Cutting device and method for manufacturing cut products

Abstract

To provide a cutting device capable of measuring the height position of a lead frame and a method for manufacturing a cut product.SOLUTION: A cutting device 1 that forms a groove in a second surface 41b of a lead frame 41 of a cutting object 4 comprises: a cutting table 22; a light source 33 that irradiates light onto the second surface 41b of the cutting object 4 placed on the cutting table 22; a shielding member 34 that blocks a part of light emitted from the light source 33; an imaging mechanism 31 that acquires a photographed image of the second surface 41b; a height changing mechanism 32 that changes a height of the imaging mechanism 31; and a computation unit 35 that can execute analysis processing of the photographed image. The imaging mechanism 31 includes a lens 31b that focuses light onto the second surface 41b and an imaging section 31a that can acquire the photographed image of second surface 41b. The imaging section 31a acquires photographed images at a plurality of different heights, and the computation unit 35 calculates a height position of the second surface 41b on the basis of a focus state of the shielding member 34 in the plurality of photographed images.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present disclosure relates to a cutting device and a method for manufacturing a cut product.

Background Art

[0002] Conventionally, a lead frame to which a semiconductor chip or the like is fixed is resin-sealed and then cut by a cutting device to be individualized. Thereby, a plurality of electronic components are manufactured. The electronic component is electrically connected to an external wiring by a lead frame drawn out from the semiconductor chip. Depending on the type of the electronic component, after forming a groove by cutting the lead frame to about half of the lead frame thickness with a blade having a large width without completely cutting the lead frame in the thickness direction, the lead frame may be completely cut with a blade having a smaller width than that (see, for example, Patent Document 1). When the lead frame is cut in this way, a step is formed at the end of the lead frame.

[0003] In Patent Document 1, a QFN (Quad Flat Non-leaded package) provided with a step on a lead frame (electrode in Patent Document 1) is disclosed. The step of this lead frame is formed by the above method.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When manufacturing a wettable flank type QFN with a stepped lead frame, as disclosed in Patent Document 1, it is necessary to avoid completely cutting the lead frame when forming a groove by cutting to about half the thickness of the lead frame. Therefore, it is necessary to measure the height position of the lead frame before forming the groove and set the amount to cut the lead frame based on the measurement result. However, Patent Document 1 does not disclose a method for measuring the height position of the lead frame, and there is room for improvement.

[0006] Therefore, there is a need for a cutting device capable of measuring the height position of the lead frame and a method for manufacturing the cut product. [Means for solving the problem]

[0007] One embodiment of the cutting apparatus according to the present disclosure is a cutting apparatus for forming a groove on a second surface opposite to the first surface of an object to be cut, which has a resin layer formed on the first surface of a plate-shaped lead frame, comprising: a cutting table on which the object to be cut can be placed; a light source that irradiates light onto the second surface side of the object to be cut placed on the cutting table; a shielding member positioned in the middle of the path of the light propagating from the light source to the object to be cut and shielding a portion of the light emitted from the light source; an imaging mechanism that acquires an image of the second surface side of the object to be cut; a height changing mechanism that can change the height of the imaging mechanism; and The imaging mechanism comprises a calculation unit capable of performing analysis processing of captured images, the imaging mechanism having a lens positioned on the side of the object to be cut rather than the shielding member in the path of the light and focusing the light of the light source onto the second surface, and an imaging unit positioned on the opposite side of the cutting table from the object to be cut and capable of acquiring the captured image by the incident light reflected by the object to be cut, the imaging unit acquires the captured image at a plurality of different heights changed by the height changing mechanism, and the calculation unit calculates the height position of the second surface based on the focus state of the shielding member in the plurality of captured images.

[0008] One embodiment of the method for manufacturing a cut product according to this disclosure includes a groove forming step of forming the groove in the object to be cut using the cutting apparatus described above, and a piece forming step of cutting the object to be cut in which the groove has been formed to divide it into a plurality of cut products. [Effects of the Invention]

[0009] According to embodiments of this disclosure, it is possible to provide a cutting device capable of measuring the height position of a lead frame and a method for manufacturing a cut product. [Brief explanation of the drawing]

[0010] [Figure 1] Plan view of the package substrate. [Figure 2] This is a cross-sectional view taken along the line II-II in Figure 1. [Figure 3] This is a plan view of the cutting device. [Figure 4] This is a front view of the cutting device. [Figure 5A] This is a cross-sectional view showing the groove formation process of a package substrate using a cutting device. [Figure 5B] This is a cross-sectional view showing the process of separating package substrates into individual pieces using a cutting device. [Figure 5C] This is a perspective view showing electronic components separated into individual pieces by a cutting device. [Figure 6] This is a schematic diagram showing the configuration of the measurement unit when the shielding member is not in focus. [Figure 7] This is a partial plan view showing a circuit board with a cross mark formed on it. [Figure 8] This diagram illustrates the process of calculating the peak contrast value using a measurement unit. [Figure 9] This graph shows the peak contrast value as a function of the distance between the support column and the second surface. [Figure 10] This is a flowchart illustrating the process of calculating the distance between the support column and the second surface. [Figure 11] This is a schematic diagram showing the configuration of the measurement unit when the shielding member is in focus.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the cutting device and the method for manufacturing a cut product according to the present disclosure will be described in detail with reference to the drawings. Note that the embodiments described below are examples for explaining the cutting device and the method for manufacturing a cut product, and the cutting device and the method for manufacturing a cut product are not limited to these embodiments. Therefore, the cutting device and the method for manufacturing a cut product according to the present disclosure can be implemented in various forms without departing from the gist thereof.

[0012] After a substrate on which elements such as semiconductor chips are fixed is resin-sealed to form a package substrate, it is cut and fragmented. Thereby, a plurality of electronic components are manufactured. In order to cut the resin-sealed package substrate, a dedicated cutting device is used.

[0013] The resin sealing of the substrate is performed by placing the substrate on a mold of a resin molding device and supplying liquid molten resin into the mold. The molten resin may be a thermoplastic resin or a thermosetting resin. The thermosetting resin has a reduced viscosity when heated, and further polymerizes and cures when heated further to become a cured resin. When resin-sealing a substrate on which elements such as semiconductor chips are fixed, it is desirable to use a thermosetting resin. The elements fixed to the substrate are protected by the sealed resin.

[0014] The cutting device manufactures a plurality of electronic components by cutting a package substrate. Here, the concept of the term "cutting" includes separating the object to be cut into a plurality of fragmented cut products, and removing a part of the object to be cut to form a groove in the thickness direction. Hereinafter, the cutting that separates the object to be cut into a plurality of fragmented cut products is sometimes referred to as a full cut, and the cutting that does not separate the object to be cut and removes a part of the object to be cut to form a groove in the thickness direction is sometimes referred to as a half cut. Hereinafter, first, the package substrate will be described, and then the cutting device that cuts the package substrate will be described.

[0015] 〔Configuration of Package Substrate〕 FIG. 1 is a plan view of a package substrate 4 (an example of an object to be cut) according to the present embodiment, and FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1. The type of the package substrate 4 targeted in the present embodiment is not particularly limited. The package substrate 4 is, for example, a wettable-flank type QFN (Quad Flat Non leaded). As shown in FIGS. 1 and 2, the package substrate 4 includes a rectangular plate-shaped substrate 41 (an example of a lead frame) formed of a metal such as a copper plate, and a rectangular resin layer 42 obtained by resin-sealing one surface of the substrate 41. Hereinafter, the surface of the substrate 41 on which the resin layer 42 is formed is referred to as a first surface 41a, and the surface opposite to the first surface 41a is referred to as a second surface 41b. As the substrate 41, a lead frame can be used.

[0016] On the first surface 41a of the lead frame (substrate 41) of the present embodiment, a plurality of semiconductor chip mounting portions (die pads, not shown) are arranged in a matrix, and electronic elements 43 such as semiconductor chips, resistance elements, and capacitor elements are fixed to each semiconductor chip mounting portion. In the present embodiment, a total of 12 electronic elements 43 are fixed, two in the short side direction and six in the long side direction of the substrate 41. The substrate 41 is made of a metal such as copper (Cu) or 42 alloy (Fe-Ni) and has conductivity. In many cases, a lead-free metal plating layer or a lead-free solder plating layer (not shown) is previously formed on the surface of the substrate 41. A large number of leads serving as connection terminals to the outside are arranged around each die pad. These numerous leads are each connected to a tie bar which is a metal frame arranged in a grid pattern on the substrate 41. Further, a plurality of electrodes (not shown) provided on each electronic element 43 are electrically connected to the respective leads arranged around the die pad via bonding wires made of gold wires or copper wires.

[0017] The substrate 41 of this embodiment consists of a rectangular usable area 411 and a non-usable area 412 surrounding the usable area 411. The non-usable area 412 is the area including the outer edge of the substrate 41, is not used in the product and is removed after cutting. On the other hand, the usable area 411 is the area used in the product and includes the die pads, leads, and tie bars of the lead frame described above. The resin layer 42 is molded in a rectangular shape so as to cover the usable area 411 of the substrate 41 and a part of the non-usable area 412 outside the usable area 411. That is, the electronic elements 43 and bonding wires placed in the usable area 411 are sealed by the resin layer 42. With the formation of such a resin layer 42, a step equal to the thickness of the resin layer 42 is formed between the first surface 41a of the substrate 41 and the end surface of the resin layer 42 (the upper surface in Figure 2). Note that the substrate 41 constituting the package substrate 4 is not limited to a lead frame.

[0018] [Configuration of the cutting device] Figures 3 and 4 show the cutting apparatus 1 according to this embodiment. The cutting apparatus 1 mainly comprises a cutting unit 10 (an example of a first cutting mechanism and a second cutting mechanism), a holding unit 20, a measuring unit 30, and a control unit 50. In other words, in this cutting apparatus 1, the package substrate 4 held by the holding unit 20 is cut by the cutting unit 10. Before cutting, the measuring unit 30 measures the height position of the second surface 41b of the substrate 41 for cutting the package substrate 4. The control unit 50 controls the series of cutting processes.

[0019] The cutting device 1 may include units other than those described above. For example, the cutting device 1 may include a substrate supply unit for supplying the package substrate 4, an inspection unit for inspecting the package substrate 4 and / or electronic components 40 (an example of cut products), a cleaning unit for cleaning and / or drying the cut electronic components 40, a transport unit for transporting the cut electronic components 40 to a storage unit, and so on. The configurations of the cutting unit 10, the holding unit 20, the measuring unit 30, and the control unit 50 will be described in detail below. In this embodiment, as shown in Figures 3 and 4, the direction perpendicular to the plate surface of the blade 11, which will be described later, is called the X-axis direction. The direction perpendicular to the X-axis direction and parallel to the mounting surface 22a of the table 22 (an example of a cutting table) is called the Y-axis direction, and the direction perpendicular to the mounting surface 22a, that is, the direction perpendicular to the X-axis direction and the Y-axis direction, is called the Z-axis direction.

[0020] As shown in Figures 3 and 4, the cutting unit 10 is positioned above the holding unit 20 and configured to cut the package substrate 4. The cutting unit 10 includes a blade 11, a spindle section 13, and a spindle section movement mechanism (not shown) that moves the spindle section 13 to a desired position within the cutting device 1. The spindle section 13 includes a shaft 13a that rotates the blade 11, which will be described later. The shaft 13a of the spindle section 13 extends in the X-axis direction. That is, the shaft 13a and the blade 11 rotate around the X-axis. The spindle section 13 is configured to be movable in the X-axis and Z-axis directions in Figures 3 and 4 by a spindle section movement mechanism (not shown). The operation of the spindle section movement mechanism, that is, the movement of the spindle section 13 and its position in the X-axis and Z-axis directions, is controlled by a control unit 50, which will be described later. Hereinafter, the Z-axis direction in Figures 3 and 4 may be referred to as the height direction of the spindle section 13 or the blade 11. Furthermore, the control unit 50 can determine the position of the spindle section 13 in the X-axis and Z-axis directions based on information from the spindle section movement mechanism.

[0021] The blade 11 has a disc shape with a cutting edge formed on its outer circumference. The blade 11 is detachably attached to the shaft 13a of the spindle portion 13. The blade 11 is configured to be movable in the X-axis and Z-axis directions in Figures 3 and 4, together with the spindle portion 13 to which the blade 11 is attached.

[0022] The blade 11 attached to the shaft 13a of the spindle section 13 is configured to rotate at high speed by transmitting rotation from the spindle section 13 via the shaft 13a, causing the outer edge of the blade to perform half-cuts and full cuts on the package substrate 4. Hereinafter, the blade 11 for half-cuts will be referred to as the first blade 11a (an example of a blade), and the blade 11 for full-cuts will be referred to as the second blade 11b, with blade 11 being a collective term for the first blade 11a and the second blade 11b. The first blade 11a has a first thickness, and the second blade 11b has a second thickness that is smaller than the first thickness. In other words, the thickness of the second blade 11b is thinner than the thickness of the first blade 11a (see Figures 5A and 5B). In this embodiment, either the first blade 11a or the second blade 11b is attached to the spindle section 13, and cutting is performed. The first blade 11a and the second blade 11b are detachable and replaceable with respect to the spindle section 13.

[0023] The holding unit 20 comprises a table 22 and a table moving mechanism 24. The package substrate 4 is placed on the mounting surface 22a of the table 22 so that the resin layer 42 is in contact with it, and is held by a method such as air suction. The table moving mechanism 24 can move the table 22 along the Y-axis and rotate it 90 degrees around the Z-axis. While the package substrate 4 is held by the holding unit 20, the table 22 moves relative to the blade 11 in the Y-axis direction and rotates around the Z-axis, making it possible to cut along its longitudinal and transverse directions.

[0024] Furthermore, it is acceptable as long as the spindle portion 13 is movable relative to the table 22. Therefore, instead of moving the spindle portion 13 in the X-axis direction, the table 22 may be moved in the X-axis direction. Also, instead of moving the spindle portion 13 in the Z-axis direction, the table 22 may be moved in the Z-axis direction. Moreover, instead of moving the table 22 in the Y-axis direction, the spindle portion 13 may be moved in the Y-axis direction.

[0025] As shown in Figures 5A to 5C, when manufacturing electronic components 40 by cutting a package substrate 4, the package substrate 4 is cut in the order of half-cut and then full-cut. That is, the method for manufacturing electronic components 40 includes a groove forming step in which a half-cut is performed on the substrate 41 of the package substrate 4 using a cutting device 1 to form a half-cut groove 44 (an example of a groove) of a desired depth, and a piece forming step in which a full-cut is performed on the grooved package substrate 4 to separate the package substrate 4 into multiple electronic components 40. Note that the cross-section of the package substrate 4 shown in Figures 5A to 5C is a cross-section along the longitudinal direction.

[0026] In the groove formation process shown in Figure 5A, a first blade 11a is attached to the shaft 13a of the spindle section 13. The package substrate 4 is then placed on the table 22 so that its longitudinal direction is parallel to the surface of the first blade 11a. With the package substrate 4 held on the table 22, the first blade 11a is positioned between adjacent electronic elements 43 (see Figure 1) among the multiple electronic elements 43 fixed to the package substrate 4. Then, by rotating the first blade 11a in place and moving the table 22 along the Y-axis direction, the longitudinal direction of the package substrate 4 along the Y-axis direction is half-cut by the first blade 11a, and a single (single row) half-cut groove 44 is formed in the substrate 41 of the package substrate 4. Specifically, in the groove formation process, a portion of the substrate 41 in the thickness direction of the package substrate 4 (for example, about half the thickness of the substrate 41 (lead frame)) is removed. After one half-cut groove 44 is formed, the first blade 11a is moved in the X direction to position it between another adjacent electronic element 43. Then, the table 22 is moved again along the Y axis to form a new half-cut groove 44 in the package substrate 4. This is repeated to form multiple half-cut grooves 44 (for example, three if in the longitudinal direction of the package substrate 4).

[0027] Next, while holding the package substrate 4, the table 22 is rotated 90 degrees around the Z axis so that the shorter side of the package substrate 4 is parallel to the surface of the first blade 11a. Then, as described above, the first blade 11a is rotated in place while the table 22 is moved along the Y axis so that the first blade 11a forms half-cut grooves 44 in the shorter side of the package substrate 4. This is repeated to form multiple half-cut grooves 44 (for example, seven grooves in the shorter side of the package substrate 4). In this way, the groove formation process is completed by forming a grid of half-cut grooves 44 extending in the longitudinal and short directions of the package substrate 4.

[0028] In the piece-making process shown in Figure 5B, first, the first blade 11a is removed from the spindle section 13 and the second blade 11b is attached. Then, a full cut is performed with the second blade 11b. Specifically, at approximately the center of the extension direction of the half-cut groove 44, the second blade 11b cuts the remaining portion of the substrate 41 and the resin layer 42 along the half-cut groove 44. The cutting procedure is the same as in the case of a half-cut, so a detailed explanation is omitted. As a result, the grid-like half-cut groove 44 is separated, and the package substrate 4 is pieced into multiple (12 in this embodiment) electronic components 40 as shown in Figure 5C.

[0029] The measurement unit 30 measures the height position of the second surface 41b of the substrate 41 of the package substrate 4. By accurately measuring the height position of the second surface 41b, a half-cut groove 44 of a desired depth can be formed in the substrate 41 with the first blade 11a. As shown in Figure 6, the measurement unit 30 includes an imaging mechanism 31, a height changing mechanism 32, a light source 33, a shielding member 34, a calculation unit 35, a half mirror 36 (an example of a mirror), and a CCS (Contact Cutter Setup) block 37 (an example of a reference block).

[0030] The imaging mechanism 31 has the function of imaging the second surface 41b of the substrate 41 of the package substrate 4, and includes a camera 31a (an example of an imaging unit), a lens 31b, and a rectangular tube-shaped first tube 31c connecting the camera 31a and the lens 31b. The camera 31a acquires an imaged image 31d, which is an image of the second surface 41b, by forming an image on an image sensor (not shown) such as a built-in CCD or CMOS (see Figure 8(a)). Therefore, the light-receiving surface of the image sensor of the camera 31a is positioned to face the second surface 41b. The lens 31b collects the light reflected from the second surface 41b, passes it through the tube of the first tube 31c (propagates), and forms an image on the image sensor of the camera 31a. Therefore, the lens 31b is positioned between the camera 31a and the second surface 41b. The camera 31a is attached to one end of the first barrel 31c, and the lens 31b is attached to the other end of the first barrel 31c. In other words, the imaging mechanism 31 is integrated.

[0031] The height adjustment mechanism 32 includes a main column 32a extending in the Z-axis direction and a holding column 32b extending from the main column 32a along the X-axis direction. The holding column 32b is configured to be movable along the Z-axis direction relative to the main column 32a. The holding column 32b holds the first cylinder 31c, and the imaging mechanism 31 also moves along the Z-axis direction as the holding column 32b moves along the Z-axis direction. The movement of the holding column 32b is performed, for example, by a motor (not shown). The control unit 50 can determine the height position of the holding column 32b, i.e., the height position of the camera 31a, by knowing the rotation speed of the motor when the holding column 32b is moved up and down.

[0032] The light source 33 illuminates the second surface 41b of the substrate 41 of the package substrate 4, and is composed of an LED or the like. The light source 33 is attached to one end of the rectangular tube-shaped second tube 33a, and the light emitted from the light source 33 travels inside the second tube 33a. The other end of the second tube 33a is connected to the side surface of the first tube 31c, and the light from the light source 33 enters the internal space of the first tube 31c. That is, there is a hole in the side surface of the first tube 31c, and this hole is blocked by the second tube 33a. The second tube 33a extends along the X-axis direction.

[0033] Inside the first cylinder 31c, a half-mirror 36 is positioned to reflect light that has passed through the second cylinder 33a along the X-axis direction, causing it to travel along the Z-axis direction toward the second surface 41b. This half-mirror 36 transmits the light that has been reflected by the second surface 41b and focused by the lens 31b, directing it towards the image sensor of the camera 31a. In other words, light emitted from the light source 33 passes through the second cylinder 33a, enters the first cylinder 31c, is reflected by the half-mirror 36, and heads toward the second surface 41b. After being reflected by the second surface 41b, it passes through the lens 31b and the half-mirror 36 before entering the camera 31a. As a result, the image sensor of the camera 31a can acquire the captured image 31d of the second surface 41b.

[0034] A shielding member 34 is positioned inside the second cylinder 33a. The shielding member 34 is a rectangular frame. That is, the inside (center) of the shielding member 34 has an opening 34a that is similar in shape to the outside (i.e., rectangular). When light is emitted from the light source 33 into the second cylinder 33a, the light that passes through the central region of the second cylinder 33a and enters the opening 34a adjacent to the shielding member 34, i.e., the opening 34a located inside the shielding member 34, passes through (propagates) the opening 34a and travels through the inside of the second cylinder 33a towards the first cylinder 31c. On the other hand, light that enters the shielding member 34 through the outer edge region of the second cylinder 33a cannot pass through the shielding member 34 and is reflected or absorbed. In other words, the shielding member 34 shields the light that enters from the light source 33 through the outer edge region. The outer edge region is the region of the second cylinder 33a that is close to the inner surface. The shielding member 34 is attached to a sliding cylinder 34c that is slidably positioned inside the second cylinder 33a. As a result, the shielding member 34 is configured to move along the X-axis direction by the movement of the sliding cylinder 34c along the X-axis direction.

[0035] Thus, the imaging mechanism 31, light source 33, second cylinder 33a, shielding member 34, and half mirror 36 are integrated. All of these are held by the holding column 32b of the height changing mechanism 32, and move along the Z-axis direction as the holding column 32b moves along the Z-axis direction.

[0036] The arithmetic unit 35 is included in the control unit 50. The control unit 50 includes a processor such as a CPU (Central Processing Unit) and a memory device such as RAM (Random Access Memory) or ROM (Read Only Memory). The arithmetic unit 35 is a processor. The control unit 50 controls the operation of the cutting unit 10, the holding unit 20, and the measuring unit 30 of the cutting device 1 by executing a control program stored in the memory device using the processor. Unless otherwise specified, the operation of the cutting device 1 is performed based on the operation commands of the control unit 50. In the following description, the operation commands of the control unit 50 will be omitted in principle, and will be described as necessary. The control unit 50 may be configured integrally with each unit or may be configured separately from each unit.

[0037] The calculation unit 35 calculates the height position (absolute position and / or relative position) of the second surface 41b of the substrate 41 of the package substrate 4, which has been measured by the measurement unit 30. In this embodiment, the height position of the second surface 41b of the substrate 41 refers to the height from the reference position (hereinafter referred to as the reference height P) to the second surface 41b, when an arbitrary point is designated as the reference position in the height direction. In this embodiment, the reference height P is the space between the upper surface 37a of the CCS block 37 and the upper surface of the table moving mechanism 24.

[0038] The CCS block 37 is attached to the side of the table 22 and can move together with the table 22.

[0039] [Method for measuring the height position of the second surface of a circuit board] Next, a method for measuring the height position of the second surface 41b of the substrate 41 of the package substrate 4 will be described using Figures 6 to 11. Before starting the measurement, the positions of the shielding member 34, half mirror 36, and lens 31b are adjusted so that when the second surface 41b of the substrate 41 is imaged by the camera 31a, a confocal image is obtained in the captured image 31d in which both the second surface 41b and the shielding member 34 are in focus. Note that Figure 6 shows a state in which the shielding member 34 is not in focus on the second surface 41b of the substrate 41, and Figure 11 shows a state in which the shielding member 34 is in focus on the second surface 41b of the substrate 41.

[0040] First, the package substrate 4 is placed on the table 22 and held in place by methods such as air suction. Then, the imaging mechanism 31, including the camera 31a, is moved above the package substrate 4 by the height changing mechanism 32, and at that location, it is moved along the Z-axis to a predetermined height position (hereinafter also simply referred to as the predetermined height position) (step S1). The predetermined height position may be, for example, a height position where the lens 31b is close enough that it does not come into contact with the substrate 41. Alternatively, it may be a height position where the lens 31b is as far away from the substrate 41 as possible, allowing for measurement of the height position by imaging the second surface 41b with the camera 31a.

[0041] The height position of camera 31a is configured to be determined as the height from a reference height P. This height position of camera 31a is input to the calculation unit 35. In addition, the focal length L of camera 31a in the imaging mechanism 31 is stored in the memory device beforehand.

[0042] Light from the light source 33 is shone onto the second surface 41b of the substrate 41 of the package substrate 4, and the second surface 41b is imaged by the camera 31a (step S2). At this time, it is preferable to image the cross mark 41c (an example of a cutting mark) formed on the second surface 41b, as shown in Figure 7. The cross mark 41c is formed on the edge of the second surface 41b and indicates the cutting locations for half-cut and full-cut of the substrate 41, that is, the locations where the blade 11 cuts the package substrate 4. The cross mark 41c is formed by printing or other methods along at least two adjacent sides of the second surface 41b of the rectangular substrate 41. Any location on the second surface 41b can be imaged by the camera 31a in order to measure the height position of the second surface 41b of the substrate 41. However, it is preferable to capture the cross marks 41c, which are the half-cut and full-cut locations of the substrate 41, and obtain the captured image 31d, as this allows for the measurement of the height position of the cut location on the second surface 41b of the substrate 41 and the identification of the cut location of the package substrate 4. This makes it possible to form a half-cut groove 44 of a desired depth at the desired cut location of the substrate 41.

[0043] The image sensor of camera 31a acquires an image 31d as shown in Figure 8(a). In this embodiment, a shielding member 34 is placed between the light source 33 and the second surface 41b of the substrate 41, and light incident on the shielding member 34 is shielded and does not reach the second surface 41b. As a result, in the image 31d captured by camera 31a, the edges 31e (areas shielded by the shielding member 34) are black (dark), and the central part 31f (areas through which light is transmitted by the opening 34a adjacent to the shielding member 34) is bright and shows a cross mark 41c. In other words, in the image 31d, the edges 31e are dark and the central part 31f is bright. The data of the image 31d acquired by imaging the second surface 41b with camera 31a, and the distance D between camera 31a and the reference height P (see Figure 6) are output to the control unit 50.

[0044] In the control unit 50, the calculation unit 35 calculates the total pixel value for each column of multiple rows (vertical arrangement of multiple pixels in Figure 8) near the boundary between the edge 31e and the central part 31f, as shown in Figure 8(b), from the input captured image 31d data. Since Figure 8(b) shows the state where the shielding member 34 is in focus, the total pixel value has two types of values, as shown in Figure 8(c). Next, as shown in Figure 8(d), the calculation unit 35 generates an approximation curve for the total pixel value, and then differentiates the approximation curve to generate a differential curve as shown by the solid line in Figure 8(e). In the differential curve, the differential value is the amount of change in the pixel value, so the differential value represents the contrast value, which is the contrast ratio between the edge 31e and the central part 31f of the captured image 31d. In other words, generating a differential curve is synonymous with calculating the contrast value. The location where the calculated contrast value (derivative value) is at its maximum corresponds to the location with the greatest change in pixel value. Therefore, the location where the contrast value is at its maximum corresponds to the boundary between the edge 31e (dark area) and the central area 31f (bright area) of the captured image 31d. Hereinafter, the maximum contrast value may be referred to as the peak contrast value. Next, the calculation unit 35 extracts the peak contrast value from the contrast value and stores it in the memory device (step S3). Note that the imaging of the second surface 41b of the substrate 41 by the camera 31a at a predetermined height, the calculation of the contrast value by the calculation unit 35, and the extraction and storage of the peak contrast value may be performed for one cross mark 41c or for multiple cross marks 41c. If performed for multiple cross marks 41c, the calculation unit 35 stores the average value of the multiple peak contrast values ​​in the memory device.

[0045] Once the imaging of the second surface 41b of the substrate 41 by the camera 31a at a predetermined height position, the calculation of the contrast value by the calculation unit 35, and the extraction and storage of the peak contrast value are completed, the camera 31a (holding column 32b) is moved by a predetermined distance (No in step S4, step S6), and imaging of the second surface 41b and extraction of the peak contrast value are performed at the height position after the move (steps S2, step S3). This is performed a predetermined number of times, or over a predetermined range of height positions in the Z-axis direction, and the measurement is stopped after the execution is completed (Yes in step S4).

[0046] In Figure 8, the shielding member 34 is shown in focus, so the differential curve shown by the solid line in Figure 8(e) rises sharply towards the peak contrast value, and the peak contrast value itself is also large. In other words, the dark and bright areas are clearly separated. However, when the shielding member 34 is not in focus (not shown), the area near the boundary between the edge 31e and the central part 31f in the image 31d captured by the camera 31a becomes gray, and the boundary between the edge 31e (dark area) and the central part 31f (bright area) cannot be clearly separated. Therefore, the sum of the pixel values ​​for each column parallel to the boundary between the edge 31e and the central part 31f rises gradually from the dark area to the bright area. In such a case, as shown by the dashed line in Figure 8(e), the differential curve rises more gradually towards the peak contrast value compared to the solid line (when the shielding member 34 is in focus), and the peak contrast value itself is also smaller. Figure 9 shows the relationship between the distance D between the camera 31a and the second surface 41b of the substrate 41 and the peak contrast value.

[0047] As shown in Figure 9, the peak contrast value changes as the distance D changes, and the distance D1 at which the peak contrast value is maximum, i.e., the distance at which the contrast ratio is highest, is the distance at which the shielding member 34 is in focus. Distance D1 is the distance D from the reference height P to the camera 31a when the shielding member 34 is in focus on the second surface 41b of the substrate 41, as shown in Figure 11 (step S5). At this time, the distance between the camera 31a and the second surface 41b of the substrate 41 is equal to the focal length L. Therefore, by subtracting the focal length L from distance D1, the distance D2 (height position of the second surface 41b) from the reference height P to the second surface 41b can be calculated (D2 = D1 - L).

[0048] Next, the calculation unit 35 illuminates the upper surface 37a of the CCS block 37 with light from the light source 33 and acquires an image of the upper surface 37a (not shown; an example of a block image). Then, using the same method as for calculating the distance D2 (height position of the second surface 41b) described above, it calculates the distance D3 from the reference height P to the upper surface 37a of the CCS block 37. Then, the calculation unit 35 calculates the distance D4 from the upper surface 37a of the CCS block 37 to the second surface 41b of the substrate 41 based on the difference between distance D2 and distance D3 (D4 = D2 - D3).

[0049] Such measurements and calculations of distance D4 are performed at multiple locations on the package substrate 4, for example, at the four corners of a rectangular substrate (4 locations), or at the four corners plus the center of the long side of the rectangular substrate (a total of 6 locations). If the values ​​of distance D4 at multiple locations vary due to reasons such as warping of the package substrate 4, a distance D4 is set such that the depth of the half-cut groove 44 falls within the allowable tolerance regardless of where the cut is made. If, for example, a single distance D4 does not result in the depth of the half-cut groove 44 falling within the allowable tolerance at any of the cutting locations, two or more different distances D4 are set so that the depth of the half-cut groove 44 falls within the allowable tolerance at all cutting locations.

[0050] Next, the spindle section 13 is moved by a spindle section moving mechanism (not shown) to bring the first blade 11a into contact with the upper surface 37a of the CCS block 37. Contact between the first blade 11a and the CCS block 37 may be detected by any method, such as detecting conductivity between the first blade 11a and the CCS block 37. Specifically, the method for detecting conductivity between the first blade 11a and the CCS block 37 is as follows: The CCS block 37 and the spindle section 13 are made of a conductive material such as metal, and for example, the CCS block 37 and the spindle section 13 are electrically connected in advance. Also, since the spindle section 13, the shaft 13a, and the first blade 11a are all made of metal, the spindle section 13 and the first blade 11a are electrically connected. As a result, the spindle section 13 is moved in the Z-axis direction by the spindle section moving mechanism to bring the first blade 11a closer to the upper surface 37a of the CCS block 37. When the CCS block 37 and the first blade 11a are not in contact, no electrical conductivity occurs between the CCS block 37, the spindle portion 13, and the first blade 11a. However, at the moment the CCS block 37 and the first blade 11a come into contact, electrical conductivity occurs between the CCS block 37, the spindle portion 13, and the first blade 11a. This electrical conductivity is detected by a known method. The detection of electrical conductivity means that the lowest point of the first blade 11a is located on the upper surface 37a of the CCS block 37.

[0051] From the state in which the first blade 11a is in contact with the upper surface 37a of the CCS block 37, the spindle portion 13 is raised by a distance D4 using the spindle portion moving mechanism. This brings the first blade 11a and the second surface 41b of the substrate 41 to the same height. The height of the first blade 11a is, in detail, the height of the lowest point of the first blade 11a, that is, the height of the point of contact between the first blade 11a and the upper surface 37a of the CCS block 37. Finally, the spindle portion 13 is lowered by the depth of the half-cut groove 44, and at that height, the first blade 11a is rotated in place to move the table 22 along the Y-axis. This makes it possible to form a half-cut groove 44 of the desired depth in the substrate 41. Alternatively, the spindle portion 13 may be directly moved from the state in which the first blade 11a is in contact with the upper surface 37a of the CCS block 37 to the height at which the half-cut groove 44 is formed in the substrate 41.

[0052] In this way, by changing the height of the camera 31a (the height of the holding column 32b of the height changing mechanism 32) to image the second surface 41b of the substrate 41, calculate the contrast value of the differential curve, and extract the peak contrast value, the height position of the second surface 41b of the substrate 41 (lead frame) can be calculated from the reference height P, and the height positions of the first blade 11a and the second surface 41b of the substrate 41 can be aligned. As a result, the cutting device 1 can be used to perform a half-cut on the substrate 41 of the package substrate 4 to form a half-cut groove 44 of a desired depth.

[0053] Furthermore, since the first blade 11a will wear down slightly when forming the half-cut groove 44, it is preferable to bring the first blade 11a into contact with the upper surface 37a of the CCS block 37 each time a half-cut groove 44 is formed, and adjust the height difference between the second surface 41b of the substrate 41 and the lowest point of the first blade 11a to a value obtained by subtracting the depth of the half-cut groove 44 from the distance D4 before performing the half-cut.

[0054] Furthermore, the height position of the first blade 11a does not have to be calculated using the upper surface 37a of the CCS block 37 as the reference height. For example, the height of the shaft 13a of the spindle section 13 when the first blade 11a is moved to its lowest point by the spindle section moving mechanism may be used as the reference height. Also, the reference height of the first blade 11a does not have to coincide with the reference height of the camera 31a and the substrate 41.

[0055] [Another embodiment] The following describes another embodiment of the above-described embodiment. For the same components as in the above-described embodiment, the same terms and reference numerals will be used for explanation to facilitate understanding.

[0056] (1) In the above embodiment, the first blade 11a and the second blade 11b were used interchangeably with one spindle section 13, but the spindle section 13 for the first blade 11a and the spindle section 13 for the second blade 11b may be separate.

[0057] (2) In the above embodiment, imaging of the second surface 41b and extraction of the peak contrast value were performed a predetermined number of times or within a predetermined range, but this is not limited to this. For example, the measurement may be stopped when the peak contrast value changes from increasing to decreasing. Even in this way, the distance D1 at which the peak contrast value is maximum can be obtained.

[0058] (3) In the above embodiment, the sliding cylinder 34c is placed inside the second cylinder 33a, but the second cylinder 33a may be divided into two parts, and the sliding cylinder 34c may be slidably arranged between them.

[0059] (4) In the above embodiment, the shielding member 34 was a rectangular frame, but it is not limited to this. The shielding member 34 can be any shape as long as one of the boundaries between the part that shields the light from the light source 33 and the part that transmits the light is a straight line.

[0060] (5) In the above embodiment, the sum of the pixel values ​​for each row was calculated in a vertical arrangement as multiple rows near the boundary between the edge portion 31e and the central portion 31f of the shielding member 34, but it is not limited to this. For example, if the upper part of the left and right center in Figure 8(a) is selected as the boundary near the boundary between the edge portion 31e and the central portion 31f, the sum of the pixel values ​​for each row may be calculated in a horizontal arrangement.

[0061] (6) In the above embodiment, the camera 31a captured an image of the cross mark 41c, but it may also capture an image of something other than the cross mark 41c.

[0062] (7) In the above embodiment, cross marks 41c were formed as the cutting points for the half-cut and full-cut of the substrate 41, but any mark other than cross marks 41c may be used.

[0063] (8) In the above embodiment, the lens 31b was positioned between the half mirror 36 and the substrate 41, but it may be positioned not only in this location, but also between the half mirror 36 and the camera 31a.

[0064] [Summary of the above embodiment] The following describes the cutting method, the method for manufacturing the cut product, and an overview of the cutting apparatus 1 as described in the above embodiment.

[0065] <1> A cutting device (1) for forming a groove (44) on a second surface (41b) opposite to the first surface (41a) of a cutting object (4) in which a resin layer (42) is molded on the first surface (41a) of a plate-shaped lead frame (41), wherein the cutting device (1) comprises a cutting table (22) on which the cutting object (4) can be placed, a light source (33) that irradiates light onto the second surface (41b) side of the cutting object (4) placed on the cutting table (22), a shielding member (34) positioned in the middle of the path of light propagating from the light source (33) to the cutting object (4) and shielding a portion of the light emitted from the light source (33), an imaging mechanism (31) that acquires an image (31d) of the second surface (41b) side of the cutting object (4), and a height changing mechanism (3) that can change the height of the imaging mechanism (31). 2) The imaging mechanism (31) comprises a lens (31b) positioned on the side of the object to be cut (4) that is closer to the object to be cut (4) than the shielding member (34) in the path of light, which focuses the light from the light source (33) onto the second surface (41b), and an imaging unit (31a) positioned on the opposite side of the cutting table (22) from the object to be cut (4), which acquires an image (31d) when light reflected by the object to be cut (4) is incident on it. The imaging unit (31a) acquires an image (31d) at multiple different heights changed by the height changing mechanism (32), and the imaging unit (35) calculates the height position of the second surface (41b) based on the focus state of the shielding member (34) in the multiple image (31d).

[0066] In this embodiment, the height position of the second surface (41b) is calculated based on the focus state of the shielding member (34) in the captured image (31d), so the height position of the second surface (41b) can be accurately determined. As a result, a cutting device (1) can be obtained that can form a groove (44) of a desired depth on the second surface (41b) of the object to be cut (4) based on the calculated height position.

[0067] <2> the above <1> In the cutting apparatus (1) described above, the shielding member (34) may be a frame that shields the outer edge region of the light emitted from the light source (33).

[0068] In this embodiment, by shielding a portion of the light emitted from the light source (33) with the shielding member (34), an image (31d) with a high contrast ratio can be obtained. This makes it possible to obtain an image (31d) in which the shielding member (34) is accurately in focus.

[0069] <3> the above <1> or <2> In the cutting apparatus (1) described above, the calculation unit (35) may calculate the contrast ratio between the shielding member (34) and the area adjacent to the shielding member (34) in each of the multiple captured images (31d), and calculate the height position of the second surface (41b) based on the height of the imaging unit (31a) when the captured image (31d) with the highest contrast ratio among the multiple calculated contrast ratios is acquired.

[0070] As the contrast ratio of the captured image (31d) increases, the boundary between bright and dark areas becomes clearer, and the shielding member (34) approaches the state of being in focus. In this embodiment, the height position of the second surface (41b) is calculated based on the height of the imaging unit (31a) when the captured image (31d) with the highest contrast ratio is acquired, so that an captured image (31d) in which the shielding member (34) is accurately in focus can be obtained.

[0071] <4> the above <1> from <3> In the cutting apparatus (1) described in any one of the above, the shielding member (34) may be movably arranged between the light source (33) and the object to be cut (4).

[0072] In this embodiment, a confocal image can be easily obtained in which both the second surface (41b) and the shielding member (34) are in focus in the captured image (31d).

[0073] <5> the above <1> from <4> In the cutting apparatus (1) described in any one of the above, the height of the light source (33) and the shielding member (34) may be changed in conjunction with the change in the height of the imaging unit (31a) by the height changing mechanism (32).

[0074] In this embodiment, an image (31d) of the second surface (41b) can be obtained simply by changing the height of the imaging unit (31a).

[0075] <6> the above <1> from <5> In the cutting device (1) described in any one of the above, a mirror (36) is further provided, which is positioned between the shielding member (34) and the lens (31b) in the path of light and reflects the light toward the second surface (41b), and the height of the mirror (36) may be changed in conjunction with the change in the height of the imaging unit (31a) by the height changing mechanism (32).

[0076] In this embodiment, an image (31d) of the second surface (41b) can be obtained simply by changing the height of the imaging unit (31a).

[0077] <7> the above <1> from <6> In the cutting apparatus (1) described in any one of the above, the imaging unit (31a) may acquire an image (31d) of the cutting marks (41c) used when cutting the object to be cut (4) into individual pieces.

[0078] In this embodiment, the imaging unit (31a) captures the cutting marks (41c) used when cutting the object to be cut (4) and acquires an image (31d), thereby accurately measuring the height position of the cutting location on the second surface (41b) of the object to be cut (4). This makes it possible to form a groove (44) of a desired depth.

[0079] <8> the above <1> from <7> In the cutting apparatus (1) described in any one of the above, the imaging unit (31a) may acquire a block imaging image of a reference block (37) which will be used as a reference height for calculating the height position of the second surface (41b).

[0080] In this embodiment, the height position of the cutting point on the second surface (41b) of the object to be cut (4) can be measured as a relative value using the block image of the reference block (37) as a reference.

[0081] <9> the above <1> from <8> The cutting device (1) described in any one of the above further comprises a blade (11a) for forming a groove (44) on the second surface (41b) of the object to be cut (4), and a spindle (13) for rotating the blade (11a), wherein the height of the blade (11a) is adjusted based on the height position of the second surface (41b) calculated by the calculation unit (35), and the blade (11a) then forms a groove (44) on the second surface (41b).

[0082] In this embodiment, after adjusting the height of the blade (11a) based on the height position of the second surface (41b) calculated by the calculation unit (35), the blade (11a) forms a groove (44) on the second surface (41b), so that a groove (44) of a desired depth can be formed on the second surface (41b) of the object to be cut (4).

[0083] <10> The method for manufacturing the cut product (40) is as described above. <1> from <9> The method includes a groove forming step of forming a groove (44) in an object to be cut (4) using a cutting device (1) described in any one of the above, and a piece forming step of cutting the object to be cut (4) in which the groove (44) has been formed to divide it into multiple cut pieces (40).

[0084] In this embodiment, it is possible to reliably manufacture cut pieces (40) having a wettable flank type substrate (41). [Industrial applicability]

[0085] The present invention can be used for cutting devices and methods for manufacturing cut products. [Explanation of Symbols]

[0086] 1: Cutting device 4: Package substrate (object to be cut) 11a: First blade (blade) 13: Spindle section 22: Table (cutting table) 31: Imaging mechanism 31a: Camera (imaging unit) 31b: Lens 31d: Acquired image 32: Height adjustment mechanism 33:Light source 34: Shielding member 35: Arithmetic section 36: Half-mirror (mirror) 37: CCS block (reference block) 40: Electronic components (cut pieces) 41: Circuit board (d) 41a: 1st page 41b: 2nd side 41c: Cross mark (cutting mark) 42: Resin layer 44: Half-cut groove (groove)

Claims

1. A cutting device for forming a groove on a second surface opposite to the first surface of an object to be cut, which has a resin layer formed on the first surface of a plate-shaped lead frame, A cutting table on which the object to be cut can be placed, A light source that illuminates the second surface of the object to be cut, which is placed on the cutting table, A shielding member is positioned in the middle of the path of light propagating from the light source to the object to be cut, and shields a portion of the light emitted from the light source. An imaging mechanism that acquires an image of the second surface of the object to be cut, A height adjustment mechanism that can change the height of the aforementioned ITY mechanism, The system comprises a calculation unit capable of performing analysis processing on the captured image, The aforementioned imaging mechanism is A lens positioned on the side of the object to be cut that is closer to the shielding member in the light path, and which focuses the light from the light source onto the second surface, The system includes an imaging unit positioned on the opposite side of the cutting table from the object to be cut, which is capable of acquiring the captured image when the light reflected by the object to be cut is incident upon it. The imaging unit acquires the captured image at a plurality of different heights changed by the height changing mechanism. The cutting device calculates the height position of the second surface based on the focus state of the shielding member in a plurality of captured images.

2. The cutting apparatus according to claim 1, wherein the shielding member is a frame that shields the outer edge region of the light emitted from the light source.

3. The calculation unit calculates the contrast ratio between the shielding member and the area adjacent to the shielding member in each of the plurality of captured images. The cutting apparatus according to claim 1, which calculates the height position of the second surface based on the height of the imaging unit when the image with the highest contrast ratio among a plurality of calculated contrast ratios is acquired.

4. The cutting apparatus according to claim 1, wherein the shielding member is movably arranged between the light source and the object to be cut.

5. The cutting apparatus according to claim 1, wherein the height of the light source and the shielding member is changed in conjunction with the change in the height of the imaging unit by the height changing mechanism.

6. The light path further includes a mirror positioned between the shielding member and the lens, which reflects the light toward the second surface. The cutting apparatus according to claim 1, wherein the height of the mirror is changed in conjunction with the change in the height of the imaging unit by the height changing mechanism.

7. The cutting apparatus according to claim 1, wherein the imaging unit acquires the captured image of the cutting mark used when cutting the object to be cut into individual pieces.

8. The cutting apparatus according to claim 1, wherein the imaging unit acquires a block imaging image of a reference block which serves as a reference height for calculating the height position of the second surface.

9. A blade that forms the groove on the second surface of the object to be cut, The system further comprises a spindle section for rotating the aforementioned blade, The cutting device according to claim 1, wherein the blade adjusts the height of the blade based on the height position of the second surface calculated by the calculation unit, and then the blade forms the groove on the second surface.

10. A groove forming step of forming the groove in the object to be cut using the cutting apparatus according to any one of claims 1 to 9, A method for manufacturing a cut product, comprising a fragmentation step of cutting the object to be cut, in which the grooves are formed, to divide it into a plurality of cut products.

Images