Mounting device

Abstract

To enable measurement of substrate temperature in a laser-based mounting device. [Solution] The mounting device 1 includes a chip holding unit 10 that holds the chip C and mounts the chip C onto a substrate W, an irradiation unit 20 that irradiates with a laser L, and a thermometer 30 that measures the temperature T of the substrate W. The laser L is irradiated from the irradiation unit 20 through the chip holding unit 10 onto the substrate W. The thermometer 30 measures the temperature T of the substrate W by detecting the thermal radiation R emitted from the substrate W.

Description

[Technical Field]

[0001] The present disclosure relates to a mounting apparatus. [Background Art]

[0002] A mounting apparatus for mounting a chip on a substrate is known. The mounting apparatus according to Patent Document 1 mounts a chip on a substrate by pressing the chip against the substrate while holding the chip heated by a heater. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2023-101866 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] In the conventional mounting apparatus according to Patent Document 1, the chip and the substrate are heated by a heater. In this type of conventional mounting apparatus, a contact-type thermometer such as a thermocouple is brought into contact with the substrate, and the temperature of the substrate is measured with the contact-type thermometer.

[0005] Incidentally, there are mounting apparatuses that use a laser instead of a heater. In a mounting apparatus using a laser, the chip and the substrate are heated by the laser. In a mounting apparatus using a laser, if a contact-type thermometer is brought into contact with the substrate as in the case of a mounting apparatus using a heater, part of the laser irradiated onto the substrate will be absorbed by the contact-type thermometer. For this reason, in a mounting apparatus using a laser, the temperature of the substrate cannot be measured with a contact-type thermometer.

[0006] An object of the present disclosure is to enable measurement of the temperature of a substrate in a mounting apparatus using a laser. [Means for Solving the Problem]

[0007] The mounting apparatus according to this disclosure comprises a chip holding unit for holding a chip and mounting the chip onto a substrate, an irradiation unit for irradiating a laser, and a thermometer for measuring the temperature of the substrate. The laser is irradiated from the irradiation unit through the chip holding unit onto the substrate, and the thermometer measures the temperature of the substrate by detecting the thermal radiation emitted from the substrate.

[0008] The thermometer measures the temperature of a substrate by detecting the thermal radiation emitted from the substrate. The thermometer measures the substrate temperature without contact with the substrate. It can suppress the absorption of the laser beam, which is irradiated onto the substrate from the irradiation unit, by the thermometer. It can measure the temperature of a substrate in a laser-based mounting device.

[0009] In one embodiment, the mounting device comprises a housing that accommodates the irradiation unit and the thermometer, the chip holding unit is provided in the portion of the housing facing the substrate, and the chip holding unit transmits the laser and the thermal radiation.

[0010] By housing the irradiation unit and thermometer within the enclosure, the temperature of the circuit board can be measured even when the enclosure and the circuit board are in close proximity during mounting.

[0011] In one embodiment, the mounting device includes a control unit that controls the output of the irradiation unit based on the temperature measurement value of the thermometer, the control unit performs a first mode and a second mode, the control unit continuously increases the output over time so that the temperature measurement value continuously increases over time until it reaches a target value, and the control unit, in the second mode, after the first mode, varies the output so that the temperature measurement value falls between an upper limit value greater than the target value and a lower limit value smaller than the target value.

[0012] In the first mode, it is possible to suppress the substrate temperature from overshooting the target value. In the second mode, the substrate temperature can be maintained near the target value. [Effects of the Invention]

[0013] According to this disclosure, the temperature of a substrate can be measured in a mounting device using a laser. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 shows the mounting device. [Figure 2] Figure 2 shows a block diagram of the mounting device. [Figure 3] Figure 3 shows the relationship between time and output in a graph. [Figure 4] Figure 4 shows the relationship between time and temperature measurements in a graph. [Modes for carrying out the invention]

[0015] Embodiments of the present disclosure will be described in detail below with reference to the drawings. The following description of preferred embodiments is illustrative in nature and is not intended to limit the present disclosure, its applications, or its uses in any way.

[0016] (Implementation device) Figure 1 shows the mounting apparatus 1. The mounting apparatus 1 is also called a bonding apparatus. The mounting apparatus 1 mounts the chip C onto the substrate W. The mounting apparatus 1 comprises a chip holding unit 10, an irradiation unit 20, a thermometer 30, a housing 40, and a control unit 50.

[0017] (substrate) The substrate W is a printed circuit board. The substrate W is mainly made of resin. The substrate W is in the shape of a plate. The substrate W is placed on the stage 2. The stage 2 extends horizontally. The surface W1 of the substrate W faces away from the stage 2. The back surface W2 of the substrate W faces the stage 2 and is in contact with the stage 2. The substrate W extends horizontally along the stage 2. Multiple electrodes W3 are formed on the surface W1 of the substrate W, arranged in a grid pattern.

[0018] (stamp) The stamp S is plate-shaped. The stamp S extends horizontally along the substrate W. The front surface S1 of the stamp S faces the side opposite to the substrate W. The front surface S1 of the stamp S is the surface of the stamp S on the side opposite to the substrate W. The back surface S2 of the stamp S faces the front surface W1 of the substrate W. The back surface S2 of the stamp S is the surface of the stamp S on the substrate W side. A plurality of chip bases S3 are provided on the back surface S2 of the stamp S.

[0019] (Chip) The chip C is based on a semiconductor material such as silicon, and integrates a complex electronic circuit by forming a fine circuit pattern. Note that the chip C may also be based on a material other than silicon.

[0020] The chip C is plate-shaped. The chip C is arranged between the stamp S and the substrate W. The front surface C1 of the chip C faces the side opposite to the substrate W. The front surface C1 of the chip C is the surface of the chip C on the side opposite to the substrate W. There are a plurality of chips C. Each chip C corresponds to one chip base S3. The front surfaces C1 of the plurality of chips C face the plurality of chip bases S3 on the back surface S2 of the stamp S. The front surface C1 of the chip C is adhered to the chip base S3 on the back surface S2 of the stamp S by an adhesive.

[0021] The back surface C2 of the chip C faces the front surface W1 of the substrate W. The back surface C2 of the chip C is the surface of the chip C on the substrate W side. The back surface C2 of the chip C is placed on the front surface W1 of the substrate W. A plurality of solder balls C3 are formed on the back surface C2 of the chip C, arranged in a grid pattern. Each solder ball C3 corresponds to an electrode W3.

[0022] (Chip Holding Unit) The chip holding unit 10 is also called a bonding head. The chip holding unit 10 has a holding surface 11. A suction hole (not shown) is formed in the holding surface 11. The suction hole communicates with a negative pressure pump (not shown).

[0023] The holding surface 11 of the chip holding part 10 faces the surface S1 of the stamp S. The holding surface 11 of the chip holding part 10 faces the substrate W via the stamp S and the chip C. The holding surface 11 of the chip holding part 10 attracts the surface S1 of the stamp S by the negative pressure of the suction hole. The chip base S3 on the back surface S2 of the stamp S adheres to the surface C1 of the chip C by adhesive force. The chip holding part 10 holds the chip C. More specifically, the holding surface 11 of the chip holding part 10 holds the chip C via the stamp S.

[0024] The chip holder 10 and the stamp S are made of, for example, glass (specifically, quartz glass). The chip holder 10 and the stamp S are transparent to the laser L. When the irradiation unit 20 (described later) irradiates the chip holder 10 with the laser L, the chip holder 10 mounts (bonds) the chip C to the substrate W.

[0025] (Irradiation area) The irradiation unit 20 emits a laser L. The irradiation unit 20 includes a laser oscillator 21 and a bend mirror 22.

[0026] The laser oscillator 21 emits a laser L. The bending mirror 22 bends and changes the direction of the laser L emitted from the laser oscillator 21. The laser L bent by the bending mirror 22 is then used for irradiation.

[0027] The laser L is emitted from the irradiation unit 20, passing through the chip holding unit 10 and irradiating the substrate W. More specifically, the laser L is emitted from the irradiation unit 20, passing through the chip holding unit 10 and the stamp S, and irradiating the surface W1 of the substrate W. A portion of the laser L is absorbed by the surface C1 of the chip C. The remaining portion of the laser L passes through the chip C (through the back surface C2 of the chip C) or through the spaces between the chips C to reach the surface W1 of the substrate W.

[0028] When the chip C and substrate W are heated by the laser L, the solder balls C3 on the chip C and the electrodes W3 on the substrate W melt, and the chip C and substrate W are pressed together. As a result, the chip C held by the chip holding unit 10 via the stamp S is mounted on the substrate W. In this way, when the irradiation unit 20 irradiates with the laser L, the chip holding unit 10 mounts the chip C onto the substrate W.

[0029] Laser L is, for example, infrared light. The wavelength λ of laser L is, for example, between 0.76 μm and 1000 μm.

[0030] (thermometer) Thermometer 30 is a non-contact thermometer. Thermometer 30 is a radiation thermometer. Thermometer 30 measures the temperature T of the substrate W. More specifically, thermometer 30 detects the thermal radiation R emitted from the substrate W. Thermometer 30 measures the temperature T of the substrate W by detecting the thermal radiation R emitted from the substrate W.

[0031] Thermal radiation R is electromagnetic radiation emitted from an object, and it depends on the object's temperature. In this example, electromagnetic radiation R is emitted from the substrate W, depending on the substrate W's temperature T. The main component of thermal radiation R is infrared radiation.

[0032] (Enclosure) The housing 40 houses the irradiation unit 20 and the thermometer 30. The housing 40 has a facing portion 41 that faces the substrate W. The facing portion 41 extends along the substrate W. The chip holding portion 10 is provided on the facing portion 41 of the housing 40 that faces the substrate W. The holding surface 11 of the chip holding portion 10 is exposed to the outside of the housing 40. The substrate W is located outside the housing 40. The housing 40 is made of, for example, metal.

[0033] As described above, the chip holder 10 is made of glass, for example (more specifically, quartz glass). The chip holder 10 transmits the laser L and thermal radiation R. The laser L starts from the irradiation unit 20 inside the housing 40, passes through the chip holder 10, and reaches the substrate W outside the housing 40. The thermal radiation R starts from the substrate W outside the housing 40, passes through the chip holder 10, and reaches the thermometer 30 inside the housing 40.

[0034] The thermometer 30 (located inside the housing 40) faces the substrate W via the chip holding section 10.

[0035] (Control Unit) Figure 2 shows a block diagram of the mounting device 1. The control unit 50 includes a processor and a memory. The memory stores a program for executing a predetermined algorithm to operate the processor. The control unit 50 also includes a PLC 51 and a personal computer 52. PLC 51 is an abbreviation for Programmable Logic Controller. The PLC 51 is connected to the laser oscillator 21 and thermometer 30 of the irradiation unit 20 by wire or wireless. The personal computer 52 is connected to the PLC 51 by wire or wireless. The personal computer 52 includes an input unit for receiving commands from the user and a display unit for displaying output results to the user.

[0036] The control unit 50 controls the output P of the irradiation unit 20 based on the temperature measurement value Ta of the thermometer 30. Specifically, the control unit 50 controls the voltage applied as the output P to the laser oscillator 21 of the irradiation unit 20. The temperature measurement value Ta is the temperature T of the substrate W measured by the thermometer 30 through thermal radiation R.

[0037] Figure 3 shows a graph illustrating the relationship between time t and output P. Figure 4 shows a graph illustrating the relationship between time t and the measured temperature Ta. In Figure 3, the horizontal axis represents time t, and the vertical axis represents output P. In Figure 4, the horizontal axis represents time t, and the vertical axis represents the measured temperature Ta. The unit of time t is, for example, [s]. The unit of output P is, for example, [W] representing power or [V] representing voltage. The unit of the measured temperature Ta is, for example, [℃].

[0038] The control unit 50 executes a first mode M1 and a second mode M2. The first mode M1 is performed before the second mode M2. The second mode M2 ​​is performed after the first mode M1.

[0039] In the first mode M1, the control unit 50 continuously increases the output P as time t progresses so that the temperature measurement value Ta continuously increases as time t progresses until it reaches the target value To. The first mode M1 is started by irradiation with the laser L by the irradiation unit 20 and ends when the temperature measurement value Ta reaches the target value To. In the first mode M1, the output P of the irradiation unit 20 continuously increases as time t progresses. The output P increases, for example, linearly. In the first mode M1, the temperature measurement value Ta continuously increases as time t progresses. The temperature measurement value Ta increases, for example, nonlinearly.

[0040] In the first mode M1, the control unit 50 determines, for example, at a period of 1 ms, whether the measured temperature value Ta is greater than the target value To. If the control unit 50 determines that the measured temperature value Ta is greater than the target value To, it terminates the first mode M1. If the control unit 50 determines that the measured temperature value Ta is less than the target value To, it continues the first mode M1.

[0041] In the second mode M2, after the first mode M1, the control unit 50 varies the output P so that the measured temperature value Ta falls between the upper limit value Tu and the lower limit value Tl. The upper limit value Tu is greater than the target value To. The lower limit value Tl is less than the target value To. The second mode M2 ​​is started when the measured temperature value Ta reaches the target value To and ends when a stop command is issued by the user or when a predetermined time has elapsed.

[0042] In the second mode M2, the control unit 50 determines, for example, at a period of 1 ms, whether the measured temperature value Ta is greater than the upper limit value Tu and whether the measured temperature value Ta is less than the lower limit value Tl. In the second mode M2, if the control unit 50 determines that the measured temperature value Ta is greater than the upper limit value Tu, it decreases the output P. In the second mode M2, if the control unit 50 determines that the measured temperature value Ta is less than the lower limit value Tl, it increases the output P. In the second mode M2, if the control unit 50 determines that the measured temperature value Ta is less than the upper limit value Tu and greater than the lower limit value Tl, it does not change the output P.

[0043] Since heat remains stored in the substrate W, even if the output P is reduced in the second mode M2, the temperature measurement value Ta remains constant with almost no decrease.

[0044] (Effects and Benefits) In the mounting apparatus 1 using a laser L, if a contact thermometer (such as a thermocouple) is brought into contact with the substrate W, as in the case of a mounting apparatus using a heater, a portion of the laser L irradiated onto the substrate W will be absorbed by the contact thermometer. Therefore, in the mounting apparatus 1 using a laser L, it is not possible to measure the temperature T of the substrate W with a contact thermometer.

[0045] In this embodiment, the thermometer 30 measures the temperature T of the substrate W by detecting the thermal radiation R emitted from the substrate W. The thermometer 30 measures the temperature T of the substrate W without contacting it (non-contact). This suppresses the absorption of the laser L irradiated onto the substrate W from the irradiation unit 20 by the thermometer 30. The temperature T of the substrate W can be measured in the mounting apparatus 1 using the laser L.

[0046] By housing the irradiation unit 20 and the thermometer 30 in the housing 40, the temperature T of the substrate W can be measured even when the housing 40 and the substrate W are in close proximity during mounting.

[0047] The thermometer 30 (located inside the housing 40) faces the substrate W via the chip holding section 10. The thermometer 30 and the substrate W can be brought closer together. The accuracy of the temperature T of the substrate W measured by the thermometer 30 can be improved.

[0048] In the first mode M1, it is possible to suppress the substrate temperature T from overshooting the target value To. In the second mode M2, it is possible to maintain the substrate temperature T near the target value To.

[0049] The substrate W, chip C, stamp S, stage 2, and the holding surface 11 of the chip holding part 10 may extend diagonally with respect to the horizontal direction.

[0050] (Other embodiments) Although this disclosure has been described above with reference to preferred embodiments, this description is not limiting, and various modifications, substitutions, or combinations are, of course, possible.

[0051] Laser L does not necessarily have to be infrared light.

[0052] The thermometer 30 may be placed outside the housing 40.

[0053] Stamp S is not necessary.

[0054] The chip holder 10 does not have to be made of glass. [Industrial applicability]

[0055] This disclosure is extremely useful and has high industrial applicability because it can be applied to mounting devices. [Explanation of symbols]

[0056] W board W1 surface W2 Reverse side W3 electrode C Chip C1 surface C2 back side C3 solder ball S Stamp S1 surface S2 Reverse side S3 Chip stand L Laser R thermal radiation t time T temperature Ta temperature measurement value To target value Tu Upper Limit Tl lower limit P output M1 First Mode M2 Second Mode 1. Mounting device 2 stages 10 Chip holding section 11 Holding surface 20 Irradiation area 21 Laser Oscillator 22 Bend Mirror 30 thermometer 40 cabinets 41. Opposite side (part) 50 Control Unit 51 PLC 52 Personal Computers

Claims

1. A chip holding unit that holds the chip and mounts the chip onto a substrate, The irradiation unit that emits the laser, The system includes a thermometer for measuring the temperature of the substrate, The laser is irradiated onto the substrate, passing through the chip holding portion from the irradiation portion. The thermometer is a mounting device that measures the temperature of the substrate by detecting the thermal radiation emitted from the substrate.

2. The casing comprises the irradiation unit and the thermometer, The chip holding portion is provided in the part of the housing facing the substrate, The mounting apparatus according to claim 1, wherein the chip holding portion transmits the laser and the thermal radiation.

3. The system includes a control unit that controls the output of the irradiation unit based on the temperature measurement value of the thermometer, The control unit executes the first mode and the second mode, In the first mode, the control unit continuously increases the output over time so that the temperature measurement value continuously increases over time until it reaches the target value. The mounting apparatus according to claim 1 or 2, wherein the control unit, in the second mode, after the first mode, varies the output so that the temperature measurement value falls between an upper limit greater than the target value and a lower limit less than the target value.

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