JPS5936419B2 - Semiconductor device mounting equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for forming 20 semiconductor elements, resistance elements, and capacitor elements (hereinafter referred to as semiconductor elements or simply elements) by connecting protrusions formed with solder on a substrate on which electrodes are formed at the terminals of conductors. The present invention relates to a method and apparatus for attaching a semiconductor element, in which a new semiconductor element is attached after a semiconductor element is removed from an integrated circuit to which a semiconductor element is bonded.

25 Melting a bonding protrusion formed with solder on the electrode of the semiconductor element and bonding it to the electrode formed on the substrate,
Integrated circuits with multiple semiconductor devices mounted on a single substrate may experience a decline in device performance during the manufacturing process or aging process, or failure to obtain desired characteristics due to incorrect mounting of semiconductor devices. There is.

In such a case, the element whose performance has deteriorated or the incorrectly mounted element is removed, and a new required element is installed. To replace this element, after removing the element, remove enough solder remaining on the electrode side of the board, align and place the new element there, and heat the entire board above the melting temperature of the solder. The devices were placed in a cool atmosphere to melt the solder and join the devices. For this reason, the elements that do not require replacement and their joints are heated at the same time, resulting in drawbacks such as deterioration of the characteristics of the elements that do not require replacement or the reliability of their joints. An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and to replace the elements of an integrated circuit without deteriorating the characteristics of the elements to be attached or the elements surrounding them, or reducing the reliability of the joints. An object of the present invention is to provide a method and apparatus for mounting a semiconductor device, which allows the device to be mounted.

In order to achieve the above object, in the present invention, the protrusions for bonding the semiconductor element are aligned with the electrodes on the substrate, the semiconductor element is placed on the substrate, and a gas is blown onto the semiconductor element from above. The method is characterized in that the semiconductor element is mounted on the substrate by heating the substrate on which the element is mounted from the back surface and the upper surface of the element to melt the projections.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention, in which reference numeral 11 is a substrate, a conductor 12 is provided on the surface of the substrate, and electrodes Al, a2, a, , a, is formed.

After removing the semiconductor element, excess solder is removed on Al, a2, a3, and a4, and a permissible amount of solder 13 is adhered when attaching a new semiconductor element. 14 is an element, and electrodes B, , b2, b3, b4 corresponding to the electrodes al to A4 are formed, and this electrode b
l to B, each has a connection protrusion S formed with solder on the top.
l5 is formed.

A nozzle 16 is connected to a gas supply source (not shown) and is configured to spray gas toward the element 14.

IT is an infrared heater and lamp 1 generates infrared light.
8 and a reflecting mirror 19, with a substrate 11 in between.
It is arranged to face the nozzle 16. In the above configuration, after the element 14 is placed on the substrate 11, the lamp 18 is
is turned on to heat the substrate 11 from the back side. When the substrate 11 is heated to a temperature higher than the melting temperature of the solder 13 and the protrusion 415, and the heat is transmitted to the solder 13 and the protrusion 15 through the substrate 11 and the conductor 12, the solder 13 and the protrusion 15 melt, and the substrate 11 and the element 14 are Joined. Then, when the lamp 18 is turned off and the solder 13 and the protrusion 15 solidify, the attachment of the element 14 is completed. In the above embodiment, the relative position between the substrate 11 and the element 14 is such that the solder 13 and the protrusion 1
The viscosity of the flux applied to 5 may be used to prevent its displacement.

The gas blown out from the nozzle 16 may be air or an inert gas such as argon, helium, nitrogen, etc., as appropriate, depending on the conditions of the element installation work, for example, the tolerance for carbonization of flux due to heating. use

Furthermore, if the temperature of the gas blown onto the element 14 is set to room temperature,
Since the element 14 is cooled, deterioration of the characteristics of the element 14 due to heating can be prevented. Further, as the heating means, a hot air blowing device may be used instead of the infrared heater IT, and hot air heated to a temperature higher than the melting temperature of the solder 13 and the protrusions 15 may be sprayed onto the back surface of the substrate 11.

2 to 4 show a second embodiment of the present invention, in which the same parts as in FIG. 1 are designated by the same reference numerals.

1γ is an infrared spot heater, and consists of a lamp 18 that generates infrared rays, and a reflector 1 that focuses the infrared rays in a predetermined range.

15 is a nozzle, and a pressure detector 20 for detecting the pressure inside the nozzle 15 is attached near the opening of the nozzle.

Reference numeral 21 denotes a preheating plate, and a hole 22 is formed through which the back surface of the mounting portion of the substrate 11 on which the element 14 is mounted is exposed.

The preheating plate 21 is connected to a pedestal device (not shown), and is heated to a predetermined temperature lower than the melting temperature of the solder 13 on the substrate 11 and the protrusion 15 of the element 14. In the above configuration, as shown in FIG. 2, the substrate 11 on which the element 14 is fixed is placed on the preheating plate 21 so that the outer surface of the mounting part is exposed through the hole 22, and is heated to a predetermined temperature. The entire substrate 11 is preheated by a preheating plate 21, and the lamp 18 is turned on while blowing gas onto the element 14 at a predetermined pressure from a nozzle 15 facing the element 14 at a predetermined distance D to perform heating. .

Then, when the solder 13 and the protrusion 15 are heated to their melting temperature, the protrusion 15 and the solder 13 are fused, as shown in FIG. 3, and the attachment of the substrate 11 and the element 14 is completed. At this time, when the solder 13 and the protrusion 15 begin to fuse, the element 14 descends relative to the substrate 11 as shown in FIG.
The distance dl between the element 14 and the nozzle 16' is increased to D2. Therefore, the pressure inside the nozzle 15 decreases and the detector 20 detects the start of melting of the solder 13 and the protrusion 15. The signal of this detector 20 is inputted to a control means (not shown),
After a predetermined period of time has elapsed, the lamp 18 is turned off. When the solder 1 is solidified, the attachment of the element 14 is completed. By attaching the element 14 in this way,
Heating can be controlled to the minimum necessary and overheating of the substrate 11 can be prevented.

In addition, by using the preheating plate 21, it works to cool the board 11 when the temperature exceeds a preset temperature, so it prevents the board 11 from deforming or cracking due to overheating, and heats one point centrally. This can prevent cracks in the substrate that would otherwise occur.

Note that in the above embodiment as well, the infrared spot heater I
Needless to say, a hot air blowing device may be used instead of the V. In this case, the fan that sends hot air may be stopped based on the output of the detector 20. FIG. 5 shows an embodiment of the present invention shown in FIG.
Components that are the same as those in FIG. 4 are designated by the same reference numerals.

25 is a base, a pair of supports 26, 26', and a frame 2.
T is placed.

An infrared spot heater IT' is housed inside the frame 2T, and a preheating plate 21 is placed on the upper end thereof via a heat insulating material 28. Reference numeral 29 is an XY table, and a holder 30 supported by a column 26 and fixed to the upper end thereof is moved in the XY direction on the preheating plate, and the element mounting position of the substrate 11 held on the holder 30 is set on the preheating plate 21. position on the hole 22 of.

31 is an XY table fixed on the support 26',
Further, the nozzle IW is rotatably supported around its axis via a support member 33 that is movably supported up and down by a guide member 32 fixed to the upper end thereof.

The nozzle 16' is rotated by turning a knob 34. The upper end of the nozzle 15 is connected to a gas supply source 36 and a vacuum supply source 3T via an electromagnetic switching valve 35. A semi-transparent mirror 40 is supported at the center of the support column 38 fixed to the base 25 via an arm 39, and an observation optical system 41 is fixed to the upper end.
Then, when the image of the protrusion 15 of the element 14 suctioned and held at the lower end of the nozzle 1ff and the image of the electrode 13 on the substrate 11 appear to overlap in the observation optical system 41, the alignment between the substrate 11 and the element 14 is completed. It's summery. In the above configuration,
After removing the element to be replaced and sufficiently removing the solder remaining on the electrodes of the board so that it is below the allowable amount, the board 11 coated with paste is placed on the preheating plate 21 and held by the holder 30. Then, adjust the element mounting position using the XY table 29 so that it is located above the hole 22 of the preheating plate 21.
.

At this time, the preheating plate 21 is preheated to a temperature approximately 30 to 60° C. lower than the melting temperature of the joining solder. On the other hand, the lower end of the nozzle 15 holds an element 14 to be newly installed, the protrusion 15 of which has been coated with flux. In this state, while looking through the observation optical system 41,
1 and knob 34 to move the nozzle 15 and align the element 14 so that the electrode on the substrate 11 and the protrusion 15 on the element 14 appear to overlap. After the alignment is complete,
The nozzle 16' is lowered and the element 14 is placed on the substrate 11. Then, by switching the switching valve 35, the nozzle 15
At the same time, while blowing air at a predetermined pressure toward the element 14, the nozzle 16' is raised to form a predetermined gap between the element 14 and the nozzle 16'. At this time, the element 14 remains fixedly placed on the substrate 11 due to the adhesive force of the flux. In this state, the lamp 18 is turned on while blowing air onto the element 14 from the nozzle 15. Then, the back surface of the substrate 11 exposed through the hole 22 is heated, and the heat passes through the substrate 11 and is transmitted to the protrusion 15 via the electrode, melting the protrusion 15 and joining the substrate 11 and the element 14. At this time, the area around the substrate 11 to which the infrared rays are irradiated is cooled down to a temperature below the melting temperature of the protrusion 15 by the preheating plate 21. In addition, the element 14 to be attached is also
Since it is cooled by the air blown from the nozzle 15, deterioration of characteristics can be prevented. Furthermore, since the elements 14 surrounding the element 14 to be attached are also cooled by the air blown out from the nozzle 16', they are less affected by heat. Then, the protrusion 15 melts and the element 1
4 decreases, the pressure inside the nozzle 1ff decreases, and the detector 2
0 melts the protrusion, that is, the element 14 and the substrate 11
The junction of is detected. Upon receiving the detection signal from the detector 20, the control device 42 turns off the lamp 18 after a predetermined period of time has elapsed. In this way, when the solder melted on the protrusion 15 solidifies, the attachment of the element 14 is completed. FIG. 6 shows a fourth embodiment of the present invention, in which the same parts as in FIG. 5 are designated by the same reference numerals.

A collar 45 rotatable in the direction of arrow B is supported on the support column 2ff, and a shielding plate 47 rotatable in the direction of arrow C is supported on the collar 45 via a shaft 46. A hole 48 facing the hole 22 of the preheating plate 21 is formed in the shielding plate 4T, and a cylindrical projection 49 is formed on the periphery of the hole 48. A temperature sensor 50 is installed near the outlet of the nozzle 16'.

The upper end of the nozzle 16' is connected to a heating tank 52 via a flexible tube 51. This heating tank 52 is provided with a heater 53 and a valve 54, which heats an inert gas such as nitrogen gas fed into the tank 51 to a predetermined temperature, and opens and closes the valve 54 to supply the gas to the nozzle IW. , and are beginning to perform a cutoff. Also, nozzle 1
ff is connected to a vacuum source via valve 55 and flexible tube 56. Each of the lamps 18, the detector 20,
The temperature detector 50, the heater 53, the valve 54, and the valve 55 are each connected to a control device (not shown), and the control device switches between adsorption of the element 14 by the nozzle 15 and blowing of nitrogen gas, and blowing out from the nozzle Ifl. The temperature of the nitrogen gas is controlled, the lighting and extinguishing of the lamp 18, and the blowing and shutting off of the nitrogen gas are controlled. In the above configuration, the substrate 11 is positioned and held on the preheating plate 21 heated to a predetermined temperature, and the valve 54 is closed and the valve 55 is opened in the same manner as in the above embodiment, and the first nozzle is supplied with vacuum. element 14 at the lower end of the nozzle IW.
After holding the element 14 and aligning the element 14 with the electrodes of the substrate 11, the shielding plate 4T is rotated and placed on the substrate 11 so that the open end of the protrusion 49 comes into contact with the substrate 11.

Next, the nozzle 15 is lowered, the element 14 is placed on the electrode of the substrate 11, the valve 55 is closed and the valve 54 is opened, and the element 14 is injected with nitrogen gas heated to a temperature higher than the melting temperature of the bonding protrusion 15. While spraying, the nozzle IW is raised to form a predetermined gap between the soil end surface of the element 14 and the opening of the nozzle IW. At the same time, the lamp 18 is turned on and the lower surface of the substrate 11 is heated with infrared rays. Then, when the protrusion 15 of the element 14 melts and the substrate 11 and the element 14 are bonded, the element 14 descends, so that the pressure inside the nozzle 16 decreases and is detected by the detector 20. Based on this detection signal, the lamp 18 is turned off and at the same time the valve 54 is closed. Then, when the bonded portion solidifies, the attachment of the element 14 is completed. In the above, the temperature of the nitrogen gas blown out from the nozzle IW is detected by the temperature detector 50, and is controlled within a predetermined range by controlling the current supplied to the heater 53 via the control device. Also, the element 1 to be installed
4 is heated to a high temperature by spraying nitrogen gas heated to a temperature higher than the melting temperature of the solder forming the protrusion 15, but it is heated from both below the substrate 11 and above the element 14, so it takes only a very short time. The effect of heat can be extremely minimized. Also, element 1 to be installed
The other elements 14 around the shielding plate 4T are the protrusions 4 of the shielding plate 4T.
Since the high-temperature nitrogen gas is blocked by the point 9, the nitrogen gas is not sprayed, and only the heat from the preheating plate 21 is transferred, and no deterioration of the characteristics occurs. In addition, the above third and fourth
In this embodiment, hot air may be blown instead of the infrared heater. Further, the semi-transparent mirror 40 has its upper surface connected to the protrusion 15 of the element 14 which is attracted to the nozzle 15 and the substrate 1.
Needless to say, it can be arranged so as to be located midway between the first and second electrodes, be slidably supported by the arm 39, and be configured to protrude to a desired position only during alignment. Furthermore, the XY table 31 in each embodiment is
May be omitted. In this case, the nozzle If and the preheating plate 21
It is desirable that the centers of the holes 22 are aligned. Further, although the detector 20 is configured to detect the pressure within the nozzle Iff, it may also be configured to detect a change in the flow rate of gas blown out from the nozzle 16'. As described above, according to the present invention, the connection protrusions soldered on the electrodes of the element are aligned and placed on the electrodes formed on the substrate, and gas is blown onto the element from above, and Since the element is attached to the substrate by heating from the back side of the substrate and melting the protrusions, the attachment can be carried out without unnecessarily heating the element to be attached and other elements adjacent to the element to be attached. This makes it possible to prevent deterioration of device characteristics and reliability of joints.

In addition, by detecting the pressure or flow rate of the gas blown onto the element, it is possible to detect when the solder that forms the bonding protrusions begins to melt, making it possible to accurately control the work and prevent defective joints and elements. It not only eliminates characteristic defects and improves the workability of element replacement work, but also
Yield can be greatly improved. Furthermore, by blowing hot air from above the element, the work time can be greatly shortened and the element can be mounted at high speed without deteriorating the characteristics of the element or the reliability of the joints. It has an extremely large effect.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of the main parts showing the basic principle of the present invention, Fig. 2 is a front view showing the main parts of the device showing an embodiment of the invention, and Fig. 3 is a state in which the semiconductor element is attached to the substrate. A front view showing
FIG. 4 is an enlarged view showing the mounting process of a semiconductor element, FIG. 5 is a partial front sectional view of a device mounting apparatus showing a third embodiment of the present invention, and FIG. 6 is a fourth embodiment of the present invention. FIG. 3 is a front partial sectional view of the device mounting device showing the device mounting device. 11...Substrate, 14...Element, 15.
...Protrusion, al゛A4゜゜e゜゜゜electrode, BIN
b4゜゜゜゜゜' Electrode, 16, Iff... Nozzle, 1T... Infrared heater, 17'...
・Infrared spot heater, 20...Detector, 2
1... Preheating plate, 22... Hole, 29, 3
1...XY table, 30...Holder, 36...Gas supply source, 40...Semi-transparent mirror, 41...Observation Optical system, 42...
Control device, 4T... Shielding plate, 48...
... Hole, 49 ... Protrusion, 50 ... Temperature detector, 52 ... Heating tank, 53 ...
Chemical, 54... Valve.

Claims (1)

[Claims] 1. A semiconductor device in which a bonding protrusion formed with solder on an electrode of a semiconductor element is placed on an electrode formed on a surface of a substrate, and the semiconductor element is attached to the substrate by melting the solder. The device mounting device includes a preheating plate, which has a hole formed in the center corresponding to the mounting position of the semiconductor element on the board, and is heated entirely to a predetermined temperature lower than the melting temperature of the solder, and a preheating plate below the preheating plate. A heating means for heating an exposed portion of the substrate placed on the preheating plate to a temperature higher than the melting temperature of the solder through a hole in the preheating plate and a semiconductor element placed on the substrate. 1. A mounting device for a semiconductor device, comprising a pressurizing means for blowing gas onto the semiconductor device to press a bonding protrusion of the semiconductor device against an electrode of a substrate. 2. In a semiconductor element mounting device for attaching a semiconductor element to a substrate by placing a bonding protrusion formed with solder on an electrode of a semiconductor element on an electrode formed on a surface of a substrate and melting the solder, A preheating plate has a hole formed in the center corresponding to the mounting position of the semiconductor element on the board, and the whole is heated to a predetermined temperature lower than the melting temperature of the solder. A heating means heats the exposed part of the board placed on the preheating plate through the hole to a temperature higher than the melting temperature of the solder, and a heating means is arranged to face the semiconductor element placed on the substrate, and the heating means heats the exposed part of the board placed on the preheating board to a temperature higher than the melting temperature of the solder. A pressurizing means for pressing the protrusions for bonding the semiconductor elements against the electrodes of the substrate by spraying the pressure, and a detection device attached to this pressurizing means for detecting the pressure of the gas in the pressurizing means to detect when bonding is completed. 1. A mounting device for a semiconductor element, comprising means.