JP2532126B2 - Waveguide type film carrier and its terminal connection method - Google Patents

Description

The present invention relates to a waveguide type film carrier used for mounting a high frequency microwave device and a terminal connecting method thereof.

[Prior Art and Problems to be Solved by the Invention] Conventionally, as shown in FIG. 11, this type of film carrier has an insulating flexible substrate 1, an opening 2 provided in the insulating flexible substrate 1, Conductors such as the high frequency electrode 3, the bias supply electrode 4, and the ground electrode 5 formed on the surface of the insulating flexible substrate 1, and the high frequency electrode 3 in the opening 2 provided in the insulating flexible substrate 1. , A high-frequency electrode 3, a bias-supplying electrode 4, and a lead R connected to the grounding electrode 5 on the extension lines of the bias-supplying electrode 4 and the grounding electrode 5, respectively.

In this type of film carrier, as shown in FIG. 12, the high frequency electrode 3, the bias supply electrode 4, the ground electrode 5 and the lead R are attached to the insulating flexible substrate 1 with an adhesive 7.
It is formed in a lump by etching a conductor foil made of copper or the like that is adhered with the above. Further, the bump 8 may be formed on the lead R and the tip end portion by plating or the like.

As shown in FIG. 13 (a), the bare chip semiconductor element and the film carrier are connected to each other by the bare chip semiconductor element 9
The electrode pad 10 formed on the surface of the film carrier and the tip of the lead R of the film carrier are heated by the capillary 11 and connected by using a technique such as thermocompression bonding or thermosonic wave. With the bare chip semiconductor element 9 and the like connected, take the film carrier to a predetermined position of the mounting substrate 12 or the like as shown in FIG. 13 (b),
After the electrode 13 formed on the mounting substrate 12 and the lead R on the opposite side to which the bare chip semiconductor element 9 is connected are heated by a capillary 11 and connected by a technique such as thermocompression bonding or thermosonic wave, The structure is such that unnecessary leads and the insulating flexible substrate 1 are discarded by cutting at the cutting portion 14 shown in FIG. 13 (a).

The plurality of leads R of the film carrier have one side on the plurality of electrode pads 10 on the surface of the bare chip semiconductor element 9 or the like, and the other side on the plurality of electrodes 13 formed on the mounting substrate 12 or the like. Since the main purpose is to connect each of them at once, it is necessary to provide a margin for the length of the lead R required for the connection at two places, and by the inductance component according to the length of the lead R, There is a drawback that the frequency characteristics of the bare chip semiconductor element 9 or the high frequency module composed of a plurality of the bare chip semiconductor elements 9 are improved.

Further, since the bare chip semiconductor element 9 and the mounting substrate 12 are electrically connected only by the lead R, it is possible to connect a plurality of bare chip semiconductor elements 9 to one film carrier. It is necessary to perform cutting for discarding unnecessary leads and the insulating flexible substrate 1 inside the bare chip semiconductor element 9, and there is a drawback that the bare chip semiconductor element 9 is damaged.

FIG. 14 and FIG. 15 show a waveguide type film carrier (patent pending) which the present inventors have previously devised for the purpose of solving such a drawback. This waveguide type film carrier has openings 2 and 15 in the insulating flexible substrate 1 and contributes to at least propagation of a high frequency signal among the high frequency electrode 3, the bias supply electrode 4 and the ground electrode 5. The high frequency electrode 3 and the ground electrode 5 are coplanar waveguide structures formed on the surface of the insulating flexible substrate 1, and the openings 2, 15 of the insulating flexible substrate 1 are formed.
At the high frequency electrode 3, the bias supply electrode 4,
This structure has the lead R connected to the ground electrode 5 and the like.

However, also in this prior art, the frequency characteristic of the high frequency module is deteriorated by the inductance of the connecting lead R, and since the lead R is held only at the connection portion with various electrodes, the lead wire breakage at the time of bonding and the gap between the leads are caused. There was a drawback that short circuits were likely to occur.

The present invention has been made in the above background, and an object of the present invention is to enable multi-chip collective mounting of microwave devices with improved frequency characteristics, and easy high-density mounting as well as a machine. An object of the present invention is to provide a waveguide type film carrier excellent in dynamic strength and a terminal connecting method thereof.

[Means for solving the problem]

In order to achieve the above object, in the waveguide type film carrier according to claim 1, an insulating flexible substrate, a high frequency electrode and a bias supplying electrode formed on the surface of the insulating flexible substrate, and the high frequency. Of the electrodes and the bias supply electrodes, at least grounding electrodes formed on both sides of the high frequency electrode, and a bonding conductor column formed by penetrating to the back surface of the insulating flexible substrate respectively connected to the electrodes. It is characterized by being composed of and.

Further, in the waveguide type film carrier according to claim 2, an insulating flexible substrate, a high frequency electrode and a bias supplying electrode formed on the surface or inside of the insulating flexible substrate, and the insulating flexible substrate. A grounding electrode formed on the back surface at a position facing the high-frequency electrode, and a bonding formed by penetrating to the back surface of the insulative flexible substrate connected to the high-frequency electrode and the bias supply electrode, respectively. And a part of the grounding electrode is cut out so as to surround the bonding conductor pillar in at least three directions.

Further, in the waveguide type film carrier according to claim 3, a plurality of sets of high frequency electrodes, bias supply electrodes and ground electrodes are formed on the insulating flexible substrate.

Further, in each of the above configurations, it is more preferable that a plurality of sets of high frequency electrodes, bias supply electrodes, and ground electrodes are formed on the insulating flexible substrate.

Further, in order to connect the waveguide type film carrier to an object to be connected such as a bare chip semiconductor element and a mounting substrate, heat and / or ultrasonic waves are applied from a surface opposite to the connection surface of the bonding conductor pillar by a capillary or the like. It may be performed by applying vibration.

[Action]

Electrodes for high frequency, electrodes for bias supply, etc. can be electrically connected to the bare chip semiconductor element by the conductor pillars for bonding, and the conductor pillars have insulating flexibility compared to the conventional connection using wires, ribbons, etc. Since it is still penetrated through the substrate, it can be mechanically firmly fixed, and since the conductor columns do not contact each other, high density mounting can be performed.

Further, in the case of forming a waveguide by combining a frequency electrode, a ground electrode, and an insulating flexible substrate, the waveguide is connected to the electrode as described above to form a waveguide. Can be electrically connected to a bare chip semiconductor element or the like, and high-frequency characteristics can be improved as compared with the conventional connection using wires, ribbons, or the like.

Furthermore, when a plurality of sets of high frequency electrodes, bias supply electrodes and ground electrodes are provided, a plurality of bare chip semiconductor elements can be connected at one time, and workability is greatly improved.

Further, when connecting the waveguide film carrier to the bare chip semiconductor element or the like, it is easy to apply heat and / or ultrasonic vibration by a capillary or the like from the surface opposite to the connection surface of the bonding conductor column, which is easy. You can connect.

〔Example〕

Embodiment 1 FIGS. 1 to 5 are views for explaining a first embodiment of the present invention. FIG. 1 is a top view and FIG. 2 is a waveguide type film carrier of a high frequency electrode 3 portion. Sectional view in the signal propagation direction, FIG. 3 is a perspective view illustrating a coplanar waveguide, and FIG.
FIGS. 5 (a) to 5 (e) are views for explaining the manufacturing process of the conductor pillar for bonding, and FIGS. 5 (a) to 5 (c) are cross-sectional views for connecting bare chip semiconductors and connecting to a mounting substrate. is there.

In the figure, reference numeral 1 is an insulating flexible substrate, 3 is a high frequency electrode formed on the surface of the insulating flexible substrate 1, 4 is a bias supply electrode formed on the surface of the insulating flexible substrate 1, and 5 is a bias supply electrode. It is a grounding electrode formed on the surface of the insulating flexible substrate 1. The high frequency electrode 3, the ground electrode 5 and the insulating flexible substrate 1 form a waveguide 6.

Further, 20 is a conductor pillar for bonding. The bonding conductor column 20 penetrates the insulating flexible substrate 1 and is connected to the respective electrodes 3, 4, 5. Also,
At least one side of the conductor column 20 is preferably projected from the surface of the flexible substrate 1 as shown in FIGS.

First, an example of the method of forming the conductor columns in the method of manufacturing the waveguide type film carrier according to the first embodiment of the present invention will be described with reference to FIGS. 4 (a) to 4 (e). In order to manufacture the waveguide type film carrier of this embodiment, a conductor film 16 of copper or the like is deposited on the front and back surfaces of the insulating flexible substrate 1 of polyimide resin, epoxy resin or the like by sputtering, vapor deposition or the like ( 4 (a)), a photoresist 17 is applied on both sides, exposed and developed (FIG. 4 (b)). The metal deposited on the insulative flexible substrate 1 and the insulative flexible substrate 1 are removed in a region 18 opened by development, and a through hole 19 is formed (FIGS. 4 (c) and (d)). 19 is filled with metal by plating or the like to form a conductor column 20 for bonding (FIG. 4 (e)).

After that, a photoresist is applied, exposed, and developed, the metal deposited on the insulating flexible substrate 1 is removed by etching, and the high frequency electrode 3, the bias supply electrode 4, the ground electrode 5 and the like are patterned. Further, the high frequency electrode 3, the bias supply electrode 4, the ground electrode 5 and the bonding conductor column 20 on the insulating flexible substrate 1 are reinforced by repeating the photo process and the plating process at predetermined locations. At the same time, bumps 8 may be further formed.

Next, an example of a method of connecting the waveguide type film carrier and the bare chip semiconductor element 9 will be described with reference to FIG. The waveguide type film carrier is brought to a predetermined position of the bare chip semiconductor element 9 so that the bonding conductor pillar 20 and the electrode pad 10 formed on the bare chip semiconductor element 9 overlap each other, and the bonding conductor pillar 20 and the bare chip are carried. The waveguide 11 and the bare chip semiconductor element 9 are connected and mounted by heating the electrode pad 10 on the surface of the semiconductor element 9 with the capillary 11 and connecting them by using a technique such as thermocompression bonding or ultrasonic waves.

Next, a method of connecting and mounting the waveguide type film carrier to which the bare chip semiconductor element 9 is connected and mounted on the mounting substrate 12 will be described with reference to FIGS. 5 (b) and 5 (c).

First, in the first embodiment, as shown in FIG. 5 (b), the waveguide type film carrier is brought to a predetermined position on the mounting substrate 12, and the conductor column 20 for bonding and the mounting substrate are mounted.
12 The surface of the electrode 13 is heated by the capillary 11, and the waveguide type film carrier and the mounting substrate 12 are connected and mounted by using a technique such as thermocompression bonding or ultrasonic waves, and then the back surface of the bare chip semiconductor element 9 is mounted. The substrates 12 are fused and connected by solder or the like (not shown).

In the mounting example of the second mounting, as shown in FIG. 5 (c), the waveguide type film carrier to which the bare chip semiconductor element 9 is connected and mounted is provided with the electrode surface of the bare chip semiconductor element 9 on the electrode 13 of the mounting substrate 12. The waveguide type film carrier is inverted so that it becomes a surface, and it is brought to a predetermined position on the mounting substrate 12 together with the waveguide type film carrier, and the bonding conductor pillar 20 and the electrode 13 on the surface of the mounting substrate 12 And a substrate 11 for mounting the waveguide type film carrier and the mounting substrate 12 by connecting with a capillary 11 by using a technique such as thermocompression bonding or ultrasonic waves.
Connect and implement.

Finally, in any of the mounting examples shown in FIG. 5 (b) and FIG. 5 (c), unnecessary insulating flexible boards are discarded by cutting at the cutting portion 14 (FIG. 5 (a)). .

According to the waveguide type film carrier shown in FIG. 1, the bare chip semiconductor element 9 and the mounting substrate 12 are connected by the coplanar waveguide 6 (see FIG. 3) which is impedance-matched, and the bonding is performed. Since the waveguide 6 can be electrically connected to the bare chip semiconductor element 9 and the mounting substrate 12 in the immediate vicinity by using the conductor pillars 20 for a high frequency, compared with the conventional connection using a wire, a ribbon, or the like, The characteristics can be improved and the bare chip semiconductor mounting can be performed at high density. In addition, the conductor column 20 for bonding
Since the insulating flexible substrate 1 is formed through the insulating flexible substrate 1, the bonding energy provided by the capillary 11 is transferred from the bonding conductor pillar 20 to the electrode pad 10 on the surface of the bare chip semiconductor element 9 and the electrode 13 on the surface of the mounting substrate 12.
It can be easily transmitted to the connected part such as, and the reliability of the connection can be improved.

The characteristic impedance of the coplanar waveguide is determined by the dielectric constant of the film, the thickness of the film, the pattern width l _{1 of} the high frequency electrode 3, and the gap dimension l ₂ between the high frequency electrode 3 and the ground electrode 5. Here, in the waveguide type film carrier, the pattern width of the high frequency electrode 3 and the gap size between the high frequency electrode 3 and the ground electrode 5 are changed to realize a waveguide type film carrier in which impedance matching is achieved. It is possible to The pattern change can be easily dealt with by changing the photomask pattern.

Although the bias supply electrode 4 is described differently from the high frequency electrode 3, the bias supply electrode sandwiched between the ground electrodes is treated by treating a part of the bias supply electrode 4 as a ground electrode. As a result, a coplanar waveguide structure is formed. Therefore, it is obvious that the idea of the coplanar waveguide structure can be applied to the bias supply electrode 4. The same applies to the following examples.

Further, in the above-described illustrated example, the conductors forming the high frequency electrode 3 and the ground electrode 5 are formed only on one surface of the insulative flexible substrate 1, but also on the other surface of the insulative flexible substrate 1. A conductor for the ground electrode may be formed.

Embodiment 2 FIGS. 6 to 9 are views for explaining the second embodiment of the present invention. FIG. 6 is a top view and FIG. 7 is a waveguide type film carrier of the high frequency electrode 3 portion. FIG. 8 is a cross-sectional view in the signal propagation direction, FIG. 8 is a cross-sectional view of a microstrip line, and FIG. 9 is a perspective view for explaining the relationship between a bonding conductor column for connecting a high frequency electrode and a grounding electrode.

In the figure, reference numeral 1 is an insulating flexible substrate, 3 is a high frequency electrode formed on the surface of the insulating flexible substrate 1,
Reference numeral 4 is a bias supply electrode formed on the surface of the insulating flexible substrate 1, 5 is a grounding electrode formed on the back surface of the insulating flexible substrate 1, 6 is a high frequency electrode 3, a grounding electrode 5 and insulation. Of the flexible flexible substrate 1, 8 is a bump, 20 is a conductor column for bonding, and 21 is an opening for preventing short circuit between the high frequency electrode 3 and the ground electrode 5.

In this embodiment, as shown in FIG.
The structure of the waveguide 6 including the grounding electrode 5 and the insulating flexible substrate 1 is a microstrip path structure. Since the waveguide structure is the microstrip structure as described above, the ground electrode 5 is always formed on the back surface of the high-frequency electrode 3, so that an opening is formed in a part of the ground electrode 5 as shown in FIG. The portion 21 is provided so as to prevent a short circuit between the high frequency electrode 3 and the grounding electrode 5.

In this embodiment, a method of manufacturing a waveguide type film carrier,
The method of connecting the bare chip semiconductor element to the waveguide film carrier and the method of connecting the waveguide film carrier to the mounting substrate are almost the same as those in the first embodiment.

The characteristic impedance of the microstrip line is
It is determined by the dielectric constant of the film, the thickness of the film, and the pattern width of the high frequency electrode. Here, it is possible to realize a waveguide-type film carrier that is impedance-matched by changing the pattern width of the high-frequency electrode in the waveguide-type film carrier. The pattern change can be easily dealt with by changing the photomask pattern. In the embodiment, the electrode width is not changed because it is assumed that the input / output impedance of the chip is constant.

According to this embodiment, similarly to the first embodiment, the bare chip semiconductor element 9 and the mounting substrate 12 are connected by the waveguide 6 which is impedance-matched, and moreover, the bonding conductor pillar 20. Since it is possible to electrically connect the waveguide 6 to the bare chip semiconductor element in the immediate vicinity by using, the high frequency characteristics can be improved and the bare chip semiconductor can be mounted at high density as compared with the conventional connection by a wire, a ribbon or the like. Can be possible. Further, since the bonding conductor pillar 20 is formed so as to penetrate the insulating flexible substrate 1, the bonding energy provided by the capillary is transferred from the bonding conductor pillar to the electrode pads on the surface of the bare chip semiconductor element and the mounting substrate surface. It can be easily transmitted to the connected part such as the electrode, and the reliability of the connection can be improved.

In the illustrated example described above, the conductor forming the high frequency electrode 3 is formed on one surface of the insulating flexible substrate 1, but instead of this, the conductor of the high frequency electrode 3 is formed on the insulating flexible substrate 1. It may be formed inside.

Embodiment 3 FIG. 10 is a view for explaining a third embodiment of the present invention, which is an example of a waveguide type film carrier for connecting a plurality of bare chip semiconductor elements. In the figure, reference numeral 1 is an insulating flexible substrate, 3 is a high frequency electrode formed on the surface of the insulating flexible substrate 1, 4 is a bias supply electrode formed on the surface of the insulating flexible substrate 1, 5
Is a grounding electrode formed on the surface of the insulating flexible substrate 1, 6 is a waveguide, and 20 is a conductor pillar for bonding.

This embodiment is an example of a coplanar waveguide type film carrier for connecting a plurality of bare chip semiconductor elements, and includes a high frequency electrode 3, a bias supply electrode 4 and a ground electrode 5.
Are formed in plural sets. The manufacturing method of this embodiment is almost the same as that of the first embodiment. In addition, in order to connect and mount a plurality of bare chip semiconductor devices (not shown) to the waveguide type film carrier, one bare chip semiconductor device (not shown) is used as the waveguide type film carrier. Connect and implement by the method described in, and repeat this. The method of connecting / mounting this waveguide type film carrier to the mounting substrate is similar to that of the first embodiment, as shown in FIG.
It is implemented by two methods shown in (c).

Also in this embodiment, the same effect as that of the first and second embodiments can be obtained. Further, in this embodiment, since the pattern of the waveguide type film carrier can be easily changed by the usual photolithography technique, it is possible to obtain an advantage that the package can be easily unified.

〔The invention's effect〕

According to the waveguide type film carrier of the present invention, it is possible to electrically connect the high frequency electrode, the bias supply electrode and the like to the bare chip semiconductor element by the bonding conductor pillar, and the conventional connection using the wire, ribbon and the like. Compared with the above, since the conductor pillar is still pierced in the insulating flexible substrate, mechanically strong fixing can be realized, and since the conductor pillars are not in contact with each other, high-density mounting is possible. I can do it.

When the high frequency electrode, the ground electrode, and the insulating flexible substrate are combined to form a waveguide, the waveguide is connected to the electrode as described above to form a waveguide. Can be electrically connected to a bare chip semiconductor element or the like, and high-frequency characteristics can be improved as compared with the conventional connection using wires, ribbons, or the like.

Furthermore, when a plurality of sets of high frequency electrodes, bias supply electrodes, and ground electrodes are provided, multichip or a plurality of bare chip semiconductor elements of a microwave device can be collectively connected, and workability is greatly improved. Further, since it is easy to change the waveguide type film carrier pattern in the manufacturing process, it is possible to unify the packages for multi-chip mounting.

Further, when connecting the waveguide film carrier to the bare chip semiconductor element or the like, it is easy to apply heat and / or ultrasonic vibration by a capillary or the like from the surface opposite to the connection surface of the bonding conductor pillar, which is easy. It has effects such as connection.

Further, in addition to the step of forming the bonding conductor pillars separately from the step of connecting the film carrier and the semiconductor element etc. by the bonding conductor pillars, the bonding conductor pillars are finished in a desired shape. This is a step before connecting the terminals and can be performed very easily because the mechanical forming method can be freely performed. Therefore, it is advantageous to obtain the waveguide as designed.

[Brief description of drawings]

FIG. 1 is a top view of a coplanar waveguide type film carrier according to the first embodiment of the present invention, FIG. 2 is a sectional view of the waveguide type film carrier of a high frequency electrode portion in a signal propagation direction, and FIG. 3 is a coplanar. FIG. 4A is a perspective view illustrating a waveguide, FIGS. 4A to 4E are diagrams illustrating a manufacturing process of a bonding conductor column, and FIG. 5A is a cross-sectional view when a bare chip semiconductor element is connected. 5 (b) and 5 (c) are cross-sectional views when connected to a mounting substrate, FIG. 6 is a top view of a waveguide type film carrier according to a second embodiment of the present invention, and FIG. 7 is a high frequency electrode. 8 is a sectional view of the waveguide type film carrier in the signal propagation direction, FIG. 8 is a sectional view of a microstrip line, and FIG. 9 is a diagram illustrating the relationship between a bonding conductor column for connecting a high frequency electrode and a grounding electrode. FIG. 10 is a perspective view showing the third embodiment of the present invention. It is a top view of a road-shaped film carrier. Further, FIGS. 11 and 12 are a top view and a sectional view of a conventional film carrier, respectively, and FIG. 13 (a) is a sectional view when a bare chip semiconductor element is connected to the film carrier, and
FIG. 1B is a sectional view when the film carrier is connected to a mounting substrate, and FIGS. 14 and 15 are a top view and a sectional view of a waveguide type film carrier of the prior art. 1 ... Insulating flexible substrate, 2 ... Aperture, 3 ...
High frequency electrode, 4 ... Bias supply electrode, 5 ... Grounding electrode, 6 ... Waveguide, R ... Lead, 7 ... Adhesive, 8
...... Bumps, 9 ... Bare chip semiconductor elements, 10 ... Electrode pads, 11 ... Capillaries, 12 ... Mounting substrate, 13 ...
… Electrode, 14… Connection part, 15… Second opening, 16… Conductor film, 17… Resist film, 18… Opening in resist film, 19… Through hole, 20… Conductivity Body column, 21 ... Opening to prevent short circuit between high frequency electrode and ground electrode.

Front Page Continuation (72) Inventor Takaaki Osaki 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Inside Nippon Telegraph and Telephone Corporation (56) Reference JP 62-199023 (JP, A) JP 64-84626 (JP, A) JP-A-64-84625 (JP, A)

Claims (4)

(57) [Claims] 1. An insulating flexible substrate, a high frequency electrode and a bias supply electrode formed on the surface of the insulating flexible substrate, and at least both sides of the high frequency electrode of the high frequency electrode and the bias supply electrode. A waveguide type film carrier, comprising: formed grounding electrodes; and bonding conductor columns that are respectively connected to the electrodes and penetrate to the back surface of the insulating flexible substrate. 2. An insulating flexible substrate, a high frequency electrode and a bias supplying electrode formed on the surface or inside of the insulating flexible substrate, and a position on the back surface of the insulating flexible substrate facing the high frequency electrode. A grounding electrode formed on the insulating high-frequency electrode and a biasing electrode connected to the high-frequency electrode and the biasing electrode, and a bonding conductor column formed to penetrate to the back surface of the insulating flexible substrate. A waveguide-type film carrier, wherein a part of the ground electrode is cut out so as to surround the conductor column for at least three directions. 3. The waveguide film according to claim 1, wherein the insulating flexible substrate is formed with a plurality of sets of high frequency electrodes, bias supply electrodes and ground electrodes. Career. 4. A method of terminal-connecting the waveguide film carrier according to any one of claims 1 to 3 to an object to be connected such as a bare chip semiconductor element and a mounting substrate, wherein the insulating flexible substrate is used. By applying heat and / or ultrasonic vibration with a connecting jig such as a capillary from the surface of the bonding conductor column previously formed so as to penetrate through the surface opposite to the connection surface to the object to be connected, A terminal connection method for a waveguide film carrier, comprising connecting the waveguide film carrier and the object to be connected.