JP2770664B2 - Semiconductor device and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a method for manufacturing the same, and more particularly, to a semiconductor device with high density mounting and low thermal resistance and a method for manufacturing the same.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view showing a conventional semiconductor device. In FIG. 4, a semiconductor chip 1 is bonded to a heat sink / cap 16 via an adhesive 2 such as Ag paste. Are hermetically sealed by seam welding. The semiconductor chip 1 and the substrate 4 are relatively positioned by a silicon rubber 17 and are electrically connected by a TAB 5.

Next, a method of manufacturing a semiconductor device having this structure will be described.

First, a TAB 5 is connected to a semiconductor chip. Next, the external lead portion of the TAB 5 is cut to an appropriate length, and is TAB-connected to the internal terminal 11 of the substrate 4 to which a silicon rubber 17 smaller than the semiconductor chip is adhered at the center. At this time, the height of the semiconductor chip is determined in accordance with the thickness of the silicon rubber.

Next, an Ag paste is applied to the back surface of the semiconductor chip 1 and a cap / heat radiating plate 16 is put on the paste to connect the semiconductor chip and the cap. After the Ag paste has cured,
A semiconductor device is obtained by sealing between the outer periphery of the cap and the ceiling 15 on the substrate by seam welding.

When a functional component such as a chip capacitor is mounted in a semiconductor device, the substrate 4 has a concave portion 1 for mounting the functional component.
9 and the functional component 13 was mounted.

[0007]

SUMMARY OF THE INVENTION In a conventional semiconductor device, heat is radiated from a semiconductor chip through a back surface → Ag paste → cap. TAB in conventional semiconductor devices
The semiconductor chip supported by the lead and the silicon rubber is connected to the cap and heat radiating plate. At this time, the height of the back surface of the semiconductor chip depends on the inclination of the semiconductor chip, the thickness of the silicon rubber, and the state of adhesion to the substrate. Due to the variation, the adhesive A between the semiconductor chip and the cap / radiator plate
The thickness of the g paste after bonding varies. Or, the bonding between the semiconductor chip and the cap / radiator plate may be incomplete due to voids, peeling, and the like, so that the thermal resistance increases, the temperature of the semiconductor chip during operation increases, and the semiconductor device stops operating, or There was a problem that the semiconductor chip was destroyed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor device having high-density mounting and low thermal resistance, and a method of manufacturing the same.

[0009]

According to a first aspect of the present invention, there is provided a semiconductor device according to the present invention, wherein a cap / heat radiator is divided into a heat radiator and a ring-shaped cap and a semiconductor chip is bonded. The configuration is characterized in that the distance between the terminal rows of the TAB electrodes for electrically connecting the semiconductor device and the internal terminals of the substrate is larger than the outer diameter, and that the sealing cap is ring-shaped.

According to a second aspect of the present invention, in a method of manufacturing a semiconductor device, the semiconductor chip and the substrate are electrically connected to each other after the semiconductor chip is securely bonded to the heat sink, and then the ring-shaped cap is placed thereon. It is characterized by hermetically sealing.

[0011]

Since the distance between the electrode terminal rows for connection to the substrate is larger than the outer shape of the heat sink, the semiconductor chip can be connected to the substrate after the semiconductor chip is securely bonded to the heat sink, and the desired electric power can be obtained. Characteristics and thermal resistance can be obtained with good reproducibility.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a semiconductor device according to one embodiment of the present invention.

In FIG. 1, a semiconductor chip 1 is joined to a heat sink 3 via an adhesive 2 having good thermal conductivity. The heat radiating plate 3 is made of a material having good heat conductivity such as AlN ceramic, and has a recess 7 for mounting a semiconductor chip, a seal ring 8 for seam welding, and legs 9 for attachment to the substrate 4 at four corners thereof. A height adjusting spacer 10 is provided at the tip of the leg.

Electrical connection between the semiconductor chip 1 and the substrate 4 is made by TAB 5, and the substrate 4 is made of, for example, Al ₂ O.
The connection between the internal terminal 11 and the external terminal 12 and the mounting of the functional component 13 such as a chip capacitor, which are formed by the _three laminated ceramic multilayer wiring boards, are also possible without a complicated structure for forming the component mounting recess.

Further, the semiconductor device of this embodiment uses the ring-shaped cap 6 and hermetically seals the inner and outer circumferences by seam welding.

A method of manufacturing the semiconductor device having the above-described structure will be described with reference to FIG.

First, the semiconductor chip 1 is die-mounted on the heat sink 3 via the adhesive 2. Here, the adhesive 2 is preferably an adhesive having good heat conductivity such as an Ag paste. This state is shown in FIG. Since this die mounting process can be realized by a conventional die mounting technology for a lead frame or a ceramic case in a semiconductor device, it is possible to secure a reliable bonding and a heat radiation path. In the conventional semiconductor device, the thickness of the adhesive has a large variation of 30 to 100 μm, but realizes 20 + 15 to 20-5 μm.

Next, the bump 18 of the semiconductor chip 1
After connecting the internal terminals of B5 and connecting the suspender section 14 of TAB to the heat sink 3, external terminals of TAB5 are formed. This state is shown in FIG. The depth of the recess 7 for mounting the semiconductor chip of the heat sink 3 is such that the TAB lead from the bump 18 to the suspender 14 is horizontal with the surface of the semiconductor chip 1 when the suspender 14 of the TAB 5 is bonded to the heat sink 3. Set to. For example, the semiconductor chip thickness T
c = 400 μm, TAB5 suspender thickness Ts = 200
When the thickness of the adhesive 2 and the height of the bump 18 are 100 μm in total, the digging depth H is H = Tc.
It is appropriate that −Ts + 100 = 300 (μm).

Next, the heat sink 3 is supported, the internal terminals 11 of the board 4 and the external terminals of the TAB 5 are aligned and connected, and the legs 9 of the heat sink are fixed to the board 4. This state is shown in FIG. Here, since the distance (e _L ) between the external terminal rows of the TAB 5 is larger than the outer shape (e _H ) of the heat sink 3,
The heat sink 3 is supported and can be connected to the substrate 4 by a conventional TAB mounting technique. Also, the suspender section 14 of TAB5
Is fixed, the stress applied to the bump 18 can be reduced, and the TAB connection is prevented from being incomplete.

Next, the ring-shaped cap 6 is covered and seam-welded to the ceiling 8.

Next, the ring-shaped cap 6 and the sealing 15
Seam welding. Here, it is possible to absorb the variation in the position of the ring-shaped cap 6 and the sealing 15 in the height direction with the height adjusting spacer 10 and to seal it. For example, the height adjusting spacer 10 is made of a material having heat resistance and flexibility of about 400 ° C. such as silicon rubber.

The semiconductor device of this embodiment is obtained by the above-described manufacturing steps.

FIG. 3 is a sectional view showing a second embodiment of the present invention.

In the figure, a semiconductor chip 1 is joined to a heat sink 3 via an adhesive 2 having good thermal conductivity. The heat radiating plate 3 is made of a material having good thermal conductivity, such as AlN ceramic, and has a concave portion 7 for mounting a semiconductor chip, an Au or Sn or solder plating pattern 20 for brazing and sealing, and a leg portion for attaching to the substrate 4. 9 is provided.

The electrical connection between the semiconductor chip 1 and the substrate 4 is made by TAB 5, and the substrate 4 is made of, for example, Al ₂
It is possible to connect the internal terminal 11 to the external terminal 12 and mount the functional component 13 such as a chip capacitor, which is formed of an O ₃ laminated ceramic multilayer wiring board. Alternatively, a plating pattern 21 of Sn or solder is provided.

Further, in the semiconductor device of this embodiment, the inner periphery and the outer periphery are brazed and sealed with low-melting metal brazing materials 22 and 23 such as solder using the ring-shaped cap 6.

A method of manufacturing the semiconductor device having the above-described configuration will be described.

The semiconductor chip 1 is manufactured by the same manufacturing method as in the first embodiment from the die mounting step to the attachment of the heat sink 3 to the substrate 4 and the connection of the external terminals of the TAB 5 to the internal terminals 11 of the substrate. .

Next, a low melting point metal 22 is disposed on the plating pattern 20 and a low melting point metal
After disposing 3, a ring-shaped cap 6 is put on and the whole semiconductor device is heated and sealed by brazing. At this time, similarly to the inner peripheral portion of the ring-shaped cap 6 and the plating pattern 20, the variation in the position in the height direction between the outer peripheral portion of the ring-shaped cap 6 and the plating pattern 21 is absorbed by the thickness of the low melting point metal.

The semiconductor device of the present embodiment is obtained by the above manufacturing steps.

The structure of the semiconductor device of this embodiment is simpler than that of the first embodiment because there is no spacer for height adjustment. Furthermore, in the first embodiment, the sealing of the ring-shaped cap 6 requires two steps for separately seam-welding the inner circumference and the outer circumference. However, in the present embodiment, the sealing is completed in one step. The process can be shortened.

[0033]

As described above, according to the present invention, the semiconductor chip and the heat radiating plate are securely joined by the prior art, and the heat radiating path of the heat generated by the semiconductor chip is stably secured. Since the semiconductor device can be electrically connected and sealed, it is possible to easily realize a uniform semiconductor device having high heat radiation performance.

In addition, since the silicon rubber for positioning the semiconductor chip is not used, a space corresponding to the silicon rubber is created, and the space can be used to mount a functional component such as a chip capacitor. Since a substrate having a structure can be used, parts costs can be reduced, and the entire semiconductor device can be densified.

[Brief description of the drawings]

FIG. 1 is a sectional view of one embodiment of the present invention.

FIG. 2 is a cross-sectional view in each assembly process of one embodiment of the present invention.

FIG. 3 is a sectional view of a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of a conventional semiconductor device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Semiconductor chip 2 Adhesive 3 Heat sink 4 Substrate 5 TAB 6 Cap 7 Semiconductor chip mounting recess 8 Seal ring 9 Leg 10 Height adjustment spacer 11 Internal terminal 12 External terminal 13 Functional component 14 TAB suspender 15 Seal ring 16 Heat sink and cap 17 Silicon rubber 18 Bump 19 Depression for mounting functional components 20 Plating pattern 21 Plating pattern 22 Row material 23 Row material e _L Distance between external terminal rows e _H External shape of heat sink

Claims (4)

(57) [Claims] 1. A substrate, a semiconductor chip TAB-connected to the substrate, a radiator plate joined in one direction of the semiconductor chip, and a ring-shaped cap attached to the substrate so as to cover the semiconductor chip. In the semiconductor device, the outer shape of the heat radiating plate is smaller than the distance between the external terminal rows of the TAB, and the heat radiating plate is made of a metal or ceramic having better heat conductivity than alumina ceramics. A semiconductor device having legs at four corners of a mounting surface of the plate on which the semiconductor chip is mounted. 2. A heat sink having a semiconductor chip mounting concave portion on a semiconductor chip mounting surface, a semiconductor chip mounted in the concave portion of the heat sink, and a TAB suspender bonded to the convex portion. The semiconductor device according to claim 1. 3. A heat radiating plate made of metal or ceramics having better heat conduction than alumina ceramic, and having legs at four corners of a semiconductor chip mounting surface of the heat radiating plate.
3. The semiconductor device according to claim 1, wherein said leg has a height adjusting spacer. 4. A substrate, a semiconductor chip TAB-connected to the substrate, a heat sink joined in one direction to the semiconductor chip, and a ring-shaped cap attached to the substrate so as to cover the semiconductor chip. A method for manufacturing a semiconductor device, comprising: a step of bonding the semiconductor chip to a heat sink; a step of electrically connecting a semiconductor chip and a substrate connected to the heat sink by TAB; A step of covering the heat sink with a heat sink and seam-welding both end faces of the ring-shaped cap through a seal ring to hermetically seal the semiconductor device.