JP2601228B2 - Method for manufacturing resin-sealed circuit device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a resin-sealed circuit device such as a resin-sealed semiconductor device and a resin-sealed hybrid integrated circuit device. The present invention relates to a method for manufacturing a resin-encapsulated circuit device that can be prevented.

[0002]

2. Description of the Related Art A plurality of support plates are provided for independently supporting a plurality of semiconductor chips, and a common connection conductor plate is provided for connecting the plurality of semiconductor chips to each other. A resin-sealed semiconductor device in which a semiconductor chip, a support plate, a conductor plate, and an internal lead thin wire are resin-sealed by connecting the board to the board with a thin internal lead and excluding an external connection portion has already been developed.

[0003]

When the lower and upper surfaces of the support plate are coated with resin by the transfer molding method, not only the upper surface but also the lower surface of the support plate are thinner than the lower support plate. On the upper side, the flow of the resin increases, and the flow of the resin from the upper side to the lower side of the support plate through the space between the support plate and the connecting conductor plate also occurs. When the flow of the resin acts on the internal lead wires between the chip on the support plate and the connection conductor plate, the internal lead wires may hang down and come into contact with the support plate or other objects, resulting in a short circuit state. Also, when the pressure of the resin is extremely large, there is a possibility that the internal lead fine wire may be cut.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing a resin-sealed circuit device that can prevent sagging of internal lead wires.

[0005]

SUMMARY OF THE INVENTION The present invention for achieving the above object will be described with reference to the reference numerals in the drawings showing the embodiments, in which a circuit element and the circuit element are supported on one main surface, And a conductive support plate having an end surface extending linearly, a connecting conductor plate 11 having an end surface extending in parallel to the end surface of the support plate, and the circuit element or the support plate. The conductive plate is electrically connected to the end plate of the support plate, and the internal lead thin wires 22 are disposed so as to pass over the end surface of the conductive plate. A protruding portion 25 protruding so that the distance between the end face and the end face of the conductor plate 11 is partially reduced;
Is provided on the conductor plate 11, the projecting direction of the projecting portion 25 is substantially the same as the extending direction of the internal lead fine wire 22, and the internal lead fine wire 22 passes over the tip of the projecting portion 25. Preparing an assembly in which the position of the projection 25 is determined;
6, 27, and has a directivity from the protruding portion 25 side to the circuit element, and has the internal lead thin wire 2
Insulating resin is injected into the molding cavity 29 having the same direction as the direction in which the circuit element 2 extends, and at least one of the circuit element, one main surface and the other main surface of the support plate, and the conductor plate 11 Part of the resin sealing body 2 covering the internal lead fine wires 22
And a step of forming a resin-sealed circuit device.

[0006]

The connecting conductor plate 11 of the present invention is provided with a protruding portion 25, and the thin inner lead 22 passes over the protruding portion 25. In the place where the protruding portion 25 is provided, the distance between the support plate and the connecting conductor plate 11 becomes narrower than other portions, the flow of the sealing resin becomes worse, and the pressure applied to the internal lead fine wires 22 also becomes smaller. . Further, since the resin is injected into the molding cavity in the same direction as the direction in which the internal lead fine wires 22 extend, the pressure applied to the internal lead fine wires 22 is further reduced. As a result, the sagging of the internal lead wires 22 is prevented, and a short circuit is less likely to occur. In addition, since the space between the support plate and the connection conductor plate 11 is not narrowed in the entire region but is only partially narrowed, the flow of the resin in other portions is not hindered.

[0007]

Next, a resin-sealed hybrid integrated circuit device and a method of manufacturing the same according to an embodiment of the present invention will be described with reference to the drawings. The assembly for the hybrid integrated circuit device shown in FIG. 1 with the insulating resin sealing member removed has first to fourth power transistor chips 1, 2, 3,.
4 and one monolithic IC chip 5.
Power transistor chips 1-4 and monolithic I
In order to electrically separate and support the C chip 5, five metal support plates 6, 7, 8, 9, 10 are provided.
Each of the support plates 6 to 10 has external leads 6a, 7a, 8a, 9a, and 10a integrally connected thereto.

The interconnecting conductor plate 11 of the four power transistor chips 1 to 4
4 are arranged longitudinally, and an external lead 11a is also provided on this.

The external leads 6a to 10a connected to the support plates 6 to 10, the external leads 11a connected to the interconnecting conductor plate 11, the external leads 12 and 13, not connected to the support plates 6 to 10, 14, 15, 16, 17, 18, 19,
20 are juxtaposed at a 2.54 mm pitch (inch pitch). The monolithic IC chip 5 is fixed to the support plate 10 with Pb-Sn solder, and each electrode on this upper surface is electrically connected to the unconnected external leads 12 to 20 and the connected external leads 10a by the internal lead thin wires 21 made of Au thin wires. It is connected to the. Each of the power transistor chips 1 to 4 has a collector electrode on the lower surface, an emitter electrode and a base electrode on the upper surface, and the collector electrode on the lower surface is fixed to each of the support plates 6 to 9 by Pb-Sn solder. Are connected to the common interconnecting conductor plate 11 by the internal lead wires 22 made of Au wires. Note that two emitter connection thin wires 22 are connected to each of the power transistor chips 1 to 4 in order to increase the current capacity.
Since the power transistor chips 1 to 4 are arranged substantially in a straight line, the interconnecting conductor plate 11 also extends linearly along the direction in which the power transistor chips 1 to 4 are arranged.

The base electrodes of the power transistor chips 1 to 4 are connected to the external leads 12, 13, 19, and 20 by internal lead wires 23 made of Au wires.
Monolithic I for external leads 12, 13, 19, 20
The C chip is connected, and the power transistor chips 1 to 4 are also connected. In order to easily achieve this connection, the external leads 12, 13, 19, 20 are formed to have portions adjacent to the support plates 6, 7, 8, 9. Therefore, the external lead 12 passes between the first support plate 6 and the second support plate 7, and the external lead 20 also passes between the third support plate 8 and the fourth support plate 9. . Since the external leads 12, 13, 19, and 20 are disposed adjacent to the support plates 6 to 9, the base connecting internal lead fine wires 23 are disposed so as not to jump over other external leads.
However, the second and third power transistor chips 2,
The third internal lead wire 22 for emitter connection is disposed so as to jump over the external leads 12 and 20. If the external lead 12 is arranged between the external leads 7a and 13,
Assuming that the external lead 20 is disposed between the external lead 19 and the external lead 8a, all the base connecting internal lead fine wires 23 of the first to fourth power transistor chips 1 to 4 jump over the external lead. It is necessary to dispose them, and the number of jumping points is four, which is more than the two points of the emitter connecting internal lead thin wires 22 in FIG.

Each power transistor and monolithic I
The C chips 1 to 5, each of the support plates 6 to 10, the interconnecting conductor plate 11, a part of each of the external leads 6a to 11a and 12 to 20, and each of the internal lead fine wires 21 to 23 are resin-sealed bodies indicated by dotted lines. 24.

Each part will be described in more detail.
-10, interconnecting conductor plate 11, external leads 12-20
Is obtained based on a lead frame obtained by punching a Cu plate and providing a Ni coating layer on the Cu plate.
g It has been plated.

The conductor plate 11 for interconnection is formed with a projection 25 at a position corresponding to the connection portion of the internal lead wire 22 for emitter connection.
Respectively. Since each protruding portion 25 protrudes in the direction in which the internal lead fine wire 22 extends, each of the support plates 1 to 4
The facing distance between the end face of the projection 25 and the end face of the protruding portion 25 is narrower than the other portions. External leads 12 and 20 are interposed between the second and third support plates 7 and 8 and the protruding portion 25.
Since the interconnecting portions 12a, 20a of the external leads 12, 20 extend linearly between the support plates 7, 8 and the interconnecting conductor plate 11, the interconnecting portions 12a, 20a and the projecting portions 2
Also, the distance between them and 5 is narrower than other portions. In order to equalize the flow of the resin during the resin molding, the interconnections 12a, 20a of the external leads 12, 20 are formed.
And the upper end faces of the support plates 6 and 9 are located on the same straight line.

FIG. 2 is an enlarged view of the vicinity of the third support plate 8 in FIG. The facing distance L5 between the protruding portion 25 and the support plate 8 is set smaller than the facing distance L4 between the lower end surface of the non-protruding portion of the interconnecting conductor plate 11 and the upper end surface of the support plate 8, and Interconnect 20a of lead 20
Is set smaller than the facing distance L2 between the non-projecting portion of the interconnecting conductor plate 11 and the interconnecting portion 20a of the external lead 20. Support plate 8 and interconnect 20a
And a gap between the interconnecting conductor plate 11 and the interconnecting portion 20a of the external lead 20 forms a resin passage. The resin passage below the emitter connecting internal lead fine wire 22 is narrowed by the protruding portion 25.
For this reason, the influence of the resin injection pressure on the internal lead fine wires 22 is small.

If L1 to L4 are set so as to satisfy the conditions of L1≤L2 / 2 and L3≤L4 / 2, the adverse effect of the resin injection pressure on the internal lead fine wires 22 can be effectively reduced.
The sagging of the internal lead fine wires 22 can be effectively prevented. Since this effect is obtained by the protruding portion 25 formed at the same time as the lead frame processing, the product cost does not increase.

FIGS. 3 and 4 show a state in which epoxy resin is injected using the upper mold 26 and the lower mold 27 to form the resin sealing body 24 by transfer molding. Each chip 1-5, each support plate 6-10, interconnecting conductor plate 1
1. When resin is injected from a gate 30 into a cavity (molding space) 29 in which a part of the external leads 12 to 20 are housed and a heat sink 28 is housed, arrows 31
The resin flows as shown by. The gate 30 is provided at a boundary between the upper mold 26 and the lower mold 27. That is, the gate 30 is provided at a position facing the side surface of the resin sealing body 24. Gate 3 adjacent to interconnecting conductor plate 11
The resin injected from zero flows in the same direction as the direction in which the internal lead wires 22 for emitter connection extend. 3 and 4, the arrow 31 indicates the direction of the resin flow and the amount of the resin flow depending on the thickness. When the protruding portion 25 is provided as shown in FIG. 3, the flow of the resin between the protruding portion 25 and the interconnecting portion 20a of the external lead 20 is limited because the opposing interval between the protruding portion 25 and the interconnecting portion 20a is narrow. The adverse effect on the connection internal lead fine wire 22 is reduced. On the other hand, as shown in FIG. 4, in the portion where the protruding portion 25 is not provided, the facing space between the interconnecting conductor plate 11 and the interconnecting portion 20 a of the external lead 20 is sufficiently large, so that the resin flows well.
Since there is a space on the lower surface side of the support plates 6 to 10, the resin also flows from the upper surface side to the lower surface side of the support plates 6 to 10. Since the lower resin layer of the support plates 6 to 10 in the resin sealing body 24 needs to be thinner than the upper resin layer in consideration of heat radiation,
The resin flow is higher on the upper side than on the lower side.

FIGS. 5 to 7 show the fine lead wires 22 inside the emitter.
2 shows wire bonding. First, as shown in FIG.
A ball 34 is formed on the Au wire 33 of μm by electric spark or hydrogen flame, and the ball 34 is pressed on the chip 3 heated to about 200 to 250 ° C. by the capillary 32 as shown in FIG. At this time, ultrasonic vibration is applied to the capillary 32. Thereby, the first bonding of the Au wire 33 is achieved.

Next, after the capillary 32 is moved right above and drawn around largely, as shown in FIG.
Then, the Au wire 33 is pressed against the interconnecting conductor plate 11 by the capillary 32 while applying ultrasonic vibration. A
The u-line 33 is partially melted by the ultrasonic vibration, and the second bonding is achieved. After a while, capillary 32
Is pressed, the Au wire 33 is pulled up, and the Au wire 33 is cut. As a result, a thin internal lead wire 22 for connecting the emitter is obtained.

The wire bonding method shown in FIGS. 5 to 7 is a combination of nail head bonding and stitch bonding in a narrow sense, and is a method belonging to nail head bonding in a broad sense. When the internal lead fine wires 22 are bonded to the chip 3 by nail head bonding in a narrow sense and stitch bonding is performed in a narrow sense on the interconnecting conductor plate 11, as shown in FIG. The height is reduced, and the inner lead fine wires 22 are more likely to come into contact with the interconnecting portions 20a of the outer leads 20. However, in this embodiment, since the flow of the resin is restricted by the protruding portions 25, the contact due to the drooping of the internal lead fine wires 22 is prevented.

In FIGS. 2 to 7, the connection of the internal lead wires 22 to the third power transistor chip 3 has been described. However, the connection of the internal lead wires 22 to the second power transistor chip 2, and the first and fourth power transistor chips 3. The connection of the internal lead wires 22 to the power transistor chips 1 and 4 is performed in the same manner, and the same operation and effect can be obtained.

[0021]

[Modifications] The present invention is not limited to the above-described embodiment, and for example, the following modifications are possible. (1) As shown in FIG. 8 and FIG. 9, a rising portion 25a may be provided at the tip of the protruding portion 25 by press working. Since the rising portion 25a is a portion that may be in contact with the internal lead fine wire 22, it is possible to prevent the internal lead fine wire 22 from sagging here. Further, since the flow of the resin is blocked by the rising portions 25a, the resin flowing down can be restricted, and the effect of preventing the internal lead fine wires 22 from drooping increases. Note that the rising portion 25a may be formed so as to gradually increase from right to left in FIG. 9 to increase the upward force of the resin flow and prevent the internal lead fine wires 22 from sagging. (2) The inner lead wires 21, 22, and 23 may be made of Au alloy other than Au, Cu, Cu alloy wire, or the like. (3) The present invention can also be applied to a case where one end of the internal lead fine wire 22 is bonded to the support plates 6 to 10 or the electrodes on the circuit board without bonding to the chips 1 to 5. (4) The present invention can also be applied to a case where the end face on one side and the end face on the other side are not located on a straight line with respect to the protruding portion 25 of the interconnection conductor plate 11. (5) Connection part 12 between support plates 1-4 and conductor plate 11
The present invention can be applied irrespective of whether or not a and 20a are interposed.

[Brief description of the drawings]

FIG. 1 is a plan view showing a resin-sealed hybrid integrated circuit according to an embodiment of the present invention.

FIG. 2 is an enlarged plan view showing a part of FIG.

FIG. 3 is a cross-sectional view showing a state at the time of molding of a portion corresponding to line AA in FIG. 1;

FIG. 4 is a cross-sectional view showing a state at the time of molding of a portion corresponding to line BB in FIG. 1;

FIG. 5 is a cross-sectional view for explaining a wire bonding method.

FIG. 6 is a sectional view showing a bonding step.

FIG. 7 is a sectional view showing a bonding step.

FIG. 8 is a plan view showing a protrusion and its vicinity in a modified example.

FIG. 9 is a cross-sectional view showing a protruding portion and its vicinity in a modified example.

[Explanation of symbols]

 1-4 Transistor chip 5 IC chip 6-10 Support plate 11 Interconnecting conductor plate 23 Internal lead thin wire 25 Projection

Claims (1)

(57) [Claims] 1. A circuit element; a conductive support plate having one main surface supporting the circuit element and having a linearly extending end face; and extending parallel to the end face of the support plate. The connection conductor plate (11) having an end surface, the circuit element or the support plate and the conductor plate (11) are electrically connected, and the end surface of the support plate and the conductor plate (11) are connected. And an inner lead thin wire (22) disposed so as to pass over the end face of the support plate, and a gap between the end face of the support plate and the end face of the conductor plate (11) is partially reduced. The protruding portion (25) is provided on the conductor plate (11), and the protruding direction of the protruding portion (25) is substantially the same as the extending direction of the thin internal lead (22). The inner lead wire (22) passes over the tip of the protrusion (25) Preparing an assembly in which the position of the protruding portion (25) is determined, and placing the assembly in a molding die (26, 27), and heading toward the circuit element from the protruding portion (25) side. Insulating resin is injected into the molding cavity (29) having a direction and having the same direction as the direction in which the internal lead thin wires (22) extend, and the circuit element and the support plate are formed. One main surface and the other main surface, at least a part of the conductor plate (11), and a resin sealing body (2) covering the internal lead fine wires (22).
And 4) forming a resin-sealed circuit device.