JP2004209506A - Nozzle for supplying brazing filler metal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nozzle for supplying brazing filler metal with which a prescribed amount of the brazing filler is supplied onto a heated substrate by bringing the tip end part of the brazing filler metal into contact with the heated substrate and melting the brazing filler metal. <P>SOLUTION: A partition wall bush 6 is arranged in a hollow part 5 of a nozzle main body 4, and an inflow port 7 and an exhaust port 8 for cooling gas are arranged in the nozzle main body 4, and a pipe member 10 is fitted to the lower part of the nozzle main body 4 and a guide pipe 10 is fixed to the pipe member 9. On the nozzle main body 4, a positioning member 12 and a nozzle guide 13 supports the guide pipe 10 concentrically with the partition wall bush 6. The cooling gas supplied from the inflow port 7 is exhausted from the exhaust port 8 through a gap formed between the circumferential surface of the pipe part 6b of the partition wall bush 6 and the inner peripheral surface of the pipe member 9 after passing through a gap formed between the inner peripheral surface of the pipe part 6b and the circumferential surface of the guide pipe 10 then returning at the tip end part of the pipe part 6b. <P>COPYRIGHT: (C)2004,JPO&amp;NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brazing material supply nozzle, and more particularly, to bond a semiconductor chip (die) to a substrate such as a lead frame by supplying a tip of a wire-shaped brazing material to a heated substrate by contact melting. And a brazing material supply nozzle.
[0002]
[Prior art]
When the semiconductor chip (die) is fixed to a substrate such as a lead frame, and when it is not necessary to electrically connect the back surface of the semiconductor chip (die) to the substrate, a resin bond method using an insulating resin to fix the semiconductor chip (die) to the substrate However, in general, in order to electrically connect the back surface of the semiconductor chip (die) to the substrate and efficiently radiate heat generated during operation of the semiconductor chip (die) to the substrate. Next, as shown in FIG. 4, an electrode 31 is formed on the back surface of the semiconductor chip (die) 30, and this electrode 31 is formed on a substrate 33 such as a lead frame by using a conductive and good heat conductive brazing material 32. It is stuck to.
[0003]
As shown in FIG. 5 (A), for example, as shown in FIG. 5 (A), the substrate 33 such as the lead frame is used for bare bonding using a copper or copper-based substrate 33a having good electrical conductivity and good thermal conductivity. As shown in (B), a plating layer 33b that is hardly rusted, such as nickel, gold, and silver, and that is easily wetted by a brazing material is provided on both surfaces of a copper or copper-based substrate 33a having good electrical conductivity and good thermal conductivity. As shown in FIG. 5C, nickel, gold, silver, or the like is formed only at the bonding position of the semiconductor chip (die) on the copper or copper-based substrate 33a having good electrical conductivity and good thermal conductivity. A plating layer 33c which is not easily rusted and is easily wetted by a brazing material. As shown in FIG. 5 (D), copper or a copper-based substrate 33a having good electrical conductivity and good thermal conductivity is formed on both surfaces of nickel or the like. Forms a relatively inexpensive plating layer 33d that is less likely to rust And, further, gold, rust hardly such as silver, and such as the brazing material to form the easily-plated layer 33e wet is used only in the bonding position of the semiconductor chip (die) of the plating layer 33d.
[0004]
The method using the brazing material includes a hard soldering method using gold-silicon eutectic and the like, and a so-called soft soldering method using solder. The former hard soldering method has high reliability in fixing the semiconductor chip (die) to the substrate, but the brazing material is expensive, and the heating temperature of the tunnel furnace for melting the hard solder is high. Because of high cost, it is used only for special applications requiring high reliability.
[0005]
The latter soft soldering method is inexpensive because the brazing material is inexpensive and the heating temperature of the substrate for melting the brazing material is low, so that the cost is low and it is most widely used in consumer semiconductor devices. In this soft soldering method, a solder layer is formed in advance on the back surface of a semiconductor chip (die), and the semiconductor chip (die) is pressed against a heated substrate to melt and fix the solder layer. Method, a solder piece supply method that supplies solder pieces to a heated substrate and melts the solder pieces, inserts a solder wire drawn from a feeder roller around which a long solder wire is wound into a solder supply tool, and from the tip There is a solder wire supply method in which a predetermined length is protruded, and the tip is brought into contact with a heated substrate to be melted and supplied.
[0006]
In the pre-soldering method, since a solder layer is formed on the back surface of the semiconductor wafer, when the semiconductor chip (die) is cut and separated later by a dicing saw (diamond cutter) or the like, the soft solder is clogged, There is a problem that it is difficult to cut the solder layer. Further, the solder piece supply method has a problem that when supplying a minute solder piece, the supply position of the solder piece is not constant, so that high-precision die bonding cannot be performed. In the solder wire supply method, since the nozzle position can be controlled with high precision, the solder supply position can also be controlled with high precision, so that high-precision die bonding can be performed.
Therefore, recently, a solder wire supply system has been widely adopted.
[0007]
A solder supply tool used in a conventional solder wire supply system will be described.
As shown in FIG. 6, the solder supply tool 41 includes a guide pipe 42 into which a solder wire is inserted, a tool main body 43 holding the guide pipe 42, and a lower part of the tool main body 43. An outer fitting member 44 is fitted on the lower end of the pipe 42, and a tapered delivery head 45 is provided at the lower end of the guide pipe 42. The delivery head 45 is provided with a guide hole 46, and a solder wire is inserted from the upper end of the guide pipe 42 and guided by the guide hole 46 to be delivered.
[0008]
An inflow port 47 and an outflow port 48 for a cooling fluid are provided on a side portion of the tool main body 43, and a cooling fluid such as water or air introduced from the inflow port 47 is supplied to the guide pipe 42 and the tool. It flows through the inflow passage 49 formed between the main body 43 and the lower end of the guide pipe 42, and through a gap 50 formed between the tool main body 43 and the outer fitting member 44. , And is configured to flow out from the outlet 48. Accordingly, the lower end of the guide pipe 42, which is disposed above the heated lead frame and is exposed to the mixed gas in the tunnel furnace for heating the lead frame, can be cooled by the cooling fluid. . (For example, see Patent Document 1).
[0009]
In addition, a solder supply tool 51 as shown in FIG. 7 has been proposed to improve the cooling effect of the cooling fluid such as water or air. The solder supply tool 51 includes a guide pipe 52 into which the solder wire 32 pulled out from the feed roller 61 is inserted, a tool main body 53 holding the guide pipe 52, and a lower part of the tool main body 53. An outer fitting member 54 is fitted to the lower end of the guide pipe 52, and a tapered delivery head 55 is provided at the lower end of the guide pipe 52. The delivery head 55 is provided with a guide hole 56, and the solder wire 32 is inserted from the upper end of the guide pipe 52 and guided by the guide hole 56 to be delivered. A plurality of heat pipes 57 are arranged along the outer peripheral surface of the guide pipe 52.
[0010]
The tool body 53 is provided with an inlet 58 and an outlet 59 for the cooling fluid. Cooling fluid, such as water or air, flowing from the inflow port 58 passes through the flow passage 60 formed between the tool body 53 and the heat pipe 57 and flows upward along the heat pipe 57. At the same time, it is configured to flow out from the outlet 59. Thus, the lower end of the guide pipe 52, which is disposed above the heated lead frame and is exposed to the mixed gas in the tunnel furnace for heating the lead frame, can be cooled by the cooling fluid. (For example, see Patent Document 1).
[0011]
As shown in FIG. 8A, the solder supply tools 41 and 51 are arranged above a tunnel furnace (not shown) that accommodates a substrate 33 such as a lead frame heated to a predetermined temperature in a mixed gas atmosphere. Then, the solder wires 32 are protruded from the tips of the solder supply tools 41 and 51 by a predetermined size, and are lowered to bring the tips of the solder wires 32 into contact with the heated substrate 33 as shown in FIG. Then, as shown in FIG. 8C, when the nozzles 41 and 51 are raised, a predetermined amount of the molten solder 32 is supplied onto the substrate 33.
[0012]
As described above, the reason why the cooling means is provided in the solder supply tools 41 and 51 is that when the tip of the solder wire 32 is brought into contact with the substrate 33 such as a heated lead frame to be melted and supplied onto the substrate 33. In addition, the solder wire 32 is prevented from being melted more than necessary, the specific component (Sn) having a low melting point in the solder wire 32 is prevented from melting, and a secondary oxide film is not formed on the surface of the solder wire 32. That's why.
[0013]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2000-252032 ([0002] to [0021]; see FIGS. 1 to 3).
[0014]
[Problems to be solved by the invention]
By the way, recently, with the miniaturization of electronic components incorporating a semiconductor device, the size of a semiconductor chip (die) has been reduced, the precision of bonding position with respect to a substrate such as a lead frame has been increased, and the size of a semiconductor chip (die) and a lead frame have been reduced. Low electrical resistance and low heat dissipation resistance between substrates are required. For that purpose, it is important to accurately control the supply position and supply amount of brazing material such as solder to a substrate such as a lead frame.
[0015]
However, the solder supply tool 41 shown in FIG. 6 has a large clearance between the guide pipe 42 and the solder wire, and does not have a sufficient cooling effect on the solder wire. As shown in A), the supply amount of the solder becomes larger than the regular supply amount 32 shown by the solid line as shown by the two-dot chain line 32 ', and the semiconductor chip (die) is placed on the excess molten solder 32'. 9), when supplied and pressurized, as shown in FIG. 9B, excess solder 32 'protrudes from the periphery of the semiconductor chip (die) 30 and rises to the end face of the semiconductor chip (die) 30. In an extreme case, there is a problem to be solved such that a short circuit occurs by crawling up to the upper surface of the semiconductor chip (die) 30. Further, the solder supply tool 51 shown in FIG. 7 has a problem to be solved because it uses the heat pipe 47 and is expensive.
[0016]
In addition, if a liquid such as water is used as a cooling medium, not only does the sealing structure become complicated, but in the event of leakage, the die bonder itself or nearby equipment is wetted, or the vapor that evaporates from the leaked liquid. As a result, there is a problem that the semiconductor chip (die) is contaminated to cause characteristic fluctuation. Further, a chiller (constant-temperature liquid circulation device) for circulating cooling water must be provided, which has been a factor of cost increase.
[0017]
Therefore, the present invention solves the above-mentioned problems, and uses a wire brazing material such as a soft brazing material such as solder, a hard brazing material such as a Pb-Sn-Ag system, or a Pb-free solder substitute brazing material. It is an object of the present invention to provide a brazing material supply nozzle capable of supplying a predetermined amount to a substrate.
[0018]
[Means for Solving the Problems]
The brazing material supply nozzle of the present invention inserts a brazing material drawn from a feeder roller wound with a long wire-shaped brazing material, and contacts and melts the tip of the brazing material protruding from the lower end with the heated substrate. A brazing material supply nozzle, a nozzle body having a cavity in the center, a partition bush mounted in the cavity in the nozzle body, a pipe member attached to a lower portion of the nozzle body, and the nozzle body A cooling gas inflow port, a cooling gas discharge port, and a guide pipe provided through the partition bush and fixed to a pipe member, and supplied from the inflow port into the nozzle body. The cooled gas is formed by the gap formed between the inner peripheral surface of the partition bush and the outer peripheral surface of the guide pipe, and the outer peripheral surface of the partition bush and the inner peripheral surface of the pipe member. Through a gap that is, it is characterized in that discharged from the discharge port (claim 1).
[0019]
In addition, the cooling gas supplied from the inflow port into the nozzle body is supplied to the gap formed between the inner peripheral surface of the partition bush and the outer peripheral surface of the guide pipe, and the outer peripheral surface of the partition bush and the pipe. The text “discharge from the discharge port through the gap formed between the inner peripheral surface of the member and the discharge port” states that the cooling gas supplied from the inflow port into the nozzle main body is “the inner peripheral surface of the partition bush and the guide. After passing through the “gap formed between the outer peripheral surface of the pipe” and the “gap formed between the outer peripheral surface of the partition bush and the inner peripheral surface of the pipe member”, this does not mean only passing through the gap. After passing through the "gap formed between the outer peripheral surface of the partition bush and the inner peripheral surface of the pipe member", it may also pass through the "gap formed between the inner peripheral surface of the partition bush and the outer peripheral surface of the guide pipe". It is meant to include.
[0020]
According to the brazing material supply nozzle, the cooling gas supplied from the inflow port mainly passes through the gap formed by the inner peripheral surface of the partition bush and the outer peripheral surface of the guide pipe, via the guide pipe. It can effectively cool the brazing material inserted with a small clearance in it, radiating heat from the substrate such as a heated lead frame, and conducting from the brazing material due to the brazing material contacting the heated substrate. By being prevented from being overheated by heat, a predetermined amount of brazing material can be accurately controlled and supplied to the substrate. Therefore, the surplus solder as shown in FIG. 9B does not rise on the side surface of the semiconductor chip (die) or creep up to the upper surface of the semiconductor chip (die), so that the semiconductor chip (die) having high reliability is obtained. Bonding becomes possible.
[0021]
Also, the brazing filler metal supply nozzle of the present invention may be configured such that the cooling gas supplied from the inflow port into the nozzle body is supplied to the partition wall through a gap formed between the inner peripheral surface of the partition bush and the outer peripheral surface of the guide pipe. The bush makes a U-turn at the leading end, and is discharged from the discharge port through a gap formed between the outer peripheral surface of the partition bush and the inner peripheral surface of the pipe member (claim 2). .
[0022]
According to the brazing material supply nozzle, the cooling gas supplied from the inflow port is first filled with a gap formed between the outer peripheral surface of the guide pipe close to the brazing material and the inner peripheral surface of the partition bush surrounding the guide pipe. By effectively cooling the brazing material, the cooling gas is U-turned at the tip of the partition bush, and further passed through a gap formed between the outer peripheral surface of the partition bush and the inner peripheral surface of the pipe member. Since it is cooled and discharged from the discharge port, the brazing material can be cooled effectively.
[0023]
Further, the brazing material supply nozzle of the present invention forms an annular groove communicating with the inflow port or the outflow port of the nozzle body, and communicates with a central vertical hole at a portion corresponding to the annular groove of the partition bush. A plurality of lateral holes are radially formed (claim 3).
[0024]
According to the brazing material supply nozzle described above, the cooling gas supplied from the inflow port enters the center vertical hole from the annular groove of the nozzle body through the radially formed horizontal hole of the partition bush, and enters the central bush. Since it is guided to the gap formed between the inner peripheral surface and the outer peripheral surface of the guide pipe, it can be smoothly guided to the gap. In addition, since the annular groove formed in the nozzle body and the plurality of radially formed lateral holes of the partition bush have a small directionality when the partition bush is mounted on the nozzle body, the assembly workability can be improved. In addition, the cooling gas can be evenly guided to the entire outer periphery of the guide pipe.
[0025]
Further, in the brazing material supply nozzle of the present invention, the partition bush is made of copper, and the guide pipe is made of stainless steel (claim 4).
[0026]
According to the brazing material supply nozzle described above, the guide pipe approaching the substrate such as a heated lead frame is made of stainless steel having a low thermal conductivity, because it is expected to have an effect as corrosion resistance and heat resistant material, Theoretically, it was confirmed that by making the pipe thinner, it was possible to sufficiently compensate for the poor heat conduction response.Moreover, the partition bush was made of copper, which has high thermal conductivity. The cooling effect of the brazing filler metal can be remarkably improved by the synergistic effect of the cooling effect by the contact of the solder and the cooling effect by the heat dissipation.
[0027]
In the brazing material supply nozzle according to the present invention, the clearance between the inner peripheral surface of the guide pipe and the outer peripheral surface of the brazing material is set to 0.05 to 0.2 mm. ).
[0028]
According to the brazing material supply nozzle described above, the cooling effect of the brazing material is improved by setting the clearance between the inner peripheral surface of the guide pipe and the brazing material to be 0.05 to 0.2 mm, so that the brazing material is overheated. This eliminates the need to supply a brazing filler metal exceeding a predetermined amount, and to prevent the supply of the required amount of brazing filler metal to the substrate, because the brazing filler metal is supercooled and becomes difficult to melt. Can be supplied. In other words, if the clearance between the inner peripheral surface of the guide pipe and the brazing material is set to less than 0.05 mm, the clearance cannot be secured due to the dimensional tolerance of the brazing material and clogging occurs. If the clearance exceeds 0.2 mm, the brazing material may be melted more than necessary due to insufficient cooling of the brazing material and the brazing material may be supplied in excess of a predetermined amount. Will deteriorate the supply position accuracy.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of a brazing material supply nozzle of the present invention will be described with reference to the drawings. 1A is a longitudinal sectional view of the brazing material supply nozzle of the present invention, and FIG. 1B is a bottom view of the brazing material supply nozzle of FIG. 1A. 2 (A) to 2 (D) are cross-sectional views taken along the line AA, cross-sectional views taken along the line BB, and cross-sections taken along the line CC of FIG. 1 (A), respectively. It is a figure and a top view.
[0030]
In FIG. 1, reference numeral 1 denotes a soft solder (Sn-Pb alloy) or a so-called solder (Pb-Sn-Ag type), which has been recently developed to solve the environmental pollution problem caused by Pb. A feed roller around which a wire-shaped brazing material 2 made of a Pb-free solder substitute brazing material (Sn-Zn-based, Sn-Ag-based, Sn-Ag-Cu-based, etc.) is wound, and 3 is inserted through the brazing material 2. This is a brazing material supply nozzle for supplying a substrate such as a lead frame. The brazing material supply nozzle 3 includes a nozzle body 4 having a cavity 5 therein, a copper partition bush 6 provided in the cavity 5 of the nozzle body 4, and an upper part of the nozzle body 4 partitioned by the partition bush 6. And a discharge port 8 provided at a lower portion of the nozzle body 4 for discharging used cooling gas. A cooling gas supply pipe 7a and a cooling gas supply pipe 8a are connected to the inflow port 7 and the discharge port 8, respectively.
[0031]
The nozzle body 4 has an annular groove 4a on an inner peripheral surface corresponding to the inflow port 7.
2A, the partition bush 6 radially has a plurality of horizontal holes 6a communicating with a central vertical hole at a portion corresponding to the annular groove 4a. The horizontal hole 6a is easily aligned with the position of the inflow port 7, so that the assembly with the nozzle body 4 is facilitated. The partition bush 6 has a pipe portion 6b extending downward along the vertical hole.
[0032]
A copper pipe member 9 is attached to the lower surface of the nozzle body 4, and a stainless steel guide pipe 10 for guiding the brazing material 2 is inserted into a pipe portion 6 a of the partition bush 6. The pipe member 9 has a flange portion 9a fixed to the lower surface of the nozzle body 4 and a pipe portion 9b forming a gap for guiding the cooling gas between the partition bush 6 and the flange portion 9a. As shown in FIGS. 3A and 3B, the lower end of the guide pipe 10 projects from the pipe member 9 by a predetermined size and is fixed to the pipe member 9 by a silver solder 11.
[0033]
An upper halfway of the guide pipe 10 is positioned concentrically with the center axis of the partition bush 6 by a positioning member 12, and the positioning member 12 is held at a predetermined position by a nozzle guide 13. I have.
[0034]
In addition, between the nozzle body 4 and the partition bush 6, between the lower surface of the nozzle body 4 and the flange portion 9a of the pipe member 9, between the upper surface of the nozzle body 4 and the lower surface of the positioning member 12, and between the nozzle body 4 and the positioning member 12. Heat-resistant O-rings 14, 15, 16, and 17 are interposed between the and the guide pipe 10, respectively, and are hermetically sealed. Further, a back roller 18 is disposed as necessary with respect to the feed roller 1 around which the brazing material 2 is wound, so that the brazing material 2 is given an appropriate drawing resistance to be fed out by a predetermined dimension.
[0035]
Next, the operation of the brazing material supply nozzle 3 will be described. First, the brazing material 2 is pulled out from the feed roller 1, the brazing material 2 is inserted into the guide pipe 10 from the opening of the nozzle guide 13, and is protruded from the lower end of the guide pipe 10 by a predetermined dimension through the guide pipe 10.
[0036]
Then, a cooling gas such as cooling air is supplied into the nozzle body 4 from the inflow port 7.
Then, the cooling gas supplied into the nozzle body 4 passes from the annular groove 4a through the radial horizontal hole 6a of the partition bush 6, and forms a gap formed between the inner peripheral surface of the pipe portion 6b and the outer peripheral surface of the guide pipe 10. 19, a U-turn after exiting from the lower end of the pipe portion 6b of the partition bush 6, and a gap formed between the inner peripheral surface of the pipe member 9 and the inner peripheral surface of the partition bush 6 this time. It rises through 20 and is discharged from outlet 8.
Here, the guide pipe 10 is cooled mainly while the cooling gas descends through the gap 19 formed between the inner peripheral surface of the pipe portion 6b of the partition bush 6 and the outer peripheral surface of the guide pipe 10. The brazing material 2 inserted into the guide pipe 10 is cooled. The thermal diffusivity of air is 2.2 × 10 ^-5 m ² / S, the thermal diffusivity of water is 1.9 × 10 ^-7 m ² / S, which is 116 times higher than that of the water-cooled type, so that the brazing material 2 can be cooled to an appropriate temperature in a short time.
[0037]
Then, the brazing material 2 protruding from the lower end of the guide pipe 10 is brought into contact with a substrate such as a heated lead frame. Then, the tip portion of the brazing material 2 is melted by heat conduction from the substrate and is separated from the brazing material 2 and supplied onto the substrate. At this time, since the clearance between the inner peripheral surface of the guide pipe 10 and the brazing material 2 is set to 0.5 to 2.0 mm, the brazing material 2 is appropriately cooled and a predetermined amount of brazing material is placed on the substrate. Material can be supplied. Therefore, when a semiconductor chip (die) is supplied and pressurized on the molten brazing material, it becomes possible to bond the semiconductor chip (die) with a predetermined amount of brazing material with high accuracy.
[0038]
[Example]
Next, examples of the present invention will be described.
Test condition
Brazing material 2: Pb-Sn solder (melting point: 183 ° C.), φ1.0 mm
Bulkhead bush 6: Made of oxygen-free copper
Guide pipe 10: SUS316L + electroless nickel plating, inner diameter φ1.2mm
Lead frame: Copper base material + Ni plating on both sides (heating temperature 350 ° C)
Spacing between lead frame and guide pipe 10: 1 to 8 mm
Projection size of brazing material 2 from guide pipe 10: 1 mm
Clearance between brazing material 2 and guide pipe 10: 0.1 mm
Cooling gas: air
Supply pressure of cooling gas: 0.3 MPa
Tunnel furnace atmosphere: 80-90% N ₂ + 20-10% H ₂ Mixed gas
Lead frame heating temperature: 350 ° C
Test cycle: Brazing material 2 was in contact with lead frame for 0.5 seconds, 0.5
Seconds apart
[0039]
[Test results]
When the temperature at the tip of the guide pipe 10 was measured under the test conditions described above, the temperature was 300 ° C., whereas the temperature at the tip of the brazing material 2 was 140 ° C. constant. No formation of a secondary oxide film or melting and separation of the brazing filler metal components were observed.
On the other hand, when the supply of the cooling gas is stopped, the temperature of the tip of the brazing material 2 becomes 260 ° C., and the formation of the secondary surface oxide film of the brazing material 2 is recognized. A phenomenon in which Sn (melting point: 235 ° C.) melts was observed. From the above results, it can be seen that the cooling effect of the brazing material supply nozzle 3 of the present invention is excellent.
[0040]
The above embodiment has been described for one embodiment of the present invention, and the present invention is of course not limited to this embodiment.
[0041]
For example, as shown in FIG. 3A, the guide pipe 10 is not only protruded from the pipe member 9 by a predetermined size, but also is made to coincide with the lower end of the pipe member 9 or slightly recessed from the lower end of the pipe member 9. You may make it enter.
[0042]
【The invention's effect】
The brazing material supply nozzle of the present invention inserts a brazing material drawn from a feeder roller around which a long wire-shaped brazing material is wound, and contacts and melts the tip of the brazing material protruding from the lower end with the heated substrate. In the brazing material supply nozzle that is supplied to the
A nozzle body having a cavity in the center, a partition bush mounted in the cavity in the nozzle body, a pipe member attached to a lower portion of the nozzle body, an inlet for cooling gas provided in the nozzle body, and cooling. A gas outlet, a guide pipe provided through the partition bush and fixed to a pipe member, and supplies the cooling gas supplied into the nozzle body from the inflow port to the inner peripheral surface of the partition bush. And discharging from the discharge port through a gap formed between the outer peripheral surface of the guide pipe and a gap formed between the outer peripheral surface of the partition bush and the inner peripheral surface of the pipe member. Therefore, the brazing material can be cooled appropriately, and a predetermined amount of the brazing material can be easily and reliably supplied to the substrate surface such as a lead frame. As shown in the figure, the excess brazing material does not rise and the semiconductor chip (die) does not crawl onto the upper surface, and no special parts such as heat pipes are used. Therefore, a brazing material supply nozzle can be provided at low cost. .
[Brief description of the drawings]
FIG. 1A is a longitudinal sectional view of a brazing material supply nozzle according to an embodiment of the present invention,
(B) is a bottom view of the brazing material supply nozzle of (A).
FIG. 2A is a cross-sectional view of the brazing material supply nozzle of FIG. 1 taken along line AA.
(B) is a cross-sectional view of the brazing material supply nozzle of FIG. 1 along the line BB,
(C) is a cross-sectional view of the brazing material supply nozzle of FIG. 1 along the line CC,
(D) is a plan view of the brazing material supply nozzle of FIG. 1.
FIG. 3A is an enlarged vertical sectional view of a tip end of the brazing material supply nozzle of FIG. 1;
(B) is a cross-sectional view of the brazing material supply nozzle of (A) taken along the line DD.
FIG. 4 is a front view of a semiconductor device in which a semiconductor chip (die) is brazed to a substrate.
FIG. 5 shows various forms of a substrate such as a lead frame;
(A) is an enlarged vertical sectional view of a bare bonding substrate exposing the base material,
(B) is an enlarged vertical cross-sectional view of the entire plating substrate having plating layers formed on both surfaces of the base material,
(C) is an enlarged vertical sectional view of a partially plated substrate in which a plating layer is formed only at a bonding position of a semiconductor chip (die) on a substrate;
(D) is an enlarged vertical cross-sectional view of a substrate in which plating layers are formed on both surfaces of a substrate, and another plating layer is formed only at a bonding position of a semiconductor chip (die).
FIG. 6 is a longitudinal sectional view of a conventional brazing material supply tool.
FIG. 7 is a longitudinal sectional view of another conventional brazing material supply tool.
FIG. 8A is an enlarged vertical sectional view of the brazing material supply tool in a standby state,
(B) is an enlarged vertical sectional view showing a state where the brazing material supply tool is lowered and the brazing material contacts the substrate;
(C) is an enlarged longitudinal sectional view showing a state in which the brazing material supply tool is raised and the brazing material is supplied to the substrate.
FIG. 9A is a front view of a state in which excessive solder is supplied on a substrate,
(B) is a front view explaining a problem in the case where a semiconductor chip (die) is bonded by pressing on an excessive solder of (A).
[Explanation of symbols]
1 feed roller
2 Brazing filler metal
3 Brazing filler nozzle
4 Nozzle body
4a annular groove
5 cavities
6 Bulkhead bush
6a Horizontal hole
6b Pipe section
7 Cooling gas inlet
8 Cooling gas outlet
9 Pipe members
9a Flange part
9b Pipe section
10 Guide pipe
12 Positioning member
13 Nozzle guide
14-17 O-ring
19, 20 gap

Claims (5)

A brazing material supply in which a brazing material drawn out from a feeder roller wound with a long wire-like brazing material is inserted, and the tip of the brazing material protruding from the lower end is brought into contact with the heated substrate to be melted and supplied to the substrate. At the nozzle
A nozzle body having a cavity at the center, a partition bush mounted in the cavity in the nozzle body, and a pipe member attached to a lower portion of the nozzle body,
An inlet for cooling gas provided in the nozzle body, and an outlet for cooling gas,
Having a guide pipe provided through the partition bush and fixed to a pipe member,
The cooling gas supplied from the inflow port into the nozzle body is supplied to a gap formed between an inner peripheral surface of the partition bush and an outer peripheral surface of the guide pipe, and an outer peripheral surface of the partition bush and an inner peripheral surface of a pipe member. And discharging from the discharge port through a gap formed by the brazing material supply nozzle. The cooling gas supplied from the inflow port into the nozzle body passes through a gap formed between the inner peripheral surface of the partition bush and the outer peripheral surface of the guide pipe and makes a U-turn at the tip end of the partition bush. The brazing material supply nozzle according to claim 1, wherein the brazing material supply nozzle is discharged from the discharge port through a gap formed between an outer peripheral surface of the pipe member and an inner peripheral surface of the pipe member. Along with forming an annular groove communicating with the inflow port or the outflow port of the nozzle body, a plurality of horizontal holes communicating with a central vertical hole are radially formed in a portion corresponding to the annular groove of the partition bush. The brazing material supply nozzle according to claim 1 or 2, wherein: 4. The brazing material supply nozzle according to claim 1, wherein the partition bush is made of copper, and the guide pipe is made of stainless steel. The brazing material supply nozzle according to any one of claims 1 to 4, wherein a clearance between the inner peripheral surface of the guide pipe and the brazing material is set to 0.05 to 0.2 mm.

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