JPH08107164A - Semiconductor device - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve cooling efficiency, reduce mounting space, facilitate height adjustment during assembly, and prevent cracking due to thermal stress. [Structure] A wiring board 7, a seal pad 9 and a board electrode 8 are formed on the wiring board 7. The solder 6 is plated on these.
Heat dissipation cap 3 made of metal with high thermal conductivity in a concave shape
The semiconductor chip 1 is adhered to the depressions with the adhesive 4. The solder 6 is connected to the chip electrode 2 of the semiconductor chip 1 and the seal portion 5 at the end of the heat dissipation cap 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device in which pads of a semiconductor chip and pads of a mother board are connected by a flip chip method, and more particularly to a semiconductor device requiring a heat dissipation cap.

[0002]

2. Description of the Related Art In recent years, there has been a demand for ever-higher computer performance, which has led to semiconductor device
High-power, ultra-multi-pin semiconductor chips mounted in a face-down structure have come to appear.
A flip chip method is generally known as an external wiring connection method for semiconductor chips in this face-down structure. An example of mounting a semiconductor device using this flip chip method is disclosed in Japanese Patent Publication No. 3-47585. In this publication, an example in which one flip chip is mounted on a substrate is shown in FIG. This configuration will be described below with reference to FIG. 5 which is the same as FIG.

Referring to FIG. 5, reference numeral 1 is a flip chip made of a semiconductor chip or the like, and 2 is an adhesive having good heat conductivity, which is a structure for joining the semiconductor chip 1 to the heat radiating metal plate 3. The heat-dissipating metal plate 3 is made of a metal having good thermal conductivity, such as copper, and its shape is substantially the same as the planar shape of the flip chip 1, and is usually formed in a substantially rectangular shape. A positioning recess 12 for the heat-dissipating metal plate 3 is formed on the inner surface of the lid body 6 at a position facing the substantially front surface of the flip chip 1 mounted on the module substrate 9. The positioning recess 12 is formed in a rectangular shape similar to that of the heat-dissipating metal plate 3, and its size is set larger than the size of the heat-dissipating metal plate 3 by the tolerance of the mounting position of the heat-dissipating metal plate 3. There is. Reference numeral 4 is a heat sink, and 5 is an adhesive having good heat conductivity, and is a structure for joining the heat sink 4 to the lid 6. In addition, the lid 6 is attached to the module substrate 9 with an adhesive 7 having good heat conductivity.
Is joined to. The module board 9 has input / output pins 8 on its lower end surface. In addition, the metal plate 3 for heat dissipation
A fine gap 10 is provided between the lid 6 and the lid 6.
The space 10 is filled with a gas 11 having a good heat transfer property such as helium. Flip-chip bonding technology is published on February 10, 1994 by the Industrial Research Institute Co., Ltd. and edited by the Hybrid Microelectronics Association "Electronics Packaging Technology Basic Course" Vol. 1, pp. 267-270. Has been described. According to it, "the element formation surface of the chip and the circuit board are opposed to each other, respective electrodes are aligned, and Sn / Pb
The usual concept was to connect electrically and mechanically via solder bumps.

[0004]

However, such a conventional technique has a problem that the gas 11 must conduct heat and the cooling efficiency cannot be improved. Further, since the heat sink 4 for forced air cooling is formed on the lid body 6 with the adhesive 5,
There is also a problem that the mounting space becomes large. Furthermore, since the lid body 6 and the module substrate 9 are adhered to each other only with the adhesive 7, it is difficult to adjust the height during assembly. If a solder bump is interposed between the semiconductor chip and the mounting substrate, there is a problem that cracks are generated due to thermal stress.

An object of the present invention is to provide a semiconductor device having improved cooling efficiency and reduced mounting space.

Another object of the present invention is to provide a semiconductor device and a method of manufacturing the same which facilitates height adjustment during assembly.

Another object of the present invention is to provide a semiconductor device in which the occurrence of cracks due to thermal stress is reduced.

[0008]

A first semiconductor device of the present invention comprises a semiconductor chip and a metal having a high thermal conductivity, which is adhered by the adhesive so as to house the semiconductor chip in a recess having a concave shape. And a formed heat dissipation cap.

A second semiconductor device of the present invention corresponds to the first semiconductor device, wherein a seal portion provided at an end of the heat dissipation cap, a wiring board, and the seal portion on the wiring board. A seal pad provided at a position and a solder formed to seal the semiconductor chip between the seal pad and the seal portion are included.

A third semiconductor device according to the present invention is the second semiconductor device according to the second semiconductor device, further comprising a protrusion ring formed on the periphery of the central portion of the seal pad, wherein the solder covers the protrusion ring. Is formed in.

According to a fourth semiconductor device of the present invention, in the first semiconductor device, a chip electrode provided on the other surface of the semiconductor chip, a wiring board, and the chip electrode on the wiring board correspond to the chip electrode. And a solder formed between the substrate electrode and the chip electrode.

A fifth semiconductor device of the present invention is the fourth semiconductor device according to the fourth semiconductor device, further comprising a protruding electrode formed on the periphery of the central portion of the substrate electrode, wherein the solder has a drum shape so as to cover the protruding electrode. Is formed in.

According to a sixth semiconductor device of the present invention, a chip electrode provided on the other surface of the semiconductor chip in the first semiconductor device, a seal portion provided at an end of the heat dissipation cap, and a wiring. A substrate, a substrate electrode provided at a position corresponding to the chip electrode on the wiring substrate, a seal pad provided at a position corresponding to the seal portion on the wiring substrate, the seal pad and the seal portion And a solder formed between the chip electrode and the substrate electrode.

A seventh semiconductor device of the present invention is the semiconductor device according to the sixth semiconductor device, wherein the protrusion ring is formed on the periphery of the central portion of the seal pad, and the protrusion is formed on the periphery of the central portion of the substrate electrode. The electrode and the solder are formed in a drum shape so as to cover both the protrusion ring and the protrusion electrode.

[0015]

An embodiment of the present invention will now be described in detail with reference to the drawings.

Referring to FIG. 1, in the first embodiment of the present invention, a semiconductor chip 1, a plurality of semiconductor chips 1 are formed on the surface of the semiconductor chip 1, and copper is used as a material by a plating method to have a thickness of 2-3 μm.
Of the chip electrode 2, which is formed to have a thickness of 2 to 3 microns (μm) and is electrically connected to internal wiring (not shown). 40-80 microns (μm) tin (Sn) -lead (P
b) Solder 6 formed of eutectic solder 6, substrate electrodes 8 formed of copper (Cu) at positions corresponding to the chip electrodes 2, a wiring substrate 7 on which the substrate electrodes 8 are mounted, chips of the semiconductor chip 1 An adhesive 4, which has good thermal conductivity and is applied to the back surface of the electrode 2 mounting surface, made of silver epoxy resin 4, a metal having a high thermal conductivity, such as copper, which is connected by the adhesive 4 and covers the semiconductor chip 1. The formed heat dissipation cap 3, the seal part 5 formed at the end of the heat dissipation cap 3, the solder 6 connected to the seal part 5, and the wiring 6 on the outside of the substrate electrode 8 correspond to the solder 6. The seal pad 9 is formed at the above position.

The chip electrodes 2 have a pitch of 200 to 400 μm (μm) and a pad diameter of 150 to 300 μm (μm).
m), and copper (Cu) having a thickness of 2 to 3 microns (μm)
And 2-3 microns (μm) of nickel (Ni) is formed on the copper (Cu).

Next, the manufacturing method of the first embodiment of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 2A, substrate electrodes 8 made of copper (Cu) are formed on the wiring substrate 7 at positions corresponding to the chip electrodes 2 of the semiconductor chip 1. On the substrate electrode 8, a solder 6 having a diameter of 150 to 300 μm (μm) and being approximately matched to the size of the chip electrode 2 is formed.

A seal pad 9 made of copper (Cu) is formed on the wiring substrate 7 outside the substrate electrode 8 at a position corresponding to the seal portion 5 of the heat dissipation cap 3. The solder 6 similar to the solder 6 formed on the substrate electrode 8 is formed on the seal pad 9. This solder is formed by making a mask or the like and transferring the image to the substrate by the mask as a main means of reducing the photograph, repeating the pattern, CA.
D, a so-called photolithography method or electrolytic or electroless plating method, which is a series of methods such as the latest electron beam method.

Referring to FIG. 2B, a semiconductor device 6 having a flip chip structure is shown. The solder 6 is made of, for example, tin (Sn) -lead (Pb) eutectic solder. After the solder is plated, the plating resist film is peeled off, and then the solder is melt-shaped (wet back) to form the spherical solder 6.

Referring to FIG. 2C, the heat dissipation cap 3 made of copper (Cu) is formed in a recessed shape capable of accommodating the semiconductor chip 1. Sealing portions 5 having a shape corresponding to the seal pads 9 of the wiring board 7 are formed at both ends of the heat dissipation cap 3. Solder 6 is formed on the seal portion 5. The adhesive 4 for fixing the back surface of the semiconductor chip 1 is dropped from the nozzle of the dispenser inside the concave portion of the heat dissipation cap 3.

The process of connecting the semiconductor chip 1 and the heat dissipation cap 3 will be described with reference to FIG.

As shown in FIG. 2 (C), after the concave portion of the heat dissipation cap 3 is turned upward and an appropriate amount of the adhesive 4 is dropped from the nozzle of the dispenser, as shown in FIG. 2 (D), the semiconductor is removed. It is fixed by vacuum suction so that the solder 6 of the chip 1 faces upward, and is lowered into the recess.

Next, after contact pressure is applied with the adhesive 4, 1
The adhesive 4 is heated at a temperature of 70 to 200 ° C. for 1 to 2 hours.
The heat dissipation cap 3 and the semiconductor chip 1 are connected via the.

At the time of this connection, the alignment is performed optically.

This connection step can be carried out in either an oxygen or nitrogen atmosphere, but it is more suitable to make a connection in a nitrogen atmosphere because solder oxidation can be prevented.

The seal portion 5 and the lower surface of the semiconductor chip 1 are parallel to each other and are kept at substantially the same height.

Referring to FIG. 2E, the semiconductor chip 1
Shows the state of being fixed to the heat dissipation cap 3.

Referring to FIG. 2 (F), the back surface of the heat dissipation cap 3 is fixed by vacuum suction in the fixed state shown in FIG. 2 (E). The alignment of the board electrode 8 of the wiring board 7 and the seal pad 9 with the solder 6 is performed optically. Next, the heat dissipation cap 3 to which the semiconductor chip 1 is fixed is lowered to bring the solder 6 of the chip electrode 2 and the solder 6 of the seal pad 9 into contact with each other and heat them in a nitrogen atmosphere.

This manufacturing method has an effect that the chip electrode 2 and the substrate electrode 8 and the seal portion 5 and the seal pad 9 are simultaneously connected.

Next, a second embodiment of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 3, one of the features of the second embodiment of the present invention is that the protruding electrode 10 is connected to the substrate electrode 8 of the wiring substrate 7. The protruding electrode 10 has a diameter of 50.
Columnar copper (Cu) having a height of about 100 microns (μm) and a height of 50 to 70 microns (μm), and nickel (Ni) formed on the surface of the copper (Cu) with a thickness of 2 to 3 microns (μm). ), A gold plating (Au) formed on the surface of the nickel (Ni) with a thickness of 2 to 3 μm (μm), and 10 to 15 μm (μ) on the gold plating (Au).
It is formed by tin (Sn) -lead (Pb) eutectic solder plating having a thickness of m).

Another one of the features of the second embodiment of the present invention is the protruding ring 11 formed on the silver pad 9. The protrusion ring 11 has a width of 500 to 700 microns (μm), and other diameters, heights, material configurations, etc. are the same as those of the protrusion electrode 10. The solder 6 on the chip electrode 2 in the second embodiment has a thickness of 4 in the first embodiment.
10 to 15 microns (μm) is sufficient for 0 to 80 microns (μm).

The other structure is the same as the corresponding structure of the first embodiment.

The protruding electrode 10 according to the second embodiment.
Is connected to the substrate electrode 8 side, but the modification of the second embodiment is characterized in that the protruding electrode 10 is connected to the chip electrode 2. The other components in the modification are the same as the other components in the second embodiment.

Next, a manufacturing method according to the second embodiment of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 4A, substrate electrodes 8 made of copper (Cu) are formed on the wiring substrate 7 at positions corresponding to the chip electrodes 2 of the semiconductor chip 1.

A protruding electrode 10 made of copper (Cu) is formed on the substrate electrode 8.

A seal pad 9 made of copper (Cu) is formed on the wiring substrate 7 outside the substrate electrode 8 at a position corresponding to the seal portion 5 of the heat dissipation cap 3.

Copper (Cu) is also formed on the seal pad 9.
The protrusion ring 11 is formed.

The projection electrodes 10 and the projection rings 11 are formed by the photolithography method or the plating method as in the case of forming the solder in the first embodiment.

Referring to FIG. 4B, for example, tin (Sn) -lead (Pb) is formed on the seal pad 9, the protrusion ring 1, the substrate electrode 8 and the protrusion electrode 10 shown in FIG. 4A.
Solder 6, such as eutectic solder, is plated.

Referring to FIG. 4C, when the solder 6 shown in FIG.
(E) Semiconductor chip 1 and heat dissipation cap 3
The back surface of the heat radiating cap 3 is fixed by vacuum suction while being fixed. Projection ring 11 and projection electrode 10
The upper solder 6 is aligned with the chip electrode 2 and the solder 6 on the seal portion 5 optically.

Next, the heat dissipating cap 3 to which the semiconductor chip 1 is fixed is lowered and the projecting ring 11 and the projecting electrode 10 are removed.
The upper solder 6 is brought into contact with the chip electrode 2 and the solder 6 on the seal portion 5, and is heated in a nitrogen atmosphere.

This manufacturing method has an effect that the chip electrode 2 and the protruding electrode 10 and the seal portion 5 and the protruding ring 11 are simultaneously connected.

The second embodiment of the present invention is assembled by combining the seal pad 9, the projection ring 11, the solder 6, and the seal portion 5, and the combination of the substrate electrode 8, the projection electrode 10, the solder 6 and the chip electrode 2. In this case, there is an effect that the height can be easily adjusted.

In addition, this second embodiment has a projection ring 11
By forming the solder 6 in a drum shape with the protruding electrode 10 as the core, it is possible to reduce the occurrence of cracks due to thermal stress.

[0049]

According to the present invention, since the heat dissipation cap is formed in a concave shape so as to cover the semiconductor chip with a metal having a high thermal conductivity, it is not necessary to mount a heat sink on the heat dissipation cap 1 and cooling efficiency is improved. There is an effect that it can be improved and the mounting space can be reduced.

Further, according to the present invention, the heat dissipation cap and the wiring board 7 are provided.
By interposing at least a seal portion, a combination of solder and a seal pad, and a combination of a chip electrode solder and a substrate electrode between and, it is possible to easily adjust the height when assembling the semiconductor device of the present invention. There is.

Further, the present invention has an effect that the generation of cracks due to thermal stress can be extremely reduced by forming the protrusion ring or the protrusion electrode in the core and forming the drum-shaped solder in the core.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

2A to 2F are views for explaining the manufacturing method according to the first embodiment of the present invention.

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

4A to 4C are views for explaining a manufacturing method according to a second embodiment of the present invention.

FIG. 5 is a diagram showing an example of a conventional technique.

[Explanation of symbols]

 1 Semiconductor Chip 2 Chip Electrode 3 Heat Dissipation Cap 4 Adhesive 5 Sealing Part 6 Solder 7 Motherboard 8 Substrate Electrode 9 Seal Pad 10 Projection Electrode 11 Projection Ring

Claims (3)

[Claims] 1. A semiconductor device comprising: a semiconductor chip; and a heat dissipation cap formed of a metal having a high thermal conductivity, which is adhered with the adhesive so as to accommodate the semiconductor chip in a concave recess. apparatus. 2. A seal portion provided at an end portion of the heat dissipation cap, a wiring board, a seal pad provided at a position on the wiring board corresponding to the seal portion, the seal pad and the seal portion. The semiconductor device according to claim 1, further comprising: a solder formed so as to hermetically seal the semiconductor chip. 3. The semiconductor device according to claim 2, further comprising a protrusion ring formed on a periphery of a central portion of the seal pad, wherein the solder is formed in a drum shape so as to cover the protrusion ring. .