JPH0661310A - Lead, tab tape, manufacture of tab tape, method of joining lead and object to be joined, method of joining tab tape and semiconductor chip, and device thereof - Google Patents

Abstract

PURPOSE:To joint a semiconductor chip and the leads of a TAB tape without damaging the leads using no pressure head. CONSTITUTION:A TAB tape 4 is fixed on a fixed carrier 10. The TAB tape 4 is composed of a leads 1, each having a porous tip parts, and a tape substrate 5. Also, a semiconductor chip 2 having bumps is placed on a bonding stage 13. The bumps 3 and the porous tip parts are superposed respectively by a rotary moving mechanism, with which the bonding stage 13 is rotated, an upward-moving mechanism 14 and the like in such a manner that the force, with which the tip parts and the bump 3 can be pressed, is generated by the deformation of the leads 1. The semiconductor 2 is heated up and the bumps 3 are melted in the above-mentioned state. Consequently, as the molten bumps 3 penetrates into the porous structure of the lead 1, strong bonding strength can be obtained. As no pressure head is used, the leads are not damaged, and the strengths of leads are not lowered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for preventing a decrease in strength of a lead when the lead is joined to a semiconductor chip or a circuit pattern and simplifying a joining device.

[0002]

2. Description of the Related Art A TAB (tape automated bonding) method is often employed as a technique for bonding a semiconductor chip and a lead. FIG. 14 shows a conventional bonding apparatus (TAB bonder) 300 using such a TAB method. This device 300 is for bonding the semiconductor chip 2 and the tape-shaped lead 26, and the bump 3 is previously formed on the semiconductor chip 2.

The bonding apparatus 300 comprises a heat block 24 for heating the bumps 3. Above the heat block 24, a pressure head 2 that moves up and down is provided.
5 are provided. Then, the lead 26 is configured to be conveyed between the heat block 24 and the pressure head 25.

When the semiconductor chip 2 and the leads are bonded using this apparatus 300, the semiconductor chip 2 is first placed on the heat block 24. At this time, the pressure head 25 is located at a position higher than the height shown in FIG.

Next, the lead 26 supported by a tape (not shown) is placed on the semiconductor chip 2 while being aligned with the bump 3. In that state, the pressure head 25 is lowered, the leads 26 are pressed by the pressure head 25, and the semiconductor chip 2 and the bumps 3 are heated by the heat block 24. As a result, bump 3
Is melted and the semiconductor chip 2 and the tape-shaped lead 26 are fused.

[0006]

However, according to the above-mentioned conventional method, since the lead 26 is pressed by the pressure head 25, there is a problem that the strength of the lead 26 is lowered at the contact portion.

Further, the lead 26 must be uniformly pressed by the pressure head 25, and the pressure head 25 and the semiconductor chip 2 must be accurately aligned, and a mechanism therefor is required.

Such a problem is a common problem not only in bonding the TAB lead and the semiconductor chip but also in bonding the lead and various objects to be bonded.

The present invention has been made in order to solve the above problems, and it is a first object of the present invention to prevent a decrease in the strength of a lead when connecting the lead and a body to be joined.

A second object is to realize such a joining process without using a complicated mechanism.

[0011]

SUMMARY OF THE INVENTION According to the present invention, a lead to be bonded to a body to be bonded by superposing it on a bump formed in advance on a predetermined body to be bonded and melting the bump. Intended.

According to the present invention, the lead has (a) an upper main surface, (b) a lower main surface, and (c) a conductive layer existing between the upper main surface and the lower main surface. Prepare

A porous structure having a plurality of through holes penetrating from the upper main surface to the lower main surface is formed in a portion of the conductive layer to be bonded to the body to be bonded.

The present invention particularly provides a novel TAB tape.

The TAB tape of the present invention comprises (a) an insulating tape, (b) formed on the insulating tape, (b-1) an upper main surface, (b-2) a lower main surface, and b-3) A conductive layer provided between the upper main surface and the lower main surface.

A porous structure having a plurality of through holes penetrating from the upper main surface to the lower main surface is formed in a portion of the conductive layer to be bonded to the semiconductor chip.

The present invention also provides a method of forming the TAB tape by selectively removing the conductive layer provided on the insulating tape.

The present invention also provides a method for connecting the lead as described above to an object to be bonded or bonding the TAB tape to a semiconductor chip.

There is also provided an apparatus suitable for bonding the TAB tape to a semiconductor chip.

[0020]

In the lead according to the present invention, the molten bump penetrates into the portion having the porous structure due to the osmotic pressure, without forcibly applying the pressure.

Therefore, the body to be joined and the lead can be firmly joined without lowering the strength of the lead.

In addition, this joining does not require a complicated mechanism for parallelizing the article to be joined and the lead.

[0023]

EXAMPLE <Structure of TAB Tape> FIG. 2 is a view showing one unit of a TAB tape 4 which is an example of the present invention.

The TAB tape 4 includes an insulating tape base material 5. This tape substrate 5 is obtained as a part of a long tape extending in the direction of the broken line in FIG.

The tape substrate 5 has an opening 5a through which a semiconductor chip is inserted, and an opening 5b through which a protruding member is inserted to push the lead 1 out of the tape substrate 5 after the lead 1 is bonded to a semiconductor. Are formed. A plurality of leads 1 are attached around these openings 5a and 5b. The lead 1 is made of a conductive material such as copper.

The tip 1t of the lead 1 protruding into the central opening 5a has a porous structure described later.

FIG. 3 is an enlarged view of the tip portion 1t of the lead 1. A porous structure 50 as a two-dimensional array of a large number of cylindrical through holes 1a is formed on the tip portion 1t of the lead 1. Each of the through holes 1a has an upper main surface TS of the lead 1.
To the lower main surface BS.

FIG. 4 shows another example of the porous structure 50. The porous structure 50 is a two-dimensional array of a large number of prismatic through holes 1b and forms a mesh structure as a whole.

As will be described later, the joining of the lead 1 and the article (semiconductor chip) to be joined is achieved by the molten bump penetrating the through holes 1a and 1b. For this reason, the fused bumps are formed in these through holes 1a, 1
The dimensions of the openings of these through holes 1a and 1b are determined so as to satisfy the condition that they can permeate into b. Such conditions can be determined by prior experimentation.

<Method of manufacturing TAB tape> Next, this T
A method of manufacturing the AB tape 1 will be described with reference to FIGS. However, FIGS. 5, 6A and 7A are cross-sectional views, and FIGS. 6B and 7B are plan views.

First, as shown in FIG. 5, an insulating tape material 5 such as a resin tape is prepared, and a copper layer 6 is provided thereon.

Next, a resist layer R1 is formed on the entire surface of the copper layer 6.
To form. This resist layer R1 is patterned by selective etching, thereby obtaining a resist pattern R2 (FIG. 6). This resist pattern R2 is
It has a contour CT1 for defining the outer shape of the lead 1, and a two-dimensional array of a large number of openings WD is formed therein.

Next, the copper layer 6 is selectively etched by using the resist pattern R2 as a mask, whereby leads 1 having a matrix arrangement of the through holes 1a are obtained (FIG. 7). The outer shape CT2 of the lead 1 corresponds to the contour portion CT1 of the resist pattern R2.

Thereafter, as shown in FIG. 8, a cut line is put in the insulating tape material 5 from the lower surface side of the structure obtained as described above, and a part of the insulating tape material 5 is defined with the cut line as a boundary. Are removed to obtain the openings 5a, 5b, 5c shown in FIG.

Then, the unit TAB tape 4 of FIG. 1 is obtained by cutting the TAB tape 40 thus obtained.

The TAB tape can be manufactured by the same process as described above even when the mesh structure having the through holes 1b of the rectangular horizontal cross section shown in FIG. 4 is adopted as the porous structure.

As described above, it is economical and preferable to simultaneously form the outer shape CT2 of the lead 1 and form the porous structure in the lead tip portion 1t.

Thereafter, the tape base material 5 provided with the leads 1 is cut to obtain individual T's as shown in FIG.
An AB tape is obtained. The tape substrate 5 may be cut first.

The openings 5a, 5b, 5c may be formed before the step shown in FIG. However, since the through hole 1a has a considerably small diameter, when the copper layer 6 is selectively etched, sufficient etching accuracy cannot be obtained unless there is a layer supporting the copper layer 6 under the copper layer 6. In some cases. Therefore, as described above, it is preferable to form the openings 5a, 5b, 5c later. Note that only the cut lines of the openings 5a, 5b, 5c are given in advance, and the openings 5a, 5 of the insulating tape material 5 are
The removal of the portions in b and 5c may be performed after the molding of the lead 1 is completed.

<Structure and Operation of Bonding Device> FIG. 9
Is a bonding apparatus (TAB) according to an embodiment of the present invention.
It is a figure which shows the bonder) 200. The bonding apparatus 200 includes a tape transfer system 100A for transferring the TAB tape 4, a chip supply system 100B for supplying the semiconductor chip 2, and a chip support system 100C for supporting and heating the semiconductor chip 2. Equipped with.

A carrier loader 7 is provided on the tape loading side of the tape transport system 100A. After the carrier 10 carrying the TAB tape 4 is supplied to the carrier loader 7, the carriers 10 are set one by one from the carrier loader 7 to the carrier feeder 9. Each carrier 10 has a tray shape having an opening 10a at the center.

The carrier feeder 9 conveys the carrier 10 to the bonding processing space P along the Y axis,
The carrier 10 is stopped in the processing space P. T
When the carrier 10 on which the AB tape 4 is placed is transported to the position of the processing space P, the carrier fixing tool 11 is moved in the X-axis direction by the push-pull solenoid to fix the carrier 10. Similarly, the push-pull solenoid moves the tape clamp 12 in the Z-axis direction to fix the TAB tape 4.

On the other hand, in the chip supply system 100B,
A semiconductor wafer 18 cut into a plurality of chips 2 is prepared on a wafer table 19. The surface of the table 19 is made of an adhesive sheet so that the positions of the chips 2 are not displaced.

A piece of semiconductor chip 2 is picked up from the wafer 18 by the transfer mechanism 17 having a vacuuming function. One semiconductor chip 2 picked up
Are transferred as indicated by arrows AR1 and AR2 and placed on the bonding stage 13.

The semiconductor chip 2 is bonded to the bonding stage 1
After being mounted on the substrate 3, the bonding stage 13 is moved in the (X, Y) plane by the horizontal moving mechanism 15 and transferred to the lower part of the bonding processing space P. Further, the bonding stage 13 is rotated in the XY plane by the rotation moving mechanism 13a so that the semiconductor chip 2 is oriented in a direction suitable for bonding. Then, the elevating mechanism 14 raises the bonding stage 13 along the Z axis.

The state at this time is shown as an enlarged view in FIG. The bumps 3 are previously formed on the semiconductor chip 2.
And the bumps 3 are formed in the openings 10 of the carrier 10.
It is in contact with the lead 1 via a. In FIG. 1, the leads 4 and the bumps 3 are drawn thick for convenience of illustration, but in reality, these thicknesses are considerably thin. Bump 3
For example, it is made of solder material.

The elevating mechanism 14 is stopped at a position where the bump 3 contacts the lead 1 and pushes the lead 1 slightly upward. The stop position is predetermined.

As a result of the force for pushing up the lead 1 acting from the bump 3, a downward reaction force is generated from the lead 1 to the bump 3. Since the lead 1 and the bump 3 are brought into close contact with each other due to the elastic force of the lead 1, the elements 2 and 4 can be joined together without providing an accurate parallel alignment mechanism between the semiconductor chip 2 and the TAB tape 4. Can be aligned. The bumps 3 and the leads 1 may be overlapped with each other while the position of the semiconductor chip 2 or the like is detected by a sensor.

In this state, the bonding stage 13 is heated by using, for example, a cartridge type heating rod 16, and the semiconductor chip 2 and the bumps 3 are heated by conduction of heat from the bonding stage 13. The bump 3 melted by heating penetrates into the porous structure of the tip 1t of the lead 1 due to the reaction force and osmotic pressure of the lead 1, and the semiconductor chip 2 and the lead 1 are bonded.

After the joining is completed, the carrier fixture 1
The restraint of the carrier 10 and the tape 4 by 1 and the tape clamp 12 is released.

After cooling the bonded body, the carrier 10 holding the bonded body of the tape 4 and the semiconductor chip 2 is conveyed to the carrier unloader 8 by the carrier feeder 9. Also, the bonding stage 13 is returned to the initial position.

In the bonded body of the TAB tape 4 and the semiconductor chip 2 thus obtained, the lead 1 is separated from the insulating tape material 5, and the other end of the lead 1 is connected to an external conductive pad. , The semiconductor chip 2 and the conductive pad are electrically connected. The semiconductor module thus obtained becomes a semiconductor device through steps such as resin sealing.

In the above procedure, the semiconductor chip 2 is set to T
Although the tape is raised toward the AB tape 4, the TAB tape 4 may be lowered onto the semiconductor chip 2 whose position is fixed by connecting an elevating mechanism to the carrier feeder 9.

The joining state thus obtained is shown in FIG.
Shown in. Since the bump 3 penetrates into the through hole 1a or 1b of the lead 1, the semiconductor chip 2 and the lead 1 are
Bonded more strongly than in the prior art. And
Since the pressure is not applied by the conventional pressing mechanism, the reduction in strength of the lead 1 can be effectively prevented.

In particular, in this embodiment, since the porous structure is formed only at the tip 1t of the lead 1 (the portion to be joined), the strength of the lead 1 as a whole does not decrease.

<Other Embodiments> FIG. 11 is a diagram showing a method of bonding leads and a body to be bonded according to another embodiment of the present invention. In this embodiment, the semiconductor device 20 is bonded onto the wiring pattern 32 on the printed board 30.

The semiconductor device 20 comprises a semiconductor chip 21 sealed by a resin package 23. The outer lead 22 extends from the resin package 23,
The outer lead 22 is connected to the semiconductor chip 21 via the inner lead 24.

A porous structure is formed at the tip 22t of the outer lead 22. As shown in FIG. 12, this porous structure has a structure from the upper main surface TS of the outer lead 22 to the lower main surface BS.
It is composed of a two-dimensional array of a large number of through holes 22a penetrating to each other. The porous structure may be the mesh structure shown in FIG.

On the other hand, the printed board 30 is an insulating board 31.
The wiring pattern 32 is provided on the upper part. This wiring pattern 3
A solder layer (bump) 33 is selectively formed on the second layer 2. Then, the tip portion 22t of the outer lead 22 is placed on the solder layer 33 and heated. The solder layer 33 thus melted penetrates into the through hole 22a due to the force exerted on the solder layer 33 from the tip portion 22t by gravity and the osmotic pressure of the molten solder layer 33. Then, the molten solder layer 32 is cured by natural cooling,
The wiring pattern 32 and the tip portion 22t of the outer lead 22 are joined. The state after joining is shown in FIG.

Also in this embodiment, the same effect as that of the TAB tape described above can be obtained. Since the porous structure is formed only in the tip portion 22t (the portion where the joining is performed) of the outer lead 22, the strength of the outer lead 22 as a whole does not decrease.

[0061]

As described above, in the lead according to the first aspect of the invention, the molten bump penetrates into the portion having the porous structure due to the osmotic pressure, without forcibly applying the pressure.

Therefore, the body to be joined and the lead can be firmly joined without lowering the strength of the lead.

Further, in such a joining process,
No complicated mechanism is required for parallel alignment of the bonded body and the lead.

In the second aspect, the same effect as described above can be obtained especially in the case of joining the lead of the TAB tape and the semiconductor chip.

Since the leads of the TAB tape are often thin, the effect of preventing a decrease in strength is particularly great.

According to the manufacturing method of the third aspect, the TAB tape having the above characteristics can be manufactured.

In the joining method according to the fourth and fifth aspects, joining utilizing the above characteristics can be realized.

The apparatus of claim 6 is particularly suitable for joining the TAB tape and the semiconductor chip.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a method of joining a TAB tape and a semiconductor chip according to an embodiment of the present invention.

FIG. 2 is a schematic view of a TAB tape of an example.

FIG. 3 is an enlarged view of the tip portion of the lead of the embodiment.

FIG. 4 is an enlarged view of a tip portion of a lead according to another mode.

FIG. 5 is a process drawing for explaining the manufacturing method of the TAB tape.

FIG. 6 is a process diagram illustrating a method of manufacturing a TAB tape.

FIG. 7 is a process diagram illustrating a method of manufacturing a TAB tape.

FIG. 8 is a process diagram illustrating a method of manufacturing a TAB tape.

FIG. 9 is a schematic view of a bonding apparatus according to an example.

FIG. 10 is a cross-sectional view showing a joint structure obtained in an example.

FIG. 11 is a diagram showing a joining method according to another embodiment of the present invention.

12 is an enlarged view of the tips of the leads in the embodiment of FIG.

FIG. 13 is a cross-sectional view showing a joint structure obtained by the embodiment of FIG.

FIG. 14 is a conceptual diagram illustrating a method of joining a conventional TAB tape and a semiconductor chip.

[Explanation of symbols]

 1 Lead 2 Semiconductor Chip 3 Bump 4 TAB Tape 5 Tape Base Material 6 Copper Layer 7 Carrier Loader 8 Carrier Unloader 9 Carrier Feeder 10 Carrier 11 Carrier Fixture 12 Tape Clamp 13 Bonding Stage 14 Lifting Mechanism 15 Transfer Mechanism 16 Heating Rod 17 Transfer Mechanism 18 Wafer 19 Wafer Table 20 Semiconductor Device 21 Semiconductor Chip 22 Outer Lead 23 Resin Package 24 Inner Lead 30 Printed Circuit Board 32 Wiring Pattern 33 Solder Layer (Bump) 200 Bonding Device

Claims (6)

[Claims] 1. A lead, which is to be joined to the body to be joined by superposing it on a bump previously formed on a predetermined body to be joined and melting the bump, comprising: A surface, (b) a lower main surface, and (c) a conductive layer that is present between the upper main surface and the lower main surface, and should be bonded to the object to be bonded of the conductive layers. A lead having a porous structure having a plurality of through holes each penetrating from the upper main surface to the lower main surface. 2. A TAB tape to be bonded to a semiconductor chip, comprising: (a) an insulating tape, (b) formed on the insulating tape, (b-1) an upper main surface, and (b- 2) a lower main surface, and (b-3) comprising a conductive layer existing between the upper main surface and the lower main surface, in a portion of the conductive layer to be bonded to the semiconductor chip, A lead formed with a porous structure having a plurality of through holes penetrating from the upper main surface to the lower main surface. 3. A method of manufacturing a TAB tape to be bonded to a semiconductor chip, comprising: (a) obtaining an insulating tape; and (b) providing an upper main surface and a lower main surface on the insulating tape. Forming a conductive layer having: and (c) selectively removing the conductive layer to form a lead having a porous structure having a plurality of through holes penetrating from the upper main surface to the lower main surface. A method of manufacturing a TAB tape, comprising: 4. A method for joining a lead onto a predetermined article to be joined, comprising: (a) an upper main surface, a lower main surface, and an upper main surface and a lower main surface. A lead having a conductive layer and a porous structure having a plurality of through holes penetrating from the upper main surface to the lower main surface is formed in a portion of the conductive layer to be bonded to the object to be bonded. A step of obtaining, (b) a step of forming a bump on the article to be joined, (c) so that the bump and the porous structure are in contact with each other,
A step of superimposing the lead and the object to be joined, (d) a step of melting the bump to form a melted bump, and allowing the melted bump to enter the through hole, (e) cooling the melted bump And a step of curing the same, and a method of joining the lead and the article to be joined. 5. A method for joining a lead of a TAB tape to a semiconductor chip, comprising: (a) an upper main surface, a lower main surface, and a conductive layer existing between the upper main surface and the lower main surface. An insulating tape having a porous structure having a plurality of through holes penetrating from the upper main surface to the lower main surface in a portion of the conductive layer to be bonded to the semiconductor chip. A step of obtaining a TAB tape formed on the semiconductor chip; (b) a step of forming a bump on the semiconductor chip; (c) a step of contacting the bump with the porous structure of the lead. Stacking a TAB tape and the semiconductor chip, (d) melting the bump to form a melting bump, and allowing the melting bump to enter the through hole, (e) cooling the melting bump And (f) removing the lead by A method of joining a TAB tape and a semiconductor chip, comprising the step of peeling from the edge tape. 6. A device for joining a lead of a TAB tape to a semiconductor chip, comprising: (a) an upper main surface, a lower main surface, and between the upper main surface and the lower main surface. A lead comprising a conductive layer, a portion of the conductive layer to be joined to the semiconductor chip, a lead having a porous structure having a plurality of through holes penetrating from the upper main surface to the lower main surface, First holding means for holding a TAB tape formed on an insulating tape, (b) second holding means for holding the semiconductor chip having bumps formed thereon, (c) the first holding means Moving means for moving the TAB tape and the semiconductor chip so that the bump and the porous structure of the lead come into contact with each other by moving the first or second holding means; and (d) the bump. Is heated to a molten bump, which The serial dissolved bump and a heating means for entering into the through hole, the bonding apparatus of the TAB tape and the semiconductor chip.