Drawing device

Abstract

Reduce the processing time required for rendering. [Solution] The drawing device 1, which performs drawing by irradiating light onto a workpiece 9, comprises a workpiece transport mechanism 3, two workpiece holding units 7, a holding unit movement mechanism, a transfer mechanism 5, and a drawing head 47. The workpiece transport mechanism 3 transports the workpiece 9 along a transport path. The two workpiece holding units 7 are located at two positions separated from the transport path: a transfer position and a drawing position. The holding unit movement mechanism swaps the positions of the two workpiece holding units 7. The transfer mechanism 5 transfers the workpiece 9 between one of the workpiece holding units 7 located at the transfer position and the workpiece transport mechanism 3. The drawing head 47 irradiates light onto the workpiece 9 held by the other workpiece holding unit 7 located at the drawing position to perform drawing. This reduces the processing time required for drawing on multiple workpieces 9.

Description

Technical Field

[0001] The present invention relates to a drawing apparatus that irradiates light onto a workpiece to perform drawing.

Background Art

[0002] Conventionally, as an apparatus for printing identification information, production lot numbers, etc. on the surface of a workpiece such as a semiconductor package, an apparatus that irradiates laser light onto a workpiece placed and conveyed on a belt conveyor to draw characters and figures is known (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, due to chip integration and the like in semiconductor packages, the amount of information such as identification information drawn on the surface of semiconductor packages has increased, and the time required for drawing has also increased. In addition, semiconductor packages are becoming smaller, and there is a demand for improving the accuracy of the drawing position of identification information and the like drawn on semiconductor packages.

[0005] Therefore, it is conceivable to position a semiconductor package on a belt conveyor and draw identification information and the like with good positional accuracy. However, in this case, while drawing is being performed on one semiconductor package, other semiconductor packages will also wait on the belt conveyor, so the time required for drawing processing for a plurality of semiconductor packages will become longer, and there is a risk that production efficiency will decrease.

[0006] The present invention has been made in view of the above problems, and aims to shorten the processing time required for drawing processing.

Means for Solving the Problems

[0007] One aspect of the present invention is a drawing apparatus that performs drawing by irradiating a workpiece with light, comprising: a workpiece transport mechanism that transports a workpiece along a transport path; two workpiece holding parts located at two positions spaced apart from the transport path, namely a transfer position and a drawing position; a holding part movement mechanism that swaps the positions of the two workpiece holding parts; a transfer mechanism that transfers a workpiece between one of the workpiece holding parts located at the transfer position and the workpiece transport mechanism; and a drawing head that performs drawing by irradiating light onto a workpiece held by the other workpiece holding part located at the drawing position.

[0008] Aspect 2 of the present invention is a drawing apparatus according to aspect 1, wherein the drawing head is an optical device that irradiates and scans the workpiece with a linearly extending array of light spots.

[0009] A third aspect of the present invention is a drawing apparatus according to aspect 1 or 2, wherein the workpiece transport mechanism is a tray transport mechanism that moves a transport tray holding a plurality of workpieces along the transport path. The transfer mechanism simultaneously transfers two or more workpieces between the transport tray and one of the workpiece holding units.

[0010] Aspect 4 of the present invention is a drawing apparatus according to aspect 1 or 2 (or any one of aspects 1 to 3), wherein the positional accuracy of the workpieces held in each of the two workpiece holding sections is higher than the positional accuracy of the workpieces in the workpiece transport mechanism.

[0011] Aspect 5 of the present invention is a drawing apparatus according to aspect 1 or 2 (or any one of aspects 1 to 4), wherein each of the two workpiece holding sections is equipped with a chuck mechanism for positioning and chucking a workpiece.

[0012] Aspect 6 of the present invention is a drawing apparatus according to aspect 1 or 2 (or any one of aspects 1 to 5), wherein the holding part moving mechanism comprises two moving mechanisms that swap the positions of the two workpiece holding parts by independently moving each of the two workpiece holding parts horizontally.

[0013] Aspect 7 of the present invention is a drawing apparatus according to aspect 1 or 2 (or any one of aspects 1 to 6), wherein the holding part moving mechanism includes a rotation mechanism that rotates the two workpiece holding parts integrally around a rotation axis located between the two workpiece holding parts, thereby swapping the positions of the two workpiece holding parts.

[0014] Embodiment 8 of the present invention is a drawing apparatus according to Embodiment 1 or 2 (or any one of Embodiments 1 to 7), wherein the drawing head performs drawing on the upper surface of a workpiece. The drawing apparatus further comprises a bottom surface inspection unit that images the bottom surface of a workpiece during transfer by the transfer mechanism and performs inspection of the bottom surface.

[0015] Aspect 9 of the present invention is a drawing apparatus according to aspect 1 or 2 (or any one of aspects 1 to 8), further comprising a drawing inspection unit that images a workpiece in transit by the workpiece transport mechanism and inspects the drawing result. [Effects of the Invention]

[0016] This invention makes it possible to shorten the processing time required for drawing. [Brief explanation of the drawing]

[0017] [Figure 1] This is a perspective view of a drawing device according to the first embodiment. [Figure 2] This is a plan view of the drawing device. [Figure 3] This is a plan view of the transport tray. [Figure 4] This is a plan view of the marking area. [Figure 5] This is a side view of the marking area. [Figure 6] It is a plan view of the work holding part. [Figure 7] It is a plan view of the work. [Figure 8] It is a diagram showing the flow of drawing on the work. [Figure 9A] It is a plan view showing the state of the marking part during drawing. [Figure 9B] It is a plan view showing the state of the marking part during drawing. [Figure 9C] It is a plan view showing the state of the marking part during drawing. [Figure 9D] It is a plan view showing the state of the marking part during drawing. [Figure 9E] It is a plan view showing the state of the marking part during drawing. [Figure 9F] It is a plan view showing the state of the marking part during drawing. [Figure 9G] It is a plan view showing the state of the marking part during drawing. [Figure 10] It is a plan view showing a part of the work holding part. [Figure 11] It is a longitudinal sectional view showing a part of the work holding part. [Figure 12] It is a diagram showing the flow of holding the work. [Figure 13] It is a plan view of the work holding part. [Figure 14A] It is a plan view showing a part of the work holding part during the work holding process. [Figure 14B] It is a longitudinal sectional view showing a part of the work holding part during the work holding process. [Figure 14C] It is a plan view showing a part of the work holding part during the work holding process. [Figure 14D] It is a longitudinal sectional view showing a part of the work holding part during the work holding process. [Figure 14E] It is a plan view showing a part of the work holding part during the work holding process. [Figure 14F] It is a longitudinal sectional view showing a part of the work holding part during the work holding process. [Figure 15]This graph shows the time required to draw a single workpiece. [Figure 16] This is a plan view of the marking section of the drawing device according to the second embodiment. [Figure 17] This is a side view of the marking area. [Figure 18A] This is a plan view showing a portion of the workpiece holding section during the process of holding the workpiece. [Figure 18B] This is a longitudinal cross-sectional view showing a portion of the workpiece holding section during the process of holding the workpiece. [Figure 18C] This is a plan view showing a portion of the workpiece holding section during the process of holding the workpiece. [Figure 18D] This is a longitudinal cross-sectional view showing a portion of the workpiece holding section during the process of holding the workpiece. [Figure 18E] This is a plan view showing a portion of the workpiece holding section during the process of holding the workpiece. [Figure 18F] This is a longitudinal cross-sectional view showing a portion of the workpiece holding section during the process of holding the workpiece. [Modes for carrying out the invention]

[0018] Figure 1 is a perspective view showing a drawing device 1 according to the first embodiment of the present invention. Figure 2 is a plan view of the drawing device 1. The drawing device 1 is a device that performs drawing on a workpiece 9 by irradiating the workpiece 9 with light. In detail, the drawing device 1 is a direct drawing device that irradiates the workpiece 9 with spatially modulated beam-shaped light and performs drawing by scanning the irradiated area of ​​the light on the workpiece 9. In Figures 1 and 2, three mutually orthogonal directions are indicated by arrows as the X direction, Y direction, and Z direction. In the example shown in Figures 1 and 2, the X direction and Y direction are mutually perpendicular horizontal directions, and the Z direction is the vertical direction (i.e., up and down direction). Note that the Z direction does not necessarily have to be the vertical direction. The same applies to other figures.

[0019] Workpiece 9 is, for example, a semiconductor package. In the examples shown in Figures 1 and 2, workpiece 9 is a substantially flat plate-shaped member that extends substantially perpendicular to the Z direction (i.e., substantially horizontally), and the shape of workpiece 9 in plan view is substantially rectangular. In the drawing device 1, light is shone on the main surface of workpiece 9 on the (+Z) side, and characters, two-dimensional codes, and figures (hereinafter also referred to as "trace codes") indicating identification information of workpiece 9 are drawn (i.e., marked) on the main surface. The main surface of workpiece 9 on the (+Z) side (hereinafter also referred to as the "top surface") is, for example, made of metal. The top surface of workpiece 9 may also be made of, for example, resin or ceramics. The shape, material, and type of workpiece 9 can be changed in various ways.

[0020] As shown in Figures 1 and 2, the drawing device 1 comprises a work supply unit 21, a work collection unit 22, a work transport mechanism 3, a marking unit 4, a transfer mechanism 5, a first imaging unit 61, a second imaging unit 62, a third imaging unit 63, and a control unit 10. The control unit 10 is a standard computer and controls various components of the drawing device 1. In Figure 2, the transfer mechanism 5, the control unit 10, and the drawing head 47 (described later) are omitted from the illustration for ease of understanding.

[0021] The work supply unit 21 houses multiple transport trays 8 stacked vertically (i.e., in the Z direction). The transport trays 8 are substantially flat members that extend approximately perpendicular to the Z direction. The transport trays 8 are open trays made of resin or metal. Multiple workpieces 9 are placed on the transport trays 8. The workpieces 9 on the transport trays 8 housed in the work supply unit 21 are undrawn workpieces 9 that have not yet been drawn by the drawing device 1. In the work supply unit 21, the transport trays 8 are moved vertically by a lifting mechanism (not shown) and supplied one by one to the workpiece transport mechanism 3.

[0022] Figure 3 is a plan view showing an enlarged view of the transport tray 8. In plan view, the transport tray 8 is roughly rectangular, elongated in the X direction. The transport tray 8 is provided with multiple recesses 81 that are recessed towards the (-Z) side, and one workpiece 9 is accommodated in each recess 81. By accommodating the workpiece 9 in the recesses 81, the horizontal movement of the workpiece 9 is restricted. In the example shown in Figure 3, the transport tray 8 has 14 recesses 81, and 14 workpieces 9 are held. Specifically, on the transport tray 8, 7 workpieces 9 are arranged in the X direction and 2 workpieces 9 are arranged in the Y direction.

[0023] In the transport tray 8, the shapes of the multiple recesses 81 are approximately the same. In the example shown in Figure 3, the shape of the recesses 81 in plan view is approximately square. Also, the shape of the top surface 91 of the workpiece 9 in plan view is approximately square. In plan view, the recesses 81 are slightly larger than the workpiece 9. For example, the length of one side of the recess 81 in plan view is 300 μm greater than the length of one side of the workpiece 9 in plan view. The workpiece 9 is roughly positioned on the transport tray 8 by being placed in the recesses 81. The number, shape, and arrangement of the recesses 81 provided on the transport tray 8, and the workpieces 9 held by the transport tray 8, can be varied.

[0024] The workpiece transport mechanism 3 shown in Figures 1 and 2 transports the transport tray 8 supplied from the workpiece supply unit 21 to the workpiece retrieval unit 22 along a predetermined transport path. In other words, the workpiece transport mechanism 3 is a tray transport mechanism that moves the transport tray 8, which holds multiple undrawn workpieces 9, along the transport path. In the example shown in Figures 1 and 2, the transport path extends substantially in a linear fashion, substantially parallel to the X direction.

[0025] The workpiece transport mechanism 3 comprises a belt conveyor 31, a transfer stage 32, and an inspection stage 33. The belt conveyor 31 extends along the transport path. The transfer stage 32 and the inspection stage 33 are positioned along the belt conveyor 31 connecting the workpiece supply unit 21 and the workpiece retrieval unit 22. The inspection stage 33 is located on the (+X) side of the transfer stage 32 (i.e., the downstream side of the transport path).

[0026] The transport tray 8, placed on the (+Z) side surface of the belt conveyor 31 from the work supply unit 21, is transported by the belt conveyor 31 to the transfer stage 32 and placed on the upper surface of the transfer stage 32. On the (+Y) side of the transfer stage 32, the marking unit 4 is positioned adjacent to the transfer stage 32. In addition, above the transfer stage 32 (i.e., on the (+Z) side), the transfer mechanism 5 is positioned spaced above the transfer stage 32.

[0027] The transfer mechanism 5 removes the workpiece 9 from the transport tray 8, which is stationary on the transfer stage 32, and moves it to the marking section 4. In the example shown in Figure 1, the transfer mechanism 5 is equipped with multiple (for example, 14) transfer heads 51, each corresponding to one of the multiple workpieces 9 on the transport tray 8. Each transfer head 51 contacts the upper surface 91 of the workpiece 9 with its lower end, and holds the workpiece 9 by suction. In other words, each transfer head 51 is a robot hand with a vacuum suction pad. The transfer head 51 may also have a chuck mechanism other than a vacuum suction pad, such as a mechanical chuck that mechanically grips the workpiece 9.

[0028] The transfer mechanism 5 removes multiple undrawn workpieces 9 from the transport tray 8 by using multiple transfer heads 51 to attract and move them upward. Subsequently, the multiple transfer heads 51 move in the (+Y) direction to move the multiple workpieces 9 from above the transport tray 8 to the marking section 4. The movement of the multiple transfer heads 51 is performed by, for example, a ball screw and motor, or an air cylinder.

[0029] In this embodiment, the transfer mechanism 5 picks up all (for example, 14) of the workpieces 9 on the transport tray 8 almost simultaneously and moves them to the marking unit 4 almost simultaneously. Alternatively, the transfer mechanism 5 may pick up two or more workpieces 9, which are part of the multiple workpieces 9 on the transport tray 8, almost simultaneously and move them to the marking unit 4, or it may pick up the multiple workpieces 9 on the transport tray 8 one by one in sequence and move them to the marking unit 4.

[0030] Multiple transfer heads 51, each holding a workpiece 9, move downward in the marking section 4, placing the multiple workpieces 9 onto the marking section 4. Then, the multiple transfer heads 51 release the suction of the workpieces 9 and retract from the marking section 4. In the marking section 4, markings are drawn on the upper surfaces 91 of the multiple workpieces 9 transferred from the transport tray 8. The drawing process in the marking section 4 will be described later.

[0031] Once the marking section 4 has finished drawing the workpieces 9, they are picked up by the multiple transfer heads 51 of the transfer mechanism 5 and moved from the marking section 4 to the upper part of the transfer stage 32. The multiple transfer heads 51 move downward and place the workpieces 9 onto the transport tray 8 which is stationary on the transfer stage 32, and then release the suction of the workpieces 9 and move away from the transport tray 8. In this embodiment, the transfer mechanism 5 picks up the maximum number of workpieces 9 that can be placed on the transport tray 8 (for example, 14) from the marking section 4 almost simultaneously and places them on the transport tray 8 almost simultaneously. The transfer mechanism 5 is a pick-and-place mechanism that transfers workpieces 9 between the marking section 4 and the transfer stage 32 of the workpiece transport mechanism 3.

[0032] The transport tray 8 on which the drawn workpieces 9 are placed is transported by the belt conveyor 31 from the transfer stage 32 to the inspection stage 33 and placed on the upper surface of the inspection stage 33. Above the inspection stage 33, a third imaging unit 63 is positioned at a distance from the inspection stage 33. The third imaging unit 63 is, for example, an area camera having a CCD or CMOS sensor. The third imaging unit 63 images the multiple workpieces 9 on the transport tray 8, which is stationary on the inspection stage 33, from above. Note that the imaging of the workpieces 9 by the third imaging unit 63 may be performed on the transport tray 8 while it is moving on the belt conveyor 31. The image acquired by the third imaging unit 63 (hereinafter also referred to as the "image") is sent to the control unit 10.

[0033] The control unit 10 compares the captured image with a reference image stored in the control unit 10 in advance and determines whether the trace code drawn on the upper surface 91 of each workpiece 9 is good or bad. For example, if the position of the trace code on the upper surface 91 of the workpiece 9 is shifted from a predetermined position, or if part of the trace code is missing, the workpiece 9 is determined to be defective. Workpieces determined to be defective are, for example, removed from the transport tray 8 and collected in a defective product collection unit (not shown) located adjacent to the inspection stage 33.

[0034] Subsequently, the transport tray 8, on which only the workpieces 9 deemed to be good quality are placed, is transported by the belt conveyor 31 to the workpiece retrieval unit 22, where the workpieces are retrieved. The workpiece retrieval unit 22 houses multiple transport trays 8 stacked vertically (i.e., in the Z direction), much like the workpiece supply unit 21. The aforementioned third imaging unit 63 and control unit 10 constitute a drawing inspection unit that images the upper surface 91 of the drawn workpieces 9 during transport by the workpiece transport mechanism 3 and inspects the drawing results for the workpieces 9.

[0035] In the drawing device 1, the first imaging unit 61 is positioned above the belt conveyor 31 (i.e., above the transport path by the workpiece transport mechanism 3) between the workpiece supply unit 21 and the transfer stage 32. The first imaging unit 61 is, for example, an area camera having a CCD or CMOS sensor. The first imaging unit 61 images the transport tray 8, which holds multiple undrawn workpieces 9, from above. The imaging by the first imaging unit 61 is performed while the transport tray 8 is moving on the belt conveyor 31. The imaging by the first imaging unit 61 may also be performed when the transport tray 8 has temporarily stopped below the first imaging unit 61. The image acquired by the first imaging unit 61 (hereinafter also referred to as the "image") is sent to the control unit 10.

[0036] The control unit 10 reads the lot number and other information displayed on the transport tray 8 in the captured image and confirms that it is the transport tray 8 on which the workpiece 9 to be drawn is placed. It also detects the markings that have been pre-placed on each workpiece 9 on the transport tray 8 and confirms that the orientation in which each workpiece 9 is placed is correct. For example, the markings are placed on one predetermined corner (for example, the corner on the (-X) side and the (+Y) side) of the upper surface 91 of the workpiece 9, which is roughly rectangular in plan view.

[0037] In the drawing device 1, a second imaging unit 62 is positioned between the transfer stage 32 and the marking unit 4 in a plan view. The second imaging unit 62 is, for example, an area camera having a CCD or CMOS sensor. The second imaging unit 62 is positioned below the movement path of the transfer head 51 (i.e., on the (-Z) side). The second imaging unit 62 images from below the multiple workpieces 9 that are held by the multiple transfer heads 51 and move from the transfer stage 32 to the marking unit 4 in the (+Y) direction. The imaging by the second imaging unit 62 may be performed while the multiple transfer heads 51 are moving, or it may be performed when the multiple transfer heads 51 have temporarily stopped above the second imaging unit 62. The image acquired by the second imaging unit 62 (hereinafter also referred to as the "image") is sent to the control unit 10.

[0038] The control unit 10 compares the captured image with a reference image stored in the control unit 10 in advance to determine whether the condition of the lower surface of each workpiece 9 is good or not. For example, if a connecting pin or other connecting terminal provided on the lower surface of a workpiece 9 is broken or tilted, the workpiece 9 is determined to be defective. Workpieces determined to be defective are discarded, for example, in a defective product collection unit (not shown) located adjacent to the second imaging unit 62. On the other hand, workpieces determined to be good are transferred to the marking unit 4.

[0039] The control unit 10 also acquires the position and orientation (i.e., orientation in the horizontal plane) of the workpiece 9 held by each transfer head 51 based on the captured image sent from the second imaging unit 62. The positions and orientations of the multiple transfer heads 51 are then individually adjusted so that each workpiece 9 is placed in a predetermined position in the marking unit 4. For example, the position of the workpiece 9 in the X and Y directions is finely adjusted by displacing the transfer head 51 from its reference position in the X and Y directions. In addition, the orientation of the workpiece 9 in the XY plane is finely adjusted by rotating the transfer head 51 around a rotation axis extending in the Z direction.

[0040] Thus, the second imaging unit 62 and the control unit 10 constitute a bottom surface inspection unit that images the bottom surface of the workpiece 9 during transfer by the transfer mechanism 5 and inspects the bottom surface. Furthermore, the second imaging unit 62 and the control unit 10 constitute a posture adjustment unit that images the bottom surface of the workpiece 9 during transfer by the transfer mechanism 5 and adjusts the position and orientation of the workpiece 9. In other words, in the drawing device 1, the second imaging unit 62 and the control unit 10 are used concurrently as the bottom surface inspection unit and posture adjustment unit described above.

[0041] Next, the configuration of the marking unit 4 will be described. Figure 4 is a plan view of the marking unit 4. Figure 5 is a side view of the marking unit 4. The marking unit 4 comprises a stage mechanism 41 and a drawing head 47. In Figure 4, the drawing head 47 is omitted from the illustration for ease of understanding.

[0042] The stage mechanism 41 comprises a first stage 42, a first stage moving mechanism 43, a second stage 44, a second stage moving mechanism 45, and a stage support section 46. The stage support section 46 supports the first stage moving mechanism 43 and the second stage moving mechanism 45 from below. The first stage moving mechanism 43 and the second stage moving mechanism 45 are arranged side by side in the Y direction on the stage support section 46. In the example shown in Figure 4, the second stage moving mechanism 45 is arranged adjacent to the (+Y) side of the first stage moving mechanism 43.

[0043] The first stage moving mechanism 43 supports the first stage 42 from below and moves the first stage 42 in the X and Y directions. The second stage moving mechanism 45 supports the second stage 44 from below and moves the second stage 44 in the X and Y directions. The first stage moving mechanism 43 can move the first stage 42 independently of the movement of the second stage 44 by the second stage moving mechanism 45. The second stage moving mechanism 45 can move the second stage 44 independently of the movement of the first stage 42 by the first stage moving mechanism 43. In other words, the first stage moving mechanism 43 and the second stage moving mechanism 45 can move the first stage 42 and the second stage 44 horizontally, respectively, independently of each other.

[0044] The first stage moving mechanism 43 comprises an X-axis moving mechanism 431 and a Y-axis moving mechanism 432. The Y-axis moving mechanism 432 supports the first stage 42 from below and moves the first stage 42 substantially linearly in a direction substantially parallel to the Y direction. The Y-axis moving mechanism 432 comprises, for example, a guide extending substantially linearly in a direction substantially parallel to the Y direction and a linear motor that moves the first stage 42 substantially linearly in the Y direction along the guide. The X-axis moving mechanism 431 supports the first stage 42 and the Y-axis moving mechanism 432 from below and moves the first stage 42 and the Y-axis moving mechanism 432 substantially linearly in a direction substantially parallel to the X direction. The X-axis moving mechanism 431 comprises, for example, a guide extending substantially linearly in a direction substantially parallel to the X direction and a linear motor that moves the first stage 42 and the Y-axis moving mechanism 432 substantially linearly in the X direction along the guide.

[0045] The second stage moving mechanism 45 comprises an X-axis moving mechanism 451 and a Y-axis moving mechanism 452. The Y-axis moving mechanism 452 supports the second stage 44 from below and moves the second stage 44 substantially linearly in a direction substantially parallel to the Y direction. The Y-axis moving mechanism 452 comprises, for example, a guide extending substantially linearly in a direction substantially parallel to the Y direction and a linear motor that moves the second stage 44 substantially linearly in the Y direction along the guide. The X-axis moving mechanism 451 supports the second stage 44 and the Y-axis moving mechanism 452 from below and moves the second stage 44 and the Y-axis moving mechanism 452 substantially linearly in a direction substantially parallel to the X direction. The X-axis moving mechanism 451 comprises, for example, a guide extending substantially linearly in a direction substantially parallel to the X direction and a linear motor that moves the second stage 44 and the Y-axis moving mechanism 452 substantially linearly in the X direction along the guide.

[0046] The first stage 42 and the second stage 44 are both substantially flat plate-shaped members that extend substantially perpendicular to the Z direction. In the state shown in Figure 4, the second stage 44 is located adjacent to the (+X) side of the first stage 42. The positions of the first stage 42 and the second stage 44 in the Y direction are substantially the same. As shown in Figure 1, the first stage 42 is positioned on the (+Y) side of the transfer stage 32 of the workpiece transport mechanism 3, spaced apart from the transfer stage 32 on the (+Y) side. The shapes of the first stage 42 and the second stage 44 in plan view are substantially rectangular. The first stage 42 and the second stage 44 are substantially the same shape.

[0047] As will be described later, in the stage mechanism 41 shown in Figures 4 and 5, the first stage 42 and the second stage 44 can be moved by the first stage moving mechanism 43 and the second stage moving mechanism 45, thereby moving the second stage 44 to the position of the first stage 42 in Figure 4, and moving the first stage 42 to the position of the second stage 44 in Figure 4. In other words, the first stage moving mechanism 43 and the second stage moving mechanism 45 can swap the positions of the first stage 42 and the second stage 44.

[0048] The upper surfaces of the first stage 42 and the second stage 44 are located in approximately the same position in the Z direction as the upper surface of the transfer stage 32 of the workpiece transport mechanism 3. One workpiece holder 7 is fixed to the upper surface of the first stage 42 and the upper surface of the second stage 44, respectively.

[0049] Figure 6 is a magnified plan view showing the workpiece holder 7 fixed on the second stage 44. The workpiece holder 7 fixed on the first stage 42 has the same structure and shape as the one shown in Figure 6. The workpiece holder 7 is a substantially flat plate-shaped member that extends substantially perpendicular to the Z direction. In plan view, the shape of the workpiece holder 7 is a substantially rectangular shape that is long in the X direction. The workpiece holder 7 is made of, for example, resin or metal. Multiple workpieces 9 can be placed on the workpiece holder 7. In the state shown in Figure 4, multiple workpieces 9 are placed on the workpiece holder 7 on the second stage 44, and no workpieces 9 are placed on the workpiece holder 7 on the first stage 42.

[0050] As shown in Figure 6, the workpiece holder 7 is provided with multiple recesses 71 that are recessed toward the (-Z) side, and one workpiece 9 is accommodated in each recess 71. By accommodating the workpiece 9 in the recesses 71, the horizontal movement of the workpiece 9 is restricted. In the example shown in Figure 6, 14 recesses 71 are formed in the workpiece holder 7, and 14 workpieces 9 are held. Specifically, on the workpiece holder 7, 7 workpieces 9 are arranged in the X direction and 2 workpieces 9 are arranged in the Y direction.

[0051] The number of recesses 71 provided in the workpiece holding section 7 and the number of recesses 81 provided in the transport tray 8 may be the same or different. In other words, the number of workpieces 9 that can be held by the workpiece holding section 7 and the number of workpieces 9 that can be held by the transport tray 8 may be the same or different. Also, in the example shown in Figure 6, the pitch between the recesses 71 in the workpiece holding section 7 is larger than the pitch between the recesses 81 in the transport tray 8, but these pitches may be the same or different.

[0052] In the workpiece holding section 7, the shapes of the multiple recesses 71 are approximately the same. In the example shown in Figure 6, the shape of the recess 71 in plan view is approximately square. In plan view, the recess 71 is slightly larger than the workpiece 9. The workpiece 9 is positioned approximately on the workpiece holding section 7 by being accommodated in the recesses 71. The positional accuracy of the workpiece 9 held in the workpiece holding section 7 is higher than the positional accuracy of the workpiece 9 held in the transport tray 8 (i.e., the positional accuracy of the workpiece 9 in the workpiece transport mechanism 3). Therefore, drawing on the workpiece 9 held in the workpiece holding section 7 can be performed with higher positional accuracy compared to drawing on the workpiece 9 on the workpiece transport mechanism 3. Details of how the workpiece 9 is held by the workpiece holding section 7 will be described later. The number, shape, and arrangement of the recesses 71 provided in the workpiece holding section 7 can be changed in various ways.

[0053] As shown in Figures 1 and 5, the drawing head 47 is positioned above the first stage 42 and the second stage 44, and spaced apart above the first stage 42 and the second stage 44. The drawing head 47 scans the upper surface 91 (see Figure 6) of the workpiece 9 held by the workpiece holding section 7 on the second stage 44 while modulating the laser beam. As a result, a trace code 99, as shown in Figure 7, is drawn on the upper surface 91 of the workpiece 9. The trace code 99 illustrated in Figure 7 includes characters and two-dimensional codes.

[0054] In this embodiment, the light irradiated onto the workpiece 9 from the drawing head 47 is a multi-spot beam composed of multiple light spots arranged linearly in a predetermined arrangement direction (for example, the Y direction). That is, the drawing head 47 is an optical device that irradiates and scans the upper surface 91 of the workpiece 9 with an array of light spots extending linearly in the above arrangement direction.

[0055] In the following explanation, the position of the second stage 44 shown in Figure 4, and the position of the workpiece holding unit 7 on the second stage 44, will also be referred to as the "drawing position." Similarly, the position of the first stage 42 shown in Figure 4, and the position of the workpiece holding unit 7 on the first stage 42, will also be referred to as the "transfer position." The drawing position and the transfer position are both located one side (i.e., in the (+Y) direction) away from the transport path of the workpiece 9 by the workpiece transport mechanism 3. Furthermore, the drawing position and the transfer position are located approximately the same position in the Y direction, but separated in the X direction. In the example shown in Figure 4, the drawing position is separated from the transfer position on the (+X) side.

[0056] The second stage 44, located at the drawing position, and the first stage 42, located at the transfer position, are positioned approximately in the center in the Y direction between the X-axis movement mechanism 431 of the first stage movement mechanism 43 and the X-axis movement mechanism 451 of the second stage movement mechanism 45. In the marking section 4, when the positions of the first stage 42 and the second stage 44 are swapped as shown in Figure 4, a trace code 99 (see Figure 7) is drawn on the upper surface 91 of the workpiece 9 held by the workpiece holding section 7 on the first stage 42, which is located at the drawing position.

[0057] As shown in Figures 1 and 5, the drawing head 47 comprises an illumination optical system 471, an optical modulator 472, a scanning unit 473, and a projection optical system 474. The illumination optical system 471 and the projection optical system 474 each include one or more optical elements such as lenses. The illumination optical system 471 guides laser light from a light source (not shown) to the optical modulator 472. The light source is, for example, a fiber laser light source that emits ultraviolet light. The light source may be provided on the drawing head 47 or outside the drawing head 47. The type of light source may be varied. In addition, the wavelength of the laser light emitted from the light source may be appropriately changed according to the type of workpiece 9, etc.

[0058] The illumination optical system 471, for example, shapes the laser light from the light source into a roughly rectangular shaped beam that is long in one direction (hereinafter referred to as the "long axis direction") and guides it to the optical modulator 472. In other words, the cross-sectional shape of the shaped beam is a roughly rectangle that is long in the long axis direction and short in the short axis direction perpendicular to the long axis direction. The long axis direction and the short axis direction are perpendicular to the direction of propagation of the shaped beam (i.e., the optical axis direction). Furthermore, the cross-sectional shape of the shaped beam is the shape of the shaped beam in a plane perpendicular to the direction of propagation of the shaped beam. The cross-sectional shape of the shaped beam can also be considered as a roughly straight line extending in the long axis direction.

[0059] The optical modulator 472, scanning unit 473, and projection optical system 474 are positioned above the second stage 44, which is located at the drawing position, and spaced upward from the second stage 44. The optical modulator 472 modulates the shaping beam from the illumination optical system 471 into a modulated beam and guides it to the scanning unit 473. As the optical modulator 472, for example, an LPLV (Linear Planar Light Valve), which is a type of PLV (Planar Light Valve), is used. The above modulated beam is a multi-spot beam composed of multiple light spots arranged linearly in the long axis direction. The gradation can be adjusted (i.e., the light intensity of the emitted light can be adjusted) at each light spot of the multi-spot beam. Note that the optical modulator 472 does not necessarily have to be an LPLV and may have other structures.

[0060] The scanning unit 473 reflects the above-mentioned modulated beam (i.e., multi-spot beam) and scans it on the upper surface 91 (see Figure 6) of the workpiece 9 via the projection optical system 474. The scanning unit 473 may include, for example, a galvanometer scanner. A galvanometer scanner is a scanning mechanism comprising a galvanometer mirror and a galvanometer motor. In the scanning unit 473, the galvanometer motor rotates the galvanometer mirror, thereby changing the direction of travel of the multi-spot beam reflected by the galvanometer mirror. As a result, the optical spot array formed by the irradiation of the multi-spot beam on the upper surface 91 of the workpiece 9 is scanned in a scanning direction (for example, the X direction perpendicular to the long axis) that is inclined with respect to the long axis direction (for example, the Y direction) of the optical spot array. Note that the scanning unit 473 does not necessarily need to include a galvanometer scanner and may have other structures.

[0061] The drawing head 47 is fixed to the frame of the drawing device 1 (not shown) and performs drawing within a predetermined drawable range. When the drawing head 47 finishes drawing within the drawable range, the second stage 44 is moved horizontally by the second stage moving mechanism 45, and the relative position of the workpiece holder 7 on the second stage 44 with respect to the drawing head 47 is changed. Then, the drawing head 47 performs drawing on the upper surface 91 of the workpiece 9 in the new area on the workpiece holder 7. In the marking unit 4, the drawing by the drawing head 47 and the displacement of the second stage 44 (i.e., the displacement of the workpiece holder 7 on the second stage 44) are repeated, thereby completing the drawing on the upper surface 91 of all workpieces 9 held by the workpiece holder 7.

[0062] Next, the drawing process on the workpiece 9 in the drawing device 1 will be explained with reference to Figure 8 and Figures 9A to 9G. Figure 8 is a diagram showing the drawing process on the workpiece 9. Figures 9A to 9G are plan views showing the state of the marking unit 4 during drawing. In Figure 8, the processing related to the first stage 42 and the processing related to the second stage 44 of the marking unit 4 are shown side by side.

[0063] In the drawing device 1 shown in Figure 1, first, a transport tray 8 holding multiple undrawn workpieces 9 is supplied from the workpiece supply unit 21 onto the belt conveyor 31 of the workpiece transport mechanism 3. The transport tray 8 moves in the (+X) direction by the belt conveyor 31 and passes below the first imaging unit 61 (i.e., on the (-Z) side). The first imaging unit 61 images the transport tray 8 and the multiple undrawn workpieces 9 on the transport tray 8. The image acquired by the first imaging unit 61 is sent to the control unit 10. A code corresponding to lot data is printed on a part of the transport tray 8 (for example, the end), and by processing the image acquired by the first imaging unit 61, it is confirmed that the imaged transport tray 8 is the transport tray 8 to be drawn on, and that the orientation of each workpiece 9 is correct.

[0064] The transport tray 8 is moved further in the (+X) direction by the belt conveyor 31 and positioned on the transfer stage 32, as shown in Figure 9A. In the state shown in Figure 9A, the workpiece 9 is not held in the workpiece holding section 7 on the first stage 42 located at the transfer position.

[0065] When the transport tray 8 is positioned on the transfer stage 32, the multiple transfer heads 51 (see Figure 1) of the transfer mechanism 5 are driven, and the multiple workpieces 9 on the transport tray 8 are held by the multiple transfer heads 51 and moved upward. Subsequently, the multiple transfer heads 51 move from above the transport tray 8 and the workpiece transport mechanism 3 in the (+Y) direction, and the multiple workpieces 9 are positioned above the workpiece holding section 7 on the first stage 42, which is located at the transfer position.

[0066] Then, as the multiple transfer heads 51 of the transfer mechanism 5 move downward, the multiple workpieces 9 are placed in the multiple recesses 71 of the workpiece holding section 7 located at the transfer position, as shown in Figure 9B. After the multiple transfer heads 51 release their suction to the multiple workpieces 9 and transfer the multiple workpieces 9 to the workpiece holding section 7, they retract from the workpiece holding section 7. As a result, the multiple undrawn workpieces 9 are transferred almost simultaneously from the transport tray 8 on the workpiece transport mechanism 3 to the workpiece holding section 7 on the first stage 42 located at the transfer position (step S11). In the state shown in Figure 9B, no workpieces 9 are held in the transport tray 8 on the transfer stage 32.

[0067] In the drawing device 1, the lower surfaces of multiple workpieces 9 are imaged by the second imaging unit 62 while multiple transfer heads 51 move from above the transfer stage 32 to above the first stage 42. The images acquired by the second imaging unit 62 are sent to the control unit 10 (see Figure 1), where the condition of the lower surface of each workpiece 9 is inspected. Based on the position and orientation of each workpiece 9 acquired from the images, the position and orientation of each transfer head 51 are individually adjusted. As a result, when multiple workpieces 9 are placed on the workpiece holding unit 7 located at the transfer position in step S11, the multiple workpieces 9 can be positioned with high positional accuracy within the multiple recesses 71.

[0068] In the marking unit 4, in parallel with the transfer of the workpiece 9 in step S11, the drawing head 47 (see Figure 1) draws trace codes 99 (see Figure 7) on multiple workpieces 9 that are pre-held in the workpiece holding unit 7 on the second stage 44 located at the drawing position (step S21).

[0069] Once the transfer of the workpiece 9 to the workpiece holding unit 7 located at the transfer position (step S11) and the drawing on the workpiece 9 on the workpiece holding unit 7 located at the drawing position (step S21) are completed, as shown in Figure 9C, the first stage 42 moves from the transfer position in the (-Y) direction by the Y-axis movement mechanism 432 of the first stage moving mechanism 43 and is positioned above the X-axis movement mechanism 431 of the first stage moving mechanism 43. Also, the second stage 44 moves from the drawing position in the (+Y) direction by the Y-axis movement mechanism 452 of the second stage moving mechanism 45 and is positioned above the X-axis movement mechanism 451 of the second stage moving mechanism 45. In the state shown in Figure 9C, the (+Y) side edge of the first stage 42 is located on the (-Y) side than the (-Y) side edge of the second stage 44.

[0070] Then, the first stage 42 moves in the (+X) direction by the first stage movement mechanism 43, and then moves in the (+Y) direction. As a result, the first stage 42 moves to the drawing position as shown in Figure 9D (step S12). Also, in parallel with step S12, the second stage 44 moves in the (-X) direction by the second stage movement mechanism 45, and then moves in the (-Y) direction. As a result, the second stage 44 moves to the transfer position (step S22).

[0071] Thus, in steps S12 and S22, the positions of the first stage 42 and the second stage 44 are swapped by the first stage moving mechanism 43 and the second stage moving mechanism 45. In other words, the first stage moving mechanism 43 and the second stage moving mechanism 45 are holding mechanism moving mechanisms 40 that swap the positions of two workpiece holding parts 7 located at the transfer position and the drawing position, respectively. In the stage mechanism 41, as described above, the first stage moving mechanism 43 and the second stage moving mechanism 45 swap the positions of the two workpiece holding parts 7 by moving them horizontally independently.

[0072] When the first stage 42 is positioned at the drawing position, light is shone onto the multiple undrawn workpieces 9 held in the workpiece holding section 7 on the first stage 42, and trace codes 99 (see Figure 7) are drawn on the upper surface 91 (see Figure 6) of each workpiece 9, as shown in Figures 9E to 9G (step S13). Also, in parallel with step S13, as shown in Figure 9D, the multiple drawn workpieces 9 held in the workpiece holding section 7 on the second stage 44, which is positioned at the transfer position, are transferred to the transport tray 8 on the transfer stage 32 by the multiple transfer heads 51 (see Figure 1) of the transfer mechanism 5 (step S23).

[0073] In step S23, first, the multiple transfer heads 51 of the transfer mechanism 5 are driven, and the multiple workpieces 9 on the workpiece holding section 7 located at the transfer position are held by the multiple transfer heads 51 and moved upward. Subsequently, the multiple transfer heads 51 move from above the second stage 44 located at the transfer position in the (-Y) direction, and the multiple workpieces 9 are positioned above the transport tray 8 on the transfer stage 32.

[0074] As multiple transfer heads 51 move from above the second stage 44 to above the transfer stage 32, the undersides of multiple workpieces 9 are imaged by the second imaging unit 62. The images acquired by the second imaging unit 62 are sent to the control unit 10 (see Figure 1), where the condition of the underside of each workpiece 9 is inspected. This makes it possible to check whether there is any damage such as scratches on the underside of the workpieces when they are transferred from the transport tray 8 on the transfer stage 32 to the workpiece holding unit 7 before drawing.

[0075] Then, as the multiple transfer heads 51 move downward, the multiple workpieces 9 are placed in the multiple recesses 81 (see Figure 3) of the transport tray 8, as shown in Figure 9E. After releasing their grip on the multiple workpieces 9 and transferring them to the transport tray 8, the multiple transfer heads 51 retract from the transport tray 8. As a result, the multiple workpieces 9 are transferred almost simultaneously from the workpiece holding section 7 on the second stage 44, which is located at the transfer position, to the transport tray 8 on the workpiece transport mechanism 3. In the state shown in Figure 9E, the workpiece holding section 7 on the second stage 44 does not hold any workpieces 9.

[0076] Once step S23 is complete, the transport tray 8 holding the multiple drawn workpieces 9 is moved in the (+X) direction by the belt conveyor 31 from the transfer stage 32, as shown in Figure 9F. The transport tray 8 is then inspected for the drawing results on the workpieces 9 on the inspection stage 33 (see Figure 1), and then collected by the workpiece retrieval unit 22 (see Figure 1).

[0077] Furthermore, once step S23 is completed, as shown in Figure 9F, a new transport tray 8 holding multiple undrawn workpieces 9 is transported by the belt conveyor 31 and placed on the transfer stage 32. Then, in much the same manner as in step S11, the multiple undrawn workpieces 9 are transferred almost simultaneously by the transfer mechanism 5 from the transport tray 8 on the workpiece transport mechanism 3 to the workpiece holding section 7 on the second stage 44 located at the transfer position, as shown in Figure 9G (step S24). In the state shown in Figure 9G, no workpieces 9 are held in the transport tray 8 on the transfer stage 32.

[0078] In the drawing device 1, the drawing time in step S13 and the total time required for transferring the workpieces 9 in steps S23 and S24 (hereinafter also referred to as "transfer time") are approximately the same. The drawing time is the time required to draw on all workpieces 9 on the workpiece holding unit 7 located at the drawing position. The drawing time is, for example, the time required from the start of drawing on the first workpiece 9 to the end of drawing on the 14th workpiece 9. The transfer time is the time required to transfer all drawn workpieces 9 from the workpiece holding unit 7 located at the transfer position to a transport tray 8 on the transfer stage 32, and then transfer all undrawn workpieces 9 from a new transport tray 8 placed on the transfer stage 32 to the workpiece holding unit 7 located at the transfer position. The transfer time is, for example, the time required from the start of driving the transfer mechanism 5, through the transfer of 14 drawn workpieces 9 to the transport tray 8, and the transfer of 14 undrawn workpieces 9 to the workpiece holding unit 7, until the transfer mechanism 5 is retracted from the workpiece holding unit 7.

[0079] Once the transfer of the workpiece 9 between the transport tray 8 located on the transfer stage 32 and the workpiece holding unit 7 located at the transfer position (steps S23, S24), and the drawing on the workpiece 9 on the workpiece holding unit 7 at the drawing position (step S13) are completed, the second stage 44 moves from the transfer position to the drawing position (step S25). Then, returning to step S21, the drawing head 47 performs drawing on the multiple workpieces 9 held in the workpiece holding unit 7 on the second stage 44 at the drawing position.

[0080] Furthermore, the first stage 42 moves from the drawing position to the transfer position in parallel with step S25 (step S14). Then, on the first stage 42 located at the transfer position, the multiple drawn workpieces 9 held in the workpiece holding unit 7 are transferred to the transport tray 8 on the transfer stage 32 (step S15). The transport tray 8 is moved from the transfer stage 32 in the (+X) direction. After that, returning to step S11, the undrawn workpieces 9 are transferred from the new transport tray 8 located on the transfer stage 32 to the workpiece holding unit 7 on the first stage 42 located at the transfer position.

[0081] As described above, in the marking unit 4, the drawing time in step S13 and the transfer time in steps S23 and S24 are approximately the same. Therefore, after the drawing on the workpiece 9 in step S13 is completed, the movement of the first stage 42 in step S14 can begin immediately. Also, after the transfer of the workpiece 9 in steps S23 and S24 is completed, the movement of the second stage 44 in step S25 can begin immediately.

[0082] The drawing time mentioned above may be longer or shorter than the transfer time. However, as previously stated, if the drawing time and transfer time are approximately the same, the movement of the first stage 42 and the second stage 44 can be started quickly. Therefore, it is preferable that the difference between the drawing time and the transfer time be small. For example, it is preferable that the difference between the drawing time and the transfer time be 50% or less of the longer of the two times.

[0083] Next, the holding of the workpiece 9 by the workpiece holding section 7 will be described. As described above, the workpiece holding section 7 is a package holding device that holds the workpiece 9, which is a semiconductor package. Figure 10 is a plan view showing an enlarged view of one recess 71 located on the (+X) side and the (-Y) side of the workpiece holding section 7 shown in Figure 6. Figure 11 is a longitudinal cross-sectional view obtained by cutting the workpiece holding section 7 and the workpiece 9 at the position XI-XI in Figure 10. The shape and structure of the multiple recesses 71 of the workpiece holding section 7 are substantially the same as those shown in Figures 10 and 11.

[0084] As shown in Figures 6, 10, and 11, the workpiece holder 7 comprises a base portion 72, a cover portion 73, and a cover portion displacement mechanism 74. The base portion 72 is a substantially flat plate-shaped member that extends substantially perpendicular to the Z direction and constitutes the bottom of the workpiece holder 7. The base portion 72 supports the multiple workpieces 9 by directly or indirectly contacting them from below.

[0085] The cover portion 73 is a substantially flat plate-shaped member that extends substantially perpendicular to the Z direction. The cover portion 73 is positioned on the (+Z) side of the base portion 72, spaced apart from the base portion 72 on the (+Z) side, and constitutes the top of the workpiece holding portion 7. The shape of the cover portion 73 in plan view is substantially the same as the shape of the base portion 72 in plan view. The cover portion 73 is supported so as to be displaceable relative to the base portion 72 in the X and Y directions (i.e., the horizontal direction).

[0086] The cover displacement mechanism 74 comprises a first displacement mechanism 741 and a second displacement mechanism 742. The first displacement mechanism 741 is located on the (+X) side of the cover portion 73. The first displacement mechanism 741 displaces the cover portion 73 in the X direction. The second displacement mechanism 742 is located on the (-Y) side of the cover portion 73. The second displacement mechanism 742 displaces the cover portion 73 in the Y direction. The first displacement mechanism 741 and the second displacement mechanism 742 are, for example, linear motors. The first displacement mechanism 741 and the second displacement mechanism 742 may be attached to the base portion 72 or the cover portion 73, or they may be independently located at a distance from the base portion 72 and the cover portion 73 and provided as external actuators that contact the cover portion 73 when the cover portion 73 is displaced.

[0087] The cover portion 73 is provided with a plurality of openings 731, and the space below each opening 731 (i.e., the space from the opening 731 to the base portion 72) becomes the aforementioned recess 71 of the cover portion 73. In other words, the opening 731 is the upper opening of the recess 71 of the cover portion 73. The shape of each opening 731 in plan view is a roughly rectangular shape that is larger than the workpiece 9 in plan view. Note that the base portion 72 is not provided with openings of a similar size to the openings 731.

[0088] Each recess 71 of the workpiece holding portion 7 is provided with two or more positioning pins 721 erected on the base portion 72. In the example shown in Figure 10, three positioning pins 721 are provided at the bottom of the recess 71. Each positioning pin 721 is a substantially cylindrical portion extending in the (+Z) direction from the upper surface of the base portion 72 (i.e., the main surface on the (+Z) side).

[0089] In the example shown in Figure 10, two positioning pins 721 are in contact with the (-X) side surface 93a of the workpiece 9. Additionally, one positioning pin 721 is in contact with the (+Y) side surface 93b of the workpiece 9. In other words, the three positioning pins 721 face two adjacent sides of the workpiece 9 (i.e., sides 93a and 93b) in the horizontal direction and make contact with these two sides from the side. This allows for the positioning of the workpiece 9 in the X and Y directions. The three positioning pins 721 constitute a lateral positioning section 722 that positions the workpiece 9 in the horizontal direction.

[0090] The number of positioning pins 721 that contact the side surface 93a of the workpiece 9 may be one or three or more. Similarly, the number of positioning pins 721 that contact the side surface 93b of the workpiece 9 may be two or more. In other words, each recess 71 is provided with two or more positioning pins 721 that are horizontally opposite to two adjacent sides of the workpiece 9 (i.e., sides 93a and 93b) and that contact these two sides from the side.

[0091] The positioning pin 721 illustrated in Figures 10 and 11 is a rotating pin comprising a rotating shaft 723a erected on a base portion 72 and a rotating part 723b attached to the rotating shaft 723a. The rotating shaft 723a is a substantially cylindrical portion extending in the (+Z) direction from the upper surface of the base portion 72. The rotating part 723b is a substantially cylindrical member extending in the Z direction with the rotating shaft 723a as its center. The rotating shaft 723a is inserted inside the rotating part 723b, and the rotating part 723b is rotatably supported by the rotating shaft 723a. The outer surface of the rotating part 723b (i.e., the side surface of the positioning pin 721) contacts the side surfaces 93a, 93b of the workpiece 9 from the side.

[0092] The outer surface of the rotating part 723b is preferably made of a material that reduces friction with the workpiece 9. The outer surface of the rotating part 723b is, for example, made of a fluororesin such as PTFE or polyethylene. In this embodiment, the entire rotating part 723b is made of a fluororesin or polyethylene. The positioning pin 721 does not necessarily have to be a rotating pin; it may be a substantially columnar pin without a rotating part. Even in this case, the surface of the positioning pin 721 (especially the side that contacts the workpiece 9) is preferably made of a fluororesin or polyethylene.

[0093] Each recess 71 of the workpiece holding portion 7 is provided with two protrusions 732 that project from the main surface on the (-Z) side of the cover portion 73 toward the (-Z) side. One protrusion 732 is located on the (+X) side of the workpiece 9, and the other protrusion 732 is located on the (-Y) side of the workpiece 9.

[0094] One of the aforementioned protrusions 732 is a substantially flat plate-shaped portion that extends substantially perpendicular to the X direction. In a plan view, the protrusion 732 extends substantially parallel to the Y direction. The (-X) side surface of the protrusion 732 faces the (+X) side surface 93c of the workpiece 9 in the X direction and contacts the side surface 93c from the side. The (-X) side surface of the protrusion 732 is formed of, for example, an elastically deformable elastic member. The other portion of the protrusion 732 is formed of the same material as the cover portion 73 (for example, hard resin or metal).

[0095] When the first displacement mechanism 741 of the cover displacement mechanism 74 applies a force to the cover portion 73 in the (-X) direction, a force is applied to the workpiece 9 from the protrusion 732 on the (+X) side of the workpiece 9 in the (-X) direction. As a result, the side surface 93a on the (-X) side of the workpiece 9 is biased toward the two positioning pins 721 located on the (-X) side of the workpiece 9. In other words, the protrusion 732 presses the side surface 93a of the workpiece 9 against the two positioning pins 721. This limits the displacement of the workpiece 9 in the X direction.

[0096] The other protrusion 732 described above is a substantially flat plate-shaped portion that extends substantially perpendicular to the Y direction. In a plan view, the protrusion 732 extends substantially parallel to the X direction. The (+Y) side surface of the protrusion 732 faces the (-Y) side surface 93d of the workpiece 9 in the Y direction and contacts the side surface 93d from the side. The (+Y) side surface of the protrusion 732 is formed of, for example, an elastically deformable elastic member. The other portion of the protrusion 732 is formed of the same material as the cover portion 73.

[0097] When a force directed in the (+Y) direction is applied to the cover portion 73 by the second displacement mechanism 742 of the cover portion displacement mechanism 74, a force directed in the (+Y) direction is applied to the workpiece 9 from the protrusion 732 on the (-Y) side of the workpiece 9. As a result, the side surface 93b on the (+Y) side of the workpiece 9 is biased toward a single positioning pin 721 located on the (+Y) side of the workpiece 9. In other words, the protrusion 732 presses the side surface 93b of the workpiece 9 against the single positioning pin 721. This restricts the displacement of the workpiece 9 in the Y direction.

[0098] The two protrusions 732 and the cover displacement mechanism 74 described above constitute a lateral biasing portion 733 that biases two adjacent sides 93a and 93b of the four sides of the workpiece 9 (i.e., sides 93a to 93d) toward the lateral positioning portion 722. The two protrusions 732 restrict the horizontal displacement of the workpiece 9 by directly contacting the other two adjacent sides 93c and 93d of the four sides of the workpiece 9 (i.e., sides 93a to 93d). In other words, in each recess 71 of the workpiece holding portion 7, the workpiece 9 is mechanically chucked in the horizontal direction by the lateral positioning portion 722 and the lateral biasing portion 733. The shape and structure of the two protrusions 732 can be changed in various ways. The lateral biasing portion 733 may also be a single continuous protrusion formed by the two protrusions 732 (i.e., a roughly L-shaped protrusion in plan view).

[0099] In the example shown in Figures 10 and 11, the substantially L-shaped portion of the cover portion 73 between the two protrusions 732 of the lateral biasing portion 733 and the opening 731 (hereinafter also referred to as the "flange portion 734") is positioned on the (+Z) side of the workpiece 9 and faces the upper surface 91 of the workpiece 9 in the vertical direction (i.e., the Z direction). The flange portion 734 protrudes in the (-X) direction from the upper end of the protrusion 732 on the (+X) side of the lateral biasing portion 733, and also protrudes in the (+Y) direction from the upper end of the protrusion 732 on the (-Y) side. In other words, the flange portion 734 protrudes substantially horizontally to the side from the upper end of the lateral biasing portion 733.

[0100] The (+X) side portion of the flange 734 is a roughly rectangular portion that extends approximately parallel to the Y direction along the (+X) side surface 93c of the workpiece 9. The (-Y) side portion of the flange 734 is a roughly rectangular portion that extends approximately parallel to the X direction along the (-Y) side surface 93d of the workpiece 9.

[0101] The flange portion 734 is provided above the base portion 72 and spaced apart from the base portion 72, and a part of the workpiece 9 (i.e., the area near the sides 93c and 93d of the workpiece 9) is located between the flange portion 734 and the base portion 72 in the vertical direction. The lower surface of the flange portion 734 (i.e., the (-Z) side surface) contacts the upper surface 91 of the workpiece 9 from above. This positions the workpiece 9 in the Z direction. The flange portion 734 is an upper positioning portion 735 that positions the workpiece 9 in the vertical direction. Note that the upper positioning portion 735 does not necessarily have to be part of the cover portion 73, and may be a separate component from the cover portion 73.

[0102] In each recess 71 of the workpiece holding section 7, a gas nozzle 724a is provided on the upper surface of the base section 72. The gas nozzle 724a is connected to a gas supply source (not shown) via a gas passage 724b provided in the base section 72. In the following description, the gas nozzle 724a and the gas passage 724b will be collectively referred to as the "gas supply section 725". The gas supply section 725 may also include the gas supply source. A gas pressure sensor 728 is provided between the gas passage 724b and the gas supply source. The gas pressure sensor 728 measures the pressure of the gas supplied from the gas supply section 725 (hereinafter also referred to as "supply gas pressure") and sends the measurement result to the attitude abnormality detection section 729. The attitude abnormality detection section 729 is a function implemented, for example, by the control unit 10 (see Figure 1).

[0103] The gas nozzle 724a is positioned below the workpiece 9 in a position that overlaps with the workpiece 9 in a plan view (i.e., in a position that is vertically opposite to the workpiece 9). In the example shown in Figures 10 and 11, one gas nozzle 724a is positioned near the flange portion 734 in a plan view. Also, the shape of the gas nozzle 724a in a plan view is a roughly circular shape, which is considerably smaller than the opening 731 of the cover portion 73.

[0104] The gas (for example, compressed air) supplied to the gas supply unit 725 by the aforementioned gas supply source is ejected from the gas nozzle 724a toward the workpiece 9 above, filling the space between the workpiece 9 and the base unit 72. The pressure of the gas then lifts the workpiece 9 (i.e., displaces it upward), and the upper surface 91 of the workpiece 9 is pressed against the flange unit 734, which is the upper positioning unit 735. In other words, the gas supply unit 725, which supplies the gas below the workpiece 9, constitutes an upward biasing unit 726 that biases the upper surface 91 of the workpiece 9 toward the upper positioning unit 735. In each recess 71 of the workpiece holding unit 7, the workpiece 9 is chucked in the vertical direction by the upper positioning unit 735 and the upward biasing unit 726.

[0105] Next, the process of holding the workpiece 9 by the workpiece holding unit 7 will be explained with reference to Figures 10 to 13 and Figures 14A to 14D. Figure 12 is a diagram showing the process of holding the workpiece 9. Figure 13 is a plan view showing the workpiece holding unit 7 before the workpiece 9 is held. Figures 14A to 14D are plan views or longitudinal cross-sectional views showing a part of the workpiece holding unit 7 during the process of holding the workpiece 9.

[0106] When a workpiece 9 is held by the workpiece holding section 7, first, an empty workpiece holding section 7 that does not hold the workpiece 9 is prepared, as shown in Figure 13. In the example shown in Figure 13, the cover section 73 and the base section 72 overlap almost entirely in a plan view. In each recess 71 of the workpiece holding section 7, as shown in Figures 14A and 14B, the three positioning pins 721 on the base section 72 and the gas nozzle 724a are positioned vertically opposite the opening 731 of the cover section 73.

[0107] Below the opening 731, four support pins 727 are provided, erected on the base portion 72. The four support pins 727 are located at the four vertices of a virtual rectangle in a plan view. The four support pins 727 are located to the (+X) side of the two positioning pins 721 on the (-X) side of the three positioning pins 721. Also, the four support pins 727 are located to the (-Y) side of the one positioning pin 721 on the (+Y) side of the three positioning pins 721. Each support pin 727 is a roughly columnar (for example, roughly rectangular columnar) portion extending from the upper surface of the base portion 72 toward the (+Z) side. On the base portion 72, the height of each support pin 727 is lower than the height of each positioning pin 721.

[0108] Next, the transfer mechanism 5 described above positions each of the workpieces 9 into the multiple recesses 71 of the workpiece holding section 7, and they are placed on the base section 72 as shown in Figures 14A and 14B (step S31). The four sides 93a to 93d of the workpiece 9 are spaced apart from the three positioning pins 721 of the lateral positioning section 722 and the two protrusions 732 of the lateral biasing section 733. In addition, the workpiece 9 overlaps with the four support pins 727 in a plan view.

[0109] The lower surface 941 of the package body 94 of the semiconductor package workpiece 9 is in direct contact with the upper ends of the four support pins 727. As a result, the substantially flat package body 94, which extends substantially perpendicular to the Z direction, is supported from below by the four support pins 727. In other words, the package body 94 is indirectly supported by the base portion 72 via the four support pins 727. The four support pins 727 are in direct contact with the four corners of the lower surface 941 of the package body 94.

[0110] In workpiece 9, a plurality of connection terminals 95 are provided that protrude downward (i.e., toward the (-Z) side) from the lower surface 941 (i.e., the main surface on the (-Z) side) of the package body 94. The length of the protrusion of the plurality of connection terminals 95 from the lower surface 941 is less than the height of each support pin 727 on the base portion 72. Therefore, because the lower surface 941 of the package body 94 is supported by the four support pins 727, the plurality of connection terminals 95 are spaced upward from the base portion 72.

[0111] Next, the first displacement mechanism 741 and the second displacement mechanism 742 of the cover displacement mechanism 74 shown in Figure 13 are driven, and the cover portion 73 is displaced in the (-X) direction and the (+Y) direction. As a result, as shown in Figures 14C and 14D, the two protrusions 732 of the lateral biasing portion 733 come into contact with two adjacent sides 93c and 93d of the workpiece 9 from the side.

[0112] The cover portion 73 is further displaced in the (-X) and (+Y) directions. This causes the workpiece 9 to be displaced in the (-X) and (+Y) directions (i.e., toward the three positioning pins 721 of the lateral positioning portion 722). Then, as shown in Figures 14E and 14F, two adjacent sides 93a, 93b of the workpiece 9 come into contact with the three positioning pins 721, and the workpiece 9 is biased toward the three positioning pins 721 (i.e., the lateral positioning portion 722) (step S32). This positions the workpiece 9 in the horizontal direction.

[0113] As described above, the positioning pin 721 is a rotating pin having a rotating shaft 723a and a rotating part 723b. Therefore, when the workpiece 9 is displaced while its sides 93a and 93b are in contact with the positioning pin 721, the frictional resistance between the sides 93a and 93b and the positioning pin 721 is reduced. Furthermore, if the sides of the rotating part 723b are made of fluororesin or polyethylene, the frictional resistance between the sides 93a and 93b and the positioning pin 721 is further reduced.

[0114] Once the horizontal positioning of the workpiece 9 is complete, the gas supply unit 725 continuously supplies gas (e.g., compressed air) below the workpiece 9, and the pressure of the gas displaces the workpiece 9 upward. As a result, as shown in Figures 10 and 11, the upper surface 91 of the workpiece 9 comes into contact with the flange portion 734, which is the upper positioning unit 735, and the workpiece 9 is biased against the flange portion 734 (step S33). As a result, the workpiece 9 is positioned in the vertical direction. In the state shown in Figures 10 and 11, the workpiece 9 is spaced upward from the four support pins 727.

[0115] In the workpiece holding unit 7, the workpiece 9 is positioned horizontally by the lateral positioning unit 722 and the lateral biasing unit 733, so that the trace code 99 (see Figure 7) can be drawn on the upper surface 91 of the workpiece 9 with good positional accuracy by the drawing head 47. Furthermore, in the workpiece holding unit 7, the workpiece 9 is positioned vertically by the upper positioning unit 735 and the upper biasing unit 726, so that the positional accuracy of the drawing by the drawing head 47 can be further improved. In the workpiece holding unit 7, the lateral positioning unit 722, the lateral biasing unit 733, the upper positioning unit 735, and the upper biasing unit 726 constitute a chuck mechanism 70 that positions and chucks the workpiece 9.

[0116] In the state shown in Figure 11, the upper surface 91 of the workpiece 9 is not tilted and is approximately perpendicular to the Z direction. That is, the posture of the workpiece 9, which is biased by the upper positioning unit 735, is normal. On the other hand, if the posture of the workpiece 9 is abnormal (for example, if the workpiece 9 is tilted because it is caught on a support pin 727, etc.), the gas continuously supplied from the gas supply unit 725 to the bottom of the workpiece 9 leaks out from around the workpiece 9 in a larger amount than when the posture of the workpiece 9 is normal. As a result, the pressure of the gas supplied from the gas supply unit 725 (i.e., the supply gas pressure) decreases.

[0117] The posture abnormality detection unit 729 determines that the posture of the workpiece 9 is abnormal when the supply gas pressure measured by the gas pressure sensor 728 decreases, and notifies the operator of the abnormal posture of the workpiece 9 through an alarm, screen display, etc. In this way, by detecting the posture abnormality of the workpiece 9 based on the measurement results of the gas pressure sensor 728, the posture abnormality of the workpiece 9 can be detected early, and the drawing of the abnormal posture on the workpiece 9 can be prevented or suppressed.

[0118] As described above, the drawing device 1, which performs drawing by irradiating light onto a workpiece 9, comprises a workpiece transport mechanism 3, two workpiece holding units 7, a holding unit moving mechanism 40, a transfer mechanism 5, and a drawing head 47. The workpiece transport mechanism 3 transports the workpiece 9 along a transport path. The two workpiece holding units 7 are located at two positions separated from the transport path: a transfer position and a drawing position. The holding unit moving mechanism 40 (in the above example, the first stage moving mechanism 43 and the second stage moving mechanism 45) swaps the positions of the two workpiece holding units 7. The transfer mechanism 5 transfers the workpiece 9 between one of the workpiece holding units 7 located at the transfer position and the workpiece transport mechanism 3. The drawing head 47 irradiates light onto the workpiece 9 held by the other workpiece holding unit 7 located at the drawing position to perform drawing.

[0119] This allows the transfer of workpieces 9 between the workpiece transport mechanism 3 and the workpiece holding unit 7, and the drawing on the workpieces 9 held in the workpiece holding unit 7, to be performed in parallel. As a result, the drawing device 1 can shorten the processing time required for drawing on multiple workpieces 9 (hereinafter also referred to as "marking processing time").

[0120] As described above, the drawing head 47 is preferably an optical device that irradiates and scans the workpiece 9 with a linearly extending array of light spots. This makes it possible to shorten the time required for drawing on each workpiece 9 compared to when drawing on the workpiece 9 is performed by a single spot beam consisting of a single light spot. As a result, the difference between the drawing time and the transfer time (i.e., the difference between the time required for step S13 and the time required for steps S23 to S24) can be reduced. Therefore, the marking processing time can be further shortened.

[0121] Figure 15 shows a comparison of the time required from the start to the end of drawing on a single workpiece 9, when drawing is performed using the drawing device 1 (i.e., multi-spot beam) and when drawing is performed using a single-spot beam. The horizontal axis represents the longitudinal length of the optical spot array irradiated onto the workpiece 9 by the drawing device 1 (in the above example, the length in the Y direction, and hereinafter also referred to as the "array length"). The vertical axis represents the value obtained by dividing the time required for drawing with the single-spot beam by the time required for drawing with the drawing device 1. In other words, the vertical axis represents the ratio of the drawing speed by the drawing device 1 to the drawing speed by the single-spot beam (hereinafter also referred to as the "speed ratio"). Figure 15 shows the case where the scanning speed of the optical spot on the workpiece 9 is 400 mm / second.

[0122] As shown in Figure 15, in the drawing device 1 that scans an array of optical spots, the drawing time for each workpiece 9 can be significantly reduced compared to the case where drawing is performed on the workpiece 9 using a single spot beam. Furthermore, as the scanning speed increases, the speed ratio also increases. Thus, in the drawing device 1, from the viewpoint of reducing the drawing time for each workpiece 9, it is preferable that the drawing head 47 scans the array of optical spots on the workpiece 9. However, if the transfer time (steps S23 to S24) is longer than the drawing time (step S13), the drawing head 47 may be an optical device that irradiates the workpiece 9 with a single optical spot and scans it.

[0123] As described above, the workpiece transport mechanism 3 is preferably a tray transport mechanism that moves a transport tray 8 holding multiple workpieces 9 along the transport path. Furthermore, the transfer mechanism 5 is preferably capable of simultaneously transferring two or more workpieces 9 between the transport tray 8 and one of the workpiece holding units 7 (i.e., the workpiece holding unit 7 located at the transfer position). This makes it possible to shorten the transfer time (steps S23 to S24).

[0124] As described above, it is preferable that the positional accuracy of the workpieces 9 held in each of the two workpiece holding sections 7 is higher than the positional accuracy of the workpieces 9 in the workpiece transport mechanism 3 (in the above example, the positional accuracy of the workpieces 9 held in the transport tray 8). This allows for high-precision drawing on the workpieces 9 held in the workpiece holding sections 7. Furthermore, when placing the workpieces 9 on the transport tray 8, the workpieces 9 can be accommodated in the recesses 81 without having to determine their position with high precision, thus facilitating the transfer of the workpieces 9 from the workpiece holding sections 7 to the transport tray 8. As a result, the marking processing time can be shortened.

[0125] As described above, it is preferable that each of the two workpiece holding sections 7 is equipped with a chuck mechanism 70 for positioning and chucking the workpiece 9 (in the above example, a lateral positioning section 722, a lateral biasing section 733, an upward positioning section 735, and an upward biasing section 726). This improves the positional accuracy of the workpiece 9 in the workpiece holding section 7. As a result, drawing on the workpiece 9 on the workpiece holding section 7 can be performed with even higher accuracy. In addition, since it is not necessary to determine the position of the workpiece 9 with high precision when placing the workpiece 9 on the workpiece holding section 7, the transfer of the workpiece 9 to the workpiece holding section 7 is made easier, and the marking processing time can be shortened.

[0126] Furthermore, from the perspective of improving the drawing accuracy on the workpiece 9, it is also conceivable to image the workpiece 9 to detect its position without chucking it, and then correct the drawing data based on that position. In this case, since correcting the drawing data takes time, the marking processing time may be extended. In the drawing device 1 described above, the workpiece 9 is positioned and chucked by the chuck mechanism 70, thereby eliminating the time required to correct the drawing data and shortening the marking processing time.

[0127] As described above, it is preferable that the holding part moving mechanism 40 includes two moving mechanisms (i.e., a first stage moving mechanism 43 and a second stage moving mechanism 45) that move the two workpiece holding parts 7 independently in the horizontal direction to swap the positions of the two workpiece holding parts 7. This allows the swapping of the positions of the two workpiece holding parts 7 to be performed suitably with a simple structure.

[0128] As described above, the drawing head 47 draws on the upper surface 91 of the workpiece 9. Preferably, the drawing device 1 further includes a bottom surface inspection unit (in the above example, a second imaging unit 62 and a control unit 10) that images the bottom surface of the workpiece 9 during transfer by the transfer mechanism 5 and inspects the bottom surface. This allows the bottom surface inspection of the workpiece 9 to be performed in parallel with the transfer of the workpiece 9 necessary for the drawing process by the marking unit 4.

[0129] As described above, it is preferable that the drawing device 1 further includes a drawing inspection unit (in the above example, a third imaging unit 63 and a control unit 10) that images the workpiece 9 in transit by the workpiece transport mechanism 3 and inspects the drawing results. This makes it possible to detect defective products with drawing defects.

[0130] Next, a drawing apparatus 1a according to a second embodiment of the present invention will be described with reference to Figures 16 and 17. The drawing apparatus 1a includes a marking section 4a that has a different structure from the marking section 4 shown in Figures 4 and 5. The other components of the drawing apparatus 1a are substantially the same as those of the drawing apparatus 1 described above, and the same reference numerals will be used for corresponding components in the following description.

[0131] Figure 16 is a plan view of the marking section 4a. Figure 17 is a side view of the marking section 4a. The marking section 4a is equipped with a stage mechanism 41a, which has a different structure from the stage mechanism 41 shown in Figures 4 and 5. In addition, the marking section 4a is equipped with a workpiece holding section 7a, which has a different structure from the workpiece holding section 7 shown in Figure 6.

[0132] The stage mechanism 41a comprises a first stage 42a, a first stage moving mechanism 43a, a second stage 44a, a second stage moving mechanism 45a, a stage support 46a, and a rotation mechanism 48a. The stage support 46a supports the first stage moving mechanism 43a and the second stage moving mechanism 45a from below. The first stage moving mechanism 43a and the second stage moving mechanism 45a are arranged side by side in the X direction on the stage support 46a. In the state shown in Figures 16 and 17, the second stage moving mechanism 45a is positioned adjacent to the (+X) side of the first stage moving mechanism 43a.

[0133] The first stage moving mechanism 43a supports the first stage 42a from below and moves the first stage 42a in the X and Y directions. The second stage moving mechanism 45a supports the second stage 44a from below and moves the second stage 44a in the X and Y directions. The first stage moving mechanism 43a can move the first stage 42a independently of the movement of the second stage 44a by the second stage moving mechanism 45a. The second stage moving mechanism 45a can move the second stage 44a independently of the movement of the first stage 42a by the first stage moving mechanism 43a. In other words, the first stage moving mechanism 43a and the second stage moving mechanism 45a can move the first stage 42a and the second stage 44a horizontally, respectively, independently of each other.

[0134] The first stage moving mechanism 43a comprises an X-axis moving mechanism 431a and a Y-axis moving mechanism 432a. The Y-axis moving mechanism 432a supports the first stage 42a from below and moves the first stage 42a substantially linearly in a direction substantially parallel to the Y direction. The Y-axis moving mechanism 432a comprises, for example, a guide extending substantially linearly in a direction substantially parallel to the Y direction and a linear motor that moves the first stage 42a substantially linearly in the Y direction along the guide. The X-axis moving mechanism 431a supports the first stage 42a and the Y-axis moving mechanism 432a from below and moves the first stage 42a and the Y-axis moving mechanism 432a substantially linearly in a direction substantially parallel to the X direction. The X-axis moving mechanism 431a comprises, for example, a guide extending substantially linearly in a direction substantially parallel to the X direction and a linear motor that moves the first stage 42a and the Y-axis moving mechanism 432a substantially linearly in the X direction along the guide.

[0135] The second stage moving mechanism 45a comprises an X-axis moving mechanism 451a and a Y-axis moving mechanism 452a. The Y-axis moving mechanism 452a supports the second stage 44a from below and moves the second stage 44a substantially linearly in a direction substantially parallel to the Y direction. The Y-axis moving mechanism 452a comprises, for example, a guide extending substantially linearly in a direction substantially parallel to the Y direction and a linear motor that moves the second stage 44a substantially linearly in the Y direction along the guide. The X-axis moving mechanism 451a supports the second stage 44 and the Y-axis moving mechanism 452a from below and moves the second stage 44a and the Y-axis moving mechanism 452a substantially linearly in a direction substantially parallel to the X direction. The X-axis moving mechanism 451a comprises, for example, a guide extending substantially linearly in a direction substantially parallel to the X direction and a linear motor that moves the second stage 44a and the Y-axis moving mechanism 452a substantially linearly in the X direction along the guide.

[0136] The first stage 42a and the second stage 44a are substantially the same components as the first stage 42 and the second stage 44 shown in Figures 4 and 5. In the state shown in Figure 16, the first stage 42a is located in the transfer position described above, and the second stage 44a is located in the drawing position described above. The second stage 44a is located adjacent to the first stage 42a on the (+X) side. The positions of the first stage 42a and the second stage 44a in the Y direction are substantially the same. The first stage 42a is positioned on the (+Y) side of the transfer stage 32 (see Figure 1) of the workpiece transport mechanism 3, spaced apart from the transfer stage 32 on the (+Y) side. The shape of the first stage 42a and the second stage 44a in plan view is substantially rectangular. The first stage 42a and the second stage 44a are substantially the same shape.

[0137] The rotation mechanism 48a is positioned below the stage support 46a and supports the stage support 46a from below. The rotation mechanism 48a is a substantially disc-shaped member centered on a rotation axis 481a that extends substantially parallel to the Z direction. The rotation axis 481a is located between the first stage 42a and the second stage 44a in the X direction. The rotation mechanism 48a rotates the stage support 46a substantially horizontally around the rotation axis 481a together with the first stage moving mechanism 43a, the second stage moving mechanism 45a, the first stage 42a, and the second stage 44a. This allows the second stage 44a to be moved to the position of the first stage 42a in Figure 16 (i.e., the transfer position), and the first stage 42a to be moved to the position of the second stage 44a in Figure 16 (i.e., the drawing position). In other words, the rotation mechanism 48a can swap the positions of the first stage 42a and the second stage 44a.

[0138] The upper surfaces of the first stage 42a and the second stage 44a are located in approximately the same position in the Z direction as the upper surface of the transfer stage 32 of the workpiece transport mechanism 3. One workpiece holder 7a is fixed to the upper surface of the first stage 42a and the upper surface of the second stage 44a, respectively.

[0139] The rotation axis 481a of the aforementioned rotation mechanism 48a is located between the two workpiece holding sections 7a on the first stage 42a and the second stage 44a in the X direction. The rotation mechanism 48a swaps the positions of the two workpiece holding sections 7a by rotating them horizontally by 180° around the rotation axis 481a together with the stage support section 46a. Specifically, the rotation mechanism 48a moves the workpiece holding section 7a located at the transfer position to the drawing position, and moves the workpiece holding section 7a located at the drawing position to the transfer position. In other words, the rotation mechanism 48a constitutes a holding section moving mechanism 40a that swaps the positions of the two workpiece holding sections 7a located at the transfer position and the drawing position, respectively.

[0140] In the drawing device 1a, the drawing process on the workpiece 9 by the drawing head 47 is substantially the same as that shown in Figure 8, except that the positions of the two workpiece holding units 7a are swapped by the rotation mechanism 48a as described above. In the drawing device 1a, as in the drawing device 1, the transfer of the workpiece 9 between the workpiece transport mechanism 3 and the workpiece holding unit 7a, and the drawing on the workpiece 9 held by the workpiece holding unit 7a can be performed in parallel. As a result, the processing time required for drawing on multiple workpieces 9 (i.e., marking processing time) can be shortened in the drawing device 1a.

[0141] Furthermore, in the drawing device 1a, the holding part movement mechanism 40a includes a rotation mechanism 48a that rotates the two workpiece holding parts 7a integrally around a rotation axis 481a located between the two workpiece holding parts 7a, thereby swapping the positions of the two workpiece holding parts 7a. This allows for the swapping of the positions of the two workpiece holding parts 7a to be performed suitably with a simple structure.

[0142] Next, the holding of the workpiece 9 by the workpiece holding section 7a will be explained with reference to Figures 18A to 18F. In the workpiece holding section 7a, the four support pins 727 and the gas supply section 725 shown in Figures 10 and 11 are omitted, and an upward biasing section 75a is provided in place of the upward biasing section 726. The other components of the workpiece holding section 7a are substantially the same as those of the workpiece holding section 7 shown in Figures 10 and 11, and the same reference numerals will be used for corresponding components in the following explanation.

[0143] As shown in Figures 18A and 18B, the upward biasing portion 75a includes an upward displacement mechanism 751 that mechanically contacts the lower surface 941 of the package body 94 of the workpiece 9 to displace the package body 94 upward. The upward displacement mechanism 751 includes four movable pins 752 and a pin movement mechanism 753. In a plan view, the four movable pins 752 are positioned in approximately the same positions as the four support pins 727 shown in Figures 10 and 11. Specifically, in a plan view, the four movable pins 752 are located at the four vertices of a virtual rectangle. The four movable pins 752 are located to the (+X) side of the two positioning pins 721 on the (-X) side of the three positioning pins 721. Also, the four movable pins 752 are located to the (-Y) side of the one positioning pin 721 on the (+Y) side of the three positioning pins 721.

[0144] The lower part of each movable pin 752 is inserted into a through hole 754 that penetrates the base portion 72a vertically. The lower end of each movable pin 752 is approximately hemispherical and protrudes downward from the lower surface of the base portion 72a. The upper part of each movable pin 752 is a roughly columnar (for example, roughly cylindrical) portion that extends from the upper surface of the base portion 72a toward the (+Z) side. On the base portion 72a, the height of each movable pin 752 (i.e., the length of the protrusion toward the (+Z) side from the upper surface of the base portion 72a) is lower than the height of each positioning pin 721.

[0145] The pin movement mechanism 753 moves the four movable pins 752 vertically. The pin movement mechanism 753 is a substantially flat plate-shaped member that contacts or is close to the lower surface of the base portion 72a from the (-Z) side and is supported by the base portion 72a. The pin movement mechanism 753 is provided with a hole portion 755 that overlaps with the through hole 754 of the base portion 72a in a plan view. The lower end of the movable pin 752 is housed in the hole portion 755. The pin movement mechanism 753 is movable in the X direction by a drive unit such as a motor (not shown).

[0146] The process of holding the workpiece 9 by the workpiece holding section 7a is substantially the same as that shown in Figure 12. When the workpiece 9 is held by the workpiece holding section 7a, first, the transfer mechanism 5 (see Figure 1) described above places multiple workpieces 9 into the multiple recesses 71a of the workpiece holding section 7a, and then places them on the base section 72a as shown in Figures 18A and 18B (Figure 12: Step S31).

[0147] The lower surface 941 of the package body 94 of the workpiece 9 is in direct contact with the upper ends of the four movable pins 752. As a result, the substantially flat package body 94, which extends substantially perpendicular to the Z direction, is supported from below by the four movable pins 752. In other words, the package body 94 is indirectly supported by the base portion 72a via the four movable pins 752. The four movable pins 752 are in contact with the four corners of the lower surface 941 of the package body 94. In addition, the four sides 93a, 93b, 93c, and 93d of the workpiece 9 are spaced apart from the three positioning pins 721 and the two protrusions 732 of the lateral biasing portion 733.

[0148] The protruding lengths of the multiple connection terminals 95 that project downward from the lower surface 941 of the package body 94 of the workpiece 9 are smaller than the protruding lengths of each movable pin 752 that project upward from the upper surface of the base portion 72. Therefore, because the lower surface 941 of the package body 94 is supported by the four movable pins 752, the multiple connection terminals 95 are spaced upward from the base portion 72a.

[0149] Next, the first displacement mechanism 741 and the second displacement mechanism 742 of the cover displacement mechanism 74 (see Figure 13) are driven, and the cover 73 is displaced in the (-X) and (+Y) directions. As a result, as shown in Figures 18C and 18D, the two protrusions 732 of the lateral biasing portion 733 come into contact with the two sides 93c and 93d of the workpiece 9, and the workpiece 9 is displaced in the (-X) and (+Y) directions (i.e., toward the three positioning pins 721 of the lateral positioning portion 722). Then, the two adjacent sides 93a and 93b of the workpiece 9 come into contact with the three positioning pins 721, and the workpiece 9 is biased toward the three positioning pins 721 (i.e., the lateral positioning portion 722) (step S32). This positions the workpiece 9 in the horizontal direction.

[0150] Once the horizontal positioning of the workpiece 9 is complete, as shown in Figures 18E and 18F, the pin movement mechanism 753 of the upward biasing section 75a moves in the (-X) direction, causing the lower ends of the four movable pins 752 to contact the pin movement mechanism 753 and be pushed upward. This causes the four movable pins 752 to move upward, displacing the workpiece 9 upward. The upper surface 91 of the workpiece 9 comes into contact with the flange section 734, which is the upward positioning section 735, and the workpiece 9 is biased against the flange section 734 (step S33). As a result, the workpiece 9 is positioned in the vertical direction.

[0151] In the workpiece holding section 7a, the workpiece 9 is positioned horizontally by the lateral positioning section 722 and the lateral biasing section 733, so that the trace code 99 (see Figure 7) can be drawn on the upper surface 91 of the workpiece 9 with high positional accuracy by the drawing head 47. Furthermore, in the workpiece holding section 7a, the workpiece 9 is positioned vertically by the upper positioning section 735 and the upper biasing section 75a, so that the positional accuracy of the drawing by the drawing head 47 can be further improved. As described above, the upper biasing section 75a is equipped with an upward displacement mechanism 751 that mechanically contacts the lower surface 941 of the package body 94 of the workpiece 9 and displaces the package body 94 upward. This allows the workpiece 9 to be displaced upward with a simple structure. In the workpiece holding section 7a, the lateral positioning section 722, the lateral biasing section 733, the upper positioning section 735, and the upper biasing section 75a constitute a chuck mechanism 70a that positions and chucks the workpiece 9.

[0152] In the state shown in Figure 18F, the upper surface 91 of the workpiece 9 is not tilted and is approximately perpendicular to the Z direction. That is, the posture of the workpiece 9, which is biased by the upper positioning unit 735, is normal. On the other hand, if the posture of the workpiece 9 is abnormal (for example, if the workpiece 9 is tilted due to being caught on the movable pin 752, etc.), the position of the edges of the workpiece 9 will also differ from that of the normal state. Therefore, by imaging the workpiece 9 with an imaging unit (not shown) and confirming the position of the edges of the workpiece 9, it is possible to detect abnormalities in the posture of the workpiece 9.

[0153] Various modifications are possible with the drawing devices 1 and 1a described above.

[0154] For example, the inspection of the drawing results for workpiece 9 may be performed by a device different from the drawing device 1. In this case, the third imaging unit 63, which constitutes the drawing inspection unit, may be omitted.

[0155] The inspection of the underside of the workpiece 9 does not necessarily have to be performed on the workpiece 9 while it is being transferred by the transfer mechanism 5. Furthermore, the inspection of the underside of the workpiece 9 may be performed by a device different from the drawing device 1. In this case, the second imaging unit 62, which constitutes the underside inspection unit, may be omitted.

[0156] In the drawing device 1,1a, the structure of the holding part moving mechanism 40,40a is not limited to the one described above and may be modified in various ways.

[0157] In the workpiece holding sections 7 and 7a, the structure of the chuck mechanism 70 and 70a is not limited to the one described above and can be modified in various ways. Furthermore, chucking of the workpiece 9 is not necessarily required in the workpiece holding sections 7 and 7a. For example, by making the size of the recesses 71 and 71a in the workpiece holding sections 7 and 7a smaller in plan view than the recess 81 of the transport tray 8, the positional accuracy of the workpiece 9 held in the workpiece holding sections 7 and 7a may be higher than that of the workpiece 9 held in the transport tray 8.

[0158] Alternatively, the positional accuracy of the workpiece 9 held in the workpiece holding sections 7, 7a does not necessarily have to be higher than the positional accuracy of the workpiece 9 held in the transport tray 8 (i.e., the positional accuracy of the workpiece 9 in the workpiece transport mechanism 3). In this case, for example, the position of the workpiece 9 on the workpiece holding sections 7, 7a may be detected by imaging from above, and the drawing data used for drawing by the drawing head 47 may be corrected based on that position.

[0159] In the workpiece transport mechanism 3, the workpiece 9 does not necessarily need to be held by the transport tray 8, and may be held and transported in various ways.

[0160] In the workpiece transport mechanism 3, a transfer stage 32 is not necessarily required. For example, the transport tray 8 may be stationary at a predetermined position on the belt conveyor 31, and the workpiece 9 may be transferred between the stationary transport tray 8 and the marking section 4.

[0161] The transfer mechanism 5 does not necessarily need to transfer all the workpieces 9 on the transport tray 8 and / or the workpiece holding sections 7, 7a simultaneously; it may transfer some of the workpieces 9 on the transport tray 8 and / or the workpiece holding sections 7, 7a simultaneously. The number of such workpieces 9 can be one or more.

[0162] Workpiece 9 is not necessarily limited to semiconductor packages and can be modified in various ways.

[0163] The configurations in the above embodiments and each modified example may be combined as appropriate, as long as they do not contradict each other. [Explanation of symbols]

[0164] 1,1a Drawing device 3. Workpiece Transfer Mechanism 5 Transfer mechanism 7,7a Workpiece holding section 8 Transport Trays 9 Work 10 Control Unit 40,40a Holding part moving mechanism 43,43a First stage moving mechanism 45,45a Second stage moving mechanism 47 Drawing head 48a Rotation mechanism 62 Imaging Unit 2 63 Third Imaging Unit 70,70a Chuck mechanism 91 Top surface (of the workpiece) 481a Rotating shaft

Claims

1. A drawing device that performs drawing by irradiating a workpiece with light, A workpiece transport mechanism that transports workpieces along a transport path, Two workpiece holding units are located at two positions separated from the aforementioned transport path: a transfer position and a drawing position, respectively. A holding mechanism for swapping the positions of the two workpiece holding parts, A transfer mechanism that transfers a workpiece between one workpiece holding unit located at the aforementioned transfer position and the workpiece transport mechanism, A drawing head that irradiates light onto a workpiece held in the other workpiece holding section located at the aforementioned drawing position to perform drawing, A drawing device equipped with the following features.

2. A drawing apparatus according to claim 1, The drawing head is a drawing device which is an optical device that irradiates and scans the workpiece with a linearly extending array of light spots.

3. A drawing apparatus according to claim 1 or 2, The workpiece transport mechanism is a tray transport mechanism that moves a transport tray holding multiple workpieces along the transport path, The transfer mechanism is a drawing device that simultaneously transfers two or more workpieces between the transport tray and one of the workpiece holding units.

4. A drawing apparatus according to claim 1 or 2, A drawing device in which the positional accuracy of the workpieces held in each of the two workpiece holding sections is higher than the positional accuracy of the workpieces in the workpiece transport mechanism.

5. A drawing apparatus according to claim 1 or 2, Each of the two workpiece holding sections is a drawing device equipped with a chuck mechanism for positioning and chucking a workpiece.

6. A drawing apparatus according to claim 1 or 2, The drawing apparatus comprises two moving mechanisms that move the two workpiece holding parts independently in the horizontal direction, thereby swapping the positions of the two workpiece holding parts.

7. A drawing apparatus according to claim 1 or 2, The drawing apparatus includes a rotation mechanism that rotates the two workpiece holding parts together around a rotation axis located between the two workpiece holding parts, thereby swapping the positions of the two workpiece holding parts.

8. A drawing apparatus according to claim 1 or 2, The drawing head performs drawing on the upper surface of the workpiece. The drawing device further comprises a bottom surface inspection unit that images the bottom surface of a workpiece during transfer by the transfer mechanism and performs inspection of the bottom surface.

9. A drawing apparatus according to claim 1 or 2, A drawing apparatus further comprising a drawing inspection unit that images a workpiece in transit by the workpiece transport mechanism and inspects the drawing results.

Images