JPH08255811A - Connection device of electronic part - Google Patents

Abstract

PURPOSE: To enable an electronic part excellent in noise resistance to be connected without using a noise eliminating part. CONSTITUTION: A wiring pattern 12 is formed on an insulating board 11 by etching and fixed for the formation of a wiring board 13. A semiconductor chip 16 possessed of bonding pads 14 each provided with a bump 15 is mounted on the wiring board 13 at a prescribed position with conductive adhesive agent 17 facing downward. Epoxy resin or the like where insulating magnetic powder 18 is dispersed and mixed is filled in a gap between the semiconductor chip 16 and the wiring board 13 covering the side face of the semiconductor chip 16. As the bonding pads 14 of the semiconductor chip 16 are sealed up in the epoxy resin mixed with magnetic powder 18, radiation noises generated from the bonding pad 14 are absorbed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flip chip electronic component connecting device for connecting a semiconductor chip or a composite component having a flat surface to a wiring substrate by face down.

[0002]

2. Description of the Related Art In recent years, with the progress of advanced information society,
In the communication field, mobile communication devices such as mobile phones have rapidly spread, and data communication and image communication have been developed. It is expected that these devices will continue to have higher speeds, higher functionality, and higher frequencies in the future, and the miniaturization of devices will also progress rapidly. In order to cope with these, particularly as a method of mounting a semiconductor on a wiring board, flip-chip connection in which a semiconductor chip is connected to the wiring board face down is used as a mounting method effective for downsizing and speeding up.

A conventional method for connecting flip-chip components will be described with reference to FIG. A wiring pattern 2 such as copper formed by an etching method or the like is fixed on an insulating substrate 1 such as alumina or glass epoxy to form a wiring substrate 3. A semiconductor chip 6 having metal bumps (bumps) 5 such as solder formed on the bonding pad 4 is connected face down using a method such as a reflow soldering method or a thermocompression bonding method, and finally the moisture resistance of the semiconductor chip 6 is obtained. The resin 7 such as epoxy is used for sealing for the purpose of improving the mechanical properties and the mechanical strength.

In particular, noise is a problem in high-speed and high-frequency circuits such as communication equipment. Wiring pattern 2 such as a signal line drawn from the semiconductor chip 6
However, it is known to act as an antenna for radiation noise. In the high frequency region of 10 MHz or more, the coupling in the space rapidly increases, so that the coupling from the high frequency circuit easily emits noise to the power supply system.

As a countermeasure against such noise, as shown in FIG. 7, a ferrite bead filter 8 is connected in series to a wiring pattern 2 such as a signal line drawn from a semiconductor chip 6. Is being done. The magnetic permeability of ferrite at high frequencies can be expressed as a complex quantity, but as the frequency increases, a dispersion phenomenon of the magnetic permeability μ ′ component occurs and its value decreases. Along with that, the magnetic permeability μ ″, which is the imaginary part, becomes relatively high, and μ ″
The core loss (tan δ) represented by / μ 'increases. By utilizing this, high-frequency conduction noise is induced in the ferrite core by the μ ′ component, and the induced high-frequency noise is absorbed in the core by the μ ″ component to suppress radiation noise.

In FIG. 7, the chip-type ferrite bead filter 8 has been described as an example.
The same effect can be obtained by using a capacitor and an inductor. In this case, generally, there are many cases in which a filter including a capacitor and an inductor is configured and used.

As described above, countermeasures against noise are indispensable in high-speed and high-frequency circuits, and conventionally, such measures have been taken by using noise removing parts for suppressing noise. Therefore, even if the semiconductor chips 6 are mounted at high density using the flip-chip mounting method, there is a limit to the size reduction of the circuit board due to the increase in the number of parts, which hinders the size reduction of communication devices and the like. Further, not only in the mounting structure of the semiconductor chip 6, but also in high-speed and high-frequency circuits,
Other electronic parts also had the same problem.

[0008]

In the above-mentioned conventional connecting device for electronic parts, it is not possible to prevent the generation of noise, and it is necessary to use a noise removing part in addition to the desired circuit. There was a problem that it hinders miniaturization.

An object of the present invention is to provide a connecting device for electronic parts which is excellent in noise resistance without using noise removing parts.

[0010]

An electronic component connecting device according to the present invention is a wiring board having a circuit pattern fixed to an insulating substrate, and a bonding pad for electrically connecting a main surface to a desired portion of the circuit pattern. An electronic component having, and a connecting member for electrically connecting the electronic component to a desired portion of the circuit pattern by face down,
It is characterized by comprising a shield member arranged in a gap between the electronic component and the wiring board for absorbing or reflecting radio waves.

[0011]

With the above structure, the periphery of the bonding pad of the electronic component is covered with the insulating shield member, so that the radiation noise generated from the bonding pad of the high frequency electronic component can be absorbed. As a result, it is possible to realize a small-sized electronic component connecting device having excellent noise resistance without using a new noise removing component.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a block diagram for explaining an embodiment of the present invention. In FIG. 1, a wiring pattern 12 made of copper or the like formed on an insulating substrate 11 made of alumina, glass epoxy resin or the like by an etching method or the like.
Are fixed to form the wiring board 13. Next, a semiconductor chip 16 in which bumps 15 of gold or the like are formed on the bonding pads 14 by a plating method, a ball bump method, or the like,
The conductive adhesive 17 is used to connect the wiring board 13 at a predetermined position face down. After that, the gap between the semiconductor chip 16 and the wiring board 13 and the side surface of the semiconductor chip 16 are covered with a sealing resin 19 such as an epoxy resin in which a magnetic powder 18 having an insulating property such as ferrite is dispersed and mixed. Then, sealing is performed.

By adopting such a connection structure, the periphery of the bonding pad 14 of the semiconductor chip 16 is covered with the magnetic powder 18 having an insulating property. Therefore, for example, when a high frequency semiconductor chip is used, the bonding pad 14 is used. Radiation noise generated from the above can be absorbed by the magnetic powder 18 dispersed / mixed in the sealing resin 19 based on the principle of ferrite noise absorption described in the conventional example.
In addition, when one semiconductor chip is composed of a plurality of circuit blocks, in addition to the radiation noise generated from the bonding pad, an effect of preventing interference between the circuit blocks can be obtained.

Here, the results of experiments on the noise absorption effect of ferrite will be described. 50MHz ~ 1800MH
The input / output terminals for the high frequency signal of z were terminated with a characteristic impedance of 50Ω, respectively, and the input terminal and the output terminal were arranged with a distance of about 20 mm. The noise removal effect was investigated by surrounding the one end only on one surface and surrounding it with a metal plate, and arranging the object to be measured at the opening.

When the epoxy resin in which ferrite powder is dispersed and mixed is arranged with a thickness of about 1 mm, the noise level can be reduced by about 10 dB especially at 900 MHz or more as compared with the released state. When a ferrite sintered body having a thickness of about 1 mm is arranged, it is about 10 d at 1 GHz or less.
It was possible to reduce the B noise level, and no effect was obtained in the higher frequency region.

This is because the ferrite of the sintered body usually has a magnetic permeability of 600 to 1000, whereas in the case of powder-form ferrite, it is significantly reduced to about 10, so that the noise absorption effect is μ (magnetic permeability) × Since the relationship of f (frequency) = constant was established, the effect was exhibited in the powder band shape in the GHz band and in the sintered body in the MHz band.

In the structure of this embodiment, since the ferrite is in the form of powder, a larger noise absorbing effect can be obtained especially in the high frequency region of the GHz band.
When considering the whole shield, a sufficient shield effect can be obtained by using it together with a simple shield structure such as covering with a metal cap.

Here, the size of the magnetic powder 18 dispersed / mixed in the sealing resin 19 varies depending on the height of the bump 15, but in consideration of the fluidity of the sealing resin 19, the bump 1
A particle size of about 1/3 or less of the height of 5 is desirable. Further, the larger the ratio of the magnetic powder 18 mixed into the sealing resin 19, the higher the noise absorbing effect, but it is necessary to suppress the fluidity of the sealing resin 19 to the extent that it is not impaired.

Further, in this embodiment, the conductive adhesive 17 is used as the connecting method of the semiconductor chip 16, but the connecting method is not limited to this, and for example, solder connection using solder bumps or sealing is performed. Any connection method may be used, such as connection by pressure contact using the shrinkage force of the resin.

Next, another embodiment of the present invention will be described with reference to FIG. A wiring pattern 12 such as copper formed by an etching method or the like is fixed on an insulating substrate 11 such as alumina or glass epoxy to form a wiring substrate 13. Further, a semiconductor chip 16 having bumps 15 made of gold or the like formed on the bonding pads 14 by a plating method, a ball bump method or the like is connected to a predetermined position of the wiring board 13 face down by a conductive adhesive 17.

At this time, an insulating magnetic thin plate 21 such as ferrite having an opening 20 at a position facing the bonding pad 14 of the semiconductor chip 16 shown in FIG.
Is interposed between the semiconductor chip 16 and the wiring board 13,
Through the opening 20 formed in the magnetic thin plate 21, the semiconductor chip 16 and the wiring board 13 are electrically connected.
When making this connection, if the opening 20 is filled with a conductive material such as a conductive adhesive in advance by a printing method or the like, more reliable connection can be achieved. After that,
A sealing resin 19 such as an epoxy resin is used to perform sealing so as to cover the gap between the semiconductor chip 16 and the wiring board 13 and the side surface of the semiconductor chip 16.

By adopting such a connection structure, it is possible to obtain the same effect as that of the above-mentioned embodiment, but since a thin plate-like ferrite is used here, especially from the above-mentioned experimental results, a larger value is obtained in the MHz band. The effect is obtained.

FIG. 4 is a sectional view for explaining another embodiment of the present invention. This embodiment is different from the embodiment of FIG. 2 in that the magnetic thin plate having an insulating property is changed, and a magnetic film is formed on the wiring board.

In FIG. 4, a magnetic film 4 having an insulating property such as ferrite is formed by a printing method or the like on a portion other than the land portion to which the semiconductor chip 16 is connected on the wiring substrate 13.
1 is formed. Next, a semiconductor chip 16 having bumps 15 made of gold or the like formed on the bonding pads 14 by a plating method, a ball bump method or the like is connected face down to a predetermined position of the wiring board 13 by a conductive adhesive 17. Finally, a sealing resin 19 such as an epoxy resin is used for sealing so as to cover the gap between the semiconductor chip 16 and the wiring board 13 and the side surface of the semiconductor chip 16.

With such a structure, the same effects as those of the above-described embodiments can be obtained. Although the magnetic film 41 is formed on the wiring substrate 13 here, it may be formed on the semiconductor chip by a printing method or the like.

In each of the above-described embodiments, the conductive adhesive 17 is used as the method of connecting the semiconductor chips 16, but
The connection method is not limited to this, and connection by soldering is also possible, and the connection method is not limited to this. In each of the embodiments, an example in which a magnetic material having an insulating property is interposed between the semiconductor chip 16 and the wiring board 13 has been described. The effect of preventing radiation noise can be obtained even by interposing.

FIG. 5 shows still another embodiment of the present invention. In this embodiment, a radio wave absorbing member is attached to a connecting member for connecting the semiconductor chip 16 and the wiring board 13.

That is, the semiconductor chip 16 is connected to the wiring board 1
3, on the surface of the metal powder 53 such as gold or solder dispersed in the insulating layer 52 such as epoxy resin shown in FIG.
Connection is made by a thermocompression bonding method or the like with an anisotropic conductive film 51 having a magnetic film 54 having an insulating property such as ferrite deposited by a deposition method or the like interposed. The electrical connection between the semiconductor chip 16 and the wiring substrate 13 is made by destroying a part of the magnetic film 54 deposited on the surface of the metal powder 53 by applying pressure to expose the metal part. I do.

By adopting such a connection structure, the periphery of the bonding pad 14 of the semiconductor chip 16 is covered with the magnetic film 54 having an insulating property, so that the same effect as each of the above-described embodiments can be obtained. it can.

Although the magnetic substance film 54 is formed on the surface of the metal powder here, a magnetic substance fine powder or a magnetic substance film in which the magnetic substance fine powder is mixed in the insulating resin is coated on the surface of the metal powder. The same effect can be obtained by wearing it. This is also possible when the connection is made only with the metal powder without using the anisotropic conductive film as the connecting member, and the same effect can be obtained.

Although each of the above-described embodiments has been described by taking the semiconductor chip as an example, for example, the surface has flatness,
Moreover, even if it is a composite component such as a device-embedded substrate having a pad for connection with a wiring substrate on the surface, the same structure and effect can be obtained, and the electronic component used is not limited to the semiconductor chip.

With such a structure, since the radio wave absorbing member or the radio wave reflecting member is arranged around the connection terminal portion of the electronic component such as the semiconductor chip, the radiation noise generated from the connection terminal portion can be absorbed. Therefore, it is possible to obtain a connection of a small electronic component having excellent electric characteristics.

[0033]

As described above, according to the electronic component connecting device of the present invention, it is possible to obtain a connection of a small electronic component having excellent electric characteristics without using a noise removing component.

[Brief description of drawings]

FIG. 1 is a sectional view for explaining an embodiment of the present invention.

FIG. 2 is a sectional view for explaining another embodiment of the present invention.

FIG. 3 is a perspective view for explaining components of a main part of FIG.

FIG. 4 is a sectional view for explaining another embodiment of the present invention.

FIG. 5 is a sectional view for explaining still another embodiment of the present invention.

FIG. 6 is an enlarged sectional view showing a part of a main part of the embodiment shown in FIG.

FIG. 7 is a sectional view for explaining a conventional method for connecting flip-chip components.

[Explanation of symbols]

11 ... Insulating substrate, 12 ... Wiring pattern, 13 ... Wiring substrate, 14 ... Bonding pad, 15 ... Bump, 16 ...
Semiconductor chip, 17 ... Conductive adhesive, 18 ... Magnetic powder, 19 ... Sealing resin, 20 ... Opening part, 21 ... Magnetic thin plate, 41 ... Magnetic film, 51 ... An anisotropic conductive film.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Shinpei Yoshioka, 8 Shinshinsita-cho, Isogo-ku, Yokohama, Kanagawa Prefecture

Claims (13)

[Claims] 1. A wiring board formed by fixing a circuit pattern to an insulating substrate, an electronic component having a bonding pad on its main surface for electrically connecting to a desired portion of the circuit pattern, and a face down A connection member for electrically connecting the electronic component to a desired portion of the circuit pattern, and a shield member disposed in a gap between the electronic component and the wiring board for absorbing or reflecting a radio wave. A connecting device for electronic parts, which is characterized in that 2. The electronic component according to claim 1, wherein the shield member for absorbing the radio waves is dispersed and arranged in a fixing member for fixing the electronic component to the wiring board. Connection device. 3. The shield member for absorbing or reflecting radio waves is formed in a film shape on or inside the wiring board at least at a position where the electronic component is mounted. The device for connecting electronic components according to claim 1. 4. The electronic component connecting device according to claim 1, wherein the shield member for absorbing or reflecting the radio wave is formed in a film shape on or inside the electronic component. 5. The electronic component according to claim 1, wherein the shield member for absorbing or reflecting the radio wave is provided as a thin plate member between the wiring board and the electronic component. Connection device. 6. The shield member formed in the shape of a film or a thin plate has an opening at a position corresponding to a bonding pad portion of the electronic component. The connection device for an electronic component according to claim 4 or claim 5. 7. The electronic component connecting device according to claim 1, wherein the shield member for absorbing the radio wave is adhered to the connecting member. 8. The electronic component connecting device according to claim 7, wherein the connecting member is a metal powder. 9. The connecting device for electronic parts according to claim 1, wherein the shield member for absorbing the radio wave is a magnetic material having an insulating property. 10. The semiconductor chip connecting device according to claim 10, wherein the magnetic material having an insulating property is ferrite. 11. The electronic component connecting device according to claim 1, wherein the shield member for reflecting the radio wave is a metal having a reference potential. 12. The electronic component connecting device according to claim 1, wherein the electronic component is a semiconductor chip. 13. The electronic component connecting device according to claim 1, wherein the electronic component is a composite component having a plurality of elements.