CN1068710C - Tape and reel automatic soldering ball array integrated circuit packaging method - Google Patents

Abstract

The invention relates to a packaging method for a rolling belt automatic welding ball array type integrated circuit, which forms a first dry film on a polyimide film pressed with double-sided thin copper, electroplates copper/nickel/gold/nickel (or nickel/gold, copper/nickel), removes the first dry film, etches the lower layer thin copper of the polyimide film through a second dry film to form a plurality of gaps, uses the lower layer thin copper as a mask to form holes on the laser drilling hole of the polyimide film, and forms an outward protruding joint point by hole electrolytic plating, etches the thin copper and peels nickel, and forms a chip mounting hole and a peripheral through hole by laser drilling, thereby enabling the external joint point to be finer, and welding a chip by a single spot welding mode to reduce the packaging area.

Description

Tape and reel automatic soldering ball array integrated circuit packaging method

The invention relates to an integrated circuit packaging method, in particular to a tape and roll automatic welding ball array integrated circuit packaging method.

In terms of the manufacturing method of the current TAB-BGA type integrated circuit package circuit board, it is basically shown in Figure 4A～I, shown in the figure is the typical manufacturing process of 3M Company, at first it is polyimide film 90 (POLYIMIDE) in Figure 4A ) above the substrate by sputtering (PVD or CVD) to form a thin thickness of sputtered copper 91 to form a polyimide film containing a thin copper layer, and then as shown in Figure 4B, the surface is covered by electroplating Thin thickness electroplated copper 92, after that, as shown in Figure 4C, press the dry film at the top and bottom surfaces and pass the steps of exposure and development to form a plurality of block dry films 93 with notches on the top and bottom surfaces, and then , as shown in Figure 4D, the step of electroplating copper at the top position to form a thicker electroplated copper 94 between the dry films 93, and secondly, as shown in Figure 4E, the polyimide film 90 is etched to form a tapered hole 97 for subsequent implantation of solder balls. Then, as shown in FIG. And the taper hole 97 place of the bottom forms electrolytic electroplating nickel and electrochrome plating layer 96, afterward, forms the pattern as Fig. 4G in order to remove the dry film 93 of top bottom layer, and through the step of etching copper layer, to the interlayer position of Fig. 4G Electroplated copper 92 and sputtered copper 91 are etched to transform into the pattern shown in Figure 4H, and finally, the step of implanting solder balls at the positions of the taper holes 97 at the bottom is formed at the relevant parts shown in Figure 4I For external solder balls 98, as for the protruding electroplating nickel and electrochrome plating layers 96 located at appropriate positions on the surface, one of them is used for bonding the chip 40, and at the same time, each pin of the chip 40 is connected with a metal wire through an interconnector (BONDER). 41 is connected to relevant positions. But the above-mentioned existing TAB-BGA integrated circuit packaging method has the following disadvantages: first, the sputtering copper 91 of thin thickness formed in the sputtering (SPUTTERING) mode on the top of the polyimide film 90, though sputtering Copper foil formed by plating can achieve a relatively uniform and thin thickness. However, this sputtering process is not only expensive, but also the cost is even higher when sputtering a large area on the surface of the polyimide film, which is not economical. sexual demands. Secondly, the external contact is used→solder ball planting→method. Since the size of the solder ball has a certain limit, and the corresponding taper hole for the solder ball implantation must also be designed with an appropriate allowable error, the size and spacing of the external contact The distance cannot be greatly reduced, resulting in the disadvantage that the external contact cannot be miniaturized, and the method of implanting solder balls is to make the solder balls roll on the circuit board and fall into each tapered hole, and then combine with the metal inside the tapered hole through high temperature. This method also has the phenomenon of insufficient positioning accuracy, that is, it is impossible to ensure that all the solder balls are aligned, so it cannot be realized under the demand for higher precision and smaller contacts. Furthermore, since chromium metal is formed on the contacts for connecting the chip, Au Wire Bonding must be used to connect the chip contacts with jumper wires. The area of the circuit board leads to a large size of the entire package circuit board, which cannot meet the requirements of high density.

The object of the present invention is to provide a tape-and-roll automatic soldering ball-array integrated circuit packaging method that can precisely position each external contact, form smaller external contacts, and appropriately reduce the area of the packaged circuit board.

The object of the present invention is achieved like this, a kind of tape and reel automatic welding ball array type integrated circuit packaging method, it is characterized in that comprising the following steps: get and use the polyimide film that contains double-sided thin copper as base material; Carry out the lamination, exposure and development of the first dry film on both sides, and only make the upper surface form a gap; in order to carry out electroplating copper, electroplating nickel, electroplating gold and electroplating nickel etc. in sequence on the upper surface not covered by the first dry film layer electroplating; remove the first dry film; press, expose and develop the second dry film on both sides of the substrate, so that only the lower surface forms a gap; use the second dry film as a mask to carry out the thin copper on the lower layer Etching: use the lower layer of thin copper as a mask to perform laser etching on the polyimide film of the substrate, and use the blocking of thin copper and the control of laser energy to form a non-through hole pattern; press the upper surface of the substrate Three dry films to protect the electroplating layer on the upper surface; electrolytic plating is performed on each hole of the polyimide film to form electrolytic plating contacts that fill each hole and slightly protrude; remove the third dry film; etch between each multilayer There is an exposed upper layer of thin copper between the electroplating layers, so that the adjacent electroplating layers are separated from each other, and the electroplating nickel layer on the surface of the multi-layer electroplating layer is etched away, so that the electroplating gold layer is exposed; and, for the center of the substrate and the required Laser drilling is performed on the part where the through hole is formed to form the chip mounting hole in the center of the substrate and the laser through hole on the periphery, so that a contact cantilever formed by a multi-layer electroplating layer is formed on the periphery of the chip mounting hole for welding and bonding chips .

The purpose of the present invention can also be achieved by the following method, a tape and reel automatic soldering ball array integrated circuit packaging method, which is characterized in that it includes the following steps: taking the polyimide film containing double-sided thin copper as the base material Carry out lamination, exposure and development of the first dry film on both sides of the substrate, and only make the upper surface form a gap; sequentially perform double-layer electroplating of electroplating nickel and electroplating gold on the upper surface not covered by the first dry film ; remove the first dry film; carry out lamination, exposure and development of the second dry film on both sides of the substrate, and only form a gap on the lower surface; use the second dry film as a mask to etch the lower layer of thin copper; use The lower layer of thin copper is used as a mask to perform laser etching on the polyimide film of the substrate, and the blocking of the thin copper and the control of the laser energy form a hole pattern that is not penetrated; the third dry film is laminated on the upper surface of the substrate , to protect the upper surface electroplating layer; implement electrolytic plating in each hole of the polyimide film to form electrolytic plating contacts that fill each hole and slightly protrude; remove the third dry film; etch between each multi-layer electroplating layer The exposed upper layer of thin copper between them separates the adjacent electroplating layers from each other; and, laser drilling is performed on the center of the substrate and the parts that need to be formed through to form the chip mounting hole in the center of the substrate and the laser holes on the periphery, respectively. Through holes, so that the periphery of the chip mounting hole is formed with a contact cantilever formed by a multi-layer electroplating layer for soldering and bonding of the chip.

The purpose of the present invention can also be achieved by the following method, a tape and reel automatic soldering ball array integrated circuit packaging method, which is characterized in that it includes the following steps: taking the polyimide film containing double-sided thin copper as the base material Carry out the steps of pressing, exposing and developing the first dry film on both sides of the base material, and only make the upper surface form a gap; Carry out electroplating copper and electroplating nickel in sequence on the upper surface not covered by the first dry film. Layer electroplating; remove the first dry film; press, expose and develop the second dry film on both sides of the substrate, and only form a gap on the lower surface; use the second dry film as a mask to etch the lower layer of thin copper ;Using the lower layer of thin copper as a mask, laser etching is performed on the polyimide film of the substrate, and through the blocking of the thin copper and the control of the laser energy, an incomplete hole pattern is formed; the upper surface of the substrate is laminated Three dry films to protect the electroplating layer on the upper surface; electrolytic plating is performed on each hole of the polyimide film to form electrolytic plating contacts that fill the holes and slightly protrude; remove the third dry film; cover the top and bottom of the substrate Combine the fourth dry film, and after exposure and development, only a gap is formed at the top specific position; the top gap is gold-plated to form a gold-plated bump; the upper layer of thin copper exposed between each double-layer electroplating layer is etched, and Separate the adjacent electroplating layers from each other; perform laser drilling on the center of the substrate and the part that needs to be formed to form a chip mounting hole in the center of the substrate and a laser through hole on the periphery, so that the periphery of the chip mounting hole is formed The contact cantilever formed by double-layer electroplating and gold-plated bumps is used for soldering and bonding chips.

Compared with the prior art, the present invention has obvious advantages and positive effects. It can be seen from the above technical solutions that in the front-end process of the present invention, since the polyimide film that has been pre-pressed or bonded with double-sided thin copper is directly used as the base material, the cost of the base material can obviously be compared with the aforementioned traditional ones. The step of sputtering thin copper in this way is cheap, and has the advantage of reducing cost, and in the step of forming the hole 12 and forming the electrolytic plating contact 17 by carrying out laser etching to the polyimide film 10, even each contact can be automatically aligned ( SELF-ALIGN) in each hole 12, without causing offset or excessive error, so it provides the advantages of precise positioning, and can control the distance between the contacts 17 at a very narrow level (20 μm), and more It can conform to the characteristics of fine contacts. In addition, for the multi-layer electroplating layer formed at the chip mounting hole 22 position at the bonding chip 40 in FIG. 1R, FIG. 2R and FIG. 3S or the cantilever structure with gold-plated bumps 20 is formed Form a chip 40 that can be bonded directly by single point welding (SINGLE POINT BOND), without the need to connect by jumping gold wires. This also reduces the overall size of the TAB-BGA package circuit board, which is a comparison with the traditional TAB -The BGA manufacturing method has a higher density effect and can make the external contacts more precise and smaller. Furthermore, the lower layer of thin copper can also be used for laser drilling by using a polyimide film with double-sided thin copper The mask makes the laser drilling more precise.

The specific structural features and purposes of the present invention will be further described below in conjunction with the accompanying drawings.

Fig. 1 is a schematic cross-sectional view of the manufacturing method of the first embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view of the manufacturing method of the second embodiment of the present invention.

Fig. 3 is a schematic cross-sectional view of the manufacturing method of the third embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view of a traditional TAB-BGA manufacturing process.

The present invention has three different embodiments, and only the material of the electroplating layer in each process is different, resulting in a slight change in the process. The following will describe each embodiment of the present invention in turn. First, as shown in Figures 1A-R, In Fig. 1A, the present invention directly uses the polyimide film 10 that has been laminated or bonded with double-sided thin copper 11, 111 as the substrate of the present invention, without having to first process the polyimide as in the traditional process. The additional step of sputtering copper on the film substrate is to avoid the complexity of the operation and the high cost of the substrate caused by sputtering the thin copper metal. In Figure 1B, the upper and lower layers of thin copper 11 , 111 carry out the steps of laminating the first dry film 13, 131 and exposing and developing, to form a plurality of bulk dry films 13 on the upper surface, and then as shown in Figure 1C, electroplating forms electroplated copper 141, electroplated nickel successively 142, multi-layer electroplating layers such as electroplating gold 143 and electroplating nickel 144, after removing the aforementioned dry film 13 in FIG. 1, as shown in FIG. As shown, the steps of lamination, exposure and development of the second dry film 16, 161 are implemented, and only an exposed gap is formed at the bottom, that is, the lower layer of thin copper 111 is etched through Fig. 1F, and after removing the second dry film 16, 161 , that is, as shown in FIG. 1G, the lower layer of thin copper 111 is etched to form a pattern with a plurality of notches 112. Afterwards, as shown in FIG. 1H, using the lower layer of thin copper 111 as a mask, laser etching The bottom of the polyimide film 10 is etched, and by controlling the laser energy, the polyimide film 10 is etched to form a plurality of non-through holes 12 (these holes are used for subsequent electrolytic plating to form downwardly extending contacts), and then After pressing the third dry film 19) on the upper surface as shown in Figure 1I so that the aforementioned patterns on the upper surface are protected, then remove the lower layer of thin copper 111 as shown in Figure 1J, and then perform the alignment as shown in Figure 1K The steps of electrolytic plating (nickel plating or copper plating) are carried out at each hole 12 positions of the polyimide film 10, and the electrolytic plating contacts 17 (forming the packaging circuit board of this packaging circuit board) are filled in each hole and the outer end is a protruding type. external contact), then, for removing the third dry film 19 (as shown in Figure 1L) covering the upper surface, after that, as shown in Figure 1M and N, the bottom surface is covered with a protective film 18 and covered with the 4th dry film successively. 51. However, in the step of FIG. 1O, the electroplated nickel 144 at the top of the electroplated layer and the upper layer of thin copper 11 between the electroplated layers are removed, so that the electroplated gold 143 of the electroplated layer is in an exposed state, and proceed as shown in FIG. 1P The step of removing the aforementioned fourth dry film 51 and the protective film 18, and finally, as shown in FIG. And the laser through hole 21, so far the process of packaging the circuit board is completed, and the way of installing the chip is as shown in Figure 1R, because the multi-layer electroplating layer located on the side of the chip mounting hole 22 basically forms a cantilever shape, and the The surface layer of the electroplating layer at the uppermost position in FIG. 1R is the material of electroplating gold 143 , so it can be directly bonded to the chip 40 through single-point welding technology.

Another embodiment of the present invention is shown in FIGS. 2A-R. The only difference is that the material of the electroplating layer in FIG. It is only necessary to etch and remove the upper layer of thin copper 11 between the electroplating layers, and the rest are the same, and the above two processes can achieve the same effect.

The third embodiment of the present invention is shown in Figures A to S in Figure 3, and the difference between them is that the material of the electroplating layer in Figure 3C is a double-layer electroplating that only consists of a thick electroplated copper 14 and an electroplated nickel 15. layer, and in the steps of lamination, exposure and development of the fourth dry film in FIG. gap 512, and in the step of FIG. 3O, electroplating is performed on the position of the gap 512 to form a gold-plated bump 20, and in the peeling off of the fourth dry film 51, 511 in FIG. The gold-plated bumps 20 above the electroplated nickel 15 can be used as soldering points for single-point soldering of the chip 40 . In terms of the detailed manufacturing process of the third embodiment, as shown in FIG. 3A, the present invention directly uses the polyimide film 10 that has been laminated or bonded with double-sided thin copper 11, 111 as the substrate of the present invention, and There is no need to add copper sputtering on the polyimide film substrate as in the traditional process, so as to avoid the complexity of the operation and the high cost of the substrate caused by the sputtering of thin copper metal, and in the figure In 3B, the steps of laminating the first dry film 13, 131 and exposing and developing the upper and lower layers of thin copper 11, 111 are performed to form a plurality of block-shaped dry films 13 on the upper surface, and then as As shown in Figure 3C, a double-layer electroplating layer of a thick electroplated copper 14 and an electroplated nickel 15 is formed by sequential electroplating, and after removing the aforementioned first dry film 13, 131, as shown in Figure 3D, an upwardly protruding electroplating layer is formed , thereafter, as shown in FIG. 3E, implement the steps of pressing, exposing and developing the second dry film 16, 161, and only form an exposed gap at the bottom, that is, the lower layer of thin copper 111 is etched through FIG. 3F, and removed After the second dry film 16, 161 is formed as shown in Figure 3G, the lower layer of thin copper 111 is etched to form a pattern with a plurality of gaps 112, and thereafter, as shown in Figure 3H, the lower layer of thin copper 111 is used as Mask, etch the bottom of the polyimide film 10 by laser etching, by controlling the laser energy, the polyimide film 10 is etched to form a plurality of non-through holes 12 (these holes are formed by subsequent electrolytic plating Downwardly extending contacts), and then press the third dry film 19 on the upper surface as shown in Figure 3I so that the aforementioned patterns on the upper surface are protected, then remove the lower layer of thin copper 111 as shown in Figure 3J, and then , then carry out the step of carrying out electrolytic plating (nickel plating or copper plating) to each hole 12 positions of polyimide film 10 as shown in Fig. 3K, and fill in each hole place and the outer end is the electrolytic plating contact of protruding type 17 (forming the external contact of this encapsulation circuit board), then, for removing the Figure 3 dry film 19 (as Figure 3L) covering the upper surface, afterwards, as shown in Figure 3M, the bottom surface is covered with a protective film 18 and In FIG. 3N, the steps of lamination, exposure and development of the fourth dry film 51, 511 are carried out, and the gap 512 is only formed at a specific position above, and then in the step of FIG. 3O, the step of electroplating the aforementioned gap 512 with gold material , to form gold-plated bumps 20, and after the fourth dry film 51, 511 and protective film 18 on the top and bottom are removed through FIG. Gold-plated bumps 20, as shown in FIG. 3Q, are etched to remove the upper layer of thin copper 11 between adjacent thick electroplated copper 14. Finally, as shown in FIG. 3R, laser drilling is performed on the central position and other positions Steps to form chip mounting holes 22 and laser through holes 21 located in the center and peripheral positions, so far the process of packaging circuit boards is completed, and the way of mounting chips is as shown in FIG. 3S. The thick electroplated copper 14 and electroplated nickel 15 on the side basically form a cantilever shape, and the gold-plated bump 20 at the uppermost position can be directly bonded to the chip 40 through single-point welding technology.

Claims (9)

1 one kinds of winding automatic-welding spherical-array type integrated circuit packing methods is characterized in that comprising the following steps:

Take contain two-sided thin copper polyimide film as base material;

To two-sided pressing, exposure and the development of carrying out first dry film of base material, and only make upper surface form breach;

For carrying out multilayer platings such as electro-coppering, electronickelling, electrogilding and electronickelling successively at the unlapped upper surface of first dry film place;

Remove first dry film;

To two-sided pressing, exposure and the development of carrying out second dry film of base material, and only make lower surface form breach;

Using second dry film is mask, so that the thin copper of lower floor is carried out etching;

The thin copper of utilization lower floor carries out laser-induced thermal etching as mask to the polyimide film position of base material, and mat approaches the control of stopping of copper and laser energy, forms non-through hole figure;

At base material upper surface pressing the 3rd dry film, with protection upper surface electrodeposited coating;

Implement metallide and form the metallide contact that fills up each hole and omit evagination at each hole of polyimide film;

Remove the 3rd dry film;

Etching is the thin copper in the upper strata of exposing between each multilayer plating layer, and adjacent electrodeposited coating is spaced from each other, and etching removes and be positioned at the electroless nickel layer of multilayer plating laminar surface, and the electrogilding layer is exposed; And

Laser drill is carried out at position central to base material and that need to form perforation, to form chip installing hole and the peripheral laser perforation that is positioned at base material central authorities respectively, form by the formed contact cantilever of multilayer plating layer so that chip installing hole position is peripheral, for the solder bond chip.

2 winding automatic-welding spherical-array type integrated circuit packing methods according to claim 1 is characterized in that: wherein being somebody's turn to do can single-point welding manner and chips incorporate by the formed contact cantilever of multilayer plating layer.

3 winding automatic-welding spherical-array type integrated circuit packing methods according to claim 1 is characterized in that: wherein this metallide contact is made of nickel or copper product.

4 one kinds of winding automatic-welding spherical-array type integrated circuit packing methods is characterized in that comprising the following steps:

Take contain two-sided thin copper polyimide film as base material;

To two-sided pressing, exposure and the development of carrying out first dry film of base material, and only make upper surface form breach;

Carry out successively at the unlapped upper surface of first dry film place electronickelling, and the bilayer of electrogilding electroplate;

Remove first dry film;

To two-sided pressing, exposure and the development of carrying out second dry film of base material, and only make lower surface form breach;

Using second dry film is mask, and the thin copper of lower floor is carried out etching;

The thin copper of utilization lower floor carries out laser-induced thermal etching as mask to the polyimide film position of base material, the stopping and to the control of laser energy, form non-through hole figure of thin copper;

At base material upper surface pressing the 3rd dry film, with protection upper surface electrodeposited coating;

Implement metallide and form the metallide contact that fills up each hole and omit evagination at each hole of polyimide film;

Remove the 3rd dry film;

Etching is the thin copper in the upper strata of exposing between each multilayer plating layer, and adjacent electrodeposited coating is spaced from each other; And

Laser drill is carried out at position central to base material and that need to form perforation, to form chip installing hole and the peripheral laser perforation that is positioned at base material central authorities respectively, form by the formed contact cantilever of multilayer plating layer so that chip installing hole position is peripheral, for the solder bond chip.

5 winding automatic-welding spherical-array type integrated circuit packing methods according to claim 4 is characterized in that: wherein being somebody's turn to do can single-point welding manner and chips incorporate by the formed contact cantilever of double-deck electrodeposited coating.

6 winding automatic-welding spherical-array type integrated circuit packing methods according to claim 4 is characterized in that: wherein this metallide contact is made of nickel or copper product.

7 one kinds of winding automatic-welding spherical-array type integrated circuit packing methods is characterized in that comprising the following steps:

Take contain two-sided thin copper polyimide film as base material;

To two-sided pressing, exposure and the step of developing of carrying out first dry film of base material, and only make upper surface form breach;

Carry out successively at the unlapped upper surface of first dry film place electro-coppering, and the bilayer of electronickelling electroplate;

Remove first dry film;

To two-sided pressing, exposure and the development of carrying out second dry film of base material, and only make lower surface form breach;

Using second dry film is mask, and the thin copper of lower floor is carried out etching;

The thin copper of utilization lower floor carries out laser-induced thermal etching as mask to the polyimide film position of base material, the stopping and to the control of laser energy, form non-through hole figure of the thin copper of mat;

At base material upper surface pressing the 3rd dry film, with protection upper surface electrodeposited coating;

Implement metallide and form the metallide contact that fills up each hole and omit evagination at each hole of polyimide film;

Remove the 3rd dry film;

Cover the 4th dry film at the base material top/bottom part, and through exposure and development, and only form breach at the top ad-hoc location;

The top breach is carried out gold-plated, and form gold-plated salient point;

The upper strata that etching exposes between each double-deck electrodeposited coating approaches copper, and adjacent electrodeposited coating is spaced from each other;

Laser drill is carried out at position central to base material and that need to form perforation, to form chip installing hole and the peripheral laser perforation that is positioned at base material central authorities respectively, form by double-deck electrodeposited coating and the formed contact cantilever of gold-plated salient point so that chip installing hole position is peripheral, for the solder bond chip.

8 winding automatic-welding spherical-array type integrated circuit packing methods according to claim 7 is characterized in that: wherein being somebody's turn to do can single-point welding manner and chips incorporate by the formed contact cantilever of double-deck electrodeposited coating.

9 winding automatic-welding spherical-array type integrated circuit packing methods according to claim 7 is characterized in that: wherein this metallide contact is made of nickel or copper product.

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