TW488046B - A process for packaging a window BGA to improve the efficiency of forming solder balls - Google Patents

Abstract

A process for packaging a window BGA structure includes in turn: providing a substrate, attaching chips, electrically connecting, forming solder balls, and forming an insulating thermosetting compound, wherein the substrate has an upper surface for attaching chips, a bottom surface for planting the solder balls, and at least a window for exposing a plurality of bonding pads of the chip. Prior to forming an insulating thermosetting compound, the solder balls are planted on the bottom surface of the substrate in advance for avoiding the contamination of the insulating thermosetting compound on the joint point of solder ball, so that this process improves the efficiency of forming solder balls.

Description

488046 V. Description of the invention (1) [Field of the invention] Kou has a window decapsulation process to improve the yield of ball implantation. In particular, it relates to a window BG Α package that includes a mold filling step. [Previous technology] In the United States Patent No. 6, 1 90, 943 "Chip Size Packaging Method" t 'Reveals a window BGA package [wind〇w baU grid a ^ "

Package] type semiconductor package and its packaging method. As shown in FIG. 3, the semiconductor package 20 mainly includes a substrate 22, a wafer 24, a plurality of metal wires 32, a plurality of solder balls 44, and a sealing metal. The protective layer 42 of the wire 32 causes the substrate 22 to have a non-conductive upper surface 30, a lower surface 38 having a V electrical circuit, and a through hole 34 (ie, a window). The chip 24 is fixed on the substrate 22 The surface 30 exposes the pads 36 on the active surface 26 of the wafer 24 to the window 34 for connection of the metal wires 32, and the solder balls 44 are bonded to the lower surface 38 of the substrate 22, so that the semiconductor package 20 has a window BGA Package [or "on-chip package" · [On Chip] type. As shown in FIG. 4, according to the packaging method of the semiconductor package 20, a substrate 22 is first provided, and then the upper surface 30 of the substrate 22 is coated with screen printing—% thermoplastic adhesive 28 ′ and then a wafer 24 is placed. On the upper surface 30 of the substrate 22, heat is applied to make the wafer 24 adhere to the substrate 22, and then a metal wire 32 'is formed by wire bonding to connect the wafer 24 and the substrate 22, and then the protective glue 42 is formed, and finally, a solder ball 44 is connected. As the protective glue 42 is formed in the process of forming the protective glue 42, especially when the protective glue 42 is formed, the protective glue 42 may be contaminated.

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The lower surface 38 of the substrate 22 affects the quality of the ball implantation, resulting in insufficient bonding force of the solder ball 44 or electrical disconnection. Therefore, as shown in FIG. 丨, in the semiconductor package 20, the back surface of the wafer 24 [corresponds to On the other surface and surface of the active surface 26:] It must be exposed for direct compression of the upper mold. Otherwise, the phenomenon of overflowing and staining the lower surface 38 of the substrate 22 is easy to occur, but the protection of the wafer 24 is reduced. And summary] The main purpose of the present invention is to provide a window BGA packaging process, in which a plurality of solder balls are formed on the lower surface of the circuit substrate before the die is filled with the glue, so as to achieve the effect of improving the yield of the ball. According to the present invention, the window BGA packaging process for improving the yield of ball implantation includes the following steps: a) providing a circuit substrate having an upper surface, a lower surface and at least one window; b) fixing at least A wafer is on the upper surface of the circuit substrate, and each wafer has an integrated circuit formation surface and a plurality of solder pads located on the integrated circuit formation surface. When the integrated circuit formation surface of the wafer faces the circuit substrate and is bonded, the plurality Each pad is exposed on the window of the circuit substrate; c) the chip and the circuit substrate are electrically connected through the window; d) a plurality of solder balls are formed on the lower surface of the circuit substrate; and e) an insulating gel is formed on the circuit substrate window. [Detailed description of the invention] With reference to the attached drawings, the present invention will enumerate the following embodiment descriptions ...

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Page 6 488046 V. Description of the invention (3)

Fig. 1 is a cross-sectional view of a semiconductor package made by the window BG A packaging process of the present invention 'and Fig. 2 is a block flow chart of the window BGa packaging process according to the present invention. As shown in Figure 1, the window BGA package manufactured by the present invention. [Window Ball Grid Array package] mainly contains a crystal

Sheet 11, a substrate 12, a plurality of metal wires i3, an insulating gel 15 and a plurality of solder balls 14, wherein the wafer has a surface on which integrated circuit elements are formed, and a plurality of solder pads are formed on the surface. The substrate 12 is a printed circuit board or a ceramic circuit board and presents a single-layer or multilayer circuit pattern. The substrate 12 includes an upper surface 121, a lower surface 122, and a window 17 penetrating the upper card surface. The upper surface 121 Adhesive 16 can be used to fix the chip u, and the surface of the chip 11 on which the integrated circuit elements are formed is bonded toward the upper surface 121 so that the bonding pad lu is exposed in the window 17; the metal wire 13 is internally electrically connected to the chip 11 with substrate! 2. Through the window 17 is connected by the wafer 11 solder pad 1J j to the connection pad 122 on the lower surface 122 of the substrate 12; the insulating gel 15 is a thermosetting insulating filler, which is formed on the window of the substrate 12 by means of molding. 17 and the upper surface 121 are sealed with the metal wire 13 and the wafer 11; the solder ball 14 is a lead-tin alloy or other metal soldering material, formed on the lower surface 122 of the substrate 12, and part of the solder ball 14 is conductive To the pads 111 corresponding to the wafer 11. ¥ The above-mentioned south mouth BGA package 10 is prepared by the window packaging process of the present invention, and has the effect of improving the yield of ball implantation. The steps include:

Page 7 488046 V. Description of the invention (4) The circuit substrate 12 has an upper surface 121, a lower surface 122, and at least one window 17; a silly 'adhesive chip' 5 2 is a circuit board 12 which is adhered to at least one chip 11 On the upper surface 121, each wafer 11 has an integrated circuit formation surface and a plurality of pads ui located on the integrated circuit formation surface. When the integrated circuit formation surface of the wafer u faces the circuit substrate 12 and is bonded, the plurality of The individual pads 111 are exposed in the window I of the circuit board 12 above; then, "electrical connection" 53 first turns the circuit board 12 over, and electrically connects the chip u and the circuit board j 2 through the solid opening 17, in In the present embodiment, the plurality of metal wires 13 are connected to the bonding pad U1 of the wafer 丨 to the lower surface 122 of the circuit substrate 12 or the electrical connection is completed by thermocompression bonding of the TAB pin; after that, "form a solder ball "54 is to form a plurality of solder balls 14 on the lower surface of the circuit board 1 2 1 2 2 'Usually printing, mold alignment bonding and other methods to form solder balls; and then' form insulation colloids' 5 5 is to apply by printing or Forming an insulating gel 15 The window 17 of the substrate 12 is sealed with a metal wire 1 3 ′. In this embodiment, the combined structure of the circuit substrate 12 and the wafer u is formed by a mold compression molding to form the insulating gel 丨 5, so that the insulating gel 1 5 The sealed wafer 11 has better protection. In addition, in actual production, the circuit substrate 12 is integrally formed with a plurality of packaging units in a large area to package and process multiple wafers u at the same time. After 55, it is cut into a plurality of separate window BGA packages 10. Therefore, the copying process of the BGA package of Mingzhi Window is "formed a solder ball" 54 before the "formation of the insulating gel" 55, on the lower surface of the circuit substrate 12.

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488046 V. Description of the invention (5) 122 Before the plurality of solder balls 丨 4 are formed on the lower surface 122 of the circuit substrate 12 before being polluted by the insulating gel 15, the solder balls η can be soldered to the insulating gel 15 without being affected by the insulating gel 15 The lower surface 122 does not affect the bonding of the solder ball 14 to the circuit substrate 12 even if there is an overflow of glue during the subsequent "formation of the insulator = body" 55, and the effect of improving the yield of the ball is achieved. This is the scope of protection of the original copy of the Ming Dynasty, which shall be determined by the scope of the attached patent application. Anyone who is familiar with this skill will make any changes and modifications within the scope: the spirit and scope of the month. 7 belongs to the protection scope of the present invention

[Illustration of the drawings] Figure 1 · Sectional view of a semiconductor package made by the window BGA packaging process of the present invention; Figure. · Block flow chart of the window BGA packaging process according to the present invention; Figure · U.S. Patent No. 6, 1 Cross-sectional view of a semiconductor package made by "Chip Size Packaging Method" No. 90, 943; and Fig. 4: US Patent No. 6, 1 90, 943 "Process Flow Chart of Chip Size Packaging Method." [Explanation of Drawing Number] 10 Window BGA package 11 Wafer 111 Solder pad 12 Substrate 121 Upper surface 122 Lower surface 13 Metal wire 14 Solder ball 15 Insulating gel 16 Adhesive 17 Window 20 Semiconductor package 22 Substrate 24 Wafer 26 Active surface 28 Thermoplastic adhesive 30 Upper surface 32 Metal wire 34 Through hole 36 Pad 38 Lower surface 42 Protective glue 44 Solder ball 51 Provide circuit board 52 Adhesive chip 53 Electrical connection 54 Form ball 55 Form insulating gel

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Claims (1)

6. Scope of patent application [Scope of patent application] 1. A step of yielding ball implantation in sequence includes: providing a circuit substrate, the surface and at least one window; cementing at least one chip on the surface of the electrical integrated circuit forming surface, and The pads, when the integrated circuit of the chip, the plurality of solder pads are exposed to form a plurality of solder balls electrically connected through the window to form an insulating gel on the electricity. The solder joints of the wafers connected to the individual wires, as in the first scope of the patent application, "provide a single-layer printed circuit board with a circuit substrate." As in the first scope of the patent application, "the combined structure of forming an insulating colloid sheet is formed by die pressing, For example, the BGA packaging process of the sealed crystal window of the insulating glue system in the patent application scope No. 4 includes a circuit substrate having an upper surface and a lower surface substrate. The integrated substrate is formed facing the circuit substrate and the circuit substrate. The circuit substrate described in the above item to the step surface of the "mentioned in the circuit basic item", each wafer has a plurality of circuit forming surfaces soldered to the circuit substrate. And when the bonding window of the substrate; circuit board; a lower surface; Ο square window and a window BGA packaging process steps "of, the plurality of lines to below the surface of the plate. The window BGA packaging process, in which the circuit substrate is the window BGA packaging process described in one item, and in the step ", the circuit substrate and the glue are potted together to form the insulating gel. The window described in item BGA packaging process, basin. Eight I Round Page 11