JP4114196B2 - Method of peeling electronic component and mounting method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to an electronic component peeling method and a mounting method thereof, for example, a method of peeling an individualized electronic component from a support after dicing a sticky semiconductor wafer on the support into individual electronic components, and a mounting method thereof It is about.
[0002]
[Prior art]
In the semiconductor device manufacturing process, in the process of cutting the wafer on which the circuit has been made into individual chip parts, the wafer circuit is cut by attaching the circuit forming surface of the wafer to an ultraviolet release tape called BG (back grind) tape. Then, a method is generally employed in which ultraviolet rays are applied from the side of the BG tape opposite to the side on which the wafer is attached to remove the adhesive force, and mounting or molding is performed by a mounting machine or the like.
[0003]
FIG. 3 shows a schematic process of attaching a wafer to a BG tape, cutting it into individual chip parts, and then peeling the chip parts using a needle. Each element on the wafer on which the circuit is formed is provided with an electrode for connection to the outside, but is not shown in FIG.
[0004]
First, as shown in FIG. 3A, after the wafer 12 is pasted on the surface of the adhesive material 13 of the BG tape 14, as shown in FIG. It is diced to a predetermined dimension L and separated into chip parts 12A. Next, as shown in FIG. 3C, the BG tape 14 is stretched in the XY directions as indicated by arrows, and the chip components 12A are arranged at a predetermined interval W.
[0005]
Next, as shown in FIG. 3D, the suction head 11 is kept close to the top surface of the chip component 12A to be peeled off, and the needle 15 is pierced from the opposite side of the BG tape 14 to select the chip component 12A. By pushing up, the sticking chip part 12A is about to peel off, and at the same time, air enters and peels between the BG tape 14 and the chip part 12A, and the chip part 12A is sucked by the suction head 11.
[0006]
The suction head 11 constitutes a part of a mounting machine (not shown), and the chip component 12A sucked by the suction head 11 is transported to the mounting board side, and is applied to the electrode 21 of the mounting board 20 as shown in FIG. The electrodes 17 a and 17 b of the chip component 12 </ b> A are flip-chip bonded using the solder 22.
[0007]
[Problems to be solved by the invention]
In the mounting process described above, although the cut semiconductor wafer and the mounting component are irradiated with ultraviolet rays from the BG tape surface opposite to the side to which these are attached, the adhesive force is lost. It is very difficult to take out these parts with a suction head or the like. When the parts are stuck on the entire surface of the tape, it is impossible to remove them unless air is put between these parts and the tape. Therefore, at present, in addition to ultraviolet irradiation, a method is used in which the needle is pierced from the back surface (the side opposite to the surface to which the circuit forming surface is adhered) and air is introduced between the component and the tape.
[0008]
However, recently, the target components and circuits have become very small, and for example, mounting components of 0.6 mm × 0.3 mm and even smaller ones have been manufactured. Therefore, it is necessary to reduce the diameter of the needle, but the needle cannot be made too thin from the viewpoint of strength. And when a mounting component is thin, the problem of damaging a component may generate | occur | produce. In addition, a phenomenon occurs in which the adhesive material remains on the adhesive surface side of the component due to piercing with the needle. In flip mounting, if an adhesive remains on the circuit forming surface of a component to be mounted, the attachment of solder or the like deteriorates, causing defective products. Therefore, various methods have been tried to solve such a phenomenon, but no definitive solution has been found.
[0009]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for peeling an electronic component that allows the electronic component to be peeled off from the support without leaving an adhesive material on the pressure-sensitive adhesive surface of the electronic component to be mounted, and to mount the electronic component. It is to provide a method.
[0010]
[Means for Solving the Problems]
That is, the present invention is a method of peeling the electronic component from a state in which the electronic component is adhesively fixed on a support with an adhesive.
The I I is an adhesive from the side opposite to the Rukoto be irradiated with ultraviolet laser light to the adhesive material through said support, peeling the electronic part is gasified by ablation of the adhesive material from the supporting lifting body
The present invention relates to an electronic part powder peeling method (hereinafter referred to as the peeling method of the present invention).
[0011]
According to the peeling method of the present invention, since the adhesive material is gasified and ablated by irradiation with ultraviolet laser light, the adhesive material gasifies and disappears without generation of heat, and the characteristics of the electronic component are contactless. It can be peeled off from the support without impairing . Therefore , since the electronic parts can be easily peeled off without leaving an adhesive material, connection failure does not occur after mounting, and the peeled electronic parts are not moved. Can do.
[0012]
Further, the present invention is a method of peeling the electronic component from a state in which the electronic component is adhesively fixed on a support with an adhesive, and mounting the peeled electronic component on a mounting substrate .
Wherein the adhesive material I by the Rukoto be irradiated with ultraviolet laser light to the adhesive through the support from the opposite side, the adhesive material is gasified by ablation and peeling the electronic part from the supporting lifting member, to implement this peeling electronic component on the mounting board
Wherein the mounting method of electronic components are those relating to (hereinafter, mounting method called. Of the present invention).
[0013]
According to the mounting method of the present invention, since the electronic component is peeled and mounted by the above-described peeling method of the present invention, it can be mounted with high accuracy under the same effect as the peeling method of the present invention.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described.
[0015]
In the peeling method and the mounting method of the present invention described above, the adhesive material is irradiated with the ultraviolet laser light (hereinafter simply referred to as laser light) through the support from the side opposite to the adhesive material, and the adhesive material is applied . By gasifying the material, the adhesive material between the electronic component and the support disappears, which is desirable in that the electronic component can be peeled without the adhesive material remaining.
[0016]
In this case, it is desirable to irradiate the laser beam while holding the electronic component with a suction head because the arrangement position of the electronic component can be held.
[0017]
And when peeling the electronic component, the semiconductor substrate to be separated into a plurality of the electronic components is adhesively fixed to the one surface of the support by the adhesive material, and the electronic components are separated into pieces in this adhesive state, Extending the support and arranging the separated electronic components at a predetermined interval, and irradiating the adhesive material with the laser light in this state allows separation without leaving the adhesive material Is desirable.
[0018]
Further, in this case, it is desirable to use a pulsed laser as the laser because the laser beam is transmitted only through the support and the electronic components are not heated and the characteristics thereof are not impaired.
[0019]
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
[0020]
In the peeling method of this embodiment, it is important to use a pulse laser. In the case of a CW (Continuous wave) laser that continuously oscillates, in many cases, electronic components may generate heat and their characteristics may change, and in order to obtain a good ablation situation, a pulse laser is used in time series. This is because the shorter the pulse width, the better.
[0021]
Although the type of laser depends on the target component, generally, an infrared laser has a characteristic of transmitting a wafer made of Si (silicon), and therefore a laser in the ultraviolet region is used. Specifically, an excimer laser, a YAG second harmonic, a third harmonic, and an LD (laser diode) are used.
[0022]
When the energy is the same, the shorter the wavelength, the better. However, in that case, the transmittance of the BG tape is deteriorated, and there is a possibility that it reacts with the base material layer or the adhesive material layer of the BG tape. The PVC (polyvinyl chloride) base material has been known to react with an ultraviolet laser. It has been confirmed that a PO (polyolefin) -based substrate transmits an ultraviolet laser up to about 300 nm.
[0023]
In the case of using a pulse laser, the laser can be focused to 1 μm or less, and it is possible in principle to peel off the mounted components to that extent. Also, there is little need to consider the effects of heat due to the pulsed laser.
[0024]
As described above, the present embodiment is a method in which a chip component cut out from a wafer and separated into pieces is peeled from the BG tape and mounted on a mounting board. However, since correction after flip-chip bonding is impossible, it is required to maintain the arrangement position of the chip parts with high accuracy and not to cause defective connection of electrodes. Therefore, after dicing the wafer that is adhesively fixed to the BG tape, the BG tape is stretched and the chip parts are arranged at a predetermined interval. It is an indispensable condition for flip chip bonding that there is no residue on the electrode surface.
[0025]
Therefore, when the chip part is peeled off from the BG tape, it is ideal that the adhesive material disappears and the chip part is peeled off in a non-contact manner. For this purpose, a laser beam is used from the back side of the BG tape. It is effective to create a space between the chip component and the adhesive material by irradiating light and ablating the adhesive material interface of the component on the order of μm (for example, 5 μm or less) to generate gas. is there.
[0026]
As a result, the adhesive material that causes connection failure is gasified and disappears, and without changing the position of the arrangement of the chip components arranged at a predetermined interval, the adhering separation is performed while maintaining the arrangement interval. It can be mounted at a predetermined position on the substrate.
[0027]
In FIG. 1, the process from peeling of the chip component by this Embodiment to conveyance of the peeled chip component is shown in order of process. In addition, the same code | symbol is used for the site | part common to the prior art example shown in FIG.3 and FIG.4.
[0028]
In the present embodiment, the process from pasting the wafer to the BG tape, dicing the wafer, and extending the BG tape and arranging the separated chip parts at a predetermined interval is the same as the conventional process. Accordingly, FIG. 1A shows a state (corresponding to FIG. 3C) in which chip parts are arranged at a predetermined interval.
[0029]
That is, in FIG. 1A, since the chip parts 12A separated into individual pieces are conveyed by the suction head 11 and mounted at a predetermined position on the mounting board, the interval W between the chip parts is predetermined. It is in a state arranged at intervals.
[0030]
Next, as shown in FIG. 1B, the suction head 11 selectively moves to the position of the chip component 12A to be mounted, and comes into contact with and sucks the back surface of the chip component 12A. In this state, the electrodes and the like formed on the surface of the chip component 12A are located on the BG tape 14 side and are adhered to the BG tape 14 by the adhesive material 13, so the suction head 11 is placed on the flat back surface of the chip component 12A. In this state, since the chip component is adhesively fixed to the BG tape 14 side in this state, the positional accuracy of the chip component 12 </ b> A is not changed by the contact of the suction head 11.
[0031]
Next, as shown in FIG. 1C, the laser is applied from the surface of the BG tape 14 opposite to the surface on which the chip component 12A is fixed to the adhesive material 13 at the position of the chip component 12A to be mounted. Irradiate light 10. Since this laser uses a pulsed laser as described above, the chip part 12A is not heated, but the adhesive material 13 is ablated and gasified, and the adhesive material 13 in that portion disappears and a missing portion 18 is generated. However, since the chip component 12A is supported by the suction head 11, the position of the chip component 12A does not move.
[0032]
Next, as shown in FIG. 1D, the chip component 12 </ b> A to be mounted is conveyed to the mounting substrate side while being sucked by the suction head 11.
[0033]
As described above, the peeling method according to the present embodiment is arranged in a predetermined interval because it can be peeled in a non-contact manner, unlike the conventional ultraviolet irradiation and mechanical peeling by pushing up from below with a needle. Without changing the position, it is possible to transport an electronic component that is peeled in a state of being held at a predetermined interval and in which the adhesive material has not disappeared and remains.
[0034]
Also, with this peeling method, even a small mounting component that cannot make a peeling needle can be securely peeled and mounted on a mounting board. Theoretically, parts of about 1 μm ² can be peeled off.
[0035]
FIG. 2 shows a state in which the chip component 12A peeled from the BG tape 14 as described above is conveyed onto the mounting substrate 20 by the suction head 11 and is flip-chip bonded. In this case, as described above, since the chip component 12A to be mounted is peeled off in a non-contact manner using laser light, the adhesive 13 is ablated while the predetermined arrangement position is maintained, and the chip component Since the adhesive 13 does not remain on the surface of the electrode 17 side of 12A, it is possible to perform flip chip bonding at a predetermined position on the mounting substrate 20 without causing any solder connection failure during bonding.
[0036]
As described above, according to the peeling method and the mounting method of the present embodiment, the separated chip component 12A is not used on the BG tape 14 on the side opposite to the side on which the chip component 12A is attached without using a needle. By irradiating the surface with laser light and ablating the adhesive 13, the adhesive 13 is gasified and disappears, so that the chip component 12 </ b> A can be reliably peeled off, and an adhesive that causes connection failure and the like. The material 13 can be prevented from remaining on the electrode surface of the chip part 12A. Conventionally, there is a limitation that it is difficult to make the needle thin, and the adhesive material 13 remains by piercing with the needle. Problems such as this causing a connection failure can be solved.
[0037]
This embodiment can be modified based on the technical idea of the present invention.
[0038]
For example, by producing a BG tape with the most suitable material for the type of laser that is most suitable for peeling chip components, the peeling process can be unified and productivity can be increased.
[0039]
Further, by configuring the adhesive material of the BG tape with a material that can be easily ablated, it is possible to use a laser having a shorter wavelength region.
[0040]
[Effects of the invention]
As described above, according to the method for peeling an electronic component and the mounting method thereof according to the present invention , the adhesive material is gasified and peeled by ablation by laser light irradiation, so that the adhesive material is gasified and disappears without generating heat. together, it can be separated from the support of the electronic component in a non-contact manner without impairing its characteristics. Therefore , since the electronic components can be easily peeled off without leaving an adhesive material, connection failure does not occur after mounting, and the peeled electronic components are not moved. While can be implemented.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an electronic component peeling method according to an embodiment of the present invention in the order of steps.
FIG. 2 is a schematic cross-sectional view showing a method for mounting an electronic component according to the embodiment.
FIG. 3 is a schematic cross-sectional view illustrating an example of a method for peeling an electronic component according to a conventional example in order of steps.
FIG. 4 is a schematic cross-sectional view showing a mounted state of the electronic component.
[Explanation of symbols]
10 ... Laser beam, 11 ... Suction head, 12 ... Wafer,
12A ... chip parts (electronic parts), 13 ... adhesive material, 14 ... BG tape,
15 ... Needle, 16 ... Diamond cutter, 17, 21 ... Electrode, 18 ... Missing part,
20 ... Mounting board, 22 ... Solder, L ... Dimension, W ... Spacing

Claims (10)

In the method of peeling the electronic component from the state where the electronic component is adhesively fixed on the support with an adhesive material,
The I I is an adhesive from the side opposite to the Rukoto be irradiated with ultraviolet laser light to the adhesive material through said support, peeling the electronic part is gasified by ablation of the adhesive material from the supporting lifting body
Wherein the peeling method of the electronic component. Irradiating the ultraviolet laser beam while holding the electronic component by the suction head, the peeling method of the electronic component according to claim 1. A semiconductor substrate to be separated into a plurality of the electronic components is adhesively fixed to the one surface of the support with the adhesive, and the electronic components are separated into pieces in this adhesive state, and the support is stretched to obtain individual pieces. between the electronic component arranged in a predetermined interval and fragmented, irradiating the ultraviolet laser light to the adhesive in this state, the peeling method of the electronic component according to claim 1. The method for peeling an electronic component according to claim 1, wherein a pulse laser is used as the ultraviolet laser. The method of peeling an electronic component according to claim 1, wherein the support is made of a material that transmits the ultraviolet laser beam. In a method of peeling the electronic component from a state in which the electronic component is adhesively fixed on a support with an adhesive, and mounting the peeled electronic component on a mounting board ,
Wherein the adhesive material I by the Rukoto be irradiated with ultraviolet laser light to the adhesive through the support from the opposite side, the adhesive material is gasified by ablation and peeling the electronic part from the supporting lifting member, to implement this peeling electronic component on the mounting board
An electronic component mounting method characterized by the above. The electronic component mounting method according to claim 6 , wherein the ultraviolet laser beam is irradiated while the electronic component is held by a suction head. A semiconductor substrate to be separated into a plurality of the electronic components is adhesively fixed to the one surface of the support with the adhesive, and the electronic components are separated into pieces in this adhesive state, and the support is stretched to obtain individual pieces. The electronic component mounting method according to claim 6 , wherein the separated electronic components are arranged at a predetermined interval, and in this state, the adhesive material is irradiated with the ultraviolet laser light. The electronic component mounting method according to claim 6, wherein a pulsed laser is used as the ultraviolet laser. The electronic component mounting method according to claim 6, wherein a support made of a material that transmits the ultraviolet laser light is used as the support.

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