JP2950338B2 - Metal mask alignment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Overview] Regarding a metal mask alignment device for forming solder bumps A metal mask while appropriately supporting a metal mask or a plate member so that the metal mask does not rub on the plate member The purpose is to enable fine adjustment of the alignment between each hole of the plate member and each electrode pad of the plate member. The metal mask and the plate member on which the solder bump is to be formed are movably supported. After placing the support plate member on the supported plate member, a fixing jig for temporarily fixing the support plate member is provided, the plate member and the metal mask are spaced apart and aligned, and then they are brought into contact with each other. After the fixing, the magnet is placed on the support plate member while the fixing jig is being applied to the support plate member, and then the fixing jig is removed.

[Industrial applications]

The present invention relates to a metal mask alignment apparatus for forming solder bumps used in flip chip bonding of semiconductor elements and the like.

In flip chip bonding of semiconductor elements, many solder bumps are formed on the semiconductor element or circuit wiring board at once, and the LSI chip without package is bonded to the semiconductor element or circuit wiring board by the solder bumps. Has become. The step of forming solder bumps on a semiconductor element or a circuit wiring board is performed by a solder vapor deposition device. The solder vapor deposition device uses a metal mask with many holes according to the position of the solder bump,
The vapor of the solder is vapor-deposited on the semiconductor element or the circuit wiring board through the hole of the metal mask. Also, instead of forming solder bumps directly on semiconductor elements or circuit wiring boards, using a transfer plate, vapor of solder is vapor-deposited on the transfer plate through holes in the metal mask,
Thereafter, the solder bumps formed on the transfer plate may be thermally transferred to a predetermined semiconductor element or circuit wiring board. As the transfer plate, a silicon or glass plate is used. In any case, a solder bump is formed on a plate member (semiconductor element or circuit wiring board or transfer plate) on which a solder bump is to be formed, using a metal mask.

[Conventional technology]

As shown in FIG. 6, in a conventional solder vapor deposition apparatus, a solder bump is formed using a metal mask 3. The metal mask 3 has a plurality of holes 2 and is arranged in contact with a plate member (semiconductor element or circuit wiring board) 1 on which a solder bump is to be formed. The metal mask 3 is attracted by a magnet 5 disposed above the support plate member 4 and is fixed to the plate member 1 so as to maintain a fixed positional relationship with the plate member 1. The solder vapor deposition apparatus includes a holder H on which the support plate member 4 is placed and a solder tank (not shown) for supplying solder vapor, and the solder vapor is supplied while rising as shown by the arrow. .
Thereby, the solder passes through the holes 2 of the metal mask 3 and reaches the plate member 1, and a solder bump having the same pattern as the pattern of the holes 2 of the metal mask 3 is formed on the surface of the plate member 1. The holder H is provided with a duct C for cooling water, so that the metal mask 3 is cooled via the holder H, the support plate member 4 and the plate member 1.

FIG. 5 shows a plate member (semiconductor element or circuit wiring board)
The example of the solder bump 6 formed on the surface of No. 1 is simplified. In addition, a plate member (semiconductor element circuit wiring board)
The area 7 on which the individual solder bumps 6 are to be formed
Each region 7 is provided with an electrode pad (which overlaps with the solder bump 6 in FIG. 5) for electrical connection with the solder bump 6. FIG. 4 shows a semiconductor device which is flip-chip bonded to such a plate member (semiconductor element or circuit wiring board) 1, in which an LSI chip 8 without a package is bonded to the plate member 1 by solder bumps 6.

[Problems to be solved by the invention]

In order to perform such solder vapor deposition, the positions of the holes 2 on which the solder bumps 6 of the metal mask 3 are to be formed and the electrode pads for electrical connection with the solder bumps 6 of the plate member 1 are aligned. It is necessary to fix the metal mask 3 to the plate member 1 so as to maintain such an alignment. For this purpose, as shown in FIG.
Is fixed to the plate member 1 by suction using the magnet 5. In this operation and procedure, the metal mask 3 and the plate member 1 are firstly subjected to simple alignment, then the metal mask 3 is fixed to the plate member 1 by suction using a magnet 5, and then, using a microscope. Fine adjustment of the alignment between each hole 2 of the metal mask 3 and each electrode pad of the plate member 1 has been performed. For this reason, the metal mask 3 rubs on the plate member 1 when performing fine adjustment with a microscope in a state where the metal mask 3 is attracted and fixed to the plate member 1, and the plate member 1 made of a semiconductor element or a circuit wiring substrate is rubbed. There is a fear that the surface of the glass may be damaged.

An object of the present invention is to finely adjust the alignment between each hole of the metal mask and each electrode pad of the plate member while appropriately supporting the metal mask and the plate member so that the metal mask does not rub on the plate member. It is an object of the present invention to provide a metal mask alignment device that can be used.

[Means for solving the problem]

The metal mask positioning apparatus according to the present invention is characterized in that a plate member on which a solder bump is to be formed is sandwiched between a metal mask and a supporting plate member, and the metal mask is placed on the surface of the supporting plate member by a magnet. A metal mask alignment device for aligning the metal mask with the plate member when the metal mask is held in close contact with the metal member, the first support means for supporting the metal mask; Second support means movable relative to the means and for supporting the plate member, and after placing the support plate member on the plate member supported by the second support means, A fixing jig for temporarily fixing the support plate member is provided. After the plate member and the metal mask are spaced from each other and aligned with each other, and these are brought into contact with each other, the fixing jig is While being applied to the plate member The magnet placed on the support plate member, and then is characterized in that it has to remove the solid Teiji tool.

(Operation)

In the above configuration, the metal mask and the plate member are supported by the first and second support means, respectively, and at this time, the metal mask and the plate member are aligned with an interval between the metal mask and the plate member. Then, each hole of the metal mask is aligned with each electrode pad of the plate member. Then, the plate member is brought into contact with the metal mask, and the support plate member is placed on the plate member. Here, the support plate member is temporarily fixed by the fixing jig, and the magnet is placed on the support plate member in the meantime. Therefore, the magnet force of the magnet approaches the magnet without disturbing the positional relationship between the metal mask and the plate member. Can be. After holding the metal mask in close contact with the plate member, the fixing jig is removed. As described above, since the alignment is performed in a state where the metal mask, the plate member, and the magnet are not in contact with each other, fine adjustment of the alignment can be performed without the metal mask rubbing on the plate member.

〔Example〕

Referring to FIGS. 1 and 2, a metal mask positioning apparatus according to an embodiment of the present invention corresponds to, for example, a pre-process of a solder vapor deposition apparatus shown in FIG. 6, and a solder bump should be formed. It includes means for supporting a plate member 1 and a metal mask 3 having a plurality of holes 2. Further, the support plate member 4 is placed on the plate member 1, and the magnet 5 is further placed thereon. 3A to 3
In FIG. 3F, the plate member 1 corresponds to the hole 2 of the metal mask 3.
Are shown in FIG. A solder bump should be formed on the electrode pad 9 in a later solder vapor deposition step.

The metal mask 3 is, for example, a Kovar plate having a diameter of 100 mm and a thickness of 200 μm. The diameter of the holes 2 for forming solder bumps is, for example, 200 μm, and the pitch between the holes 2 is, for example, 400 μm. On the other hand, the plate member 1 on which the solder bumps 6 are to be formed is, for example, a silicon plate having a diameter of 75 mm and a thickness of 400 μm. The support plate member 4 is formed of a copper plate, has an outer shape larger than that of the metal mask 3, and has a thickness determined to have sufficient rigidity when the plate member 1 and the metal mask 3 are supported. The magnet 5 is, for example, ferrite or Sm-
It consists of a disk made of Co.

1 and 2, an apparatus for positioning a metal mask 3 includes a frame base 10, an X-direction moving plate 1 movable along a guide groove 10a provided in the frame base 10.
2. It includes a Y-direction moving plate 14 movable along a guide groove 12a provided on the X-direction moving plate 12, and a turntable 16 rotatably provided on the Y-direction moving plate 14. The metal mask 3 is supported by the turntable 16. Although actuators for the X-direction moving plate 12, the Y-direction moving plate 14, and the turntable 16 are omitted, a known motor-driven actuator can be provided, for example.

Above the turntable 16, a suction pad 18 is arranged. A vacuum suction hole 20 (FIG. 3B) is formed inside the suction pad 18 so that the plate member 1 on which the solder bump is to be formed is supported by vacuum. The suction pad 18 is mounted movably in the vertical direction by an actuator (not shown). The vacuum suction hole 20 is connected to a valve (not shown) to control the supply of vacuum.

Further, the turntable 16 and the Y-direction moving plate 14
Are arranged so as to form the same surface, and a pair of fixing jigs 22 and 24 are arranged thereon. In the embodiment, the fixing jigs 22, 24 are provided with bars 22b, 24 supported by legs 22a, 24a at both ends.
The height of the bottom surface of each bar 22b, 24b is substantially equal to the total thickness of the metal mask 3, the plate member 1, and the support plate member 4. A weak magnet is attached to the legs 22a, 24a at both ends of the fixing jigs 22, 24, and the fixing jigs 22, 2,
4 can be temporarily fixed on the turntable 16 and the Y-direction moving plate 14, or can be detached.

Next, referring to FIGS. 3A to 3F, the metal mask 3
The operation of aligning and attaching to the plate member 1 will be described.

As shown in FIG. 3A, the metal mask 3 is roughly aligned and the Y-direction moving plate 14 (turntable
16) Put on top. Next, as shown in FIG. 3B, the suction pad 18 supporting the plate member 1 is moved down to bring the plate member 1 to a position slightly above the metal mask 3 with a slight gap. Therefore, fine adjustment of the alignment between the metal mask 3 and the plate member 1 is performed. Fine adjustment of the alignment between the metal mask 3 and the plate member 1 is performed so as to align two reference holes 2 of the metal mask 3 with two related electrode pads 9 of the plate member 1. For this purpose, when the suction pad 18 is lowered, the positions of the hole 2 and the electrode pad 9 are read by the monitor television 26 or 28, respectively, and the respective positions are stored, and the X-direction moving plate 12, the Y-direction moving plate 14 and aligning the electrode pad 9 associated with the hole 2 by operating the turntable 16.

Next, as shown in FIG. 3C, the suction pad 18 supporting the plate member 1 is further lowered to bring the plate member 1 into contact with the metal mask 3 and then the plate member 1 is released to release the suction pad 18. Only actuate the lift. Then, as shown in FIG. 3D, the support plate member 4 is placed on the plate member 1 and the 3E
As shown in the figure, the support plate member 4 is temporarily fixed by the fixing jigs 22 and 24. At this time, the bars 22 of the fixing jigs 22, 24
b and 24b lightly suppress the peripheral edge of the support plate member 4, and the legs 22a and 24a are fixed to the Y-direction moving plate 14 (turntable 16). In this state, the magnet 5 is placed on the support plate member 4 as shown in FIG. 3F. Finally, the fixing jigs 22 and 24 are removed, and the magnet 5 integrates the metal mask 3, the plate member 1, and the support plate member 4. This integrated structure can then be transferred, for example, to the solder deposition apparatus shown in FIG.

〔The invention's effect〕

As described above, according to the present invention, the metal mask and the plate member are supported by the first and second support means, and at this time, the metal mask and the plate member are spaced apart from each other by increasing the distance between the metal mask and the plate member. The magnet was placed on the support plate while the plate was brought into contact with the metal mask, and the support plate was temporarily fixed by the fixing jig. Fine adjustment of the alignment can be performed without rubbing on the member, and it is possible to prevent a positional shift between the metal mask and the plate member even when the magnet acts.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an apparatus for aligning a metal mask according to an embodiment of the present invention, and FIG. 2 is a view showing a state in which a magnet is placed on a support plate member held by a fixing jig in the apparatus shown in FIG. FIGS. 3A to 3F are views for explaining the operation of performing alignment and assembly using the apparatus of FIG. 1, FIG. 4 is a view showing a flip chip bonding structure, and FIG. FIG. 6 is a plan view showing the formed plate member, and FIG. 6 is a view showing a conventional solder vapor deposition apparatus. DESCRIPTION OF SYMBOLS 1 ... Plate member, 2 ... Hole, 3 ... Metal mask, 4 ... Support plate member, 5 ... Magnet, 6 ... Solder bump, 9 ... Electrode pad, 12 ... X direction moving plate, 14 ... Y-direction moving plate, 16 ... Turntable, 18 ... Suction pad, 22,24 ... Fixing jig.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-69936 (JP, A) JP-A-2-17835 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01L 21/60

Claims (2)

(57) [Claims] 1. A plate member (1) on which a solder bump is to be formed is sandwiched between a metal mask (3) and a support plate member (4), and a magnet (5) arranged on the surface of the support plate member. A metal mask positioning device for positioning the metal mask with respect to the plate member when the metal mask is held in close contact with the plate member, wherein the first support means supports the metal mask. (16), second support means (18) movable relative to the first support means and supporting the plate member, and the second support means supported by the second support means. Fixing jigs (22, 24) for temporarily fixing the support plate member after placing the support plate member on the plate member,
After the plate member and the metal mask are spaced apart from each other and aligned with each other and then brought into contact with each other, the magnet is removed while the fixing jig is applied to the support plate member. A metal mask positioning device which is placed on a support plate member and from which the fixing jig is removed. 2. A detecting means (26, 28) for detecting a reference position of the plate member and the metal mask when the plate member and the metal mask are held in a state of being spaced apart from each other. 2. The metal mask according to claim 1, wherein said first support means and said second support means are moved relative to each other in accordance with an output of said detection means, so that said plate member and said metal mask are aligned. Positioning device.