JP2008109001A - Electronic component mounting apparatus and electronic component mounting method - Google Patents

Abstract

An electronic component mounting apparatus and an electronic component mounting method are provided that prevent a mounting level error from occurring as much as possible when an upper electronic component is mounted on a lower electronic component mounted on a printed circuit board.
A line sensor detects a thickness t1 of a lower package component 22A, and a CPU subtracts a measured thickness t1 from a thickness A according to component library data of the lower package component 22A to a standard stroke value ST. The value is added, and the vertical axis motor is controlled so that the suction nozzle 24 is lowered by the distance, and the lower package component 22A is mounted on the printed circuit board. Similarly, the thickness t2 of the upper package component 22B is detected, and the CPU subtracts the thickness t2 measured by the line sensor of the upper package component 22B from the value obtained by subtracting the thickness t1 measured from the ST, and the distance The upper package component 22 </ b> B is mounted on the lower package component 22 </ b> A by controlling the suction nozzle 24 to be lowered by that amount.
[Selection] Figure 2

Description

  The present invention relates to an electronic component mounting apparatus. More specifically, an electronic component mounting apparatus and an electronic device for mounting a lower electronic component sucked and held by a suction nozzle on a printed circuit board and mounting the upper electronic component by the suction nozzle on the mounted lower electronic component The present invention relates to a component mounting method.

  A semiconductor having a POP (Package-on-Package) structure in which a lower package component, which is a lower electronic component, is mounted on a printed circuit board, and an upper package component, which is an upper electronic component, is mounted on the mounted lower package component. The apparatus is disclosed in, for example, Patent Document 1.

Here, in mounting an electronic component, it is important to control the mounting level in order to prevent cracking of the electronic component during mounting and to control mounting load. For this reason, in an electronic component mounting apparatus in which the upper package component is mounted on the lower package component mounted on the printed circuit board by the suction nozzle, the lower package in consideration of the nominal thickness of the lower package component. The upper package part was mounted on the part.
JP-A-2005-72190

  However, an error occurs between the nominal thickness of the lower package component and the thickness of the lower package component mounted on the printed circuit board, and when mounting on the lower package component of the upper package component, Since the actual thickness of the lower package component is not taken into account, an error in the mounting level occurs, which is insufficient as a countermeasure against cracking of the electronic component during mounting.

  Accordingly, an object of the present invention is to prevent as much as possible a mounting level error when mounting an upper electronic component on a lower electronic component mounted on a printed circuit board.

For this reason, the first invention mounts the lower electronic component sucked and held by the suction nozzle on the printed circuit board, and mounts the upper electronic component by the suction nozzle on the mounted lower electronic component. A device,
A thickness detection sensor for detecting the thickness of the lower electronic component before mounting on the printed circuit board and the thickness of the upper electronic component before mounting on the lower electronic component;
Based on the detection result of the thickness detection sensor of the lower electronic component, control is performed so that the lower electronic component is mounted on the printed circuit board, and the thickness detection sensors of the lower electronic component and the upper electronic component are controlled. And a control device for controlling the upper electronic component to be mounted on the lower electronic component based on the detection result.

According to a second aspect of the present invention, there is provided an electronic component mounting method in which the lower electronic component sucked and held by the suction nozzle is mounted on a printed circuit board, and the upper electronic component is mounted on the mounted lower electronic component by the suction nozzle. Because
A thickness detection sensor detects the thickness of the lower electronic component,
Mounting the lower electronic component on a printed circuit board based on the detection result of the thickness detection sensor of the lower electronic component,
The thickness detection sensor detects the thickness of the upper electronic component,
The upper electronic component is mounted on the lower electronic component based on detection results of the thickness detection sensors of the lower electronic component and the upper electronic component.

  According to the present invention, it is possible to prevent a mounting level error as much as possible when mounting an upper electronic component on a lower electronic component mounted on a printed circuit board.

  Hereinafter, an electronic component mounting apparatus according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a plan view of an electronic component mounting apparatus, and FIG. 2 is a side view of a semiconductor device having a POP structure.

  In FIG. 1, a pair of rails 5 for guiding movement of the A beam 3 and the B beam 4 in the Y direction are arranged on a base 2 of the electronic component mounting apparatus 1. The A beam 3 and the B beam 4 are long in the X direction, and the mounting heads 7 and 8 are arranged so as to be movable by the X axis motors 13 and 15 along the longitudinal direction. Therefore, the mounting heads 7 and 8 are movable in the XY directions.

  A ball screw shaft 11 rotated by the Y-axis motor 10 on the A side is screwed into a nut (not shown) fixed to the A beam 3, and the A beam 3 is attached to the rail 5 by the rotation of the ball screw shaft 11. It can move along. The B beam 4 moves along the rail 5 when the ball screw shaft 12 having the same structure is rotated by the Y-axis motor 14 on the B side.

  Further, a component supply table 6 is formed at each of the upper and lower positions of the base 2 in FIG. 1, and a component supply device 16 for supplying various electronic components is detachably mounted on the component supply table 6. Yes. The component supply device 16 includes a so-called storage tape supply type component supply device, a stick supply type component supply device, a tray supply type component supply device, and the like.

  Reference numeral 30 denotes a flux transfer device that is detachably mounted on the component supply base 6. As shown in FIG. 2, an electronic component having protruding electrodes (solder bumps) supplied from a certain component supply device 16. For example, BGA (Ball Grid Array) or POP (Package-on-Package) for mounting the upper package component 22B, which is the upper electronic component, on the lower package component 22A, which is the lower electronic component mounted on the printed circuit board 18. The flux is transferred to the protruding electrode 22C of the upper package component 22B with respect to the semiconductor device 22 having the structure. A land 22D is provided on the peripheral edge of the upper surface of the lower package component 22A, and a protruding electrode 22C onto which the flux of the upper package component 22B is transferred is mounted on the land 22D.

  The mounting heads 7 and 8 are for transporting and mounting electronic components taken out from each component supply device 16 by vacuum suction to desired positions on the printed circuit board 18. The printed circuit board 18 is transported by a transport conveyor 20 installed on the base 2 and positioned and fixed by a fixing mechanism (not shown) at a predetermined work stage position.

  Further, electronic components taken out from the component supply device 16 by the suction nozzle 24 of the mounting heads 7 and 8 are picked up by the component recognition camera 21 with respect to the suction position deviation, the component dropping state, the flux transfer state, and the like. Is imaged and recognized by the recognition processor 19. Reference numeral 17 denotes a board recognition camera which images a positioning mark (not shown) attached to the printed board 18 and is subjected to recognition processing by the recognition processing device 19.

  Reference numeral 25 denotes a line sensor as a thickness detection sensor, which is a predetermined portion of the lower package component 22A constituting the semiconductor device 22 held by suction by the suction nozzle 24, that is, a land 22D on the upper surface from the lower end of the protruding electrode 22C on the lower surface. , And a predetermined portion of the upper package component 22B that constitutes the semiconductor device 22 that is also sucked and held by the suction nozzle 24, that is, a thickness t2 from the lower end to the upper end of the protruding electrode 22C on the lower surface. (See FIG. 2).

  The line sensor 25 includes a projector 26 that emits a light beam that goes straight in the horizontal direction, and a light receiver 27 in which a large number of CCD elements are arranged in parallel on a straight line so as to receive the light beam. Has been. The light projector 26 may collect the light from the LED with a lens and emit a light beam that goes straight in parallel, or may use a laser. About 1000 CCD elements are juxtaposed in a vertical width of about 10 mm, and the light receiver 27 can be realized. Each CCD element can detect the amount of light received, and can be used as an ON / OFF sensor by determining the threshold value of the amount of light received. By the ON / OFF output, the portion shielded by the lower package component 22A and the upper package component 22B can be detected as the thickness.

  Next, based on the control block diagram concerning the electronic component mounting apparatus 1 of the present invention of FIG. Reference numeral 40 denotes a CPU (Central Processing Unit) as a control unit that performs overall control of the mounting apparatus 1, and the CPU 40 is connected to a RAM (Random Access Memory) 42 and a ROM (Read. Only memory) 43 is connected. Based on the data stored in the RAM 42, the CPU 40 controls the operation related to the component mounting operation of the electronic component mounting apparatus 1 according to the program stored in the ROM 43. That is, the CPU 40 moves the mounting heads 7 and 8 in the X direction via the interface 44 and the drive circuit 45, and the Y axis motor 10 that moves the A beam 3 and the B beam 4 in the Y direction. 14, the vertical axis motor 50 that moves the suction nozzle 24 up and down, and the θ axis motor 51 that rotates the suction nozzle 24 are controlled.

  The RAM 42 stores mounting data related to component mounting. For each mounting order (step number), the X coordinate, Y coordinate and angle information in the printed circuit board, and the arrangement of the component supply devices 16 are stored. Number information and the like are stored. The RAM 42 stores component arrangement data relating to the type (component ID) of each electronic component corresponding to the arrangement number of each component supply device 16. Furthermore, component library data including a type, a size in the X direction, a size in the Y direction, a size in the thickness direction, and the like for each electronic component (component ID) is also stored.

  Reference numeral 19 denotes a recognition processing device connected to the CPU 40 via an interface 44, which performs recognition processing of an image captured by the component recognition camera 21 and an image captured by the board recognition camera 17 and captured. The recognition process is performed. An image captured by the component recognition camera 21 or the board recognition camera 17 is displayed on a monitor 48 as a display device. The monitor 48 is provided with various touch panel switches 49, and the operator can perform various settings related to electronic component mounting by operating the touch panel switches 49.

  Next, the operation of the electronic component mounting apparatus 1 will be described below. First, the printed circuit board 18 is transported to the work table position of the electronic component mounting apparatus 1 by the transport conveyor 20, and is positioned and fixed by the positioning mechanism. Subsequently, the CPU 40 controls the X-axis motors 13 and 15 and the Y-axis motors 10 and 14 to move the mounting heads 7 and 8 so that the board recognition camera 17 is positioned above the positioning mark of the printed board 18. Then, the positioning mark is imaged, and the recognition processing device 19 performs recognition processing to grasp the position of the printed circuit board 18.

  Next, when the CPU 40 controls the X-axis motors 13 and 15 and the Y-axis motors 10 and 14, the mounting heads 7 and 8 move XY to the electronic component take-out position of the desired component supply device 16, where they move up and down. By controlling the shaft motor 50, the suction nozzle 24 is lowered and the lower package component 22A supplied to the suction position is picked up and taken out.

  The suction nozzle 24 is moved between the light projector 26 and the light receiver 27 of the line sensor 25 by moving the suction nozzle 24 as described above in a state where the lower package component 22A taken out from the component supply device 16 is sucked and held. The CPU 40 stores the thickness data of the lower package part 22A in the RAM 42 by detecting the thickness t1 of the lower package part 22A.

  Subsequently, the mounting heads 7 and 8 move XY again above the component recognition camera 21, and the component recognition camera 21 images the lower package component 22 </ b> A sucked and held by the suction nozzle 24. The recognition processing device 19 recognizes the image, and recognizes the suction position deviation state and the component drop state of the lower package component 22A with respect to the suction nozzle 24 of the mounting heads 7 and 8.

  When there is no recognition abnormality, the mounting heads 7 and 8 move XY to a desired electrode pad of the printed circuit board 18 on which the solder paste is printed, and then descend to fall on the electrode pad to the lower package component 22A. The protruding electrodes 22C are mounted so as to be positioned. In this case, the CPU 40 corrects the positional deviation of the printed circuit board 18 and the positional deviation of the lower package component 22A based on the recognition processing result by the recognition processing device 19, and the CPU 40 uses the X-axis drive motors 13 and 15 and the Y-axis motor. 10 and 14 and the θ-axis motor 51 are controlled.

  That is, the CPU 40 controls the vertical axis motor 50 to move the suction nozzle 24 downward by a predetermined distance and correctively move the suction nozzle 24 in the plane direction and the angular direction so that the lower package component 22A is mounted on the printed circuit board 18 without misalignment. However, in this case, the control of the vertical axis motor 50 related to the lowering of the suction nozzle 24 is performed as follows. First, the CPU 40 adds the value obtained by subtracting the thickness t1 measured by the line sensor 25 from the thickness A based on the component library data of the lower package component 22A stored in the RAM 42 to the standard stroke value ST, that is, ST + (A-t1) is calculated, and the vertical axis motor 50 is controlled so that the suction nozzle 24 is lowered by the distance.

  The standard stroke value ST is a descending amount of the suction nozzle 24 based on the thickness A based on the component library data of the lower package component 22A.

  Next, the board recognition camera 17 images the opposite corners of the lower package component 22A having a square shape in plan view mounted on the printed board 18. That is, as shown in FIG. 4, the recognition processing device 19 recognizes the center of the captured image SG at the upper left corner as a recognition area NR, and the land 22D1 at the corner of the 10 lands 22D is subjected to pattern matching. Similarly, the recognition processing device 19 recognizes the center portion of the captured image at the lower right corner as a recognition area, and based on the recognition processing result, the CPU 40 selects the land 22D1 at the corner of the ten lands 22D. The position is found by pattern matching, and the position of the lower package component 22A is calculated and grasped, and stored in the RAM.

  Next, when the CPU 40 controls the X-axis motors 13 and 15 and the Y-axis motors 10 and 14, the mounting heads 7 and 8 move XY to the electronic component take-out position of the desired component supply device 16, where they move up and down. By controlling the shaft motor 50, the suction nozzle 24 is lowered and the upper package component 22B supplied to the suction position is picked up and taken out.

  The suction nozzle 24 is positioned between the light projector 26 and the light receiver 27 of the line sensor 25 by moving the suction nozzle 24 in a state where the upper package component 22B taken out from the component supply device 16 is sucked and held. The CPU 40 detects the thickness t2 of the upper package component 22B, and causes the RAM 42 to store the thickness data of the upper package component 22B.

  Subsequently, the suction nozzle 24 that sucks and holds the upper package component 22B is moved XY above the component recognition camera 21, and the component recognition camera 21 images the upper package component 22B that is sucked and held by the suction nozzle 24. The recognition processing device 19 performs recognition processing on the image thus recognized, and recognizes the suction position deviation state and the component fall state of the upper package component 22B with respect to the suction nozzle 24 of the mounting heads 7 and 8.

  Then, the mounting heads 7 and 8 move XY from above the component recognition camera 21 to the flux transfer position of the flux transfer device 30, where the protruding electrodes (on the upper package component 22 </ b> B attracted and held by the suction nozzle 24 to the flux) The solder bump is lowered until 22C is immersed.

  Subsequently, after the suction nozzle 24 is lowered to the transfer position and the flux F is transferred to the protruding electrode 22C of the upper package component 22B, the mounting heads 7 and 8 again move XY above the component recognition camera 21 and there. The component recognition camera 21 images the upper package component 22B sucked and held by the suction nozzle 24, the recognition processing device 19 performs recognition processing of the captured image, and the upper side of the mounting heads 7 and 8 with respect to the suction nozzle 24. It recognizes the suction position deviation situation, the part fall situation, and the flux transfer situation of the package part 22A.

  When there is no recognition abnormality, the mounting heads 7 and 8 move XY to the upper side of the lower package component 22A, descend there, and project on the land 22D of the lower package component 22A. Implement so that is located. In this case, the CPU 40 controls the vertical movement motor 50 in consideration of the thickness data of the upper package component 22B, and the lower package component mounted on the printed circuit board 18 based on the recognition processing result by the recognition processing device 19. The CPU 40 controls the X-axis drive motors 13 and 15, the Y-axis motors 10 and 14, and the θ-axis motor 51 to correct the positional shift of 22A and the positional shift of the upper package component 22B.

  That is, the CPU 40 controls the vertical axis motor 50 to move the suction nozzle 24 downward by a predetermined distance and correctively move the suction nozzle 24 in the plane direction and the angular direction so that the upper package part 22B is placed on the lower package part 22A without any positional deviation. In this case, the control of the vertical axis motor 50 related to the lowering of the suction nozzle 24 is performed as follows. First, the CPU 40 adds a value obtained by subtracting the thickness t1 measured by the line sensor 25 of the lower package component 22A from the thickness A based on the component library data of the lower package component 22A to the standard stroke value ST. The thickness t2 measured by the line sensor 25 of the upper package component 22B is subtracted from the value, that is, ST + (A−t1) −t2 is calculated, and the vertical axis is set so that the suction nozzle 24 descends by that distance. The motor 50 is controlled.

  Therefore, the upper package part 22B can be mounted on the lower package part 22A without applying excessive stress to the lower package part 22A, and the suction nozzle 24 is corrected and moved in the planar direction and the angular direction without any positional deviation. The upper package component 22B can be mounted on the lower package component 22A.

  Thereafter, similarly, necessary electronic components are mounted on the printed circuit board 18, and each electronic component is fixed on the printed circuit board 18 by reflowing the solder.

  Although the embodiments of the present invention have been described above, various alternatives, modifications, and variations can be made by those skilled in the art based on the above description, and the present invention is not limited to the various embodiments described above without departing from the spirit of the present invention. It encompasses alternatives, modifications or variations.

It is a top view of the electronic component mounting apparatus with which this invention flux transfer apparatus is applied. It is a side view of the semiconductor device of a POP structure. It is a control block diagram. It is a figure which shows the picked-up image of a lower package component.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electronic component mounting apparatus 18 Printed circuit board 19 Recognition processing apparatus 21 Component recognition camera 22A Lower package component 22B Upper package component 22C Projection electrode 24 Adsorption nozzle 25 Line sensor 40 CPU
42 RAM
50 Vertical axis motor

Claims (2)

An electronic component mounting apparatus for mounting a lower electronic component sucked and held by a suction nozzle on a printed circuit board and mounting the upper electronic component by the suction nozzle on the mounted lower electronic component,
A thickness detection sensor for detecting the thickness of the lower electronic component before mounting on the printed circuit board and the thickness of the upper electronic component before mounting on the lower electronic component;
Based on the detection result of the thickness detection sensor of the lower electronic component, control is performed so that the lower electronic component is mounted on the printed circuit board, and the thickness detection sensors of the lower electronic component and the upper electronic component are controlled. And a control device that controls to mount the upper electronic component on the lower electronic component based on the detection result of the electronic component mounting device. An electronic component mounting method in which a lower electronic component sucked and held by a suction nozzle is mounted on a printed circuit board, and an upper electronic component is mounted by the suction nozzle on the mounted lower electronic component,
A thickness detection sensor detects the thickness of the lower electronic component,
Mounting the lower electronic component on a printed circuit board based on the detection result of the thickness detection sensor of the lower electronic component,
The thickness detection sensor detects the thickness of the upper electronic component,
An electronic component mounting method comprising mounting the upper electronic component on the lower electronic component based on detection results of the thickness detection sensors of the lower electronic component and the upper electronic component.

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