JPH0590341A - Bonder - Google Patents

Abstract

(57) [Abstract] [Purpose] Regarding a bonding device for bonding leads in a lump, it is possible to prevent misalignment between the leads and the pattern of the substrate and perform ultra-precision positioning, and pressure heating by even parallel surface contact. The purpose is to do. [Structure] The mounting table 2 has a cylindrical surface 2b centered on the X-axis passing through the center point O of the substrate 3 on the lower side, and a cylindrical inner surface 4 of the rotary table 4.
A ball 5 is interposed between a and the cylindrical surface 2b so that the mounting table 2 can be rotated around the X axis. The tension spring 8 balances the mounting table 2 and makes it stand still. The rotary table 4 has a cylindrical surface 4b centered on the Y-axis passing through the center point O and having a radius larger than the radius of the cylindrical surface 2b of the mounting table 2 below. A ball 10 is interposed between the cylindrical inner surface 9a of the fixed base 9 and the cylindrical surface 4b so that the rotary base 4 can rotate about the Y axis. The tension spring 13 balances the turntable 4 and keeps it stationary.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for positioning and parallel-contacting a semiconductor lead on a pattern of a substrate with an accuracy of a micron unit and heating it under pressure to collectively bond (gang bonding).

[0002]

2. Description of the Related Art At present, as a method of bonding a semiconductor chip to a pattern of a substrate, there are generally two methods of wire bonding and tab automated bonding (Tape Automated Bonding).
It is not possible to use a lead wire having μ or less and 125 to 250 or more leads unless tab bonding.

As is well known in tab bonding, leads are formed on a tape by printing and etching,
The semiconductor chip is bonded to the inner lead of the tape (ILB), and the outer lead is bonded to the pattern of the substrate (OLB), which is performed by the bonding apparatus 30 of FIG.

Taking the OLB as an example, the substrate 33 is placed on the mounting surface 3 parallel to the pressure heating surface 34a of the thermotool 34.
It is placed on 2. On the substrate 33, the semiconductor chip 35 after the ILB processing is preliminarily precisely aligned with the pattern of the leads 36 and the substrate 33 by an optical means, and the leads 36 are pressurized and heated by the thermo-tool 34 to perform bonding.

[0005]

However, the mounting surface 32 of the stage 31 and the pressing surface 34 of the thermod tool 34 are not provided.
It is unlikely that a is exactly parallel. Therefore,
When bonding a large number of thin and narrow lines (for example, a semiconductor semiconductor chip for computers has a lead pitch of 50 μ (micron) or less, a lead width of 40 μ or less, and a number of leads of 500 or more) at the same time, the thermod tool 3
When the pressing surface 34a of No. 4 abuts on the lead 36, a fine tilt error occurs between them. Therefore, the pressing surface 3 as it is
When the lead 4 is pressed against the lead 36, the lead 36 and the substrate 33
There is a positional deviation from the pattern, and the applied pressure has partial strength unevenness.

Therefore, if the lead 36 and the pattern of the substrate 33 are misaligned, the lead 36 and the pattern may not be connected or may be erroneously connected to an adjacent lead. Further, non-welding or incomplete welding of the leads 36 due to unevenness of the applied pressure, or melting of the leads 36 due to excessive applied pressure occurs.

In this way, even if one lead is erroneously connected or the welding is defective, the entire product becomes a defective product, and the above is a very serious problem. Therefore, in order to perform accurate tab bonding, It has been a conventional problem to obtain contact (average surface contact without displacement).

In order to solve the above problems, a stage 39 provided with a mounting table 38 via an elastic body 37 as shown in FIG. 10 is conventionally disclosed in Japanese Patent Laid-Open No. 62-149142. However, with this structure, it is not possible to eliminate the lateral minute deviation ΔC due to the elastic deformation of the elastic body 37 as shown in FIG. 11 when it is pressed by a thermod tool (not shown). For example, when the inclination angle θ is set to 0.3 °, the deviation amount becomes very large, 15 μ to 25 μ,
There is a problem that the thin lead 13 is deformed by the displacement force between the pressing surface of the thermo-tool and the substrate 33.

The present invention has been made to solve the above-mentioned problems. It is possible to prevent the positional deviation between the lead and the pattern of the substrate and to perform ultra-precision positioning, and to perform parallel and uniform The purpose is to be able to perform pressure heating by surface contact.

[0010]

In order to achieve the above object, the present invention provides a stage having a mounting surface for a substrate or a semiconductor chip and a center point of a non-welding side plane formed by leads provided on a tape. A thermo-tool having a contact portion having at least two sides contacting the lead on both sides of the lead, and bonding the leads collectively by heating under pressure to the pattern of the substrate or the electrode portion of the semiconductor chip; and the contact portion. A parallel abutting mechanism for abutting against the lead so as to be parallel to the mounting surface, the parallel abutting mechanism having a first axis in a non-welding side plane passing through the center point as a center. Having at least a part of a curved surface other than a curved spherical surface
In a non-welding side plane, a first mechanism portion including a rotating body and a first support body that supports a curved surface of rotation of the first rotating body and rotates the first rotating body around the first axis. At least a part of which has a rotation curved surface other than a spherical surface having a maximum curvature radius larger than the maximum curvature radius of the rotation curved surface of the first rotating body with a second axis passing through the center point and intersecting the first axis as a center. A second rotating body; and a second mechanism portion including a second supporting body that supports the curved curved surface of the second rotating body and rotates the second rotating body around the second axis. , First and second
A mechanical unit is provided on the stage and / or the thermod tool.

Further, according to the present invention, the abutting portion has a planar rectangular shape,
The first axis of the first rotating body and the second axis of the second rotating body are orthogonal to each other. Further, according to the present invention, the first mechanism portion is provided with a first returning means for returning the first rotating body to the initial position, and the second mechanism portion is provided with a second returning means for returning the second rotating body to the initial position. A reset means was provided.

Further, according to the present invention, the first supporting member is provided with a roller for supporting the rotating curved surface of the first rotating member, and the second supporting member is provided with a roller for supporting the rotating curved surface of the second rotating member. Further, according to the present invention, the first support body of the first mechanism portion and the second rotating body of the second mechanism portion are integrally provided.

[0013]

Therefore, according to the present invention, when the lead is bonded to the pattern of the substrate or the electrode portion of the semiconductor chip, first, one corner of the contact portion of the thermod tool comes into point contact with the first rotating body. Is rotated about the first axis, and one side starting from the contact point comes into line contact, and when one side comes into line contact, the second rotating body rotates about the second axis and starts from the contact line. The (entire surface) is in surface contact, and is brought into contact with the lead so that the contact portion of the thermod tool is parallel to the mounting surface of the stage.
As a result, it becomes possible to perform pressure heating by even surface contact without unevenness.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a stage of a bonding apparatus will be described below with reference to FIGS.

1 is an exploded perspective view of the stage, FIG. 2 is a plan view of the stage, FIG. 3 is a sectional view taken along the line AA of FIG. 2, and FIG.
2 is a cross-sectional view taken along the line BB of FIG. 2, FIG. 5 is an explanatory view showing the deviation, and FIG. 6 is an enlarged cross-sectional view showing the cylindrical surfaces of the mounting table and the rotary table in phase. Further, the contact portion of the thermo-tool in this embodiment will be described as having a planar rectangular shape capable of collectively bonding the leads extending in all directions of a rectangular semiconductor chip.

As shown in FIG. 1, the mounting table 2 as the first rotating body of the stage 1 has a rectangular substrate 3 (to be precise, a non-welding formed by a lead) mounted on the mounting surface 2a. It has a first surface parallel to a pair of opposite sides of the abutting part of the thermod tool, that is, a cylindrical surface 2b centered on the X axis, which passes through the center point O of the side plane).

The turntable 4 as the first support and the second turning body has a cylindrical inner surface 4a centered on the X-axis, and the cylindrical inner surface 4
A large number of balls 5 serving as rollers are interposed between a and the cylindrical surface 2b so that the mounting table 2 can be rotated around the X axis with a small force, and these balls 5 have a large number of accommodation holes 6a. The spacing is maintained by the retainer 6 having the. A regulation plate 7 is fixed to opposite end surfaces of the rotary table 4, and the mounting table 2 is rotated only around the X axis to move the mounting table 2 in the X axis direction and other axes (Y axis). The rotation around is restricted.

A tension spring 8 is provided as a return means for determining the initial position of the mounting table 2 between a pair of side surfaces of the mounting table 2 which face each other in parallel with the X-axis and the rotating table 4, and the mounting table 2 is provided with a tension spring 8. Balanced and stationary. In this embodiment, the mounting table 2, the rotary table 4, the regulating plate 7, the tension spring 8 and the like constitute a first mechanism section.

The rotary table 4 passes through the central point O and is parallel to a second axis, that is, the Y axis, which is parallel to the other pair of opposite sides of the abutting part of the thermo-tool, and the mounting table 2 is provided. It has a cylindrical surface 4b having a radius R2 larger than the radius R1 of the cylindrical surface 2b.

The fixed table 9 as the second support has a cylindrical inner surface 9a centered on the Y axis, and the rotary table 4 is arranged around the Y axis between the cylindrical inner surface 9a and the cylindrical surface 4b of the rotary table 4. A large number of balls 10 that can be rotated with a small force
, And these balls 10 have a large number of receiving holes 11a.
The spacing is maintained by the retainer 11 having the. A regulation plate 12 is fixed to the opposite end faces of the fixed base 9, and the rotary base 4 is rotated only around the Y axis to move the rotary base 4 in the Y axis direction and another axis (X axis). The rotation around is restricted.

A pair of regulating plates 7 fixed to the rotary table 4
A tension spring 13 is interposed as a return means for determining the initial position of the rotary table 4 between the fixed table 9 and the fixed table 9, and the rotary table 4 is kept stationary while being balanced. In this embodiment, the rotary table 4, the fixed table 9, the regulating plate 12, the tension spring 13 and the like constitute a second mechanism section.

Now, with the sides of the substrate 3 placed on the placing surface 2a of the placing table 2 so as to be parallel to the X and Y axes, the thermotool 14 is lowered as shown in FIG. Let
When one corner of the contact portion 15 comes into point contact with the contact point D ₀ of the substrate 3 (accurately, via a lead (not shown)), the pressing force Fg of the thermo-tool 14 acts on the ball 5. Pressing force F
g acts on the point P _{1 on} the cylindrical surface 2b on the lower part of the mounting table 2 and the point P ₂ on the cylindrical surface 4a of the rotary table 4 to generate component forces Fc ₁ and Fc _{2 in the} rotational direction, respectively. Try to rotate 2.

At this time, the radius R1 of the cylindrical surface 2b of the mounting table 2
And the radius R2 of the cylindrical surface 4b of the turntable 4 are

[0024]

Since R1 <R2, the relationship between the component forces Fc ₁ and Fc _{2 in the} rotation direction is

[0025]

## EQU2 ## Fc ₁ > Fc ₂ . Further, comparing the rolling resistance f ₁ of the cylindrical surface 2b of the mounting table 2 with the rolling resistance f ₂ of the cylindrical surface 4b of the rotating table 4, the weight applied to the cylindrical surface 2b is only the weight of the mounting table 2 The weight applied to 4b is the weight of the mounting table 2 and the turntable 4, and since the weight applied to the cylindrical surface 4b is large,

[0026]

## EQU3 ## f ₁ <f ₂ .

Therefore, the contact portion 15 of the thermo-tool 14
When one corner of the table comes into point contact with the substrate 3, the mounting table 2 that is easy to move first
Starts rotating around the X axis against the urging force of the tension spring 8, and when one side of the abutting portion 15 parallel to the Y axis starting from the contact point D ₀ makes a line contact, the rotation of the mounting table 2 The movement stops.

Further, when the thermo-tool 14 is lowered and pressed against the substrate 3, this time, the rotary table 4 is pulled by the tension spring 1.
3 starts to rotate about the Y-axis against the urging force of 3, and the surface starting from the contact line (the entire lower surface of the contact portion 15 of the thermod tool 14) comes into surface contact.

The substrate 3 is attached to the contact portion 15 of the thermo-tool 14.
The center of rotation (fixed point) when the (non-welding side plane formed by the leads) comes into parallel contact is the center point O, but the amount of deviation ΔD in the plane direction of the initial contact point D ₀ is as shown in FIG. As shown in, when the width of the thermo-tool 14 is W and the inclination angle of the mounting table 2 from the initial position is θ,

[0030]

## EQU4 ## It is represented by .DELTA.D = W / 2 (1-cos .theta.). Therefore, for example, when the tool width W of the thermo-tool 14 is 15 mm and the inclination angle θ is 0.3 °, the deviation amount ΔD≈1 × 10 ⁻⁴ mm = 0.1 μ, which can be considered to be zero.

As described above, in the gang bonding by the bonding apparatus of the present embodiment, first, one corner of the abutting portion 15 of the thermod tool 14 is brought into point contact with the substrate 3 (correctly, the lead), and then from the contact point. When one side of the abutting portion 15 parallel to the starting Y-axis is brought into line contact, it is interposed between the cylindrical surface 2b of the mounting table 2 and the cylindrical inner surface 4a of the rotary table 4 so that the displacement of the initial contact point hardly occurs. Since rolling is performed by the mounted balls 5, line contact with the lead on one side of the contact portion 15 can be performed extremely accurately and smoothly.

Next, when the contact portion 15 of the thermo-tool 14 is moved from one side in line contact to surface contact in the X direction, first, the rotating table 4 can be rotated after rotating the mounting table 2. Therefore, the transition from the line contact of the contact portion 15 to the surface contact in the X direction can be performed very naturally and with almost no risk of misalignment of the lead.

As a result, it is possible to prevent the positional deviation between the lead and the pattern of the substrate 3 and perform super-precision positioning, and it is possible to perform pressure heating by even parallel surface contact.

In this embodiment, the outer lead bonding (OLB) in which the leads are collectively bonded to the pattern of the substrate 3 has been described as an example. However, the inner lead bonding in which the leads are collectively bonded to the electrode portion of the semiconductor chip. It goes without saying that the same effect can be obtained even if it is carried out in (ILB).

In this embodiment, the thermo-tool 14 is fixed and the stage 1 is attached to the abutting portion 1 of the thermo-tool 14.
Although the stage 1 is fixed, the stage 1 may be fixed, and a mechanism similar to that of the present embodiment may be provided on the side of the thermotool 14 so that the abutting portion 15 of the thermotool 14 is directed toward the stage 1. ..

As shown in FIGS. 7 and 8, the stage 1
It is also possible to provide a bonding device in which the first mechanical section 6 is provided and the thermod tool 20 is provided with the second mechanical section. That is, the fixed base 17 as the first support of the stage 16 is the substrate 3
A cylindrical inner surface 17a having an X-axis (an axis in the direction orthogonal to the paper surface in FIG. 7) passing through the center point O of (correctly, the non-welding side plane formed by the lead) is provided, and the cylindrical inner surface 17a and the mounting table 2 are A large number of balls 18 are interposed between the mounting table 2 and the cylindrical surface 2b so that the mounting table 2 can be rotated around the X axis with a small force. A retainer that holds the space between the balls 18 is not shown. The mounting table 2 is rotated only around the X axis on the opposite end surfaces of the fixed table 17 to move the mounting table 2 and to move the Y table.
A regulation plate 19 that regulates the rotation around the shaft is fixed. A tension spring 8 for determining an initial position of the mounting table 2 is interposed between a pair of side surfaces of the mounting table 2 facing each other and the fixed table 17.

The tool main body 21 as the second rotating body of the thermod tool 20 is centered on the Y axis passing through the center point O (the axis orthogonal to the paper surface in FIG. 8) at the upper part and on the cylindrical surface 2b of the mounting table 2. Cylindrical surface 21 with radius R2 larger than radius R1
a and the contact portion 15 at the bottom. The mounting base 22 as the second support body also has a cylindrical inner surface 22a centering on the Y axis, and between the cylindrical inner surface 22a and the cylindrical surface 21a of the tool main body 21, the tool main body 21 exerts a small force around the Y axis. A large number of balls 23 are interposed so that they can be rotated by. A retainer that holds the space between the balls 23 is not shown. On the opposing end surfaces of the mounting base 22, the tool body 21 is rotated only around the Y axis, and the tool body 21 is rotated.
A regulation plate 24 that regulates the movement of and the rotation around the X-axis is fixed. A tension spring 1 is provided between the tool body 21 and the mount 22 to determine the initial position of the tool body 21.
3 is interposed.

When performing gang bonding with the bonding apparatus configured as described above, the thermotool 20 is lowered and one corner of the contact portion 15 makes point contact with the substrate 3 (correctly, not shown). Contact via the lead)
First, the easy-to-move mounting table 2 resists the urging force of the tension spring 8 and
Starting to rotate about the axis, one side of the contact portion 15 makes a line contact, and the rotation of the mounting table 2 stops. When the thermo-tool 20 is further lowered and pressed against the substrate 3, the tool body 21 starts to rotate around the Y-axis against the biasing force of the tension spring 13 and starts from the contact line. The surface (the entire surface of the contact portion 15 of the tool body 21) comes into surface contact. Therefore, also in this embodiment, it is possible to obtain the same actions and effects as those of the above embodiment.

Further, in the above embodiment, the cylindrical surface 2 of the mounting table 2 is used.
b and the cylindrical inner surface 4a of the rotary table 4, and between the cylindrical surface 4b of the rotary table 4 and the cylindrical inner surface 9a of the fixed table 9, balls 5 and 10 are provided as rollers to roll and slide. However, a roller may be used as the roller. Further, the relative rotation between the mounting table 2 and the rotary table 4 and the relative rotation between the rotary table 4 and the fixed table 9 are made by sliding without the rollers (balls 5 and 10), or an air layer is used. An air guide or a magnetic guide utilizing magnetic reaction force may be used.

Further, in the above embodiment, the mounting table 2 and the rotary table 4 are used.
Although the tension springs 8 and 13 are used as the returning means for determining the initial position of, respectively, the present invention is not limited to this.
A compression spring or a leaf spring may be used, or an air cylinder may be used.

Further, in the above embodiment, the mounting table 2 and the rotary table 4 are used.
Is provided with the cylindrical surfaces 2b and 4b, but the present invention is not limited to this. It is assumed that the curved surfaces around the X axis and the Y axis, for example, the curved surface of the outer circumference of the truncated cone are provided in part. The rotary base 4 and the fixed base 9 may be those capable of supporting the corresponding rotary curved surfaces.

Further, in the above embodiment, the thermod tool 14 is used.
Although the contact portion 15 has a rectangular shape in plan view, the contact portion is not limited to this and may be, for example, a contact portion having two side portions capable of collectively bonding leads extending from a pair of opposite sides of a rectangular semiconductor chip. It may be a flat U-shaped contact portion having three sides.

[0043]

As described in detail above, according to the present invention,
There is an excellent effect that the positional deviation between the leads and the pattern of the substrate can be prevented, ultra-precision positioning can be performed, and the pressure and heating can be performed by even parallel surface contact.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment in which the present invention is embodied in a stage.

FIG. 2 is a plan view showing a stage.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a sectional view taken along line BB of FIG.

FIG. 5 is a diagram showing calculation of a deviation amount.

FIG. 6 is an enlarged cross-sectional view showing the cylindrical surfaces of the mounting table and the rotary table in phase with each other.

FIG. 7 is a front sectional view showing another embodiment.

FIG. 8 is a side sectional view of FIG.

FIG. 9 is a front view showing a conventional bonding apparatus.

FIG. 10 is a front view showing a conventional bonding apparatus.

FIG. 11 is an explanatory diagram showing a shift of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 stage 2 mounting base as a 1st rotation body 2a mounting surface 3 substrate 4 rotation base as a 1st support body and a 2nd rotation body 14,20 thermod tool 15 contact part 17 fixed base as a 1st support body 21 Tool Main Body as Second Rotating Body 22 Mounting Base as Second Supporting Body O Center Point

Claims (5)

[Claims] 1. A stage (1) having a mounting surface (2a) for a substrate (3) or a semiconductor chip and both sides of a center point (O) of a non-welding side plane formed by leads provided on a tape. A thermod tool (14, which has a contact portion (15) having at least two sides for contacting the lead, and presses and heats the lead to the pattern of the substrate (3) or the electrode portion of the semiconductor chip to collectively bond the leads. Two
0) and a parallel contact mechanism for contacting the lead so that the contact portion (15) is parallel to the mounting surface (2a). A first rotating body (2) having at least a part of a rotating curved surface other than a spherical surface centering on the first axis in a non-welding side plane passing through (O), and a first rotating body (2)
In the non-welding side plane, and a first mechanism part including a first support body (4, 17) for supporting the rotation curved surface of the first rotation body (2) for rotating the first rotation body (2) around the first axis. At a center other than the spherical surface having a maximum radius of curvature larger than the maximum radius of curvature of the rotating curved surface of the first rotating body (2), with the second axis passing through the central point (O) and intersecting the first axis as a center. A second rotating body (4, 21) having a curved surface in at least a part thereof, and a second rotating body (4, 21).
21) A second support body (9, 22) for supporting the rotation curved surface of (21) and rotating the second rotation body (4, 21) around the second axis.
And a second mechanism section including a second mechanism section, wherein the first and second mechanism sections are provided on the stage (1) and / or the thermotool (14, 20). 2. The bonding according to claim 1, wherein the abutting portion has a planar rectangular shape, and the first axis of the first rotating body and the second axis of the second rotating body are orthogonal to each other. apparatus. 3. The first mechanism portion includes a first returning means for returning the first rotating body to the initial position, and the second mechanism portion includes a second returning portion for returning the second rotating body to the initial position. The bonding apparatus according to claim 1, further comprising means. 4. The first supporting body includes rollers that support the curved surface of rotation of the first rotating body, and the second support body includes rollers that support the curved surface of rotation of the second rotating body. The bonding apparatus according to. 5. The first support body of the first mechanism portion and the second rotating body of the second mechanism portion are integrally provided.
The bonding apparatus according to.