KR100709129B1 - Method for manufacturing flip chip package - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a flip chip package, and more particularly, a semiconductor chip transferred on a substrate through solder balls involves a separate reflow process. The present invention relates to a method of manufacturing a flip chip package, which excludes a reflow process during the manufacturing process. To this end, a semiconductor chip is bonded to a substrate by using a base block provided with a heating means when transferring and bonding the semiconductor chip onto a substrate. In addition, the present invention discloses a method of manufacturing a flip chip package in which flip chip bonding is performed without a separate reflow process by applying heat to melt the solder balls, and according to the characteristics of the present invention, the work time required for the reflow process can be reduced. Reduce the total time required to manufacture flip chip packages and eliminate the need to install reflow devices The eopeojim has a space efficiency of the work area according to the prior art reflow apparatus was installed to prevent the release of the pharmaceutical according to the.

Flip chip package, Substrate, Base block, Ultrasonic, Heater, Solder ball

Description

Method for manufacturing flip chip package

1 is a flowchart illustrating a conventional flip chip package manufacturing process step by step;

2a to 2d is a process diagram schematically showing each step of FIG.

3 is a flowchart illustrating a step-by-step manufacturing process of a flip chip package according to an embodiment of the present invention;

4A to 4D are process diagrams schematically showing the steps of FIG. 3.

<Description of Symbols for Main Parts of Drawings>

20, 120: semiconductor chip 22, 122: solder ball

24, 124: boundary 30, 130: tape

40, 140: substrate 42, 142: upper surface

44, 144: lower surface 46, 146: ball pad

48, 148: External connection terminal 60, 160: Feed axis

62, 162: feed collet 70, 170: base block

72, 172: support block 80: reflow apparatus

82: carrier 84: roller

86: conveyor belt 88, 188: heating means

100, 200: flip chip package                 

150: holder 152: release pin

164: axis of rotation 166: die collet

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a flip chip package, and more specifically, a semiconductor chip transferred onto a substrate through solder balls is separately reflowed. The manufacturing method of the flip chip package characterized by eliminating the reflow process among the conventional manufacturing processes involving a process).

A process of forming a plurality of solder balls on an active surface of a semiconductor chip and directly mounting a semiconductor chip on a mounting area such as a substrate by using the protruding solder balls is called a flip chip bonding process. The package implemented by the so-called flip chip package (Flip chip package). The flip chip package is widely used because the data transfer speed of the semiconductor chip is relatively faster than that of the bonding wire, and the mounting area of the semiconductor chip is minimized. An example is a semiconductor device used as a central processing unit (CPU) such as a computer.

A device such as a central processing unit basically includes a semiconductor chip on which an integrated circuit (IC) is formed and a substrate on which an outer connector such as a pin is formed, and is formed on an active surface of the semiconductor chip. A semiconductor chip is formed by flip chip bonding on a substrate using solder balls.

FIG. 1 schematically illustrates a conventional flip chip package manufacturing process step by step, and FIGS. 2A to 2D schematically illustrate each process of FIG. 1. Referring to Figures 1 to 2D it will be described as follows.

A conventional flip chip package manufacturing method includes a step 10 of providing a semiconductor chip in which a plurality of solder balls are arranged in a predetermined arrangement on an active surface and largely divided, and a top surface on which the semiconductor chip is mounted and a bottom surface on which external connection terminals are formed. A step 12 of providing a substrate, a step 14 of transferring a semiconductor chip onto the substrate, and then flip chip bonding 14, and a step 16 of melting the solder balls through a reflow process to secure the bonding. .

Each step is described in more detail as follows. Since the flip chip bonding process uses solder balls 22, solder balls are formed and supplied in a predetermined arrangement on the active surface of the semiconductor chip 20, and these solder balls are generally formed in a wafer state. to be. That is, as shown in FIG. 2A, a plurality of semiconductor chips 20 are formed on the wafer, and each semiconductor chip is cut along the boundary 24, and these cut semiconductor chips 20 are taped at the bottom thereof. Supported by 30) and provided in a fixed state.

FIG. 2B illustrates a perspective view of an example of a substrate 40 on which each semiconductor chip of FIG. 2A is mounted. According to FIG. 2B, the substrate 40 has ball pads 46 formed on the upper surface 42 corresponding to the solder balls of the semiconductor chip so that the semiconductor chip can be mounted, and a plurality of the lower surfaces 44 along the periphery of the substrate 40. External connection terminals 48, such as the pins are formed. The plurality of pins are used as external connection terminals for transmitting electrical signals between the semiconductor chip and the motherboard when the flip chip package is later mounted on the mother board. As such, as a plurality of pins are used as external connection terminals, Also called a pin grid array package (PGA package).

2C shows a process in which each semiconductor chip 20 is mounted on a substrate 40.

First, a plurality of substrates 40 are aligned on a one-to-one corresponding support block 72, and these support blocks are fixed on the base block 70. Since the external connection terminal 48 such as a plurality of pins is formed on the lower surface of the substrate, each support block 72 is formed to correspond to the center of the lower surface of the substrate so as to support the substrate 40.

Ball pads (46 in FIG. 2B) are formed on the upper surface 42 of the substrate, and flux is provided on the ball pads. The transfer collet 62 driven by the transfer shaft 60 onto the upper surface of the flux-coated substrate transfers the semiconductor chip 20 by using vacuum, and then places the solder balls 22 on the corresponding ball pad. After alignment, they are pressed and flip chip bonded. As such, the flip chip package 100 is completed as the semiconductor chip is mounted and bonded onto the substrate. However, since the temporary bonding state using the flux between the semiconductor chip and the substrate, the reflow process described next must be performed.

2D illustrates an example in which a reflow process is performed, which will be described below with reference to this. The reflow apparatus 80 of FIG. 2D comprises a rotation drive means, such as a roller 84, and a conveyor belt 86 that is moved by the roller 84, further adding a heater to the heating means 88. Include.                         

The reflow process involves placing the flip chip packages 100 loaded in the carrier 82 on the conveyor belt 86 when the conveyor belt 86 moves in a constant direction and speed by the rotation A of the roller 84. The solder ball 22 is melted by the heating means and transported by the conveyor belt.

The reflow apparatus 80 of FIG. 2d is briefly illustrated to illustrate its structure, and the horizontal distance that the actual conveyor belt moves is long enough to allow multiple carriers 82 to be placed simultaneously, with the carrier being moved horizontally. The transfer time from end to end is about 3 minutes.

As described above, the conventional flip chip package manufacturing method requires a reflow process in addition to a process of flip chip bonding a semiconductor chip onto a substrate, and a work time is required for a reflow process to be performed for each flip chip package. The manufacturing process of flip chip packages has been delayed in the reflow process, resulting in an increase in total process time. In addition, the reflow process may require a larger number of reflow devices in order to eliminate the delay of the above working time, and since these reflow devices require considerable space on the work line during installation, This can be a big constraint.

An object of the present invention is to provide a method of manufacturing a flip chip package that can prevent the delay of the working time that can be generated by the reflow process during the manufacturing process of the flip chip package.                         

Another object of the present invention is to provide a method for manufacturing a flip chip package, characterized in that the solder ball is melted and completely bonded without a separate reflow device.

In order to achieve these objects, the present invention provides a method for manufacturing a semiconductor device, the method comprising: (a) providing semiconductor chips to which solder balls having a predetermined arrangement are attached; (b) providing a substrate in which ball pads corresponding to solder balls are formed on an upper surface and external connection terminals corresponding to the ball pads are formed on a lower surface corresponding to each semiconductor chip; And (c) transferring the semiconductor chip onto the upper surface of the substrate and bonding the flip chip, wherein the step (c) comprises: (c-1) placing the substrate on a base block provided with heating means; Being aligned; (c-2) transferring the semiconductor chip onto the upper surface of the substrate with the active surface facing downward; And (c-3) pressing the semiconductor chip transferred onto the substrate to press the solder balls of the semiconductor chip onto the corresponding ball pads, respectively, by pressing the semiconductor chip through the heating means and the pressing means. Disclosed is a method of manufacturing a flip chip package, characterized in that flip chip bonding is performed on an upper surface of a substrate.

In addition, in the flip chip package manufacturing method according to the present invention, the heating means of the base block is characterized in that each corresponding to a plurality of substrates arranged on the base block.

As described above, the method for manufacturing a flip chip package according to the present invention is characterized in that a base block having a heating means such as a heater is provided in each of the support blocks on which the substrate is aligned, thereby heating means during the process of mounting the semiconductor chip onto the substrate. The present invention relates to a method of manufacturing a flip chip package, in which solder balls are melted so that they can be completely combined and thus eliminate a separate reflow process.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

Figure 3 is a simplified step-by-step description of the flip chip package manufacturing process according to an embodiment of the present invention, Figures 4a to 4d schematically illustrates each process of FIG. Referring to FIGS. 3 to 4D, the flip chip package manufacturing method according to the present invention will be described.

According to an embodiment of the present disclosure, a method of manufacturing a flip chip package according to an embodiment may include providing a semiconductor chip in which a plurality of solder balls are formed on an active surface, and a top surface on which the semiconductor chip is mounted and a bottom surface on which external connection terminals are formed. Providing a substrate comprising a 112, and flip chip bonding 114 after transferring the semiconductor chip over a substrate aligned with a base block provided with a heating means. In other words, the method of manufacturing a flip chip package according to the present invention is characterized in that the progress in a state excluding a conventional reflow process.

Each step is described in more detail as follows. Since the flip chip bonding process uses solder balls 122, solder balls are formed in a predetermined arrangement on the active surface of the semiconductor chip 120, and these solder balls are generally formed in a wafer state. to be. That is, as shown in FIG. 4A, a plurality of semiconductor chips 120 are formed on a wafer, and each semiconductor chip is cut along the boundary 124, and the cut semiconductor chips 120 are taped at the bottom thereof. 130 is supported and provided in a fixed state.

4B is a perspective view illustrating an example of a substrate 140 on which each semiconductor chip of FIG. 4A is mounted. According to FIG. 4B, the substrate 140 has ball pads 146 formed on the upper surface 142 corresponding to the solder balls of the semiconductor chip so that the semiconductor chip can be mounted, and a plurality of the lower surfaces 144 along the outer edge of the substrate 140. External connection terminals 148, such as pins, are formed. The plurality of pins are used as external connection terminals for transmitting electrical signals between the semiconductor chip and the motherboard when the flip chip package is later mounted on the mother board. As such, as a plurality of pins are used as external connection terminals, Also called a pin grid array package.

4C to 4D illustrate a process of flip chip bonding after a semiconductor chip in a wafer state is transferred. This will be described below with reference to FIGS. 4C to 4D.

The semiconductor chips 120 having the lower surface supported and fixed by the tape 130 are vacuum-adsorbed by the die collet 166 using a vacuum on the holder 150 provided with the release pin 152. The tape 130 is separated one by one. The die collet 166 adsorbs an active surface of the semiconductor chip on which the solder balls 122 are formed, and may be temporarily aligned with the active surface of the semiconductor chip downward as the rotation shaft 164 rotates 180 °. have. The temporarily aligned semiconductor chip 120 is re-adsorbed on the opposite side of the active surface to the transfer collet 162 corresponding to the die collet 166, and the substrate 160 as the transfer shaft 160 to which the transfer collet 162 is connected is driven. It is transported over this aligned base block 170.

As in the prior art, a plurality of substrates 140 are aligned on the one-to-one corresponding support block 172, and these support blocks are fixed on the base block 170. Since the external connection terminal 148 such as a plurality of pins is formed on the lower surface of the substrate, each support block 172 is formed to correspond to the center of the lower surface of the substrate so as to support the substrate 140.

Ball pads 146 of FIG. 4B are formed on the top surface 142 of the substrate, and flux is provided on the ball pads. The transfer collet 162 driven by the transfer shaft 160 over the upper surface of the flux-coated substrate transfers the semiconductor chip 120 using vacuum, and then places the solder balls 122 on the corresponding ball pad. After alignment, they are pressed and flip chip bonded. As such, the flip chip package 200 is completed as the semiconductor chip is mounted and bonded onto the substrate.

At this time, unlike the prior art base block 170 according to the present invention is characterized in that the heating means 188 is provided in each of the support block 172 for supporting each substrate 140. That is, when the semiconductor chip 120 is mounted on the substrate 140 by the transfer collet 162, a heating means 188 such as a heater provided in the support block applies heat to the substrate to separate the reflow. The solder ball 122 may be melted without a process, and thus, a semiconductor chip may be mounted on a substrate, and flip chip bonding using solder balls may be completely performed.

In addition, after the semiconductor chip is placed on the substrate, a transfer collet or a separate pressing means (not shown) may press the semiconductor chip onto the substrate so that the flip chip bonding may be well performed. (Not shown), an ultrasonic wave may be applied when the semiconductor chip is pressed, so that the bond between the semiconductor chip and the substrate may be better formed. Alternatively, it is also possible in some cases to connect the ultrasonic oscillator directly to the transfer collet.

As such, the reason why the ultrasonic wave is applied to the semiconductor chip by connecting the ultrasonic wave oscillator to the pressing means is to help the flip chip bonding coupling between the semiconductor chip and the substrate more efficiently. Whereas the conventional reflow process is performed while applying heat for about 3 minutes, the process according to the present invention has a heating means for a relatively short time such that the semiconductor chip is placed on the substrate and pressurized without a separate reflow process. Since heat is applied to the substrate, flip chip bonding may be further facilitated by applying ultrasonic waves to the pressing means for pressing the semiconductor chip.

As described above, the present invention relates to a method of manufacturing a flip chip package without a separate reflow process, and in particular, an embodiment of the present invention provides a flip chip package including a substrate to which a plurality of pins are applied as external connection terminals. Although described in the center, the technical spirit of the present invention is not necessarily limited thereto. In the manufacturing process of a semiconductor device in which flip chip bonding is performed using solder balls, a separate reflow process should be performed after the solder balls are temporarily bonded. It is apparent that the technical spirit of the present invention may be freely applied to other manufacturing processes for completing flip chip bonding.

The flip chip package manufacturing method according to the present invention is characterized by performing a flip chip bonding process without a separate reflow process by improving the flip chip bonding process consisting of a conventional semiconductor chip bonding process and a reflow process. According to the characteristics of the reflow process can be reduced the total work time required to manufacture the flip chip package can be reduced, and there is no need to install the reflow device, the conventional reflow device was installed The space efficiency of the workplace can be prevented.

Claims (3)

(a) providing semiconductor chips with solder balls having a predetermined arrangement; (b) providing a substrate in which ball pads corresponding to the solder balls are formed on an upper surface and external connection terminals corresponding to the ball pads are formed on a lower surface corresponding to each of the semiconductor chips; And (c) transferring the semiconductor chip onto an upper surface of the substrate and flip chip bonding; In the flip chip package manufacturing method comprising: Step (c) is (c-1) aligning the substrate on a base block provided with heating means; (c-2) transferring the semiconductor chip onto the upper surface of the substrate with the active surface facing downward; And (c-3) bonding the solder balls of the semiconductor chip onto corresponding ball pads by pressing the semiconductor chip transferred onto the substrate by pressing means; The method of claim 1, wherein the semiconductor chip is flip chip bonded on the upper surface of the substrate through the heating means and the pressing means. The method of claim 1, wherein the pressing means is connected to an ultrasonic oscillator, and the pressing means presses the semiconductor chip and simultaneously ultrasonic waves are applied to the semiconductor chip. The method of claim 1, wherein the heating means of the base block is formed corresponding to each of the plurality of substrates arranged on the base block.

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