thermoplastic adhesive, it is not necessary to heat the substrate 1. In such a case, no warpage of the substrate 1 occurs, so that even when the pressing means 6 as shown in FIG. Work can be performed, and the device operation rate is improved. In addition, the substrate pattern can be accurately recognized, and a highly accurate chip mounting function can be exhibited.

  However, when the substrate 1 is heated using a thermoplastic adhesive, the substrate 1 is warped as shown in FIG. When the warp occurs in this way, the pressing pieces 16A and 16A extend along the vertical direction with respect to the adapter plate 2, and the pressing force in the direction in which the side portions 1a and 1b are separated from the substrate 1 is used. Cannot be granted. For this reason, even if there is a suction action from the suction hole 15, it is difficult to make the substrate 1 adhere to the adapter plate 2 as shown in FIG. For this reason, as shown in FIG. 3, it is preferable to use pressing pieces 16, 16 made of inclined pieces that are sequentially separated from the upper side to the lower side.

  As described above, the embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the arrangement pattern of the islands 10 is not limited to the illustrated example. Rather, the number of island groups 11 and the number of islands in each island group 11 can be increased or decreased arbitrarily. The adhesive may be applied to the island 10 of the substrate 1 or may be applied to the back surface of the chip.

  As the material of the rectangular frame 20, the pressing pieces 16, 16 are elastically deformed by lowering the rectangular frame 20 from the state shown in FIG. As shown in FIG. 3B, the angle θ formed between the inner surface 16b of the inclined piece 16 and the substrate 1 becomes small, the warp of the substrate 1 can be corrected, and the rectangular frame 20 is lifted to increase its holding force. Various materials such as metal, rubber, and resin can be used as long as they return to the initial state by the restoring force upon release and are not deformed by heating of the adapter plate 2.

  Further, since it is not preferable that the lower end surfaces 16a and 16a of the pressing pieces 16 and 16 are in sliding contact with the substrate 1, only the lower end surfaces 16a and 16a are used to cover the entire pressing pieces 16 and 16 as the rectangular frame 20. The material may be made of a material having a high sliding resistance, and the other part may be made of a material that is not a material having a high sliding resistance. That is, the rectangular frame 20 may be formed of one material or two or more materials.

  The inclination angle θ of the holding pieces 16 and 16 in the free state is not limited to 70 ° as in the embodiment, and by pushing down the rectangular frame 20, the direction of the arrow F shown in FIG. As long as the pressing force is applied and the pressing force is released, the restoring force can be used to return to the initial state, and various changes can be made according to the material, the thickness of the pressing pieces 16, 16 and the length. For this reason, the thickness, length dimension, etc. of the pressing pieces 16, 16 can be arbitrarily changed. Moreover, in the said embodiment, although the pressing pieces 16 and 16 are connected by the connection bars 17 and 17 and comprise the rectangular frame 20, it does not connect as a pair of pressing pieces 16 and 16, but separates. It may be.

  As the suction holes 15, the number of suction holes 15 and the positions of the suction holes 15 are only required when the substrate 1 is stretched by the pressing pieces 16, 16 so that the substrate 1 can be sucked closely to the adapter plate 2. The diameter of the suction hole 15 can be arbitrarily set. Moreover, as a connection hole which connects each adsorption | suction hole 15, the concave groove formed in the lower surface of the adapter plate 2 may be sufficient as the concave groove formed in the upper surface of a heater plate.

1 Board (lead frame)
2 Adapter plate 3 Conveying means 4 Adsorbing means 5 Heating means 6 Substrate pressing means 10 Island 16 Pressing piece 16a Lower end surface 18 High sliding resistance means 20 Rectangular frame 21 Observation opening

Claims (8)

A conveying means for conveying the substrate onto the adapter plate, an adsorption means for adsorbing the substrate conveyed on the adapter plate by the conveying means on the adapter plate, and heating the substrate through the adapter plate, A heating device for bonding a chip disposed at a chip bonding site of a substrate to the chip bonding site, and a substrate pressing unit for pressing the substrate,
The substrate pressing means has a pair of pressing pieces for pressing both side portions parallel to the substrate transport direction, and pressing the both side portions with the pair of pressing pieces makes it possible to separate the both side portions. A bonding apparatus, wherein pressure is applied.   The pair of pressing pieces of the substrate pressing means is composed of inclined pieces that are sequentially separated from the upper side to the lower side. When the pressing force is applied, the angle formed between the inner surface of the inclined piece and the substrate is reduced, and the pressing force is released. The bonding apparatus according to claim 1, wherein the initial state is restored by the restoring force.   3. The bonding apparatus according to claim 1, wherein the pair of pressing pieces of the substrate pressing unit are connected by a connecting bar extending in a direction orthogonal to the substrate transport direction.   The bonding apparatus according to any one of claims 1 to 3, wherein a lower surface of the pair of pressing pieces of the substrate pressing means and the substrate are in surface contact.   5. The bonding according to claim 4, wherein high sliding resistance means for reducing relative displacement due to sliding with the substrate is applied to at least lower end surfaces of the pair of pressing pieces of the substrate pressing means. apparatus.   6. The bonding apparatus according to claim 5, wherein the high sliding resistance means is constituted by an uneven portion provided on a lower end surface of the pressing piece.   6. The bonding apparatus according to claim 5, wherein the high sliding resistance means comprises a high coefficient of friction material provided on the lower end surface of the pressing piece.   The bonding apparatus according to any one of claims 1 to 7, wherein the substrate pressing unit is formed with an observation opening for recognizing the substrate by the recognition unit.

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