JP2002217365A - Semiconductor device and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a semiconductor device wherein plating work of base material, formation of solder resist and cleaning of residual flux are made unnecessary and manufacturing cost is reduced, and to provide a semiconductor device. SOLUTION: A region on a main surface of a bottom surface metal substrate 1 to which region an insulating substrate is soldered in the later process is cut and eliminated by using a rotary head 2, and an elimination region 3 is formed. Consequently, impurities such as organic matter and oxide on the main surface can be eliminated. Depth of cutting is set at least 0.1 μm. The elimination region 3 is set to be a region having an area equivalent to a conductor pattern for soldering which is formed on the rear of an insulating substrate, or a region which is enlarged by about 0.2 mm from the peripheral part of the conductor pattern. The surface roughness by cutting is made Rz=1.5 (μm) or smaller when defined by using, e.g. 10 points average roughness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a semiconductor device and a semiconductor device, and more particularly to a method for manufacturing a modularized power semiconductor device and a semiconductor device.

[0002]

2. Description of the Related Art A modularized power semiconductor device is provided so as to cover a bottom metal substrate, an insulating substrate mounted on the bottom metal substrate and mounting a semiconductor element (power semiconductor element), and a bottom metal substrate. The main component is a resin case, and an electrode plate for connection between the semiconductor element on the insulating substrate and the outside, and a thermosetting epoxy resin or the like is sealed inside the resin case. I have.

In a power semiconductor device having such a configuration, a bottom metal substrate and an insulating substrate are joined by soldering in a manufacturing process. Then, cream solder containing a large amount of flux is used as the solder used at that time.

[0004] The reason is that the surface of the base material (here, the bottom metal substrate) is oxidized by oxygen contained in the air, or the surface of the base material is oxidized by heating during soldering. This is because the surface of the base material is cleaned by the flux to improve the wettability of the base material.

[0005]

As described above,
In a conventional manufacturing process of a power semiconductor device, a cream solder containing a large amount of flux is used, and thus has the following problems.

First, as a first problem, the growth of an oxide film is suppressed by plating the surface of the base material which is relatively harder to oxidize than the base material. However, the plating process increases the manufacturing cost. There was a problem.

[0007] The plating process also has the purpose of eliminating unevenness of the surface generated when processing a soft base material such as copper and improving the flatness. If the unevenness exists on the surface of the base material, cracks due to the unevenness occur due to stress due to heat history when the semiconductor device is used. When the crack progresses in the solder layer portion with the use of the semiconductor device, the thermal resistance increases similarly to the presence of the cavity, and the temperature of the semiconductor element soldered on the insulating substrate becomes high, causing a problem. There was a possibility.

As a second problem, since the solder containing the flux has good wettability, there is a high possibility that the activated solder will flow to unnecessary portions when the solder is melted.
When the solder spreads, the components disposed thereon are also washed away, and cannot be fixed at an accurate position. To prevent this, a resin material called a solder resist is provided around the soldering area, but a process such as coating and curing of the solder resist is required, which has caused an increase in manufacturing cost.

As a third problem, when the flux-containing cream solder is heated and melted, there is a possibility that the eluted flux is baked on the base material or solidified without being baked and remains between circuit patterns. If this happens, the insulation resistance between the circuit patterns will be reduced. Therefore, it is necessary to remove the residual flux with a solvent such as an organic solvent.

Prior to injecting the epoxy resin into the resin case, a silicone gel is applied to protect the semiconductor elements on the insulating substrate and the wiring for electrical connection between the semiconductor element and various electrode plates. The resin is poured into a resin case and cured. In the gel curing step, an uncured portion is generated due to the residual flux. Therefore, it was necessary to clean the residual flux to prevent this.

Further, in the soldering using a flux, a gas generated when the flux is activated and a flux eluted at a bonding portion between the bottom metal substrate and the insulating substrate are locally accumulated, and the solder is formed in the solder layer. There was a possibility of generating voids and other cavities.

The voids increase the thermal resistance when radiating the heat generated when the semiconductor element is energized to the bottom metal substrate. Therefore, the temperature of the semiconductor element soldered on the upper part of the insulating substrate becomes high. Could occur.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a method of manufacturing a semiconductor device which does not require plating of a base material, formation of a solder resist, and cleaning of residual flux, thereby reducing manufacturing costs. It is an object to provide a semiconductor device.

[0014]

According to a first aspect of the present invention, there is provided a method for manufacturing a semiconductor device, comprising: a metal substrate; and a conductor pattern on a main surface for bonding the metal substrate to the metal substrate. A method for manufacturing a semiconductor device comprising an insulating substrate disposed on a substrate, wherein the step of removing the mounting region of the insulating substrate over a predetermined depth of the metal substrate to form a removed region ( a) and a step (b) of bonding the insulating substrate to the removal region by fluxless solder.

According to a second aspect of the present invention, in the method of manufacturing a semiconductor device according to the second aspect, in the step (a), the predetermined depth is at least 0.1 μm when the insulating substrate has a width larger than the conductor pattern. Forming the removal region as described above.

4. The method of manufacturing a semiconductor device according to claim 3, wherein in the step (b), a molten fluxless solder is provided on the removal area, and the molten fluxless solder is provided on the insulating substrate. The method includes a step of pressing the solder while controlling the speed.

According to a fourth aspect of the present invention, in the method of manufacturing a semiconductor device according to the fourth aspect, the step (b) includes a step of pressing the insulating substrate at a speed at which the molten fluxless solder spreads uniformly without involving gas. Contains.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: an insulating substrate having a circuit pattern on a main surface; and a semiconductor element mounted on the circuit pattern. (A) forming a removed region by removing the mounting region of the semiconductor element of the circuit pattern over a predetermined depth, and bonding the semiconductor device to the removed region by fluxless soldering. Step (b).

According to a sixth aspect of the present invention, in the method of manufacturing a semiconductor device according to the sixth aspect, the step (a) is performed so that the predetermined depth is 0.1 μm
The method includes the step of forming the removal region as described above.

8. The method of manufacturing a semiconductor device according to claim 7, wherein in the step (b), a molten fluxless solder is provided on the removal area, and the semiconductor element is melted by the fluxless soldering. The method includes a step of pressing the solder while controlling the speed.

According to a eighth aspect of the present invention, in the method of manufacturing a semiconductor device according to the eighth aspect, the step (b) includes a step of pressing the semiconductor element at a speed at which the molten fluxless solder spreads uniformly without involving gas. Contains.

According to a ninth aspect of the present invention, in the method of manufacturing a semiconductor device according to the ninth aspect, in the step (a), the removal region is formed such that a 10-point average roughness of the surface is Rz = 1.5 μm or less. Process.

According to a tenth aspect of the present invention, in the method of manufacturing a semiconductor device according to the tenth aspect, in the step (b), the molten fluxless solder is extruded with an extruding pressure of a piston. And a step of discharging and supplying the molten fluxless solder.

12. A semiconductor device according to claim 11, wherein the insulating substrate has a metal substrate and a conductor pattern on the main surface for bonding to the metal substrate, and is provided on the metal substrate. Wherein the metal substrate has a removal region in which a mounting region of the insulating substrate is removed over a predetermined depth, and the insulating substrate has a fluxless solder on the removal region. It is joined by.

According to a twelfth aspect of the present invention, in the semiconductor device, the removal area has a width larger than the conductor pattern of the insulating substrate, and the predetermined depth is 0.1 μm or more.

14. A semiconductor device according to claim 13, wherein the semiconductor device includes an insulating substrate having a circuit pattern on a main surface and a semiconductor element mounted on the circuit pattern. The pattern has a removal area in which a mounting area of the semiconductor element is removed over a predetermined depth, and the semiconductor element is joined to the removal area by fluxless solder.

In a semiconductor device according to a fourteenth aspect of the present invention, the removal region has a width larger than a solder bonding pattern of the semiconductor element, and the predetermined depth is 0.1 μm or more.

According to a fifteenth aspect of the present invention, in the semiconductor device according to the fifteenth aspect, the removal region has a surface having a 10-point average roughness Rz =
1.5 μm or less.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a semiconductor device according to an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a diagram showing a surface processing step of a bottom metal substrate 1 constituting a bottom portion of a modularized power semiconductor device (referred to as a power semiconductor device module).

FIG. 1 shows that the bottom metal substrate 1 has an oxygen concentration of 10%.
A state in which processing is performed in a closed processing chamber 4 is schematically illustrated so that processing can be performed in an atmosphere of ppm or less.

As shown in FIG. 1, a region of the main surface of the bottom metal substrate 1 to which an insulating substrate (not shown) is to be soldered in a later step is removed by cutting (or polishing) by the rotary head 2. By forming the removal region 3, impurities such as organic substances and oxides on the main surface can be removed.

Needless to say, a jig such as an end mill or a grindstone for cutting or polishing is attached to the rotary head 2.

Here, the cutting depth L is at least a depth at which the native oxide film can be surely removed, that is, at least 0.1 mm.
The removal region 3 is set to 1 μm or more, and the removal region 3 is a region of the same size as a conductor pattern for soldering provided on the back surface of an insulating substrate (not shown) or approximately 0.2 mm from the edge of the conductor pattern. It is set to be an expanded area.

Incidentally, the surface roughness due to cutting (or polishing) is, for example, Rz = 1.5 when defined by 10-point average roughness.
(Μm) or less.

Further, since the cutting is performed in the processing chamber 4 having an oxygen concentration of 10 ppm or less, it is possible to prevent the removal region formed by the cutting from being oxidized.

In order to keep the oxygen concentration in the processing chamber 4 at 10 ppm or less, the processing chamber 4 is closed, the chamber is evacuated with a vacuum pump, and then an inert gas such as nitrogen (N ₂ ) gas or hydrogen (H ₂ ) Can be achieved by supplying a forming gas to which) is added. If the oxygen concentration exceeds 10 ppm, the oxidation is likely to proceed. Therefore, it is desirable to keep the oxygen concentration at 10 ppm or less.

Next, in the step shown in FIG. 2, molten fluxless solder SD is supplied to the removal area 3 of the bottom metal substrate 1. The fluxless solder SD contains no components other than flux and solder, and is not oxidized.

As shown in FIG. 2, the bottom metal substrate 1 is placed on the heater 5 for preventing the molten solder from solidifying, and the molten fluxless solder SD is supplied from the movable needle 66 of the solder supply device 6. Discharge is supplied.

<A. Configuration and operation of solder supply device>
Here, the configuration and operation of the solder supply device 6 will be described with reference to FIGS. FIG. 3 is a schematic diagram showing a state in which the fluxless solder SD melted in the solder melting tank MB is sucked into the needle 66 of the solder supply device 6. FIG. 4 is a schematic diagram showing the inside of the needle 66 during suction of the fluxless solder SD.

As shown in FIG. 3, the solder supply device 6 drives a piston pump 60 for generating suction pressure and discharge pressure for suction and discharge of the molten fluxless solder SD, and a piston pump 60. And a drive mechanism 70.

The piston pump 60 includes a cylinder 61
A piston 62 that slides in close contact with the inner wall of the cylinder 61, a nozzle portion 64 that discharges air from the cylinder 61 and sucks air into the cylinder 61, and a flexible member that connects the nozzle portion 64 and the needle 66. Pipe 6
5 is provided. The piston 62 is connected to a support shaft 63 extending outside the cylinder 61, and the piston 62 can be driven by sliding the support shaft 63.

The drive mechanism 70 transmits the torque of the motor 73 to the ball screw 72 via gears 741 and 742,
The transmission shaft 71 engaged with the ball screw 72 is
By rotating linearly along the ball screw 72 with the rotation of, the rotational force is converted into a linear driving force.

Accordingly, by connecting one end of the transmission shaft 71 to the support shaft 63, a linear driving force can be applied to the piston 62. The other end of the transmission shaft 71 is slidably engaged with the fixed shaft 75 which is fixed.

In the solder supply device 6 having such a configuration, the fluxless solder S
In order to inhale D, the tip of the needle 66 is immersed in the solder melting tank MB as shown in FIGS.
By rotating the ball screw 72, the piston 62 is moved to the cylinder 6
Move in the direction to pull out from 1. As a result, the pressure in the needle 66 is reduced through the flexible pipe 65, and the molten fluxless solder SD can be sucked from the tip of the needle 66. The suction pressure is set so that the molten fluxless solder SD accumulates only in the needle 66 and does not enter the flexible pipe 65.

In order to prevent the fluxless solder SD from solidifying in the needle 66, the needle 6
6 has a built-in heater (not shown).

In order to discharge the molten fluxless solder SD accumulated in the needle 66, as shown in FIG.
2 is moved in a direction to be pushed into the cylinder 61. As a result, the pressure in the needle 66 increases through the flexible pipe 65, and the molten fluxless solder SD is discharged from the tip of the needle 66.

FIG. 2 shows a state in which the fluxless solder SD is discharged onto the removal area 3 of the bottom metal substrate 1.
A desired amount of fluxless solder SD is supplied from a needle 66 movable by being connected to a flexible pipe 65.
To a desired position on the bottom metal substrate 1.

By using a servomotor as the motor 73, the movement amount of the piston 62 can be accurately controlled, and the discharge amount of the molten fluxless solder SD can be arbitrarily adjusted. 3. The thickness of the solder layer formed on 3 can be arbitrarily adjusted. For example,
The thickness of the solder layer can be set to 100 to 200 μm, and in some cases, 400 μm.

Next, in the step shown in FIG. 5, on the molten fluxless solder SD on the bottom metal substrate 1,
The insulating substrate 8 is placed while controlling the speed.

That is, the speed at which the insulating substrate 8 is pressed against the molten fluxless solder SD in the direction of the arrow is lower than the speed at which the fluxless solder SD spreads on the bottom metal substrate 1 by capillary action. Control.

As can be said not only for the fluxless solder SD but also for the solder in general, when spreading by the capillary phenomenon, it has the property of spreading first from a wettable portion. Therefore, if there is a portion that is difficult to get wet for some reason (due to unevenness or dirt) on the course where the solder spreads, it spreads while avoiding the portion, and contains gas to form a void.

In order to prevent the generation of the voids, the insulating substrate 8 is not simply pressed on the fluxless solder SD but is pressed at a speed lower than the speed of spreading by the capillary phenomenon, so that the insulating substrate 8 gets wet on the bottom metal substrate 1. Even if there is a difficult part, it is surely covered and spreads while forming an alloy layer of the solder material and the base material, so that it is possible to prevent generation of voids by containing gas.

According to the above, the pressing speed of the insulating substrate 8 can be rephrased as the speed at which the fluxless solder SD spreads uniformly without involving gas.

More specifically, for example, in the case of a 50 mm square substrate, the substrate is mounted on a molten fluxless solder SD, and when the fluxless solder SD is naturally (ie, by capillary action) spread, it spreads in a few seconds. But
In the present invention, the insulating substrate 8 is spread so as to spread in about 10 seconds.
Adjust the pressing speed of.

Here, the insulating substrate 8 has conductor patterns formed on two main surfaces of the insulating plate. The conductor patterns are formed on a predetermined circuit pattern CP on the side on which the semiconductor element is mounted, and on the bottom metal. On the side facing the substrate 1, a conductor pattern D for solder bonding over substantially one surface is provided.
P.

<B. Configuration and Operation of Substrate Mounting Apparatus> Here, the configuration and operation of the substrate mounting apparatus 100 capable of controlling the pressing speed of the insulating substrate 8 will be described with reference to FIGS.

FIG. 6 is a schematic diagram showing the configuration of the substrate mounting apparatus 100, and FIG. 7 is a diagram showing the control operation of the substrate mounting apparatus 100.

As shown in FIG. 6, the substrate mounting apparatus 100
A suction device 80 that vacuum-sucks a substrate (here, the insulating substrate 8) and slides in a linear direction, a driving mechanism 90 that drives the suction device 80, a servo amplifier SA that operates a servomotor 93 that is a driving source, and a servo amplifier And a pulse output unit PU for controlling the SA.

The suction device 80 has a suction portion 81 having a suction pad 82 for vacuum suction on the main surface of the insulating substrate 8, one end connected to the vacuum pump VC, and the other end connected to the suction portion 81. A flexible pipe 83 for reducing the pressure in the suction section 81;

The drive mechanism 90 transmits the rotational force of the motor 93 to the ball screw 92 via gears 941 and 942,
The transmission shaft 91 engaged with the ball screw 92 is
By rotating linearly along the ball screw 92 with the rotation of, the rotational force is converted into a linear driving force.

Therefore, one end of the transmission shaft 91 is connected to the suction portion 81.
, A linear driving force can be applied to the suction section 81. Note that the other end of the transmission shaft 91 is slidably engaged with the fixed shaft 95 that is fixed.

The control operation of the substrate mounting apparatus 100 having such a configuration will be described with reference to FIG. To slide the suction device 80, a pulse signal corresponding to the slide amount and the slide speed of the suction device 80 is provided as a pulse train from the pulse output unit PU to the servo amplifier SA. In addition,
The slide speed of the suction device 80 is determined by the pulse output unit P.
It can be controlled by the number of pulses per unit time of the pulse signal from U.

In the servo amplifier SA, an AC output (current and voltage are controlled) corresponding to the number of pulses of the given pulse train is supplied to the servo motor 93, and the servo motor 9
3 is driven.

The servo motor 93 has an encoder that outputs a rotation state by a pulse signal, and a pulse train output from the encoder is fed back to the servo amplifier SA. The servo amplifier SA detects the pulse train output from the encoder and the pulse train given from the pulse output unit PU, stops the servomotor 93 when both become zero, and slides the suction device 80 (for example, the insulating substrate). 8) to stop pressing.

As described above, by digitally controlling the pressing speed of the insulating substrate 8, the pressing speed of the insulating substrate 8 can be arbitrarily and easily changed. Can respond.

<C. Configuration of Semiconductor Device> FIG. 8 shows a configuration example of a power semiconductor device manufactured through the above-described manufacturing steps.

In the power semiconductor device 200 shown in FIG. 8, the insulating substrate 8 is joined by the solder layer SDL to the removal area 3 of the bottom metal substrate 1 and the circuit pattern CP of the insulating substrate 8 made of copper or the like is formed. Is mounted with power semiconductor elements PE1 and PE2 joined by soldering. Needless to say, the bottom metal substrate 1 is disposed such that the conductor pattern DP on the back surface faces the solder layer SDL.

An example of the power semiconductor elements PE1 and PE2 is an IGBT (Insulated Gate Bipolar Transistor).
stor) and a diode.
E1 and PE2 are connected to each other by a metal wiring WR, and are also connected to an electrode plate TE for electrical connection to the outside by a metal wiring WR.

A resin case RC is provided so as to cover bottom metal substrate 1, and a silicone gel SG for protecting metal wiring WR is provided in a region defined by resin case RC and bottom metal substrate 1. , And an epoxy resin ER are enclosed.

<D. Operation and Effect> As described above, according to the embodiment of the present invention, a region of the main surface of bottom metal substrate 1 to which insulating substrate 8 is soldered is removed by cutting (or polishing), With the removal region, impurities such as organic substances and oxides on the main surface can be removed. As a result, the insulating substrate 8 is replaced with the fluxless solder SD.
When soldering is performed, the fluxless solder SD that has been melted spreads smoothly in the removal area without generating voids. On the other hand, in the non-cutting region, the flux-free solder SD does not easily spread because unnecessary factors such as adhesion of an oxide film and an organic substance and irregularities are present. Thus, the plating step and the solder resist forming step, which were conventionally required, become unnecessary, and the unit cost of the product can be reduced.

Further, the surface roughness of the removal area is set to Rz = 1.
When the thickness is 5 μm or less, the wettability is improved, and a fluxless solder SD containing no flux can be used. Therefore, cleaning with an organic solvent or the like for preventing a problem due to residual flux is unnecessary, and a cleaning machine or the like is not required. This eliminates the need for initial costs and reduces the running cost of organic solvents, thereby reducing manufacturing costs.

Further, the surface roughness of the removal area is set to Rz = 1.
When the thickness is 5 μm or less, unevenness on the surface of the bottom metal substrate 1 made of a soft material such as copper can be eliminated, cracks in the solder layer caused by the unevenness can be suppressed, and the thermal resistance of the solder layer increases. By doing so, it is possible to prevent the temperature of the semiconductor element from becoming high, thereby extending the life of the semiconductor device.

Further, the insulating substrate 8 is mounted on the molten fluxless solder SD on the bottom metal substrate 1 while controlling the speed by using the substrate mounting apparatus 100, so that the insulating substrate 8 is wet on the bottom metal substrate 1. Even if there is a difficult part, it can be reliably covered and an alloy layer of the solder material and the base material can be formed, so that it is possible to prevent the inclusion of gas in the solder layer and to prevent the generation of voids, It is possible to prevent the semiconductor element from increasing in temperature due to the increase in resistance, and to extend the life of the semiconductor device.

<E. Modifications> In the above-described embodiment of the present invention, the soldering of bottom metal substrate 1 and insulating substrate 8 has been described as an example, but the application of the present invention is not limited to this.

For example, as described with reference to FIG. 8, the power semiconductor element PE is placed on the circuit pattern CP of the insulating substrate 8.
1 and PE2 are joined by soldering, and in this case, the circuit pattern CP is expanded in an atmosphere having an oxygen concentration of 10 ppm or less, approximately the same as the bonding region of the power semiconductor elements PE1 and PE2, or expanded by about 0.2 mm. By cutting about 0.1 μm deep, plating on the circuit pattern CP becomes unnecessary. Then, the molten fluxless solder SD is supplied to the removal region from the solder supply device 6 described with reference to FIG. And FIG.
By mounting the power semiconductor elements PE1 and PE2 while controlling the speed using the substrate mounting apparatus 100 described with reference to, the above-described effects can be obtained.

Further, power semiconductor elements PE1 and PE1
By using the fluxless solder SD for the joining of E2, the flux does not remain between the circuit patterns to reduce the insulation resistance, and the silicone injected before the epoxy resin ER is injected into the resin case RC. It is possible to prevent the gel SG from generating an uncured portion due to the residual flux.

[0078]

According to the method of manufacturing a semiconductor device according to the first aspect of the present invention, the removal region is formed by removing the mounting region of the insulating substrate of the metal substrate over a predetermined depth.
Impurities such as organic substances and oxides on the main surface can be removed. As a result, when the insulating substrate is soldered with the fluxless solder, the molten fluxless solder spreads smoothly without voids in the removed area. On the other hand, in the non-cutting area, there is a factor that hinders the spread of the solder, for example, the adhesion of an oxide film and an organic substance, and the unevenness. The possibility of spreading can be reduced, and the plating process that was conventionally required,
The step of forming the solder resist becomes unnecessary, and the unit cost of the product can be reduced.

According to the method of manufacturing a semiconductor device according to the second aspect of the present invention, the removal region is formed so as to have a width equal to or larger than the conductor pattern of the insulating substrate and a predetermined depth of 0.1 μm or more. In addition, it is possible to completely cover the conductor pattern of the insulating substrate with the removal area, and it is possible to reliably remove impurities such as organic substances and oxides on the main surface.

According to the method of manufacturing a semiconductor device according to the third aspect of the present invention, the molten fluxless solder is disposed on the removal area, and the insulating substrate is pressed onto the molten fluxless solder while controlling the speed. Therefore, even if there is a hardly wet portion on the removal area, it can be reliably covered and an alloy layer of the solder material and the base material can be formed.

According to the method of manufacturing a semiconductor device according to the fourth aspect of the present invention, since the molten fluxless solder presses the insulating substrate at a speed that spreads uniformly without entraining the gas, the gas is included in the solder layer. As a result, it is possible to prevent the occurrence of voids, prevent problems caused by an increase in the thermal resistance of the solder layer, and extend the life of the semiconductor device.

According to the method of manufacturing a semiconductor device according to the fifth aspect of the present invention, the removal region is formed by removing the mounting region of the circuit pattern for the semiconductor element over a predetermined depth. Impurities such as organic substances and oxides can be removed. As a result, when the semiconductor element is soldered with fluxless solder, the molten fluxless solder spreads smoothly in the removed area without voids. On the other hand, in the non-cutting area, there is a factor that hinders the spread of the solder, for example, the adhesion of an oxide film and an organic substance, and the unevenness. The possibility of spreading can be reduced, and a plating step and a solder resist forming step which have been required in the past become unnecessary, and the unit cost of the product can be reduced.

According to the method of manufacturing a semiconductor device according to the sixth aspect of the present invention, the removal region is formed so as to have a width equal to or larger than the solder junction pattern of the semiconductor element and a predetermined depth of 0.1 μm or more. Therefore, the solder junction pattern of the semiconductor element can be completely covered with the removal region, and impurities such as organic substances and oxides on the main surface can be surely removed.

According to the method of manufacturing a semiconductor device according to the seventh aspect of the present invention, the molten fluxless solder is disposed on the removal area, and the semiconductor element is pressed onto the molten fluxless solder while controlling the speed. Therefore, even if there is a hardly wet portion on the removal area, it can be reliably covered and an alloy layer of the solder material and the base material can be formed.

According to the method of manufacturing a semiconductor device according to the present invention, the molten fluxless solder presses the semiconductor element at a speed that spreads uniformly without entraining the gas, so that the gas is included in the solder layer. As a result, it is possible to prevent the occurrence of voids, prevent problems caused by an increase in the thermal resistance of the solder layer, and extend the life of the semiconductor device.

According to the method of manufacturing a semiconductor device according to the ninth aspect of the present invention, the ten-point average roughness of the surface is Rz = 1.
Since the removal region is formed so as to be 5 μm or less, when the metal substrate or the circuit pattern is made of a soft material and has irregularities on the surface, the irregularities are eliminated and cracks in the solder layer caused by the irregularities are reduced. It is possible to suppress the problem and prevent a problem caused by an increase in the thermal resistance of the solder layer, thereby extending the life of the semiconductor device.

According to the semiconductor device manufacturing method of the present invention, since the molten fluxless solder is discharged and supplied onto the removal area using the piston type pump, the pushing pressure of the piston can be controlled. The discharge amount can be adjusted arbitrarily, and the thickness of the solder layer can be adjusted arbitrarily.

According to the semiconductor device of the eleventh aspect of the present invention, since the mounting region of the metal substrate on the insulating substrate is removed over a predetermined depth, the insulating substrate is removed by fluxless solder. At the time of soldering, the molten fluxless solder spreads smoothly without generating voids in the removed area, and a semiconductor device can be obtained in which the thermal resistance of the solder layer is increased due to the presence of the voids. .

According to the semiconductor device of the twelfth aspect of the present invention, the removal region has a width larger than the conductor pattern of the insulating substrate and the predetermined depth is 0.1 μm or more. The conductor pattern can be completely covered in the removal area,
Bonding can be reliably performed with the solder layer extending to the removal area. In addition, since impurities such as organic substances and oxides on the main surface are surely removed, the solder layer spreads evenly, and a semiconductor device that prevents a problem that occurs due to an increase in thermal resistance of the solder layer due to the presence of voids. Can be obtained.

According to the semiconductor device of the thirteenth aspect of the present invention, since the mounting area of the semiconductor element of the circuit pattern has the removed area removed over a predetermined depth, the semiconductor element is removed by the fluxless solder. When soldering,
The molten fluxless solder spreads smoothly without voids in the removed area, and a semiconductor device can be obtained in which the problem that the thermal resistance of the solder layer increases due to the presence of voids and is prevented from occurring.

According to the semiconductor device of the fourteenth aspect of the present invention, the removal region has a width larger than the solder junction pattern of the semiconductor element and has a predetermined depth of 0.1 μm or more. Can be completely covered by the removed area, and the solder layer can be surely joined by the solder layer extending to the removed area. In addition, since impurities such as organic substances and oxides on the main surface are reliably removed, the solder layer spreads evenly, and a semiconductor device that prevents a problem that occurs due to an increase in thermal resistance of the solder layer due to the presence of voids. Can be obtained.

According to the semiconductor device of the fifteenth aspect of the present invention, the ten-point average roughness of the surface of the removal area is Rz = 1.
Since the thickness is 5 μm or less, when the metal substrate or the circuit pattern is formed of a soft material and has irregularities on the surface, the irregularities can be eliminated, and the occurrence of cracks in the solder layer due to the irregularities can be suppressed. A semiconductor device in which a problem caused by an increase in resistance is prevented can be obtained.

[Brief description of the drawings]

FIG. 1 is a process chart illustrating a method for manufacturing a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a process diagram illustrating a method for manufacturing a semiconductor device according to an embodiment of the present invention.

FIG. 3 is a process diagram illustrating a method for manufacturing a semiconductor device according to an embodiment of the present invention.

FIG. 4 is a process chart illustrating a method for manufacturing a semiconductor device according to an embodiment of the present invention;

FIG. 5 is a process chart illustrating a method of manufacturing a semiconductor device according to an embodiment of the present invention.

FIG. 6 is a diagram illustrating a configuration of a substrate mounting apparatus.

FIG. 7 is a diagram illustrating the operation of the substrate mounting apparatus.

FIG. 8 is a diagram illustrating a configuration of a semiconductor device according to an embodiment of the present invention;

[Explanation of symbols]

1 bottom metal substrate, 3 removal area, 8 insulating substrate, 60
Piston pump, CP circuit pattern, DP conductor pattern, SD fluxless solder.

 ────────────────────────────────────────────────── ─── Continued on front page (72) Inventor Nozomi Sennehara 1-1-1, Imajuku-higashi, Nishi-ku, Fukuoka City, Fukuoka Prefecture F-term Semicon Engineering Co., Ltd. F-term (reference)

Claims (15)

[Claims] 1. A method for manufacturing a semiconductor device, comprising: a metal substrate; and a conductor pattern on a main surface for bonding to the metal substrate, and an insulating substrate provided on the metal substrate. (A) removing the mounting region of the insulating substrate of the metal substrate over a predetermined depth to form a removed region; and (b) forming the insulating substrate on the removed region by fluxless soldering. And a method of manufacturing a semiconductor device. 2. The method according to claim 1, wherein the step (a) includes a step of forming the removal region such that the predetermined depth is equal to or greater than 0.1 μm and is equal to or larger than the conductor pattern of the insulating substrate. 2. The method for manufacturing a semiconductor device according to claim 1. 3. The step (b) includes arranging a molten fluxless solder on the removal area and pressing the insulating substrate onto the molten fluxless solder while controlling the speed. 1
The manufacturing method of the semiconductor device described in the above. 4. The method according to claim 3, wherein the step (b) includes a step of pressing the insulating substrate at a speed at which the molten fluxless solder spreads uniformly without involving gas. 5. A method for manufacturing a semiconductor device comprising: an insulating substrate having a circuit pattern on a main surface; and a semiconductor element mounted on the circuit pattern, wherein: (a) the semiconductor element of the circuit pattern; Removing the mounting region to a predetermined depth to form a removed region; and (b) joining the semiconductor element on the removed region by fluxless solder. 6. The method according to claim 1, wherein the step (a) includes a step of forming the removal region so as to have a width equal to or larger than a solder bonding pattern of the semiconductor element and the predetermined depth to be 0.1 μm or more. 6. The method for manufacturing a semiconductor device according to item 5. 7. The step (b) includes arranging a molten fluxless solder on the removal area, and pressing the semiconductor element onto the molten fluxless solder while controlling the speed. 6. The method for manufacturing a semiconductor device according to item 5. 8. The method of manufacturing a semiconductor device according to claim 7, wherein the step (b) includes a step of pressing the semiconductor element at a speed at which the molten fluxless solder spreads uniformly without involving gas. 9. The semiconductor according to claim 2, wherein the step (a) includes a step of forming the removal region such that a 10-point average roughness of the surface is Rz = 1.5 μm or less. Device manufacturing method. 10. The step (b) includes a step of extruding the molten fluxless solder with an extruding pressure of a piston, and discharging and supplying the molten fluxless solder onto the removal area using a piston type pump. A method for manufacturing a semiconductor device according to claim 1. 11. A semiconductor device, comprising: a metal substrate; and a conductor pattern on a main surface for bonding to the metal substrate, and an insulating substrate provided on the metal substrate. The semiconductor device, wherein the metal substrate has a removal region in which a mounting region of the insulation substrate is removed over a predetermined depth, and the insulation substrate is bonded to the removal region by fluxless solder. 12. The semiconductor device according to claim 11, wherein said removal region has a width equal to or larger than said conductor pattern of said insulating substrate, and said predetermined depth is 0.1 μm or more. 13. A semiconductor device comprising: an insulating substrate having a circuit pattern on a main surface; and a semiconductor element mounted on the circuit pattern, wherein the circuit pattern has a region where the semiconductor element is mounted. A semiconductor device having a removal region removed over a predetermined depth, wherein the semiconductor element is joined to the removal region by fluxless solder. 14. The removal region has a width equal to or larger than a solder junction pattern of the semiconductor element, and the predetermined depth is 0.1 μm or more.
13. The semiconductor device according to claim 1. 15. The removal region, wherein the surface has a 10-point average roughness of Rz = 1.5 μm or less;
The semiconductor device according to claim 12 or claim 14.