Manufacturing apparatus for semiconductor device and cleaning method for substrate

Abstract

The present invention provides a manufacturing apparatus for a semiconductor device and a method for cleaning a substrate, capable of more effectively cleaning the back surface of the substrate before mounting a chip. The manufacturing apparatus (10) for a semiconductor device is characterized by including: a transfer mechanism (16) that transfers a substrate (100) on which a chip is mounted on its surface in a posture with its surface facing the upper side in the direction of gravity to the downstream side in a specified transfer direction; one or more roller brushes (30U, 30D) provided below the transfer height of the substrate (100) in the middle of the transfer path of the substrate (100), while contacting the back surface (104) of the substrate (100), rotating around an axis inclined with respect to the transfer direction, thereby cleaning the back surface (104); and a suction mechanism (50) that sucks foreign matter erased by one or more of the roller brushes (30U, 30D) through one or more suction holes (54).

Description

Technical Field

[0001] This specification discloses a manufacturing apparatus for manufacturing a semiconductor device by mounting chips on the surface of a substrate, and a cleaning method for cleaning the substrate during the manufacturing process of the semiconductor device. Background Art

[0002] Conventionally, a manufacturing apparatus for manufacturing a semiconductor device by mounting one or more chips on the surface of a substrate has been widely known. When mounting a chip on a substrate, it is required that the surface of the substrate (i.e., the mounting surface) be clean. Therefore, in many cases, before mounting the chip, foreign matter attached to the surface of the substrate is removed by a suction blower or the like.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Laid-Open No. 09-246298 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] Here, conventionally, various techniques have been proposed for cleaning the surface of the substrate, but techniques for cleaning the back surface of the substrate have hardly been proposed in the past. However, in recent years, for semiconductor devices, further high density or miniaturization has been required, and in order to meet this requirement, the thinning of the substrate and the chip has been further promoted. As a result of the promotion of the thinning of the substrate and the chip, when pressure is applied to the thinned substrate and chip, the substrate and the chip sometimes bend around foreign matter attached to the back surface of the substrate. And sometimes, due to such bending, the substrate and the chip may be cracked or damaged.

[0008] Furthermore, Patent Document 1 discloses a resin molding apparatus in which a conductive brush is provided at a height in contact with the lower surface of a product obtained by resin-sealing a lead frame to which a semiconductor element is wire-bonded and then carrying the product out to a storage cassette by an unloader. According to the technique of Patent Document 1, foreign matter attached to the lower surface of the product as a semiconductor device can be removed to some extent by the conductive brush. However, Patent Document 1 makes the conductive brush contact the lower surface of the completed product. Therefore, in the technique of Patent Document 1, it is impossible to prevent manufacturing defects caused by foreign matter. Moreover, the conductive brush of Patent Document 1 is a plate brush formed by arranging a large number of hairs in a line. Therefore, in Patent Document 1, the same hairs always contact the cleaning target surface, and thus foreign matter once attached to the hairs may be attached to the lower surface of the product again.

[0009] Therefore, in this specification, a manufacturing apparatus and a cleaning method for a semiconductor device that can more effectively clean the back surface of a substrate before mounting a chip are disclosed.

[0010] Technical means for solving the problem

[0011] The manufacturing apparatus of the semiconductor device disclosed in this specification is characterized by including: a transfer mechanism that transfers a substrate with a chip mounted on its surface in a posture with its surface facing the upper side in the direction of gravity to the downstream side in a specified transfer direction; one or more roller brushes provided below the transfer height of the substrate in the middle of the transfer path of the substrate, rotating around an axis inclined with respect to the transfer direction while contacting the back surface of the substrate to clean the back surface; and a suction mechanism that sucks foreign matter erased by the one or more roller brushes through one or more suction holes.

[0012] At this time, it is also possible that the one or more roller brushes have: an upstream roller brush that rotates in a direction in which the moving direction at the contact point with the back surface becomes the downstream side in the transfer direction; and a downstream roller brush arranged on the downstream side in the transfer direction with respect to the upstream roller brush, rotating in a direction in which the moving direction at the contact point with the back surface becomes the upstream side in the transfer direction, and one or more of the suction holes are provided between the upstream roller brush and the downstream roller brush.

[0013] Moreover, it is also possible that the transfer speed of the substrate during the period when the substrate contacts the upstream roller brush is less than the peripheral speed of the upstream roller brush.

[0014] Moreover, it may also include: a single power source; an input transmission mechanism that transmits the power output from the power source as a rotational force to one of the upstream roller brush and the downstream roller brush; and an intermediate transmission mechanism that reverses the rotational direction of the rotation of one of the upstream roller brush and the downstream roller brush and transmits it to the other.

[0015] Moreover, it may also include: a removal bar that contacts the rotating roller brush to separate foreign matter from the roller brush.

[0016] At this time, it is also possible that the removal bar can move between a contact position where it contacts the roller brush and a retracted position where it does not contact the roller brush, and the removal bar is in the retracted position during the period when the substrate contacts the roller brush.

[0017] Moreover, it is also possible that one or more of the roller brushes are detachable from the manufacturing apparatus, and the type of the roller brush installed in the manufacturing apparatus can be changed according to the type of the substrate.

[0018] Moreover, it is also possible that the dimension of the substrate in the transfer direction is shorter than the length of the transfer path, and the transfer speed during the cleaning period when the transfer mechanism makes the substrate contact one or more of the roller brushes is less than the transfer speed during other transfer periods.

[0019] Furthermore, it may also include an ionizer for removing static electricity from at least one of the back surface and the front ends of the bristles of the roller brush.

[0020] Furthermore, it may also include a pressing member for pressing a part of the substrate in the thickness direction of the substrate when the substrate comes into contact with one or more of the roller brushes, so as to correct the warping of the substrate.

[0021] The method for cleaning a substrate disclosed in this specification is characterized by including: a conveying step of conveying the substrate in a posture with its surface facing the upper side in the direction of gravity to the downstream side in a specified conveying direction; a cleaning step of cleaning the back surface of the substrate using one or more roller brushes in parallel with the conveying step; and a suction step of sucking foreign matters wiped off by one or more of the roller brushes through one or more suction holes in parallel with the cleaning step. The roller brush is provided in the middle of the conveying path of the substrate and is located below the conveying height of the substrate, and rotates around an axis inclined with respect to the conveying direction while contacting the back surface of the substrate, thereby cleaning the back surface.

[0022] Effects of the Invention

[0023] According to the technology disclosed in this specification, the back surface of the substrate before mounting the chip can be cleaned more effectively. Brief Description of the Drawings

[0024] Figure 1 is a schematic plan view of a manufacturing apparatus.

[0025] Figure 2 is an enlarged view of the periphery of the cleaning unit.

[0026] Figure 3 is Figure 2 a sectional view taken along line A-A in

[0027] Figure 4 is a graph showing the time variation of the conveying speed of the substrate and the peripheral speed of the roller brush.

[0028] Figure 5 is a graph showing the situation of foreign matter removal performed by the upstream roller brush.

[0029] Figure 6 is a graph showing the situation of foreign matter removal performed by the downstream roller brush.

[0030] Figure 7 is a graph showing an example of a removal strip.

[0031] Figure 8 is a graph explaining the positional relationship between the removal strip and the bristles.

[0032] Figure 9It is a diagram showing the positional relationship between the removal strip and the bristles.

[0033] Figure 10 It is a diagram showing another example of the cleaning section.

[0034] Figure 11 It is a diagram showing another example of the cleaning section.

[0035] Figure 12 It is a diagram showing another example of the cleaning section.

[0036] Figure 13 It is a diagram showing another example of the cleaning section.

[0037] [Explanation of symbols]

[0038] 10: Manufacturing device

[0039] 12: Loading section

[0040] 14: Joining section

[0041] 16: Conveying mechanism

[0042] 18: Gripping claw

[0043] 20: Conveying path

[0044] 22: Cleaning section

[0045] 24: Pick-up opening

[0046] 30D: Downstream roller brush

[0047] 30U: Upstream roller brush

[0048] 32: Rotating shaft

[0049] 33: Core material

[0050] 34: Bristles

[0051] 36: Motor

[0052] 38: Input transmission mechanism

[0053] 40: Relay transmission mechanism

[0054] 42a~42f: Gears

[0055] 43: Coupling

[0056] 50: Suction mechanism

[0057] 52: Suction pipe

[0058] 54: Suction holes

[0059] 56: Vacuum generator

[0060] 58: Air filter

[0061] 60: Removal strip

[0062] 70: Controller

[0063] 70a: Processor

[0064] 70b: Memory

[0065] 74: Ionizer

[0066] 76: Pressing member

[0067] 78: Reference plane

[0068] 100: Substrate

[0069] 102: Mounting surface

[0070] 104: Back surface

[0071] 110: Foreign matter Detailed implementation manner

[0072] Hereinafter, the structure of the manufacturing apparatus 10 for semiconductor devices will be described with reference to the accompanying drawings. Figure 1 is a schematic plan view of the manufacturing apparatus 10. The manufacturing apparatus 10 is an apparatus for manufacturing a semiconductor device by mounting one or more semiconductor elements and other chips (not shown) on the surface of the substrate 100 (hereinafter referred to as the "mounting surface 102").

[0073] The manufacturing apparatus 10 includes: a loading unit 12 that supplies a new substrate 100 to the manufacturing apparatus 10; a bonding unit 14 that mounts chips on the mounting surface 102 of the substrate 100; and a transfer mechanism 16 that transfers the substrate 100 from the loading unit 12 to the bonding unit 14. Among them, the detailed description of the structures of the loading unit 12 and the bonding unit 14 is omitted.

[0074] The transfer mechanism 16 transfers the substrate 100 along the transfer path 20. Figure 1 In the example of, the transfer path 20 is a straight line extending in the Y direction. However, the transfer path 20 can of course be appropriately zigzag or curved. Furthermore, hereinafter, the direction orthogonal to both the transfer direction and the vertical direction will be referred to as the "cross-sectional direction". Figure 1 In the example of, the X direction is the cross-sectional direction.

[0075] The transfer mechanism 16 has a plurality of gripping claws 18 that grip the substrate 100, and an actuator (not shown) that moves the gripping claws 18 along the transfer path 20. The gripping claws 18 grip one end of the substrate 100 in the cross-sectional direction. Here, chips are mounted on the substrate 100 only in the effective region that is more than a specified distance from its periphery and is located inside. Figure 1The dashed line in [the figure] indicates the periphery of the effective area. The outside of the effective area is a non-effective area where no chips are installed. The gripping claws 18 grip the non-effective area. Moreover, in this example, the actuator has a linear motor that moves the gripping claws 18 linearly. However, as long as the actuator can move the gripping claws 18, there is no particular limitation. For example, a linear motion mechanism formed by combining a motor that outputs rotational power with a rack-and-pinion, or a linear motion mechanism formed by combining a motor with a ball spline, etc. can also be used as the actuator. Furthermore, as long as the conveying mechanism 16 can convey the substrate 100 along the conveying path 20, its structure is not limited, and it can also be a structure without the gripping claws 18. For example, the conveying mechanism 16 can also have a belt conveyor, etc., and the belt conveyor has a conveying belt that places the substrate 100 and moves in the conveying direction.

[0076] In the middle of the conveying path 20, a cleaning unit 22 is provided. The cleaning unit 22 is a part that cleans the back surface 104 of the substrate 100, that is, the surface opposite to the mounting surface 102. In the cleaning unit 22, one or more roller brushes 30U and 30D are provided. More specifically, in the cleaning unit 22, an upstream roller brush 30U and a downstream roller brush 30D that is downstream of the upstream roller brush 30U in the conveying direction are provided. Moreover, in the conveying path 20, the parts corresponding to these two roller brushes 30U and 30D are formed with an access opening 24 for exposing the two roller brushes 30U and 30D to the outside. Furthermore, hereinafter, when not distinguishing between the upstream roller brush 30U and the downstream roller brush 30D, they are simply referred to as "roller brush 30".

[0077] Figure 2 is an enlarged view of the periphery of the cleaning unit 22. Moreover, Figure 3 is Figure 2 the A-A sectional view in [the figure]. Furthermore, Figure 2 、 Figure 3 in [the figure], the illustration of the conveying path 20 is omitted. As Figure 2 、 Figure 3 shown, and as described above, an upstream roller brush 30U and a downstream roller brush 30D are provided in the cleaning unit 22.

[0078] The roller brush 30 has a rotation axis 32 that extends in a direction orthogonal to the conveying direction, that is, in the transverse cross-sectional direction, and rotates around the rotation axis 32. Moreover, the roller brush 30 has a core material 33 that is long in the rotation axis direction and a large number of bristles 34 implanted on the core material 33. In this example, in order to prevent the generation of static electricity on the back surface 104 of the substrate 100, the bristles 34 contain conductive fibers, such as acrylic conductive fibers. However, as long as the material of the bristles 34 has a softness that will not damage the substrate 100, there is no particular limitation, and it can also contain fibers other than conductive fibers.

[0079] The roller brush 30 is disposed at a height position such that the vertical distance from the back surface 104 of the substrate 100 to the rotation center is substantially the same as or slightly smaller than the radius of the roller brush 30. With the above structure, when the substrate 100 passes through the roller brush 30, at the top Pt which is the uppermost part in the gravity direction in the roller brush 30, the ends of the bristles 34 contact the back surface 104 of the substrate 100. Further, the roller brush 30 rotates while contacting the back surface 104, whereby foreign matter attached to the back surface 104 is effectively removed.

[0080] The cross-sectional dimension of the brush portion of the roller brush 30 (i.e., the range where the bristles 34 are implanted) is not particularly limited. However, in order to effectively clean the entire substrate 100, the cross-sectional dimension of the brush portion may be substantially the same as or slightly larger than the cross-sectional dimension of the effective area of the substrate 100. Further, the roller brush 30 can be replaced as needed so that an appropriate roller brush 30 can be used according to the substrate 100 to be processed. Moreover, at this time, in order to replace the roller brush 30 while maintaining the meshing relationship of the gears 42a to 42f described later, the core material 33 of the roller brush 30 is connected to the gears 42c and 42f via the coupling 43.

[0081] Here, in this example, the rotation directions of the two roller brushes 30U and 30D are opposite to each other. Specifically, the upstream roller brush 30U rotates in a direction ( Figure 2 the right-handed direction in ) such that the moving direction at the contact point (i.e., the top Pt) with the substrate 100 is the downstream side in the conveying direction, and the downstream roller brush 30D rotates in a direction ( Figure 2 the left-handed direction in ) such that the moving direction at the contact point with the substrate 100 is the upstream side in the conveying direction. In other words, in this example, the two roller brushes 30U and 30D rotate in a direction in which the bristles 34 contacting the substrate 100 approach the other roller brush 30 after the contact. Hereinafter, such a rotation direction will be referred to as the "inward direction". Further, the rotation in which the moving direction at the contact point is the downstream side in the conveying direction is referred to as "forward rotation", and the rotation in which the moving direction at the contact point is the upstream side in the conveying direction is referred to as "reverse rotation". In this example, by rotating the two roller brushes 30U and 30D in the inward direction with respect to each other, a single suction pipe 52 can be shared by the two roller brushes 30U and 30D, and foreign matter can be removed more reliably, which will be described later.

[0082] Downstream of the downstream roller brush 30D in the conveying direction, a motor 36 is further provided. The motor 36 generates power for rotating the two roller brushes 30U and 30D. The output shaft of the motor 36 extends in a direction parallel to the rotation shaft 32 of the roller brush 30. Moreover, the rotation of the output shaft of the motor 36 is transmitted to the downstream roller brush 30D through the input transmission mechanism 38, and the rotation of the downstream roller brush 30D is transmitted to the upstream roller brush 30U by reversing its rotation direction through the relay transmission mechanism 40. Here, both the input transmission mechanism 38 and the relay transmission mechanism 40 may include gears, pulleys, etc. Figure 2 In the example of Figure 2 , the input transmission mechanism 38 includes three gears 42a, 42b, and 42c, and the relay transmission mechanism 40 includes four gears 42c, 42d, 42e, and 42f. Furthermore, in this example, a single drive source (i.e., the motor 36) is used to drive the two roller brushes 30U and 30D, but the number of drive sources can also be appropriately changed. Therefore, a drive source can also be provided for each roller brush 30. Moreover, in this example, the reduction ratio of the relay transmission mechanism 40 is "1", and the two roller brushes 30U and 30D rotate at the same speed as each other. However, a speed difference can also be set for the two roller brushes 30U and 30D as needed.

[0083] The manufacturing apparatus 10 further has a suction mechanism 50 that sucks and collects foreign matter wiped off from the back surface 104 of the substrate 100 by the roller brush 30. The suction mechanism 50 has: a suction pipe 52 formed with a plurality of suction holes 54; a vacuum generator 56 that causes the suction pipe 52 to generate a vacuum force (suction force); and an air filter 58 that captures the sucked foreign matter. The suction pipe 52 is a long and hollow tubular member in the transverse direction, and a plurality of suction holes 54 are formed at intervals in the transverse direction on its peripheral surface. The suction pipe 52 is Figure 2 , Figure 3 As shown, it is disposed between the upstream roller brush 30U and the downstream roller brush 30D and at a position below the rotation shafts 32 of the two roller brushes 30. And as described above, the upstream roller brush 30U and the downstream roller brush 30D rotate inwardly with respect to each other, and after the bristles 34 in contact with the substrate 100 contact, they rotate downward in a direction approaching the suction pipe 52. As a result, foreign matter adhering to the bristles 34 of the two roller brushes 30U and 30D is effectively sucked by the suction holes 54 of a single suction pipe 52. In other words, in this example, a single suction pipe 52 can be shared by the two roller brushes 30U and 30D, thereby reducing the number of parts. And as a result, the manufacturing cost of the manufacturing apparatus 10 can be reduced, and moreover, miniaturization of the cleaning unit 22 can be achieved.

[0084] The vacuum generator 56 generates a vacuum force in the suction pipe 52. The vacuum generator 56 may be, for example, a vacuum ejector which narrows the supplied compressed air using a nozzle and then discharges it at high speed toward a diffuser, thereby generating a vacuum. However, the structure of the vacuum generator 56 is not particularly limited as long as it can generate a vacuum force sufficient to suck foreign matter from the suction hole 54, and it may have other structures, such as a vacuum pump or the like. After removing foreign matter from the air sucked through the suction hole 54, the filter discharges the air to the outside.

[0085] The controller 70 controls the driving of each part of such a manufacturing apparatus 10. The controller 70 is a computer physically having a processor 70a and a memory 70b. In this example, the controller 70 controls the conveyance speed of the substrate 100 and the rotation speed of the roller brush 30 so as to appropriately clean the back surface 104 of the substrate 100. Regarding this, reference is made to Figure 4 for description.

[0086] Figure 4 is a graph showing the time changes in the conveyance speed of the substrate 100 and the peripheral speed of the roller brush 30. Figure 4 In this graph, the line L1 represents the conveyance speed of the substrate 100, the line L2 represents the peripheral speed of the upstream roller brush 30U, and the line L3 represents the peripheral speed of the downstream roller brush 30D. Furthermore, the peripheral speed refers to the moving speed of a point on the outer peripheral surface of the roller brush 30. Therefore, if the diameter of the upstream roller brush 30U is Ru (mm) and the rotational speed is Nu (rpm), the peripheral speed Vu (mm / sec) of the upstream roller brush 30U can be obtained by Vu = π·Ru·Nu / 60.

[0087] Moreover, Figure 4 in this graph, the time t1 represents the timing when the front end of the substrate 100 reaches the top Pt of the upstream roller brush 30U, and the time t2 represents the timing when the rear end of the substrate 100 reaches the top Pt of the downstream roller brush 30D. Therefore, the period from the time t1 to the time t2 can be said to be the period during which at least a part of the substrate 100 is in contact with any one of the roller brushes 30 and is cleaned by the roller brush 30. Hereinafter, the period during which the substrate 100 is in contact with any one of the roller brushes 30 (the period from the time t1 to the time t2) is referred to as the "cleaning period".

[0088] According to Figure 4It is clear that in this example, the conveyance speed of the substrate 100 (reference line L1) is temporarily decreased during cleaning. That is, the substrate 100 is normally conveyed at a preset standard conveyance speed V1. The standard conveyance speed V1 is a relatively fast speed set for the purpose of improving the conveyance efficiency of the substrate 100. If, as a result of conveyance, just before the front end of the substrate 100 reaches the top Pt of the upstream roller brush 30U, that is, just before the arrival time t1, the controller 70 decreases the conveyance speed of the substrate 100 to a cleaning conveyance speed V2 that is sufficiently lower than the standard conveyance speed V1. Decreasing the conveyance speed of the substrate 100 in this way is to extend the contact time with the roller brush 30, thereby more effectively cleaning the back surface 104 of the substrate 100. And, just after the rear end of the substrate 100 has passed the top Pt of the downstream roller brush 30D, that is, just after the arrival time t2, the controller 70 restores the conveyance speed of the substrate 100 to the standard conveyance speed V1 again.

[0089] On the other hand, the roller brush 30 rotates at a prescribed speed during cleaning, but stops rotating during other periods. That is, the upstream roller brush 30U starts rotating just before the arrival time t1 and stops rotating just after the arrival time t2. During cleaning, the upstream roller brush 30U rotates at a fixed peripheral speed Vu. The peripheral speed Vu is sufficiently higher than the cleaning conveyance speed V2. Setting Vu > V2 in this way is for the following reason. The moving direction at the contact point (i.e., the top Pt) between the upstream roller brush 30U and the substrate 100 is downstream in the conveyance direction, that is, the same as the moving direction of the substrate 100. Therefore, if Vu = V2, no speed difference will be generated between the substrate 100 and the bristles 34 of the upstream roller brush 30U, and thus the substrate 100 cannot be properly cleaned. Therefore, in this example, Vu ≠ V2 is set to actively generate a speed difference between the substrate 100 and the upstream roller brush 30U.

[0090] Moreover, if the purpose is only to generate a speed difference, it is also possible to consider setting V2 > Vu. However, when increasing the cleaning conveyance speed V2, the substrate 100 will pass through the upstream roller brush 30U in a short time. At this time, during the passing period, the total area of contact between the upstream roller brush 30U and the substrate 100, and even the total number of bristles 34 in contact with the substrate 100 will become smaller, and the cleaning efficiency of the substrate 100 will decrease. Therefore, in this example, the cleaning conveyance speed V2 of the substrate 100 is made lower than the peripheral speed Vu of the upstream roller brush 30U, thereby achieving an improvement in cleaning efficiency.

[0091] The downstream roller brush 30D also starts rotating before the approaching time t1 and stops rotating after the arrival time t2, just like the upstream roller brush 30U. However, the rotation direction of the downstream roller brush 30D is opposite to that of the upstream roller brush 30U. Therefore, the peripheral speed Vd of the downstream roller brush 30D is a value with the same magnitude as the peripheral speed Vu of the upstream roller brush 30U but with the polarity reversed, that is, Vd = -Vu.

[0092] Here, the moving direction at the contact point of the downstream roller brush 30D with the substrate 100 is opposite to the conveying direction of the substrate 100. Therefore, the relative speed ΔVd between the substrate 100 and the downstream roller brush 30D is ΔVd = V2 + Vd, which is larger than the relative speed ΔVu = V2 - Vu of the upstream roller brush 30U. Therefore, compared with the upstream roller brush 30U, the downstream roller brush 30D has a higher cleaning efficiency and can more effectively remove foreign matters on the back surface 104 of the substrate 100.

[0093] Next, the reason for the inward rotation of the two roller brushes 30U and 30D with respect to each other will be described. As described above, by rotating the two roller brushes 30U and 30D inward with respect to each other, the foreign matters wiped off by the bristles 34 can be gathered between the two roller brushes 30U and 30D. And thereby, a single suction pipe 52 can be shared by the two roller brushes 30U and 30D.

[0094] Moreover, by rotating the two roller brushes 30U and 30D inward with respect to each other, both damage to the substrate 100 can be prevented and the back surface 104 of the substrate 100 can be cleaned more effectively. Regarding this, refer to Figure 5 、 Figure 6 for explanation. Figure 5 is a diagram showing the removal of foreign matter 110 by the upstream roller brush 30U, Figure 6 is a diagram showing the removal of foreign matter 110 by the downstream roller brush 30D.

[0095] The upstream roller brush 30U rotates in the forward rotation direction, that is, the direction in which the moving direction at the contact point with the substrate 100 is the same as the conveying direction of the substrate 100. Therefore, the relative speed ΔVu between the upstream roller brush 30U and the substrate 100 is relatively small, and the force of the bristles 34 brushing against the back surface 104 is small. On the other hand, the downstream roller brush 30D rotates in the reverse rotation direction, that is, the direction in which the moving direction at the contact point with the substrate 100 is opposite to the conveying direction of the substrate 100. Therefore, the relative speed ΔVd between the downstream roller brush 30D and the substrate 100 is relatively large, and the force of the bristles 34 brushing against the back surface 104 is large. That is to say, it can be said that the force for removing foreign matter 110 is higher in the case of reverse rotation than in the case of forward rotation.

[0096] Therefore, in order to improve the removal effect of the foreign matter 110, it is also considered to reverse the upstream roller brush 30U. However, in the case of adopting the above structure, the bristles 34 of the upstream roller brush 30U will brush the back surface 104 of the substrate 100 with a large amount of foreign matter 110 attached thereto with a strong force. At this time, the possibility that the foreign matter 110 detached from the back surface 104 and attached to the bristles 34 scratches the back surface 104 increases. Moreover, among the foreign matters 110, there are also foreign matters that are closely and firmly attached to the back surface 104. When the foreign matter 110 is strongly brushed and scraped off by the bristles 34, a large reaction force will be generated when the foreign matter 110 detaches, and it is also possible to damage the substrate 100. That is, when the upstream roller brush 30U that first contacts the substrate 100 is reversed, the damage to the substrate 100 is likely to increase. Therefore, in this example, the upstream roller brush 30U that first contacts the substrate 100 is rotated forward to suppress the damage to the substrate 100.

[0097] Moreover, in consideration of the damage to the substrate 100, it is also considered to rotate both the upstream roller brush 30U and the downstream roller brush 30D forward. However, when the downstream roller brush 30D also rotates forward, the removal ability of the foreign matter 110 decreases, and the possibility that the foreign matter 110 remains on the substrate 100 increases. On the other hand, if the upstream roller brush 30U brushes the back surface 104 with a weak force and then the reversed downstream roller brush 30D brushes the back surface 104 with a strong force, the damage to the substrate 100 can be reduced. That is, at this time, when the downstream roller brush 30D contacts the substrate 100, the upstream roller brush 30U has substantially removed the foreign matter 110. Therefore, even if the downstream roller brush 30D is reversed and the bristles 34 brush the back surface 104 of the substrate 100 with a strong force, since the foreign matter 110 attached to the bristles 34 is less, the possibility that the foreign matter 110 scratches the back surface 104 is also low. Moreover, at first, for the foreign matter 110 firmly attached to the back surface 104, the bristles 34 of the upstream roller brush 30U brush it with a weak force to vibrate the foreign matter 110, so that the adhesion force of the foreign matter 110 to the back surface 104 decreases. Therefore, the reaction force generated when the bristles 34 of the subsequent downstream roller brush 30D scrape off the foreign matter 110 can also be suppressed to be small. That is, as long as the upstream roller brush 30U rotates forward, even if the downstream roller brush 30D is reversed, the damage to the substrate 100 can be suppressed to be small.

[0098] Moreover, when both the upstream roller brush 30U and the downstream roller brush 30D rotate forward, it may not be possible to remove the foreign matter 110 that is pushed by the bristles 34 and slides while still attached to the substrate 100. That is, a part of the foreign matter 110 brushed by the bristles 34 detaches from the back surface 104 and falls off, or attaches to the bristles 34. However, another part of the foreign matter 110 is sometimes pushed by the bristles 34 and slides on the back surface 104 while still attached to the back surface 104 of the substrate 100.

[0099] When the roller brush 30 rotates forward, as Figure 5 shown, the sliding direction of the foreign object 110 is downstream in the conveying direction. At this time, the sliding foreign object 110 leaves the roller brush 30 along with the conveyance of the substrate 100, so it still adheres and remains on the substrate 100.

[0100] On the other hand, when the roller brush 30 rotates reversely, as Figure 6 shown, the foreign object 110 slides upstream in the conveying direction. Therefore, the foreign object 110 will contact the roller brush 30 again due to the further conveyance of the substrate 100. And, by contacting the roller brush 30 again, the foreign object 110 becomes easier to detach from the substrate 100. That is, by reversing the rotation of the roller brush 30, compared with the case of rotating it forward, the remaining of the foreign object 110 on the substrate 100 can be more effectively prevented. In particular, for the foreign object 110 attached near the rear end of the substrate 100, it is difficult for the upstream roller brush 30U rotating forward to remove it, but by reversing the rotation of the downstream roller brush 30D, the foreign object 110 near the rear end can also be more effectively removed.

[0101] Moreover, it is clear from the above description that by rotating the two roller brushes 30U and 30D inwardly with respect to each other, the removal ability of the foreign object 110 can be gradually improved. And, thereby, both the damage of the substrate 100 can be suppressed and the foreign object 110 can be effectively removed.

[0102] In addition, a part of the foreign object 110 detaches from the back surface 104 of the substrate 100 and adheres to the bristles 34 of the roller brush 30U and the roller brush 30D. For the foreign object 110 thus attached to the bristles 34, it is necessary to detach it from the bristles 34 before the bristles 34 contact the back surface 104 again. In order to more effectively remove such a foreign object 110 from the bristles 34, a removal strip may also be provided, and the removal strip contacts the rotating roller brush 30 to detach the foreign object 110 from the roller brush 30. Figure 7 It is a diagram showing an example of the removal strip. Figure 7 In, the removal strip 60a and the removal strip 60b (hereinafter, simply referred to as "removal strip 60" when not distinguishing between the two) are long members extending in a direction parallel to the rotation axis 32, and the removal strip 60 contacts near the front end of the bristles 34, thereby detaching the foreign object 110 from the bristles 34. Here, as long as the removal strip 60 can contact near the front end of the bristles 34, its installation position is not particularly limited. Figure 7 In the example of, a part of the removal strip 60a is arranged at a position away from the suction pipe 52 but above the suction pipe 52. The removal strip 60a is as Figure 8As shown, it is arranged at a position where only the extreme front end of the bristles 34 comes into contact. In the case of adopting the said arrangement, when the bristles 34 cross over the removal strip 60a, they are greatly deflected all at once and then elastically restored. When they are elastically restored, the foreign matter 110 attached to the bristles 34 is flung downward, i.e., toward the suction pipe 52 side, and thus is easily guided to the suction pipe 52.

[0103] Moreover, the removal strip 60b is arranged at a position below the suction pipe 52 but near the suction pipe 52. As shown in Figure 9 it is arranged at a position where the front end of the bristles 34 comes into contact slightly inward. In the case of adopting the said arrangement, when the bristles 34 cross over the removal strip 60b, they slide on the surface of the removal strip 60 in a greatly deflected state. Through the said sliding, the foreign matter 110 attached to the bristles 34 is wiped off by the removal strip 60. Moreover, through the impact during the said wiping, the foreign matter 110 bounces up slightly, and thus is easily guided to the nearby suction pipe 52.

[0104] In addition, such a removal strip 60 can clean the roller brush 30 either in parallel with the cleaning of the substrate 100 by the roller brush 30 or at staggered times. That is, the removal strip 60 can also be fixedly arranged at a position in contact with the roller brush 30, and during the period when the roller brush 30 cleans the substrate 100, the cleaning of the roller brush 30 by the removal strip 60 is necessarily carried out. Moreover, as another embodiment, the removal strip 60 can also be moved between a contact position in contact with the roller brush 30 and a retracted position not in contact with the roller brush 30. The said movement can be realized, for example, by using an actuator such as an electromagnetic plunger or an air spring. And at this time, the removal strip 60 can also be retracted to the retracted position during the period when the roller brush 30 is in contact with the substrate 100, and move to the contact position during the period when the roller brush 30 is not in contact with the substrate 100 to clean the roller brush 30. By adopting the said structure, the foreign matter 110 flying off from the bristles 34 can be effectively prevented from adhering to the substrate 100 again.

[0105] Moreover, so far, mechanical force has been used to remove the foreign matter 110 attached to the substrate 100 or the bristles 34. However, in order to assist in the removal of the foreign matter 110 by such mechanical force, as shown in Figure 10 an ionizer 74 for removing static electricity can be provided. The ionizer 74 can be, for example, a corona discharge type that emits ions generated by corona discharge to the object, or a photoionization type that irradiates high-energy electromagnetic waves (such as ultraviolet rays or X-rays) to the object. Moreover, the object for removing static electricity can be either the back surface 104 of the substrate 100 or the bristles 34.

[0106] Moreover, the structures described so far are all examples. As long as there is at least one roller brush 30 that rotates while being in contact with the back surface 104 of the substrate 100 on one side, and a suction mechanism 50 that sucks the foreign matter 110 wiped off by the roller brush 30, other structures can also be appropriately changed. Therefore, the number of roller brushes 30 can also be single as shown in Figure 11 or three or more as shown in Figure 12 . Moreover, the rotation direction of the roller brush 30 can also be appropriately changed. For example, as shown in Figure 12 , all of the multiple roller brushes 30 can rotate in the same direction. At this time, a suction pipe 52 can be provided for each roller brush 30.

[0107] Moreover, as shown in Figure 1 , in this example, the holding claw 18 only holds one end in the cross-sectional direction of the substrate 100. At this time, as shown in Figure 13 , if the substrate 100 is warped, a part of the substrate 100 may sometimes be separated from the roller brush 30. Therefore, in order to correct such warping of the substrate 100, a pressing member 76 that presses a part of the substrate 100 in its thickness direction may be provided. The pressing member 76 can also be a clamper that presses the substrate 100 against a reference plane 78 parallel to both the rotation axis 32 and the conveying direction as shown in Figure 13 . When the pressing member 76 is a clamper, the substrate 100 cannot be sent downstream while the substrate 100 is being pressed against the reference plane 78D. Therefore, at this time, the following operations are alternately performed: after releasing the pressing by the pressing member 76 (clamper), a minute feeding process of feeding the substrate 100 a minute distance downstream; and after temporarily stopping the conveyance of the substrate 100, a pressing process of pressing the substrate 100 against the reference plane 78. Moreover, as another embodiment, the pressing member 76 can also be a roller that rotates around an axis substantially parallel to the cross-sectional direction (X direction) and can be lifted and lowered. If the pressing member 76 is a roller, the substrate 100 can be conveyed downstream while the substrate 100 is being pressed against the roller brush 30 by the pressing member 76 (roller), so that the conveyance of the substrate 100 does not need to be temporarily stopped.

[0108] Moreover, the rotation axis 32 of the roller brush 30 only needs to be not parallel to the conveyance direction, and may be inclined with respect to the cross-sectional direction. Further, in the description so far, the upstream roller brush 30U and the downstream roller brush 30D of the same type have been used, but the types of the two roller brushes 30U and 30D may also be different from each other. For example, at least one of the material, thickness, length, and density of the bristles 34 of the two roller brushes 30 may be different from each other. For example, in order to make the upstream roller brush 30U contact the back surface 104 smoothly, the bristles 34 of the upstream roller brush 30U may include a raw material softer than the bristles 34 of the downstream roller brush 30D, or thinner than the bristles 34 of the downstream roller brush 30D, or longer than the bristles 34 of the downstream roller brush 30D.

[0109] Moreover, the magnitudes of the rotational speeds of the two roller brushes 30U and 30D may also be different from each other. For example, the absolute value |Vd| of the peripheral speed of the downstream roller brush 30D may be made greater than the absolute value |Vu| of the peripheral speed of the upstream roller brush 30U. By adopting the above structure, the relative speed ΔVd between the downstream roller brush 30D and the substrate 100 can be made larger, so that the foreign matter 110 can be more effectively removed. Further, as another embodiment, |Vd| < |Vu| may also be set.

Claims

1. A manufacturing apparatus for a semiconductor device, characterized in that Comprising: A conveying mechanism that conveys a substrate with a surface-mounted chip in a posture with its surface facing the upper side in the direction of gravity to the downstream side in a specified conveying direction; One or more roller brushes provided midway in the conveying path of the substrate and below the conveying height of the substrate, rotating around an axis inclined with respect to the conveying direction while contacting the back surface of the substrate to clean the back surface; and A suction mechanism that sucks foreign matter wiped off by one or more of the roller brushes through one or more suction holes, wherein the dimension of the substrate in the conveying direction is shorter than the length of the conveying path, and the conveying speed during the cleaning period, i.e., the period when the substrate is in contact with one or more of the roller brushes, is less than the conveying speed during other conveying periods.

2. The manufacturing apparatus for a semiconductor device according to claim 1, wherein The one or more roller brushes have: An upstream roller brush that rotates in a direction downstream of the conveyance direction with respect to the moving direction at the contact point on the back surface; and A downstream roller brush that is disposed downstream of the upstream roller brush in the conveyance direction and rotates in a direction upstream of the conveyance direction with respect to the moving direction at the contact point on the back surface, One or more of the suction holes are provided between the upstream roller brush and the downstream roller brush.

3. The manufacturing apparatus for a semiconductor device according to claim 2, wherein The conveyance speed of the substrate during the period when the substrate contacts the upstream roller brush is less than the peripheral speed of the upstream roller brush.

4. The manufacturing apparatus for a semiconductor device according to claim 2 or 3, characterized in that Further comprising: A single power source; An input transmission mechanism that transmits the power output from the power source as a rotational force to one of the upstream roller brush and the downstream roller brush; And An intermediate transmission mechanism that reverses the rotational direction of the rotation of one of the upstream roller brush and the downstream roller brush and transmits it to the other.

5. The manufacturing apparatus for a semiconductor device according to any one of claims 1 to 3, characterized in that Further comprising: A removal strip that contacts the rotating roller brush to detach foreign matter from the roller brush.

6. The manufacturing apparatus for a semiconductor device according to claim 5, characterized in that The removal strip can move between a contact position in contact with the roller brush and a retracted position not in contact with the roller brush, and the removal strip is in the retracted position during the period when the substrate is in contact with the roller brush.

7. The manufacturing apparatus for a semiconductor device according to any one of claims 1 to 3, characterized in that One or more of the roller brushes can be loaded and unloaded relative to the manufacturing device, and the type of the roller brush installed in the manufacturing device can be changed according to the type of the substrate.

8. The manufacturing apparatus for a semiconductor device according to any one of claims 1 to 3, characterized in that Further comprising: An ionizer that removes static electricity from at least one of the back surface and the tips of the bristles of the roller brush.

9. The manufacturing apparatus of a semiconductor device according to any one of claims 1 to 3, characterized in that Further comprising: A pressing member that presses a part of the substrate in the thickness direction when the substrate is in contact with one or more of the roller brushes to correct the warping of the substrate.

10. A cleaning method for a substrate on which chips are surface-mounted, the cleaning method for the substrate being characterized by comprising: A conveying step of conveying the substrate in a posture with its surface facing the upper side in the direction of gravity to the downstream side in a specified conveying direction; A cleaning step of cleaning the back surface of the substrate using one or more roller brushes in parallel with the conveying step; And A suction step of sucking foreign matter wiped off by one or more of the roller brushes through one or more suction holes in parallel with the cleaning step, wherein the roller brush is provided midway in the conveying path of the substrate and below the conveying height of the substrate, rotating around an axis inclined with respect to the conveying direction while contacting the back surface of the substrate to clean the back surface, wherein the dimension of the substrate in the conveying direction is shorter than the length of the conveying path, and in the conveying step, the conveying speed during the cleaning period, i.e., the period when the substrate is in contact with one or more of the roller brushes, is less than the conveying speed during other conveying periods.

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