TWI234857B - Structure of the ball-grid array packaged substrate with the heat sink layer containing function of grounding layer and manufacturing method of the same - Google Patents

Abstract

The present invention relates to one kind of substrate structure for improving efficiency of the heat sink layer of a ball-grid array packaged (BGA) substrate and manufacturing method of the same, wherein the disclosed BGA substrate contains a single pattern layer which is used as a connection of the solder ball and the conductor pattern. On the other side of the substrate is bonded with one heat sink layer, which provides the BGA substrate with grounding function to disperse the necessary area required for the grounding conductive pattern of the pattern layer of the BGA substrate whose solder balls for ground are connected by utilizing the sprocket holes which are filled with conductive adhesives.

Description

1234857 V. Description of the invention (1) Field of the invention: The present invention discloses a packaging technology related to BGA (ba 1 1-gridarray), especially a packaging technology with a heat sink (heatsink 1 ayer). The hole is connected to the ground solder ball (so 1 d ba 1 1 for ground) ° Jingbei Mingfa, some feet, a temple body M full period} more 6 i d C industry element crystal guide from half borrowed, The progress of progress has been made. The unit volume of the electric potential system of the manufacturing system is lower and lower, and the small contraction is the guide, and the connection is improved, and the small internal contraction is reduced to make a significant difference. This is the case. As a result, youth can increase. If you can reduce the speed and do not work, you can implement multiple pieces. For example, if you are more familiar with the example, you can use a functional piece of ea surface crystal plus a resistance-increasing line-as long as it is inside the capacitor. The emergence of the birth of the electric warrior is reflected in the nature of the reason. The chip set is denser to make the addition more uniform. The value of the reverse addition and increase is this. To solve the above problems, the semiconductor manufacturing industry, in addition to using Low-resistance copper wires replace traditional aluminum wires to reduce the resistance of the wires, and a low-k dielectric layer is sought to solve the problem of parasitic capacitance. Another technology that has a direct and critical impact on cost and performance is packaging technology. Because it is conceivable that when chip components are added with new functions, a large number of I / O terminals will inevitably be added to respond to the connection to the system. At the same time, the power consumption and heat dissipation problems of the chip will become more prominent. To overcome these problems, even the new generation of

1234857 V. Description of the invention (2) Crystal packaging technology and ball-pin array (BGA) substrate packaging technology also needs to be reviewed Within the boundary of the substrate 5, TAB through-holes 10 facilitate the transportation of the substrate 5 on the conveyor belt. The substrate 5 may be one of insulating substrates such as B T, polyurethane, or glass fiber reinforced epoxy resin. The substrate 5 is laminated with a copper 8. For T-B G A, there is only one metal pattern on a typical substrate. Copper foil 8 is used to define the wire pattern and the connection pattern of the solder balls.

Subsequently, as shown in Fig. 1b, first, demear, chemical polishing and the like are performed. Next, a photoresist (not shown) is formed on the copper foil 8 and a lithography process is performed to define a pattern. After development, baking and setting, the photoresist pattern is used as the etching mask to etch the copper foil to form the electrical wiring pattern and / or solder ball connection pattern 20. Finally remove the photoresist.

Subsequently, as shown in FIG. 1c, a back adhesive film 25 is covered on the back surface of the substrate 5 to prevent the solder mask from sticking. Subsequently, a layer of solder-resistant green paint 30 having an insulation property and preventing solder sticking is formed on the copper foil 8. After that, the solder mask green paint on the connection pattern 20 of the solder ball of the copper foil 8 is removed through a lithography process and a developing step. Please refer to Figure 1d, and then perform the plating process

Used in steel foil technology

1234857 V. Description of the invention (3) The recording and gold film layers 35 are sequentially formed. Immediately thereafter, the adhesive film 25 is removed. Please refer to Figure-e, cut the substrate ', and then apply a dead layer 42 on the back of the substrate 5®. The material in the core area of the substrate is cut away, and the recessed area 40 is used to receive the crystal 4. If necessary, also form a bus bar through-hole, and the component through-hole ‘finally’ and then attach another-copper 羯 55 to the dry layer, use: 乂 to dissipate heat and support the BGA substrate. Finally, a solder ball gamma screen printing method is formed on the gold film layer 35. The result is shown in Figure 1f. In the traditional process, a heat sink layer is formed, and a heat sink needs to be pasted up. Therefore, it is not only time consuming ', but also effective. 5 The 5 series is separated by a layer of insulating substrate and the front surface is faint as + + ε…, / 1 electric wires are far away. This is not true: Connected; the electrical wires or grounding of the pattern layer are shown in Figure 1g and Figure 1h. The method of 3M company, 3M company, surface, and through-hole 10 uses electroless electroplating method; = pattern front and politics Thermal layer is on. Alas, the above-mentioned connection has not fully exerted the heat dissipation effect of the pattern layer. In fact, the electrical wires to the ground have not been connected. Therefore, the heat dissipation layer of the BGA substrate produced by the conventional technology is ineffective. 5 改 i ί = ί, $ !! The present invention will provide a new bga substrate structure to improve the above-mentioned problem, and provide a corresponding manufacturing method. 1234857 V. Description of the invention (4) Purpose and summary of the invention: ^ The purpose of the present invention is to provide a substrate structure for improving the efficiency of a heat dissipation layer of a ball-foot array package (B G A) substrate and a manufacturing method thereof. Still another object of the present invention is to apply a substrate structure for improving the efficiency of a heat dissipation layer of a ball-foot array package (β G A) substrate and a manufacturing method thereof. ^ The present invention discloses a substrate structure having an improved heat dissipation layer efficiency of a ball-foot array package (BG A) substrate. The BGA substrate has a single pattern layer 'to connect the wires and the ball. A heat-dissipating layer is bonded to the other side of the substrate. The political and thermal layer is also a ground layer to disperse the required area of the ground conductive pattern of the BGA substrate. The ground solder balls of the BGA substrate are connected by through-holes filled with conductive glue. The method of the present invention is to first drill and cut the substrate to form a through hole and a recessed area. There are non-stick films on the upper and lower sides of the substrate. The conductive adhesive is filled in the holes twice. In the first embodiment, the non-stick film on one side is removed first to fit the heat-dissipating layer on the surface. The remaining non-stick film is used to mask the surface of the substrate, and black is formed. The oxide layer is in the recessed area. After removing the remaining surface without sticking to the film, a copper foil is formed on the surface of the substrate. The photolithography and etching techniques were used to form a BGA pattern, including a wire pattern, and a pattern connected to a solder ball. After that, black ink is applied on the surface of the heat-dissipating layer for insulation, and the fG / A pattern surface uses lithographic technology to cover the solder mask with green paint. Finally, nickel, gold film plating, and screen printing are used to connect the solder. Ball and chip

1234857 V. Description of the invention (5) Place it in the recessed area and make the final wafer, then connect the pin to the BGA pattern 'and inject resin to seal the wafer and the pin. In the second embodiment of the present invention, after the conductive adhesive is injected into the through hole, the upper and lower non-stick films are simultaneously removed, and then the copper foil and the heat dissipation layer are simultaneously attached to the substrate. Next, a copper foil is formed by lithography and etching techniques to form a BGa pattern ', and then a protective film is pasted on the BGA pattern surface, and then a black oxide layer is formed in the recessed area to remove the protective film. The subsequent steps are as described in the first embodiment. Detailed description of the invention: In view of the background of the invention, in the conventional technology, the heat dissipation layer attached to the substrate is opposed to the pattern layer through the substrate, and therefore, the heat dissipation effect that can be achieved must be limited. Even if the traditional B G A substrate is connected, for example, the patent of 3M Company, there are only 8 TAB through holes (sprocket holes) reserved on the conveyor belt, which can only increase the heat dissipation effect. In view of this, the present invention provides a method that can solve the above problems. For the steps of the method of the present invention, please refer to FIG. 2 a to FIG. 2. First, please refer to FIG. The non-stick film is a film that has no affinity with the conductive adhesive. Such as polyethylene film (polyethy lene polypropylene film), polyester film (PET) or

1234857 V. Description of the invention (6) Either acrylic resin is acceptable. Subsequently, a C0 2 laser is drilled to form a through hole 2 1 5, and the substrate is cut to form a recessed area 2 2 0 in the substrate 2 5. Please note that the position of the through hole 2 1 5 is set at a predetermined solder ball for ground position. Next, as shown in FIG. 2b, the conductive adhesive 2 2 5 is squeezed into the through hole 2 1 5 by a roller printing method or a scraper. Since the substrate 2 0 5 has a non-sticking film 2 1 0 b, only the through hole 2 1 5 is adhered with the conductive adhesive 2 2 5 to form a rivet shape as shown in FIG. 2 b. Subsequently, the conductive adhesive above the surface of the substrate 205 is removed by a squeegee. Immediately after that, the non-stick film 2 1 Oa is removed, and the non-stick film 2 1 Ob is retained. The result is shown in Figure 2c. Please refer to FIG. 2d, and then use the hot pressing method to form a thicker copper plate 2 3 0 'on the substrate 2 05 as a heat dissipation layer 2 3 0. An oxide layer 2 3 5 is then formed on the surface of the recessed area 2 0. The black oxide layer 2 3 5 is used to isolate the contact between the substrate 2 05 and the wafer. At the same time, the wafer is also fixed in the recessed area. As shown in Figure 2e. Please refer to FIG. 2f, and then, remove the non-stick film layer 21b. Another second copper cancer 2 4 0 ′ is then laminated on the side of the substrate 2 05 without a heat dissipation layer. As a conductive pattern layer of the BG A substrate. Then, as shown in Fig. 2g, a negative photoresist 245 'is formed again, and the photomasks 250a and 250b are used as the lithographic mask, and then an exposure process is performed to define the pattern. After the development process, photoresist patterns 245c, 2 4 5a, and 2 4 5b shown in FIG. 2 are formed. Please note that since the heat-dissipating layer 23 is covered with a light-transmitting curtain 2 3 0a, the photoresist 245c will not be removed by development after the photoresist illuminates the light. The pattern layer 24 0 is in addition to the photoresist pattern Mg 8 connected by solder balls.

1234857 V. Description of the invention (7) Photoresist pattern 2 4 5 b with electric wires (c ο n d u c t i V e t a c e) is used as an etching mask. Referring to FIG. 2I, the photoresist patterns 245c, 245a, and 245b are used as a mask 'to etch the second copper foil 2 4 0 with an acidic solution or plasma to form a pattern layer 240a. Finally, the photoresist patterns 245c, 245a, and 245b are removed. Next, as shown in FIG. 2j, a black ink 2 5 2 is coated on the heat dissipation layer 2 3 0 as an insulating layer. Please note that a black ink may be optionally plated with a nickel layer on the heat sink layer 230 before forming the black ink layer. Then, a solder mask 2 5 5 is applied on the pattern layer 24 0a. Please refer to FIG. 2k, and then perform the exposure and development process with a mask pattern 2 60 to expose the copper foil to which the solder ball is to be connected. Finally, a "nickel and gold film" was plated on the exposed copper foil in order by the key bonding process. The result is shown in Figure 2-1. Finally, the solder ball 2 80 is seeded on the gold-plated film layer 27 by screen printing. The chip 2 7 5 is disposed in the recessed area 2 2 0, and the contact pads on the chip 2 7 0 are connected to the pattern layer 2 4 0 a with a wire pin 2 8 0. Finally, the wafer 2 7 5 and the wires are covered with a resin 2 8 5 to obtain the structure shown in FIG. 2 m. In the above process procedure, some steps can be changed in sequence without affecting the final result. For example, please refer to the second embodiment of the present invention. As shown in FIG. 3a, after the conductive adhesive 2 2 5 is injected into the through hole 2 1 5, the copper foil 2 4 0 and the heat dissipation layer 2 3 0 are simultaneously pressed on Both sides of the substrate 2 0 5. Next, the figure

Page 10 1234857 V. Description of the invention There is no need to adhere the heat sink to the substrate in a piece-by-piece manner. 4. The heat-dissipating layer of the present invention is not only a heat-dissipating layer but also a grounding layer. Therefore, the area required for grounding required by the BGA substrate pattern layer can be dispersed. The above is only a preferred embodiment of the present invention, and is not intended to limit the scope of patent application of the present invention. Any other equivalent changes or modifications made without departing from the spirit disclosed by the present invention shall be included in the following Within the scope of patent application. For example, in the above embodiment, the heat dissipation layer can be used as the ground layer at the same time, and the present invention can also be used as the power supply layer.

Page 1234857 The diagram briefly illustrates the preferred embodiment of the present invention and will be explained in more detail in the following explanatory text with the following figures: Figures 1a to 1f show the traditional BGA substrate formation process, heat dissipation layer It is not connected to the BGA pattern layer. Figures 1g to 1h show a BGA substrate made by another conventional technique. The BGA pattern layer of the substrate is only connected to the heat dissipation layer through the TAB through hole. Figures 2a to 21 show the steps of the BGA substrate produced in the first embodiment according to the method of the present invention. In the BGA pattern layer, the heat sink is connected to the ground solder balls of the BGA pattern layer through through holes. FIG. 2m shows a BGA substrate structure fabricated according to the method of the present invention in the first embodiment. Figures 3a to 3d show the steps of the BGA substrate manufactured according to the method of the second embodiment of the present invention. Only the parts different from the steps of the first embodiment are shown in the figure. Drawing number comparison table: Substrate 5 Copper pig 8 TAB through hole 10 Through hole 15 Connection pattern of electrical wires and / or solder balls 20 Adhesive film 25 Solder green paint 30 Nickel and gold film layer 35 Depressed area 40 Adhesive layer 42 Solder ball 45 Heat dissipation layer 55 Substrate 205 Non-stick film layer 210

Page 13 1234857 Simple illustration of perforation 215 recessed area 220 conductive adhesive 225 heat dissipation layer 230 love oxide layer 235 pattern layer 24 0 > 2 4 0a photoresist 2 4 5c, 245a, 245b photomask 2 5 0 a, 2 5 0b Solder mask green paint 255 Permanent ink 252 Mask pattern 260 Nickel and gold film 270 Chip 275 Lead wire 280 Resin 285 Protective film 254

Page 14

Claims (1)

1234857 VI. Scope of patent application 1 · A substrate structure with improved heat dissipation layer efficiency of a ball-foot array package (BGA) substrate 'The BGA substrate has a single pattern layer to connect solder balls, and the heat dissipation layer is bonded to the other side of the substrate. The characteristics of the substrate structure are: In addition to providing heat dissipation for the BGA substrate, the heat dissipation layer also provides a ground conductive pattern of the BGA substrate to disperse the required area of the ground pattern of the BGA substrate pattern layer, among which the ground tin of the BGA substrate The balls are connected using through-holes filled with conductive leads. '2 · The substrate structure according to item 1 of the scope of patent application, wherein the aforementioned conductive adhesive includes at least one of silver adhesive and copper adhesive. / 3 · —A method for improving the efficiency of a ball-foot array package (BGA) substrate heat dissipation layer, the method includes at least the following steps: Provide a substrate 'the upper and lower sides of the substrate each have a non-stick film And a recessed area in the substrate, the through hole is formed at a predetermined solder ball position for the ground of the BGA substrate; a conductive paste is formed in the through hole of the substrate; The sticking film prevents the conductive adhesive from attaching to areas outside the through hole of the substrate; removing the non-sticking film; A heat dissipation layer and a copper box are respectively formed on the upper and lower sides of the substrate; a pattern and a wire pattern of solder ball connection of the BGA substrate are formed on the copper pig; black ink is formed on the heat dissipation layer; 1234857 6. Scope of Patent Application 7. The method of claim 3, wherein the forming of the black ink described above further includes plating a nickel layer on the heat dissipation layer before the heat dissipation layer. 8. The method of claim 3, wherein the step of forming a black oxide layer in the recessed area further includes the following steps after forming a black ink on the heat dissipation layer: forming a protective film on the BGA substrate solder The ball-connected pattern and the wire pattern layer; forming a black oxide layer on the recessed area; and removing the protective film. 9. A method for improving the efficiency of a ball-foot array package (BG A) substrate heat dissipation layer, the method includes at least the following steps: • providing a substrate, each of which has a non-stick film on the upper and lower sides; And a recessed area in the substrate, the through-hole is formed at a predetermined ground solder ball (s ο 1 derba 1 1 for ground) position of the BGA substrate; a conductive paste is formed in the through-hole of the substrate, and the Film adhesion prevents the conductive adhesive from adhering to areas outside the substrate through-holes; removing one of the two non-adhesive films on the substrate; forming a heat dissipation layer on the substrate with the non-adhesive film removed; forming a black oxide Layer on the recessed area; removing only one side without sticking film; forming a copper foil on the substrate, the copper pig and the heat dissipation layer separating the substrate 1234857 6. The scope of the patent application is opposite; the pattern of the solder ball connection of the BGA substrate and the wire pattern are formed; the black ink is formed on the heat dissipation layer; the solder resist green paint is formed on the pattern of the solder ball connection of the BGA substrate and the wire pattern; A lithography process is used to expose the pattern of solder ball connection of the BGA substrate; and an electroplating process is used to plate a nickel film on the electrical wire. Therefore, the ground bump of the substrate passes through the conductive paste of the substrate through hole Connect to this heat sink. 10. The method according to item 9 of the scope of patent application, wherein the above-mentioned conductive glue includes at least one of silver glue and copper glue, and the above-mentioned conductive glue is injected into the through hole with one of a scraper or a roller. 11. The method according to item 9 of the scope of patent application, wherein the non-stick film mentioned above is a thin film having no affinity with the conductive adhesive. 12. The method according to item 11 of the scope of patent application, wherein the non-stick film mentioned above contains at least one of a polyethylene film, a polypropylene film or a polyester film or an acrylic resin. 13. The method according to item 9 of the scope of patent application, wherein forming the black ink described above before the heat dissipation layer further includes plating a nickel layer on the heat dissipation layer.