WO2008001982A1

WO2008001982A1 - Apparatus and method for eliminating molding compound of semi-conductor and electronic device

Info

Publication number: WO2008001982A1
Application number: PCT/KR2006/004840
Authority: WO
Inventors: Kyeongwook Shin
Original assignee: M.I.Semiconductor Co., Ltd.
Priority date: 2006-06-26
Filing date: 2006-11-17
Publication date: 2008-01-03
Also published as: KR100801150B1; KR20080000027A

Abstract

With regards to semi-conductor and electronic devices which comprise more than one wafer, oxide films for forming electric elements by being accumulated as plural layers on at least one side of each wafer, wafer layers including nitride films and metal films, epoxy layers accumulated as epoxies to insulate between wafer layers accumulated on one wafer and another neighboring wafer, for each wafer, and surface molding compounds covering each wafer, the wafer layers, and the epoxy layers, and wherein the wafer layers comprise soluble wafer layers easily removed by a chemical wet-etching method and insoluble wafer layers which are not easily removed by the chemical wet-etching method and which randomly form plural layers, the present invention relates to an apparatus and a method for eliminating the molding compounds of the semi-conductor and electronic devices for removing surface molding compounds covering the outside of samples which are the semi-conductor and electronic devices for inspecting internal circuit state and inferior state, for independently separating each wafer by removing the epoxy layers and cutting wires that connect each wafer, and for removing the wafer layers until layers to be inspected are exposed for each of the independently separated wafers.

Description

APPARATUS AND METHOD FOR ELIMINATING MOLDING COMPOUND OF SEMI-CONDUCTOR AND ELECTRONIC

DEVICE

Technical Field

[1] The present invention generally relates to an apparatus and a method for eliminating molding compound of semi-conductor and electronic device, and more specifically, to an apparatus and a method for eliminating molding compound of packaged semiconductor and electronic device for eliminating molding compounds of the packaged semi-conductor chip or thepackagedelectronic device so as to connect and protect component parts of an IC and prevent semi-conductor chips or electronic devices from malfunctioning owing to excessive power supply and external vibration, and particularly, for eliminating surface molding compounds and wafer layers of the semiconductor chip or the electronic device through a mechanical milling method, a mechanical polishing method, and a chemical wet-etching method. Background Art

[2] It is required to observe wafers which constitute a semi-conductor chip or a circuit in order to analyze a cause of inferiority of a product which is decided as being inferior in quality inspection of a semi-conductor or an electronic device. So, molding compound packages of the semi-conductor and the electronic device are eliminated to observe the wasfers, and in this case, the existing elimination of the molding compound packages is conducted through a manual work. However, there are thousands of types of the currently used semi-conductors or electronic devices, and the shapes are diversified while numerous products exist, therefore, if the molding compounds are eliminated through the manual work, working speed is reduced remarkably, resulting in deterioration of inspection efficiency. Besides, chemical substances are used to remove these molding compounds, which is very dangerous if the chemical substances are directly treated through the manual work, and also the process is complicated, thus it is difficult to conduct a lot of operations.

[3] Meanwhile, if one wafer only is included in a semi-conductor or an electronic device, that is, in case of a single layer, it is available to observe the wafer after removing surface molding compounds only of the semi-conductor or electronic device. But, in case plural wafers of a semi-conductor or an electronic device form multiple layers, each wafer should be separated by eliminating wafer layers between the wafers after removing the surface molding compounds so as to observe the respective wafers. As a result, with the existing method, working efficiency tremendously deteriorates and risk gets severer. Disclosure of Invention

Technical Problem

[4] It is therefore an object of the present invention to provide an apparatus and a method for eliminating molding compounds of packaged semi-conductor and electronic device for effectively removing the molding compounds of the semiconductor and the electronic device by eliminating surface molding compounds through a mechanical milling method and a chemical wet-etching method and by eliminating wafer layers between wafers through a mechanical polishing method and a chemical wet-etching method according to each type of the wafer layers, and for being commonly applied to various kinds of semi-conductors and electronic devices by automating and standardizing each unit process as remarkably improving working pace with safety. Technical Solution

[5] So as to accomplish the above object, with regards to packaged semi-conductor and electronic devices for including: more than one wafer; wafer layers forming electric elements by being accumulated on at least one side of each wafer as plural layers; epoxy layers accumulated as epoxies for each wafer to insulate between the wafer layers accumulated on one wafer and another neighboring wafer; and surface molding compounds covering each wafer, the wafer layers and the epoxy layers, an apparatus for eliminating the molding compounds of the semi-conductor and electronic devices for removing the surface molding compounds covering the outside of samples which are the semi-conductor and electronic devices for inspecting internal circuit state and inferior state, for independently separating each wafer by removing the epoxy layers, and for removing the wafer layers until layer to be inspected is exposed for each of the independently separated wafers, comprises: jigs for fixing the samples; a milling device for independently separating each wafer by cutting wires that connect the respective wafers, the wires being exposed by removing the epoxy layers; a chucking device for chucking each of the independently separated wafers to transfer the chucked wafers; a etching solution injector for generating etching solutions by mixing more than one chemical substance with a diluted solution, and for injecting the etching solutions into the wafer layers and the epoxy layers of the samples to chemically wet- etch the wafer layers and the epoxy layers; and a washing device for washing the samples into which the etching solutions are injected, with wash liquids.

[6] Furthermore, so as to achieve the above object, with regards to packaged semiconductor and electronic devices for including: more than one wafer; wafer layers including oxide films, nitride films and metal films, the oxide films, the nitride films and the metal films forming electric elements by being accumulated as plural layers on at least one side of each wafer; and surface molding compounds covering each wafer and the wafer layers, and wherein the wafer layers comprise soluble wafer layers which are easily removed by a chemical wet-etching method and insoluble wafer layers which are not easily removed by the chemical wet-etching method, and the soluble wafer layers and the insoluble wafer layers randomly forming plural layers, an apparatus for eliminating the molding compounds of the semi-conductor and electronic devices for removing the surface molding compounds covering the outside of samples which are the semi-conductor and electronic devices for inspecting internal circuit state and inferior state, and for independently separating each wafer to remove the wafer layers until layer to be inspected is exposed for each of the independently separated wafers, comprises: jigs for fixing the samples; a polishing device for contacting with the insoluble wafer layers of the samples, and for mechanically polishing the insoluble wafer layers by a frictional force to remove the insoluble wafer layers; a etching solution injector for generating etching solutions by mixing more than one chemical substance with a diluted solution, and for injecting the etching solutions into the soluble wafer layers of the samples to chemically wet-etch the soluble wafer layers; and a washing device for washing the samples into which the etching solutions are injected, with wash liquids.

[7] Desirably, the jigs comprise: plates where the samples are disposed; heating portions including plural heating wires for emitting heat by being supplied with electricity; and temperature sensors sensing surface temperature of the jigs; and wherein the heating portions heat the samples at a temperature that chemical reaction of the etching solutions is activated. It is also possible for the jigs to comprise: plates; heating portions including plural heating wires for emitting heat by being supplied with electricity, and being disposed in the upper part of the plates; wells for mounting the samples inside by being in a concavely caved-in shape, and containing etching solutions injected through etching solution injector; tightening plates for fixing the samples by covering the girth of the samples; more than one spring for fixing the tightening plates to the wells by supporting the gaps of the tightening plates and inner side of the wells; and temperature sensors for sensing surface temperature of the jigs; and wherein the heating portions heat the samples at a temperature that chemical reaction of the etching solutions is activated. The apparatus for eliminating the molding compounds of the semi-conductor and electronic devices can further comprises a lamp applying radiant heat to the samples when the etching solutions are injected. The etching solution injector comprises: etching solution injecting pipes for injecting the etching solutions; gas inhaling portions for inhaling gas generated during the chemical reaction of the etching solutions to discharge the inhaled gas; and wash liquid injecting pipes for injecting wash liquids into the samples so as to prevent the remnants generated during the chemical reaction of the etching solutions from sticking to the etching solution injecting pipes. The etching solution injecting pipes are made of industrial diamond materials, and the surface is coated to absorb shock. Besides, the etching solution injector generates etching solutions for wet-etching the epoxy layers by mixing more than one chemical substance of sulfuric acid(H SO ), nitric acid(HNO

2 4 3

), fuming sulfuric acid(H SO _F) and fuming nitric acid(HNO _F) with a diluted solution including pure water(DI water), and generates etching solutions for wet- etching the wafer layers by mixing more than one chemical substance of acetic acid(CH COOH), sulfuric acid(H SO ), nitric acid(HNO ), fuming sulfuric acid(H SO

3 2 4 3 2 4

_F), fuming nitric acid(HNO _F), hydrofluoric acid(HF), hydrochloric acid(HCL), PAE(PoIy Alyene Ethers, AL Etchant, H PO :HN0 ), BOE(Buffered Oxide Etchants, HF:NH F), Poly Etchant(HNO :HF:CH COOH) and sodium hydroxide(NaOH) with a diluted solution including pure water(DI water). More desirably, the etching solution injector generates etching solutions for wet-etching the soluble wafer layers by mixing more than one chemical substance of acetic acid(CH COOH), sulfuric acid(H SO ), nitric acid(HN0 3 ), fuming sulfuric acid(H 2 SO 4 _F), fuming nitric acid(HN03 _F), hy- drofluoric acid(HF), hydrochloric acid(HCL), PAE(PoIy Alyene Ethers, AL Etchant, H 3PO₄:HNO₃), BOE(Buffered Oxide Etchants, HFiNH₄F), Poly Etchant(HNO₃:HF:CH₃ COOH) and sodium hydroxide(NaOH) with a diluted solution including pure water(DI water). More than one of pure water(DI water), acetone and isopropyl alcohol (IPA) is used for the wash liquids. In addition, the chucking device comprises: a chucking plate contacting with each of the independently separated wafers; an absorbing portion for vacuously absorbing each wafer and being configured as gasket made of a fluororubber material; and an air inhaling portion for inhaling air to generate a vacuous inhaling force in the absorbing portion. [8] Moreover, so as to achieve another object, with regards to semi-conductor and electronic devices which comprise more than one wafer; wafer layers including oxide films, nitride films and metal films, the oxide films, the nitride films and the metal films forming electric elements by being accumulated as plural layers on at least one side of each wafer; epoxy layers accumulated as epoxies for each wafer to insulate between wafer layers accumulated on one wafer and another neighboring wafer; and surface molding compounds covering each wafer, the wafer layers and the epoxy layers, and wherein the wafer layers comprise soluble wafer layers which are easily removed by a chemical wet-etching method and insoluble wafer layers which are not easily removed by the chemical wet-etching method, and the soluble wafer layers and the insoluble wafer layers randomly forming plural layers, a method for eliminating the molding compounds of the semi-conductor and electronic devices for removing the surface molding compounds covering the outside of samples which are the semiconductor and electronic devices for inspecting internal circuit state and inferior state, for independently separating each wafer by removing the epoxy layers and cutting wires that connect each wafer, and for removing the wafer layers until layer to be inspected is exposed for each of the independently separated wafers, comprises: a first step of removing the epoxy layers through the chemical wet-etching method by injecting etching solutions into the epoxy layers of the samples; a second step of independently separating the wafer by cutting the wires for one of the respective wafers, when the wires are exposed by removing the epoxy layers; a third step of absorbing the independently separated wafer to transfer the absorbed wafer; a fourth step of contacting a polishing device with the insoluble wafer layers of the wafer, and mechanically polishing the insolube wafer layers by a frictional force to remove the insoluble wafer layers; and a fifth step of removing the soluble wafer layers through the chemical wet-etching method by injecting the etching solutions into the soluble wafer layers of the wafer; and wherein the first to third steps are selectively performed when the samples include the plural wafers, the fourth and fifth steps are selectively performed according to the wafers to be removed, the fourth and fifth steps are repeatedly executed until the layer to be inspected are exposed, for the respective wafers, and the second to fifth steps are repeatedly performed until all of the wafers are independently separated.

[9] Desirably, the first step comprises a 1-1 step of generating the etching solutions by mixing more than one chemical substance of sulfuric acid(H SO ), nitric acid(HNO ), fuming sulfuric acid(H SO _F) and fuming nitric acid(HNO _F) with a diluted

2 4 3 solution, and the fifth step comprises a 5-1 step of generating the etching solutions by mixing more than one chemical substance of acetic acid(CH COOH), sulfuric acid(H SO ), nitric acid(HNO ), fuming sulfuric acid(H SO _F), fuming nitric acid(HNO _F), hydrofluoric acid(HF), hydrochloric acid(HCL), PAE(PoIy Alyene Ethers, AL Etchant, H PO :HN0 ), BOE(Buffered Oxide Etchants, HF:NH F), Poly Etchant(HNO :HF:CH

3 4 3 4 3

COOH) and sodium hydroxide(NaOH) with a diluted solution. More desirably, the fifth step comprises: a 5-2 step of chemically wet-etching the soluble wafer layers by injecting the etching solutions into the soluble wafer layers of the wafer; and a 5-3 step of washing the wafer with wash liquids after a certain time elapses; and wherein the 5-2 and 5-3 steps are repeatedly performed until the soluble wafer layers to be removed are perfectly eliminated. Brief Description of the Drawings

[10] The present invention will be described in detail with reference to the drawing showing the preferred embodiment of the present invention, wherein: [11] Fig. 1 is a plane figure of an apparatus for eliminating molding compounds in accordance with the present invention;

[12] Fig. 2 is a left side view of an apparatus for eliminating molding compounds in accordance with the present invention;

[13] Fig. 3 is a front view of an apparatus for eliminating molding compounds in accordance with the present invention;

[14] Fig. 4 is a right side view of an apparatus for eliminating molding compounds in accordance with the present invention;

[15] Fig. 5 is a format diagram of a jig in accordance with the present invention;

[16] Fig. 6 is a format diagram of another embodiment of a jig in accordance with the present invention;

[17] Fig. 7 is a format diagram of an etching solution injector in accordance with the present invention;

[18] Fig. 8 is a format diagram of a chucking device in accordance with the present invention; and

[19] Fig. 9 and Fig. 10 are flow charts of a process for eliminating molding compounds in accordance with the present invention. Best Mode for Carrying Out the Invention

[20] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which perferred embodiments of the invention are shown.

[21] In semi-conductor and electronic devices decapped by the present invention, layers molded as covering the outside of the semi-conductor and electronic device are called 'surface molding compounds', oxide films, nitride films, and metal films for forming electric elements by being accumulated as plural layers on at least one side of each wafer are commonly called 'wafer layers', and gaps between the wafer layers and the wafers, that is, layers accumulated as epoxies to insulate between wafer layers accumulated on one wafer and another neighboring wafer for each wafer are called 'epoxy layers'. Also, the wafer layers randomly form plural layers by soluble wafer layers and insoluble wafer layers. Namely, the wafer layers are accumulated as plural layers, and in this case, each layer may refer to the soluble wafer layers or the insoluble wafer layers. The soluble wafer layers indicate layers made of a certain material which is removable by a chemical wet-etching method, that is, a material easily melted by etching solutions, and representatively, there are oxide films and metal films. And, the insoluble wafer layers indicate layers made of a certain material unremovable by the chemical wet-etching method, that is, a material which has difficulty in reacting, for instance, it is not melted by the etching solutions or it takes a long time for reaction, and representatively, there are nitride films.

[22] Fig. 1 through Fig. 4 are diagrams illustrating an apparatus for eliminating molding compounds of packaged semi-conductor and electronic devices in accordance with the present invention, Fig. 1 is a plane figure of the apparatus for eliminating the molding compounds in accordance with the present invention, Fig. 2 is a left side view of the apparatus for eliminating the molding compounds in accordance with the present invention, Fig. 3 is a front view of the apparatus for eliminating the molding compounds in accordance with the present invention, and Fig. 4 is a right side view of the apparatus for eliminating the molding compounds in accordance with the present invention. Especially, in Fig. 2, illustrations of a milling device(40) and a polishing device(45) are omitted to clearly illustrate configurations of etching solution injectors(50) and a washing device(60), and in Fig. 4, illustrations of the etching solution injectors(50), the washing device(60), and a chucking device(70) are omitted to clearly illustrate configurations of the milling device (40) and the polishing device(45). Likewise, in Fig. 2, so as to clearly illustrate features that each configured part is interlocked together, a state that jigs(20) are disposed under the etching solution injectors(50) is drawn in a solid line, while a state that the jigs(20) are disposed under the washing device(60) to wash etching solutions from samples(lθ) and a state that the jigs(20) are disposed under the chucking device(70) to separate the samples(lθ) are drawn in a dotted line. Referring to Fig. 1 through Fig. 4, a configuration of the apparatus for eliminating the molding compounds of the semi-conductor and electronic devices in accordance with the present invention will be described as follows.

[23] The apparatus(lOO) for eliminating the molding compounds in accordance with the present invention removes surface molding compounds of the packaged semiconductor and electronic devices(10, hereinafter, 'samples'), through a mechanical milling method using a milling device and a chemical wet-etching method using etching solutions. In addition, if one wafer constitutes a single layer in the samples(lθ), wafer layers of the wafer are eliminated, and if plural wafers constitute multiple layers in the samples, epoxy layers between each wafer and each wafer layer are removed through the chemical wet-etching method and wires are cut to separate each wafer before the wafer layers are removed. The separated wafers are transferred through a chucking method to remove the wafer layers. At this time, since the wafer layers can include both soluble wafer layers and insoluble wafer layers, the soluble wafer layers and the insoluble wafer layers should be eliminated in different methods. So, the insoluble wafer layers are eliminated by a mechanical polishing method using a polishing device, while the soluble wafer layers are eliminated by a chemical wet- etching method using etching solutions. When the wafer layers are eliminated so that desired layers, namely, layers to be inspected are exposed, the corresponding wafers are chucked and transferred again to analyze a structural defect or an electrical defect of a circuit. A detailed configuration of the apparatus(lOO) for eliminating the molding compounds in accordance with the present invention will be described below.

[24] The apparatus(lOO) for eliminating the molding compounds in accordance with the present invention comprises: the jigs(20) for fixing various kinds of the samples(lθ); XYZ-axis stages(25,26,27) for moving the jigs to desired positions as fixing the jigs; a camera(30) for taking pictures of the samples; the milling device(40) for mechanically milling surface molding compounds of the samples and cutting wires between the wafers; the polishing device(45) for mechanically polishing the insoluble wafer layers of the wafer layers of the samples to eliminate the insoluble wafer layers; the etching solution injectors(50) for injecting etching solutions into the samples to wet-etch the surface molding compounds, the epoxy layers, and the wafer layers(particularly, the soluble wafer layers); the washing device(60) for washing the etching solutions injected into the samples; and the chucking device(70) for chucking each wafer whose wires are cut after the epoxy layers are eliminated or each wafer whose wafer layers are eliminated, and separating the chucked wafers. Operation of the apparatus(lOO) for eliminating the molding compounds is controlled by a controlling device (not shown), and the user controls the operation of the apparatus(lOO) for eliminating the molding compounds by manipulating the controlling device as viewing images of the samples(lθ), which are taken by the camera(30).

[25] The jigs(20) stably fix the samples(lθ) of various sizes and shapes, and move the samples to each process for removing the molding compounds as moving by the XYZ- axis stages(25 ,26,27). The XYZ-axis stages(25,26,27) are devices for moving the jigs(20), to which the samples are fixed, to desired positions, and consist of 3 axes such as X, Y, and Z axes, then rails are attached to each axis. An arm(28) is combined with the Z-axis stage(27), in order that the X-axis and Z-axis stages(25,27) can independently move together. Besides, the Z-axis stage(27) is combined with the jigs(20) through the arm(28) and an axis(29), and the jigs move to the Z axis by rotation of the axis(29). In the meantime, a connecting means for letting the jigs rotate as forming a 90-degree angle with the axis can be further comprised. Accordingly, it is possible to 3-dimensionally and freely move the samples(lθ) fixed to the jigs(20), by motions of the arm(28) and the axis(29).

[26] Meanwhile, when the etching solutions are injected into a milled part or a part where the milling process is not performed, to remove the surface molding compounds, the epoxy layers, and the wafer layers of the samples(lθ), the samples should be heated at proper temperature so as to activate chemical reaction of the etching solutions. Generally speaking, to lead reaction of chemical substances, a circumstance that the chemical reaction occurs is very important, not to speak of the chemical substances. Thus, to activate the chemical reaction of the etching solutions injected into the samples(lθ), the samples should be thermally stabilized while heat should be continuously supplied. Therefore, the apparatus (100) for eliminating the molding compounds in accordance with the present invention includes a heating device for heating the samples at proper temperature so as to activate the chemical reaction, when the chemical reaction occurs by injecting the etching solutions into the samples(lθ). The heating device consists of a heating portion for generating heat by using heating wires and a lamp (24) for heating by using radiant heat. The heating portion is comprised in each jig(20) to heat the samples by generating heat with the use of the inside heating wires. Moreover, the lamp(24) is adjacent to the etching solution injectors(50), and applies the radiant heat to the samples to immediately heat the samples once the jigs(20) dispose the samples under the etching solution injecting pipes(55) and inject the etching solutions. A halogen lamp can be used as the lamp(24). Consequently, the samples are quickly and continuously heated at proper temperature, by instantly heating the etching solutions to spray the heated etching solutions on the samples(lθ) and heating the samples up and down with the heating portion and the lamp(24). On this occasion, it is desirable that the proper temperature of the samples(lθ) becomes from room temperature to 300⁰C. It is also possible that the apparatus (100) for eliminating the molding compounds in accordance with the present invention selectively includes or includes both heating portion and lamp(24) as the heating device.

[27] The camera(30) takes pictures of the samples(lθ), and transmits the taken pictures to the controlling device. A digital camera is used as the camera(30). The pictures taken by the camera(30) are displayed on the controlling device, so that the user can input a range of eliminating the molding compounds. Since there are thousands of diversified types, sizes, and shapes of finished semi-conductor products or electronic devices, the user can properly control a range and positions where the molding compounds of the samples (10) are to be eliminated, by taking the pictures of the samples(lθ) with the camera(30) and monitoring the taken pictures through the controlling device.

[28] The milling device(40) is a device for mechanically milling the surface molding compounds of the samples in set thickness before injecting the etching solutions through the etching solution injectors(50), so as to remove the surface molding compounds of the samples (10). When the user observes the surface of the samples displayed on the controlling device and sets thickness and a range of milling, the milling device mechanically eliminates the set part under control of the controlling device. If the samples are thin, when the surface molding compounds of the samples (10) are eliminated, the surface molding compounds can be effectively removed with a chemical wet-etching method only by injecting the etching solutions. However, in case the samples(lθ) are thick, it takes a lot of time for removing the surface molding compounds as much as the thickness, and furthermore, the surface molding compounds cannot be effectively removed with the chemical wet-etching method only.In addition, since the etching solutions used for eliminating the surface molding compounds have fluidity as liquids, partial etching solutions only show chemical reaction when the etching solutions are injected into the samples, while the remaining etching solutions run down along the surface of the samples. But, if the surface molding compounds are first milled by using the milling device(40) and the remaining surface molding compounds only are eliminated through the chemical wet- etching method, the surface molding compounds of the thick samples(lθ) can be efficiently eliminated. Also, if the etching solutions are injected after surface molding compounds of a desired part are removed through milling, the etching solutions gather in the milled part without running down, thereby effectually eliminating the surface molding compounds. Particularly, the milling device(40) cuts wires for connecting each wafer when each wafer and the wafer layers are exposed by removing the surface molding compounds and removing epoxy layers for insulating between each wafer and wafer layers, for the samples (10) where plural wafers constitute multiple layers. Accordingly, it is possible to eliminate the wafer layers after separating the respective wafers.

[29] When removing the wafer layers after eliminating the surface molding compounds and the epoxy layers, the polishing device(45) mechanically eliminates the insoluble wafer layers which are not melted by the etching solutions. Likewise, the wafer layers are composed of the soluble wafer layers made of a material melted in the etching solutions and the insoluble wafer layers made of a material which has difficulty in reacting, for instance, it is not melted by the etching solutions or it takes a long time, and representatively, there is a nitride-series material. Therefore, when removing the wafer layers, the soluble wafer layers can be eliminated by the chemical wet-etching method with the use of the etching solutions, while the insoluble wafer layers cannot be removed by the chemical wet-etching method. The polishing device(45) is a device for mechanically polishing the insoluble wafer layers as much as set thickness, comprises a polishing pad on a pushing plate, and removes the insoluble wafer layers as rotating after mounting the samples(lθ) on the pushing pad. While the milling device(40) eliminates the surface molding compounds in slightly rough way by removing some of the surface molding compounds before eliminating the surface molding compounds with the etching solutions, the polishing device(45) removes the insoluble wafer layers by finely grinding the layers (generally, less than 2D). To do this, slurries which function as lubricants are supplied to a frictional surface with the samples(lθ). So, the insoluble wafer layers can be finely eliminated by using a frictional force generated by the slurries. The polishing device(45) removes the insoluble wafer layers of a set range under control of the controlling device, and at this time, the polishing device(45) mechanically eliminates a set part under control of the controlling device, once the user sets thickness and a range to be polished by observing the surface of the samples displayed on the controlling device. On the other hand, if a structure of the wafer layers, that is, thickness and positions of the soluble wafer layers and the insoluble wafer layers are previously inputted, the polishing device(45) may eliminate the insoluble wafer layers as much as the automatically set range under control of the controlling device.

[30] The etching solution injectors(50) generate the etching solutions by mixing chemical substances with a diluted solution(pure water, DI water), and inject the etching solutions into the samples to remove the surface molding compounds of the samples through the chemical wet-etching method, when the surface molding compounds of the samples(lθ) are mechanically milled by the milling device(40). Also, once the surface molding compounds of the samples (10) are eliminated, the etching solution injectors(50) inject the etching solutions into the epoxy layers between each wafer and the wafer layers to remove the epoxy layers through the chemical wet- etching method, and inject the etching solutions into the soluble wafer layers of the wafer layers formed on each wafer after each wafer is separated, then remove the soluble wafer layers through the chemical wet-etching method. Chemical substances used for generating the etching solutions are made by mixing one or more than two of chemical substances such as sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid, hydrochloric acid, sodium hydroxide, fuming sulfuric acid, and fuming nitric acid. Desirably, different etching solutions are used when the surface molding compounds, the epoxy layers, and the soluble wafer layers of the samples(lθ) are etched. Concretely, the etching solutions for removing the surface molding compounds and the epoxy layers are used by diluting one or more than two of sulfuric acid(H SO ), nitric acid(HNO ), fuming sulfuric acid(H SO _F), and fuming nitric acid(HNO _F)

3 2 4 3 with pure water(DI water). Besides, the etching solutions for removing the soluble wafer layers are used by diluting one or more than two of acetic acid(CH 3 COOH), sulfuric acid(H SO ), nitric acid(HNO ), fuming sulfuric acid(H SO _F), fuming nitric acid(HNO 3 _^' F), hydrofluoric acid(HF), hydrochloric acid(HCL), PAE(PoIy Alyene

Ethers, AL Etchant, H 3 PO 4 :HN03 ), BOE(Buffered Oxide Etchants, HF:NH 4 F), poly etchant(HNO :HF:CH COOH), and sodium hydroxide(NaOH) with pure water(DI water). The etching solution injectors(50) separately comprise etching solution suppliers for supplying the etching solutions for eliminating the surface molding compounds, etching solution suppliers for supplying the etching solutions for eliminating the epoxy layers, and etching solution suppliers for supplying the etching solutions for eliminating the soluble wafer layers. With regards to the surface molding compounds and the epoxy layers, the same etching solution suppliers may be equipped. The etching solution injectors(50) control an injected amount of the etching solutions according to an amount of the surface molding compounds, the epoxy layers, and the soluble wafer layers to be eliminated. At this time, when the samples(lθ) are taken by the camera(30) and the taken pictures are transmitted to the controlling device, the controlling device calculates the amount of the surface molding compounds, the epoxy layers, and the soluble wafer layers to be eliminated, and the etching solution injectors inject the etching solutions as much as the calculated amount into the samples(lθ) through the etching solution injecting pipes(55). The etching solution injecting pipes(55) for injecting the etching solutions into the samples(lθ) are made of industrial diamond materials, and particularly, the surface of the etching solution injecting pipes is coated to absorb shock, in order to prevent the wafers from being broken or damaged as the wafers are contacted with the etching solution injecting pipes when the soluble wafer layers are etched.

[31] The washing device(60) washes the samples(lθ) before and after a process of removing the molding compounds or in the middle of the process, with wash liquids. Acetone, pure water(DI water) or isopropyl alcohol(IPA) can be used as the wash liquids. The washing device(60) includes wash liquid injecting pipes(61,62) that spray the wash liquids to the surface of the samples(lθ). Desirably, the wash liquid injecting pipe(61) for spraying the wash liquids in straight line type and the wash liquid injecting pipe (62) for sraying the wash liquids in sprayer type are individually disposed, so that either of the pipes(61,62) can be selectively used according to a washing range or a type of the samples. That is to say, the straight line-type or sprayer- type wash liquid injecting pipe is selected according to the washing range or the type of the samples, and the wash liquids are discharged from the selected wash liquid injecting pipe with a valve, in order that the wash liquids can be sprayed in straight line type or sprayer type. Accordingly, it is possible to minimize physical shock applied to the samples, which is caused by the sprayed wash liquids, and to increase washing efficiency.

[32] Meanwhile, it is also available to wash the samples(lθ) by soaking the samples in the wash liquids, without spraying the wash liquids by the wash liquid injecting pipes(61,62). In this case, the washing device(60) is configured in container type for containing the wash liquids, and the samples (10) are washed by directly injecting the jigs(20) mounted with the samples(lθ) to the washing device. At this moment, the jigs(20) are injected at certain inclined angle, so as to increase washing effect by extending contact between the samples (10) and the wash liquids. Furthermore, the jigs(20) shortly reciprocate up and down on top of the Z-axis stage(27) in a state of the samples(lθ) being injected into the washing device(60), thereby enhancing washing effect. Desirably, an ultrasonic oscillator is attached to a container where the wash liquids are contained, so that the remnants sticking to the samples (10) soaked in the wash liquids can be eliminated by using ultrasonic waves.

[33] After the washing process is performed with the washing device(60), the wash liquids remaining on the surface of the samples (10) should be dried. A drying device for drying the wash liquids is a device for eliminating the wash liquids remaining on the surface of the samples by evaporating the wash liquids, comprising an air discharge pipe(65) for spraying compressed air to the surface of the samples and a lamp(66) for drying with radiant heat by irradiating light on the surface of the samples. Thus, since the compressed air by the air discharge pipe(65) as well as the heat-drying method by the lamp(66) can be used together, the wash liquids may be effectively eliminated while working hours are reduced. Actually, if both compressed air and lamp are used together, it can reduce drying time in half, compared to a case that the lamp only is used.

[34] The chucking device(70) is a device for separating each wafer of the samples (10) to transfer the separated wafers. The chucking device(70) absorbs each wafer and transfers the absorbed wafer to a next process for eliminating wafer layers formed on each wafer, after the surface molding compounds and the epoxy layers of the samples(lθ) are removed by the etching solution injectors(50) and wires of the wafers are cut by the milling device(40). Also, the chucking device(70) absorbs and transfers each wafer where desired layers (that is, layers to be observed) are exposed by eliminating the wafer layers(soluble wafer layers, insoluble wafer layers) by the polishing device(45) and the etching solution injectors(50), then keeps the wafer in a separate storage box. The chucking device(70) uses a vacuous absorptive method to prevent the wafers from being damaged. Consequently, the user can analyze a structural defect or an electrical defect of a circuit in each wafer of a semi-conductor and an electronic device.

[35] Fig. 5 is a format diagram of a jig in accordance with the present invention. Like shown in Fig. 5, a jig(20) in accordance with the present invention includes a plate(21) where a sample(lθ) is disposed and a heating portion(22) for heating the sample, in order to mount the sample(lθ) and heat the sample to activate chemical reaction of etching solutions injected into the sample. The heating portion(22) includes plural heating wires(23) for emitting heat by being supplied with electricity, and heats the sample(lθ) by also using a lamp(24), then it is desirable to use a SUS(steel use stainless) material for the heating portion. The position of heating portion(22) is determined to warm the center of the sample(lθ). And, a temperature sensor(not shown) for sensing surface temperature of the jig(20) can be further comprised to detect temperature of the sample(lθ). Desirably, the temperature sensor is disposed in horizontal direction on the center of the jig(20), and is closely disposed, in vertical direction, to the surface of the jig where the sample(lθ) is located, in order to sense a temperature which is nearest to the temperature of the jig surface. The temperature of the jig surface sensed by the temperature sensor is transmitted to a controlling device, and the controlling device detects the temperature of the sample(lθ) and controls a heating value of the heating portion(22) and the lamp(24), to maintain the temperature of the sample(lθ) so that the maintained temperature can become optimum temperature for chemical reaction of the etching solutions. On this occasion, the temperature of the sample(lθ) is from room temperature to 300⁰C, for example, it is desirable that the temperature is 7O⁰C when nitric acid is used as the etching solutions, and 9O⁰C in case of sulfuric acid.

[36] Fig. 6 is a format diagram of another embodiment of a jig in accordance with the present invention. Fig. 6(a) is a perspective view of another embodiment of the jig in accordance with the present invention, and Fig. 6(b) is a sectional view of another embodiment of the jig in accordance with the present invention. Especially, Fig. 6(b) illustrates a state that a sample(lθ) is mounted on the jig and etching solutions are injected. Like shown in Fig. 6(a) and Fig. 6(b), another embodiment(80) of the jig in accordance with the present invention refers to a configuration that the sample(lθ) is mounted on the inside of a well(84) which is in concavely caved-in shape like a bathtub, comprising a plate(81), a heating portion(82) for heating the sample(lθ), the well(84) for mounting the sample inside and into which the etching solutions are injected, and tightening plates(85) for fixing the sample to the well. A heating wire(83) for emitting heat by being supplied with electricity is disposed inside the heating portion(82), and heats the sample with the lamp(24). Moreover, the tightening plates(85) cover the girth of the sample so that the the sample(lθ) cannot be separated, and are supported on an inner side of the well(84) by more than one spring(86). Namely, the springs(86) are mounted between the tightening plates(85) and the inner side of the well(84), to fix the tightening plates to the well as supporting the tightening plates and the inner side of the well. As a result, if the etching solution injectors (50) injects the etching solutions into the well(84) in a state of the sample(lθ) being disposed in the well(84), the sample becomes in soaked state in the etching solutions, thereby more activating chemical reaction by the etching solutions. Consequently, elimination of the surface molding compounds, the epoxy layers, and the soluble wafer layers can be more effectively conducted. Likewise, since the sample(lθ) is fixed to the inside of the well(84) by the tightening plates(85) and the springs(86), it is possible to prevent the sample from being separated, when the etching solutions are injected by the etching solution injecting pipes(55) or the wash liquids are sprayed by the wash liquid injecting pipes(61,62), and to absorb shock applied to the sample. In the meantime, another embodiment(80) of the jig also further comprises a temperature sensor for sensing surface temperature of the jig to detect temperature of the sample(lθ). A controlling device detects the temperature of the sample(lθ) from the temperature of the jig surface sensed by the temperature sensor, and controls a heating value of the heating portion(82) and the lamp(24) to maintain the temperature of the sample, in order that the maintained temperature becomes optimum temperature for chemical reaction of the etching solutions.

[37] Fig. 7 is a format diagram of an etching solution injector in accordance with the present invention. Like shown in Fig. 7, an etching solution injector(50) in accordance with the present invention generates etching solutions by mixing chemical substances with a diluted solution, and injects the generated etching solutions into samples(lθ) to remove surface molding compounds, epoxy layers, and soluble wafer layers, comprising: etching solution suppliers(51,52,53) for generating the etching solutions to supply the etching solutions; a body portion(54), etching solution injecting pipes(55) for injecting the etching solutions supplied from the etching solution suppliers to the samples, a gas inhaling portion(56) for inhaling gas generated during chemical reaction of the samples and the etching solutions to discharge the inhaled gas; and wash liquid injecting pipes(57) for injecting wash liquids to the samples.

[38] The etching solution suppliers(51,52,53) generate the etching solutions for eliminating the surface molding compounds, the epoxy layers, and the soluble wafer layers of the samples(lθ) by mixing chemical substances with a diluted solution, and supply the generated etching solutions to the etching solution injecting pipes(55). The chemical substances are used by mixing one or more than two of sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid, hydrochloric acid, sodium hydroxide, fuming sulfuric acid, and fuming nitric acid. Desirably, different etching solutions are generated and used for the surface molding compounds, the epoxy layers, and the soluble wafer layers. Thus, the etching solution suppliers(51,52,53) are divided into the first etching solution supplier(51) for supplying the etching solutions which eliminate the surface molding compounds of the samples (10), the second etching solution supplier(52) for supplying the etching solutions which eliminate the soluble wafer layers, and the third etching solution supplier(53) for supplying the etching solutions which eliminate the epoxy layers. It is needless to say that one etching solution supplier can be configured for the surface molding compounds and the epoxy layers. The first etching solution supplier(51) and the third etching solution supplier(53) generate the etching solutions by diluting one or more than two of sulfuric acid(H SO ), nitric acid(HNO 3 ), fuming sulfuric acid(H 2 SO 4 _F), and fuming nitric acid(HNO 3 _F) with pure water(DI water). Besides, the second etching solution supplier(52) generates the etching solutions by diluting one or more than two of acetic acid(CH COOH), sulfuric acid(H SO ), nitric acid(HNO ), fuming sulfuric acid(H SO _F), fuming nitric acid(HNO _F), hydrofluoric acid(HF), hydrochloric acid(HCL), PAE(PoIy Alyene Ethers, AL Etchant, H PO :HN0 ), BOE(Buffered Oxide Etchants, HF:NH F), poly etchant(HNO :HF:CH COOH), and sodium hydroxide(NaOH) with pure water(DI water). Each chemical substance is selectively used, or more than two of the chemical substances can be usable by being mixed together. The etching solutions generated by the first etching solution supplier(51), the second etching solution supplier(52), and the third etching solution supplier(53) are supplied to the etching solution injecting pipes(55) through a first etching solution supply line(51a), a second etching solution supply line(52a), and a third etching solution supply line(53a), respectively, and are injected into the samples(lθ) to wet-etch the surface molding compounds, the soluble wafer layers, and the epoxy layers. The first etching solution supplier, the second etching solution supplier, and the third etching solution supplier may include pumps for discharging the etching solutions to the etching solution injecting pipes. On the other hand, configurations of each of the etching solution suppliers, the etching solution supply lines, and the etching solution injecting pipes illustrated in Fig. 7 show one embodiment, therefore transformations different from the above configurations will be also available.

[39] The etching solution injecting pipes(55) inject the etching solutions supplied from the first to third etching solution suppliers(51,52,53) into the samples(lθ), to remove the surface molding compounds, the soluble wafer layers, and the epoxy layers through wet-etching. 3 etching solution injecting pipes(55) can be equipped to individually inject the etching solutions supplied from the first to third etching solution suppliers(51,52,53), or one etching solution injecting pipe may be used by connecting with the 3 etching solution suppliers(51,52,53). Moreover, like shown in Fig. 7, the first to third etching solution suppliers may be connected to the one etching solution injecting pipe. The etching solution injecting pipes(55) are nozzles capable of spraying in a range of 1 OD and ID to a minimum, locally or entirely wet-etching the samples (10). The etching solution injecting pipes(55) should not be etched by the etching solutions, and also the etching solution injecting pipes(55) should not get dull even though being frequently contacted with the samples(lθ). Desirably, the etching solution injecting pipes(55) are suggested to be made of industrial diamond materials, and particularly, the surface of the etching solution injecting pipes should be coated to absorb shock, in order to prevent wafers from being broken or damaged while the etching solution injecting pipes are contacted with the wafers when the soluble wafer layers between the wafers are eliminated. In the past, titanium materials were used for the etching solution injecting pipes(55). In this case, there occurs no special problem when removing the surface molding compounds or the epoxy layers of the samples (10), but when removing the soluble wafer layers between the wafers, the etching solution injecting pipes are frequently contacted with the wafers, which may cause the wafers to be broken or damaged by intensity of the etching solution injecting pipes. So, by generating the etching solution injecting pipes (55) with the industrial diamond materials and coating the surface to absorb shock, it is possible to prevent the wafers from being broken or damaged even though the etching solution injecting pipes are contacted with the wafers. Furthermore, though one-time discharge is 2D in case of the etching solution injecting pipes made of the titanium materials, the etching solution injecting pipes made of the diamond materials have ID of one-time discharge, thereby being more properly used for 1 to IOOD local wafer etching. The etching solution injecting pipes(55) can be manufactured by finely processing an end part of a metal tip consisting of a metal line or a metal plate which is in more than tens of D thickness, so that the end part can have several nm of the radius of curvature, coating a certain material like diamond, removing both coated end parts, and removing the metal tip which is a substrate material. Meanwhile, in case the etching solution injecting pipes(55) are individually comprised for the first etching solution supplier(51), the second etching solution supplier(52), and the third etching solution supplier(53), the etching solution injecting pipes for injecting the etching solutions which eliminate the surface molding compounds and the epoxy layers can be also made of the titanium materials as in the past.

[40] The gas inhaling portion(56) inhales fine chemical gas generated when chemical reaction occurs by injecting the etching solutions into the samples(lθ), and the gas inhaled by the gas inhaling portion is discharged through an exhaust pipe(56a).

[41] The wash liquid injecting pipes(57) eliminate pollutants sticking to the samples, by injecting wash liquids in a state that the etching solution injecting pipes(55) are contacted with the samples(lθ), and inject the wash liquids into the samples in the middle of etching to remove the remnants, so that the remnants generated by chemical reaction cannot be attached to the etching solution injecting pipes. Acetone or pure water(DI water) may be used as the wash liquids, and the wash liquids injected into the wash liquid injecting pipes(57) flow down over the etching solution injecting pipes, and are injected into the samples.

[42] Fig. 8 is a format diagram of a chucking device in accordance with the present invention. Like shown in Fig. 8, a chucking device(70) in accordance with the present invention comprises a chucking plate(71) contacting with separated wafers of a sample(lθ), an absorbing portion(72) for absorbing the wafers, and an air inhaling portion(73) for generating a vacuous inhaling force in the absorbing portion(72) by inhaling air. Desirably, the absorbing portion(72) is configured as a gasket made of rubber, to prevent the wafers from being broken by shock when the wafers are absorbed, and fluororubber is used as a material for the absorbing portion in order to prohibit corrosion caused by high temperature and strong acids. The chucking device(70) vacuously absorbs each of the independently separated wafers and transfers the wafers to a process for removing wafer layers, after eliminating both surface molding compounds and epoxy layers of the sample(lθ) and cutting wires that connect each wafer by a milling device(40). In addition, if desired layers are exposed by the elimination of the wafer layers, the chucking device vacuously absorbs the wafers again, and keeps the wafers in a separate storage box by classifying the wafers. Consequently, the user can analyze a structural defect or an electrical defect of a circuit by observing each of the classified and kept wafers.

[43] Fig. 9 and Fig. 10 are flow charts of a process for eliminating molding compounds in accordance with the present invention. Referring to Fig. 9 and Fig. 10, the process for eliminating the molding compounds in accordance with the present invention will be described as follows.

[44] Packaged semi-conductor chip or electronic devices(samples, 10) for analyzing structural/electrical defects of a circuit by removing the molding compounds are fixed to the jigs(20). In case the jig(80) is configured like shown in Fig. 6, the sample(lθ) is fixed to the inside of the well(84) by using the tightening plates(85) and the springs(86). The jig(20) moves to a lower section of the camera(30) by the XYZ-axis stages(25 ,26,27), and the camera takes a picture of the sample(lθ) to transmit the taken picture to the controlling device(ST800). The controlling device displays the taken picture of the sample(lθ), and calculates depth and a range in which milling work is to be conducted and a part in which the surface molding compounds of the sample are to be eliminated(ST805).

[45] The milling device(40) mills the surface molding compounds of the sample(lθ) by a control signal of the controlling device(ST810). At this point, the surface molding compounds are mechanically eliminated by contacting the milling device(40) with the surface molding compounds to be removed from the sample (10), as moving the milling device(40) and the jig(20) together in up/down/right/left directions by the XYZ-axis stages(25,26,27).

[46] When the milling work is completed, the jig(20) moves to the camera(30) again, and the picture taken by the camera is transmitted to the controlling device. The controlling device displays the taken picture, calculates a range for eliminating the surface molding compounds, that is, an amount of the surface molding compounds to be removed, and calculates a mixing ratio and an amount of injection of etching solutions(ST815). Also, proper reactive temperature is calculated as well according to the etching solutions.

[47] The jig(20) moves to the lower part of the etching solution injecting pipes(55) by the XYZ-axis stages(25 ,26,27). The first etching solution supplier(51) of the etching solution injector(50) generates etching solutions by mixing chemical substances with a diluted solution according to a control signal of the controlling device, and supplies the etching solutions to the etching solution injecting pipe(55) through the first etching solution supply line(51a), then the etching solution injecting pipe inject the etching solutions into the sample to wet-etch the surface molding compounds(ST820). On this occasion, if the samples(lθ) consist of one wafer, a minimum amount of etching solutions should be sprayed to ID to IOOD unit sections to a minimum so as to gradually remove the surface molding compounds within desired sections, because the wafer can be immediately exposed if the surface molding compounds are eliminated. Gas generated by chemical reaction of the etching solutions is discharged to the exhaust pipe(56a) through the gas inhaling portion(56). And, the wash liquid injecting pipes(57) remove the remnants caused by the chemical reaction, by injecting wash liquids into the sample before injecting the etching solutions into the sample(lθ) or in the middle of the etching process. It is also available to remove the remnants of the surface molding compounds remaining on the surface of the sample, through milling work, by transferring the jig(20) to the washing device(60) to wash the sample(lθ) before injecting the etching solutions after the milling work. In the meantime, in case the jig(80) is configured like shown in Fig. 6, if the jig moves to the lower part of the etching solution injectors(50) so that a certain amount of etching solutions are injected from the etching solution injecting pipes(55), the sample(lθ) becomes in a state of being soaked in the etching solutions like shown in Fig. 6(b). Thus, it is possible to more effectively eliminate the surface molding compounds by more activating reaction of the etching solutions.

[48] Temperature sensors of the jigs(20,80) sense surface temperature of the jigs, and transmit the sensed temperature to the controlling device, so that the controlling device calculates temperature of the sample through the surface temperature of the jigs, and operates the lamp(24) and heating portions(22,82) according to the calculated temperature(ST825). In other words, power is supplied to the lamp(24) and the heating wires(23,83) to complexly heat the sample(lθ) up and down. The temperature sensors transmit the temperature of the jig surface to the controlling device at certain intervals or in real time, and the controlling device maintains the sample(lθ) at proper temperature by controlling the lamp(24) and the heating portions (22, 82) according to the received temperature. The steps 'ST820' and 'ST825' are simultaneously carried out, and the step 'ST825' can be performed before the step 'ST820' of injecting the etching solutions. On the other hand, an oscillator may be installed on the surface of the jig(20) so as to reduce etching process time, in order that the jig vibrates by the oscillator, thereby promoting the chemical reaction of the molding compounds and the etching solutions.

[49] When a certain time elapses after the etching solutions are injected, the jig(20) moves to the washing device(60) by the XYZ-axis stages(25 ,26,27), and the wash liquid injecting pipes(61,62) spray wash liquids into the sample to wash the remnants and the etching solutions on the surface of the sample(lθ), then the air discharge pipe(65) and the lamp(66) dry the sample(ST830). In this case, if the jig(80) is configured like Fig. 6, the jig is rotated at 180 degrees to dump the etching solutions and the remnants, and the wash liquid injecting pipes(61,62) spray the wash liquids in the lower part. In such circumstances, the wash liquid injecting pipes(61,62) illustrated in Fig. 2 would be disposed in vertically opposite direction. At this moment, since the sample(lθ) is stably fixed to the well(84) by the tightening plates(85) and the springs(86), the sample is not separated from the well by the spraying of the wash liquids.

[50] After washing and drying the sample(lθ), the jigs(20,80) move to the camera(30), and the camera takes a picture of the sample(lθ) to transmit the taken picture of the sample to the controlling device. The controlling device displays the taken picture, in order that the user can confirm whether the surface molding compounds are perfectly eliminated(ST835).

[51] If the surface molding compounds are not perfectly eliminated in the step 'ST835', the etching and washing processes of the steps 'ST815 to ST830' are repeatedly executed. The etching and washing processes are performed until the surface molding compounds of the sample(lθ) are sufficiently removed. At this time, if the sample(lθ) consists of one wafer, the etching solutions should be injected by being gradually diluted once the wafer starts to be exposed while the etching and washing processes are repeated. It is because the wafer is immediately exposed when the surface molding compounds are removed. As a result, it can prevent the wafer or an electronic device from being damaged.

[52] Once the surface molding compounds are perfectly removed in the step 'ST835', the jigs(20,80) move to the camera(30) again, and the picture taken by the camera is transmitted to the controlling device. The controlling device displays the taken picture, and calculates a range for eliminating the epoxy layers, that is, an amount of the epoxy layers to be removed, then calculates a mixing ratio, an amount of injection, and reactive temperature of the etching solutions(ST840).

[53] The jigs(20,80) move to the lower part of the etching solution injecting pipes(55), and the third etching solution supplier(53) of the etching solution injector(50) generates the etching solutions by mixing chemical substances with a diluted solution according to a control signal of the controlling device, and supplies the etching s olutions to the etching solution injecting pipes(55) through the third etching solution supply line(53a), then the etching solution injecting pipes inject the etching solutions into the sample(lθ) to wet-etch the epoxy layers(ST845). On this occasion, the controlling device calculates temperature of the sample(lθ) from surface temperature of the jigs sensed by the temperature sensors, and operates the lamp(24) and the heating portions (22, 82) according to the calculated temperature to heat the sample. Meanwhile, if the sample(lθ) does not include the epoxy layers, an epoxy layer elimination process is omitted, and the sample is transferred to wafer layer elimination processes(ST870-ST915).

[54] If a certain time elapses after the etching solutions are injected, the jigs(20,80) move to the washing device(60), and the wash liquid injecting pipes(61,62) spray the wash liquids into the sample(lθ) to wash the remnants and the etching solutions on the surface of the sample(lθ), then the air discharge pipe(65) and the lamp(66) dry the sample(ST850). As shown above, if the jig(80) is configured like Fig. 6, the jig is rotated at 180 degrees to dump the etching solutions and the remnants, and the wash liquid injecting pipes(61,62) spray the wash liquids in the lower part to wash the sample.

[55] After washing and drying the sample(lθ), the jigs(20,80) move to the camera(30), and the camera takes a picture of the sample(lθ) to transmit the taken picture of sample to the controlling device. The controlling device displays the taken picture, in order that the user can confirm whether the epoxy layers are perfectly eliminated(ST855).

[56] If the epoxy layers are not perfectly eliminated in the step 'ST855', the etching and washing processes of the steps 'ST840 to ST850' are repeatedly carried out.

[57] If the epoxy layers are perfectly removed in the step 'ST855', wires for connecting plural wafers of the sample(lθ) are exposed. The jigs(20,80) move to the lower part of the milling device(40) by the XYZ-axis stages(25,26,27), and the milling device cuts wires of wafer disposed on the top and separates the wafer disposed on the top from the sample(lθ) by a control signal of the controlling device(ST860). The jig(20) moves to the lower part of the chucking device(70) by the XYZ-axis stages(25,26,27), and the chucking device vacuously absorbs the independently separated top wafer and tranfers the absorbed wafer to a wafer layer elimination process(ST865). In detail, the separated wafer is mounted by being transferred to the separate jigs(20,80) for eliminating wafer layers. Meanwhile, the chucking device(70) vacuously absorbs the sample(lθ) whose surface molding compounds and epoxy layers are removed, and keeps the sample in a separate storage, then the milling device separates the top wafer from the sample kept in the separate storage, and the chucking device can transfer and mount the separated wafer to and on the original jigs(20,80).

[58] The jigs(20,80) mounted with the wafer separated from the sample(lθ) move to the camera(30), and the picture taken by the camera is transmitted to the controlling device. In case of wafer separated after the surface molding compounds and the epoxy layers are eliminated, wafer layers are exposed. The controlling device decides whether wafer layers to be eliminated are soluble wafer layers or insoluble wafer layers, through the taken picture received from the camera(30)(ST870).

[59] If the wafer layers to be eliminated are the soluble wafer layers in the step 'ST870', the controlling device calculates an amount of the soluble wafer layers to be eliminated and a mixing ratio and an amount of injection of the etching solutions, then calculates proper reactive temperature of the etching solutions(ST875).

[60] The jigs(20,80) move to the lower part of the etching solution injecting pipes(55) again by the XYZ-axis stages(25 ,26,27), and the second etching solution supplier(52) of the etching solution injector(50) generates the etching solutions for eliminating the soluble wafer layers by mixing chemical substances with a diluted solution, to supply the generated etching solutions to the etching solution injecting pipes(55) through the second etching solution supply line(52a), then the etching solution injecting pipes inject the etching solutions into the sample(lθ) to wet-etch the soluble wafer layers (ST880). At this time, a minimum amount of etching solutions should be sprayed to ID to IOOD unit sections to a minimum so as to gradually remove the wafer layers within desired sections, because the wafers can be immediately exposed if the soluble wafer layers of the sample(lθ) are eliminated. Likewise, the controlling device receives surface temperature of the jigs from the temperature sensors of the jigs(20,80), and controls the lamp(24) and the heating portions (22, 82) to heat the sample(lθ) at proper temperature that the etching solutions can show chemical reaction. And, the gas inhaling portion(56) of the etching solution injector(50) inhales gas generated during the chemical reaction to discharge the gas, while the wash liquid injecting pipes(57) eliminate the remnants caused by the chemical reaction, with wash liquids.

[61] If a certain time elapses after the etching solutions are injected, the jigs(20,80) move to the washing device(60), and the wash liquid injecting pipes(61,62) spray the wash liquids into the sample(lθ) to wash the remnants and the etching solutions on the surface of the sample(lθ), then the air discharge pipe(65) and the lamp(66) dry the sample(ST885). As stated above, if the jig(80) is configured like Fig. 6, the jig is rotated at 180 degrees to dump the remnants and the etching solutions, and the wash liquid injecting pipes(61,62) spray the wash liquids in the lower part to wash the sample.

[62] After washing and drying the sample(lθ), the jigs(20,80) move to the camera(30), and the camera takes a picture of the sample to transmit the taken picture of the sample to the controlling device. The controlling device displays the taken picture, in order that the user can confirm whether the soluble wafer layers are perfectly eliminated(ST890).

[63] If the soluble wafer layers are not perfectly eliminated in the step 'ST890', the wet- etching and washing processes of the steps 'ST875 to ST885' are repeatedly carried out.

[64] If the wafer layers to be eliminated are not the soluble wafer layers in the step

'ST870', that is, in case of insoluble wafer layers, the controlling device calculates a range for removing the insoluble wafer layers, namely, depth and a range to be polished(ST895).

[65] The polishing device(45) polishes the insoluble wafer layers of the smaple(lθ) by a control signal of the controlling device, and removes the insoluble wafer layers (ST900). In other words, slurries are supplied to a frictional surface with the sample(lθ), and the insoluble wafer layers are removed by using a frictional force of the slurries. When the polishing work is completed, the jigs(20,80) move to the camera(30) again, and the picture taken by the camera is transmitted to the controlling device.

[66] When the soluble wafer layers and the insoluble wafer layers are eliminated in the steps 'ST875 to ST890' or 'ST895 to ST900', the controlling device decides whether desired layers, namely, layers to be observed are exposed(ST905). As mentioned above, the wafer layers consist of the soluble wafer layers and the insoluble wafer layers, and the respective wafer layers are unspecifically accumulated as multiple layers. Accordingly, by deciding whether the desired layers are exposed after removing one wafer layer, a next wafer layer is eliminated, or the wafer layer elimination process is completed, then the sample is discharged.

[67] If the desired layers are not exposed in the step 'ST905', that is, the wafer layers to be removed(soluble wafer layers, insoluble wafer layers) remain, the wafer layers are removed again through the steps 'ST870 to ST900'.

[68] If the desired layers are exposed in the step 'ST905', the jigs(20,80) move to the lower part of the chucking device(70), and the chucking device vacuously absorbs the wafer whose wafer layer elimination process is completed, and tranfers the absorbed wafer to a storage box to keep the wafer in the storage box(ST910).

[69] The controlling device decides whether all of the wafers of the sample(lθ) are separated(ST915). If unseparated wafers exist in the step 'ST915', the steps 'ST860 to ST910' are repeatedly performed for a next wafer of the sample. In other words, wires of a second wafer are cut with the milling device(40), so that the second wafer is separated, and wafer layers (soluble wafer layers, insoluble wafer layers) of the separated wafer are removed, and the wafer is moved to the storage box. [70] Once all of the wafers are separated and stored in the storage box, the user observes each wafer to decide whether a circuit has a defect. Industrial Applicability

[71] An apparatus and a method for eliminating molding compounds of packaged semiconductor and electronic devices in accordance with the present invention show the following effects:

[72] 1. Since the molding compounds are eliminated through an optimum method according to types of each molding compound, decapping of the semi-conductor and electronic devices can be easily conducted. Concretely, since surface molding compounds are removed by a mechanical milling method and a chemical wet-etching method, epoxy layers are removed by the chemical wet-etching method, and soluble wafer layers of wafer layers are removed by the chemical wet-etching method while insoluble wafer layers are removed by a mechanical polishing method, fast and accurate decapping is available through proper methods for characteristics of each layer. In addition, each unit process is automated and standardized, being commonly applicable to a semi-conductor and an electronic device where plural wafers constitute multiple layers and even to a case that the soluble wafer layers and the insoluble wafer layers are mixed together between the wafers, not to mention a semi-conductor and an electronic device consisting of one wafer;

[73] 2. Since samples are complexly heated up and down through heating portions and a lamp while surface temperature of jigs is sensed through temperature sensors to calculate temperature of the samples, the samples can be effectively heated at optimum temperature when etching solutions show chemical reaction, and the heated temperature can be maintained, thereby reducing chemical reaction time of the etching solutions;

[74] 3. Since different etching solutions are used for surface molding compounds, the epoxy layers, and the soluble wafer layers during a wet-etching process, a faster and more effective etching work is available;

[75] 4. Since the insoluble wafer layers (nitride series, etc.), which were unable to be removed with the etching solutions, can be eliminated by the mechanical polishing method, the insoluble wafer layers can be efficiently removed without damaging the wafers;

[76] 5. Since a caved- in type well like a bathtub is disposed in a jig, a wet-etching process is conducted in a state of a sample being soaked in the etching solutions. Thus, the etching work can be executed in faster and more effectual way. Also, the sample is fixed to the inside of the well by using tightening plates and springs, thereby preventing the sample from being separated from the well when the etching solutions are injected or wash liquids are sprayed;

[77] 6. Since etching solution injecting pipes are made of industrial diamond materials and the surface is coated to absorb shock, it is possible to prevent the wafers from being broken or damaged even though the etching solution injecting pipes are contacted with the wafers when the etching solutions are injected;

[78] 7. A gas inhaling portion can inhale and discharge gas generated by chemical reaction during wet-etching of the surface molding compounds, the epoxy layers, and the soluble wafer layers. And, it is possible to prevent the remnants caused by the chemical reaction from sticking to the etching solution injecting pipes, by injecting wash liquids into the samples through wash liquid injecting pipes before the wet- etching process or in the middle of the process; and

[79] 8. Since the wafer layers are removed and wires are cut to chuck each of the independently separated wafers through a vacuous absortive method so that the chucked wafers can be classified and stored in a storage box, damage of the wafers may be prevented during the chucking process and circuits of the plural wafers can be effectually inspected. Moreover, an absorbing portion for absorbing the wafers is configured as a gasket made of rubber, particularly, fluororubber, thereby preventing the wafers from being damaged and preventing the absorbing portion from corroding owing to high temperature and strong acids.

[80] Although the invention has been herein shown and described in what is perceived to be the most practical and preferred embodiments, it is to be understood that the invention is not intended to be limited to those specific embodiments. Rather, it is recognized that modifications may be made by one of skilled in the art without departing from the spirit or intent of the invention.

Claims

[1] With regards to packaged semi-conductor and electronic devices for including: more than one wafer; wafer layers forming electric elements by being accumulated on at least one side of each wafer as plural layers; epoxy layers accumulated as epoxies for each wafer to insulate between the wafer layers accumulated on one wafer and another neighboring wafer; and surface molding compounds covering each wafer, the wafer layers and the epoxy layers, an apparatus for eliminating the molding compounds of the semi-conductor and electronic devices for removing the surface molding compounds covering the outside of samples which are the semi-conductor and electronic devices for inspecting internal circuit state and inferior state, for independently separating each wafer by removing the epoxy layers, and for removing the wafer layers until layer to be inspected is exposed for each of the independently separated wafers, comprising: jigs for fixing the samples; a milling device for independently separating each wafer by cutting wires that connect the respective wafers, the wires being exposed by removing the epoxy layers; a chucking device for chucking each of the independently separated wafers to transfer the chucked wafers; a etching solution injector for generating etching solutions by mixing more than one chemical substance with a diluted solution, and for injecting the etching solutions into the wafer layers and the epoxy layers of the samples to chemically wet-etch the wafer layers and the epoxy layers; and a washing device for washing the samples into which the etching solutions are injected, with wash liquids.

[2] With regards to packaged semi-conductor and electronic devices for including: more than one wafer; wafer layers including oxide films, nitride films and metal films, the oxide films, the nitride films and the metal films forming electric elements by being accumulated as plural layers on at least one side of each wafer; and surface molding compounds covering each wafer and the wafer layers, and wherein the wafer layers comprise soluble wafer layers which are easily removed by a chemical wet-etching method and insoluble wafer layers which are not easily removed by the chemical wet-etching method, and the soluble wafer layers and the insoluble wafer layers randomly forming plural layers, an apparatus for eliminating the molding compounds of the semiconductor and electronic devices for removing the surface molding compounds covering the outside of samples which are the semi-conductor and electronic devices for inspecting internal circuit state and inferior state, and for independently separating each wafer to remove the wafer layers until layer to be inspected is exposed for each of the independently separated wafers, comprising: jigs for fixing the samples; a polishing device for contacting with the insoluble wafer layers of the samples, and for mechanically polishing the insoluble wafer layers by a frictional force to remove the insoluble wafer layers; a etching solution injector for generating etching solutions by mixing more than one chemical substance with a diluted solution, and for injecting the etching solutions into the soluble wafer layers of the samples to chemically wet-etch the soluble wafer layers; and a washing device for washing the samples into which the etching solutions are injected, with wash liquids.

[3] The apparatus for eliminating the molding compounds of the semi-conductor and electronic devices of claim 1 or 2, wherein the jigs comprise: plates where the samples are disposed; heating portions including plural heating wires for emitting heat by being supplied with electricity; and temperature sensors sensing surface temperature of the jigs; and wherein the heating portions heat the samples at a temperature that chemical reaction of the etching solutions is activated.

[4] The apparatus for eliminating the molding compounds of the semi-conductor and electronic devices of claim 1 or 2, wherein the jigs comprise: plates; heating portions including plural heating wires for emitting heat by being supplied with electricity, and being disposed in the upper part of the plates; wells for mounting the samples inside by being in a concavely caved-in shape, and containing etching solutions injected through etching solution injector; tightening plates for fixing the samples by covering the girth of the samples; more than one spring for fixing the tightening plates to the wells by supporting the gaps of the tightening plates and inner side of the wells; and temperature sensors for sensing surface temperature of the jigs; and wherein the heating portions heat the samples at a temperature that chemical reaction of the etching solutions is activated.

[5] The apparatus for eliminating the molding compounds of the semi-conductor and electronic devices of claim 1 or 2, wherein the apparatus further comprises: a lamp applying radiant heat to the samples when the etching solutions are injected.

[6] The apparatus for eliminating the molding compounds of the semi-conductor and electronic devices of claim 1 or 2, wherein the etching solution injector comprises: etching solution injecting pipes for injecting the etching solutions; gas inhaling portions for inhaling gas generated during the chemical reaction of the etching solutions to discharge the inhaled gas; and wash liquid injecting pipes for injecting wash liquids into the samples so as to prevent the remnants generated during the chemical reaction of the etching solutions from sticking to the etching solution injecting pipes.

[7] The apparatus for eliminating the molding compounds of the semi-conductor and electronic devices of claim 6, wherein the etching solution injecting pipes are made of industrial diamond materials, and the surface is coated to absorb shock.

[8] The apparatus for eliminating the molding compounds of the semi-conductor and electronic devices of claim 1, wherein the etching solution injector generates etching solutions for wet-etching the epoxy layers by mixing more than one chemical substance of sulfuric acid(H SO ), nitric acid(HNO ), fuming sulfuric acid(H SO _F) and fuming nitric acid(HNO _F) with a diluted solution including pure water(DI water), and generates etching solutions for wet-etching the wafer layers by mixing more than one chemical substance of acetic acid(CH COOH), sulfuric acid(H SO ), nitric acid(HNO ), fuming sulfuric acid(H SO _F), fuming

2 4 3 2 4 nitric acid(HNO _F), hydrofluoric acid(HF), hydrochloric acid(HCL), PAE(PoIy Alyene Ethers, AL Etchant, H PO :HN0 ), BOE(Buffered Oxide Etchants, HF:NH F), Poly Etchant(HNO :HF:CH COOH) and sodium hydroxide(NaOH) with a diluted solution including pure water(DI water).

[9] The apparatus for eliminating the molding compounds of the semi-conductor and electronic devices of claim 2, wherein the etching solution injector generates etching solutions for wet-etching the soluble wafer layers by mixing more than one chemical substance of acetic acid(CH COOH), sulfuric acid(H SO ), nitric

3 2 4 acid(HN0 ), fuming sulfuric acid(H SO _F), fuming nitric acid(HN0 _F), hydrofluoric acid(HF), hydrochloric acid(HCL), PAE(PoIy Alyene Ethers, AL Etchant, H PO :HN0 ), BOE(Buffered Oxide Etchants, HF:NH F), Poly Etchant(HNO :HF:CH COOH) and sodium hydroxide(NaOH) with a diluted solution including pure water(DI water).

[10] The apparatus for eliminating the molding compounds of the semi-conductor and electronic devices of claim 1 or 2, wherein more than one of pure water(DI water), acetone and isopropyl alcohol (IPA) is used for the wash liquids.

[11] The apparatus for eliminating the molding compounds of the semi-conductor and electronic devices of claim 1, wherein the chucking device comprises: a chucking plate contacting with each of the independently separated wafers; an absorbing portion for vacuously absorbing each wafer and being configured as gasket made of a fluororubber material; and an air inhaling portion for inhaling air to generate a vacuous inhaling force in the absorbing portion.

[12] With regards to semi-conductor and electronic devices which comprise more than one wafer; wafer layers including oxide films, nitride films and metal films, the oxide films, the nitride films and the metal films forming electric elements by being accumulated as plural layers on at least one side of each wafer; epoxy layers accumulated as epoxies for each wafer to insulate between wafer layers accumulated on one wafer and another neighboring wafer; and surface molding compounds covering each wafer, the wafer layers and the epoxy layers, and wherein the wafer layers comprise soluble wafer layers which are easily removed by a chemical wet-etching method and insoluble wafer layers which are not easily removed by the chemical wet-etching method, and the soluble wafer layers and the insoluble wafer layers randomly forming plural layers, a method for eliminating the molding compounds of the semi-conductor and electronic devices for removing the surface molding compounds covering the outside of samples which are the semi-conductor and electronic devices for inspecting internal circuit state and inferior state, for independently separating each wafer by removing the epoxy layers and cutting wires that connect each wafer, and for removing the wafer layers until layer to be inspected is exposed for each of the independently separated wafers, comprising: a first step of removing the epoxy layers through the chemical wet-etching method by injecting etching solutions into the epoxy layers of the samples; a second step of independently separating the wafer by cutting the wires for one of the respective wafers, when the wires are exposed by removing the epoxy layers; a third step of absorbing the independently separated wafer to transfer the absorbed wafer; a fourth step of contacting a polishing device with the insoluble wafer layers of the wafer, and mechanically polishing the insolube wafer layers by a frictional force to remove the insoluble wafer layers; and a fifth step of removing the soluble wafer layers through the chemical wet- etching method by injecting the etching solutions into the soluble wafer layers of the wafer; and wherein the first to third steps are selectively performed when the samples include the plural wafers, the fourth and fifth steps are selectively performed according to the wafers to be removed, the fourth and fifth steps are repeatedly executed until the layer to be inspected are exposed, for the respective wafers, and the second to fifth steps are repeatedly performed until all of the wafers are independently separated.

[13] The method for eliminating the molding compounds of the semi-conductor and electronic devices of claim 12, wherein the first step comprises a 1-1 step of generating the etching solutions by mixing more than one chemical substance of sulfuric acid(H SO ), nitric acid(HNO ), fuming sulfuric acid(H SO _F) and

2 4 3 2 4 fuming nitric acid(HNO _F) with a diluted solution.

[14] The method for eliminating the molding compounds of the semi-conductor and electronic devices of claim 12, wherein the fifth step comprises a 5-1 step of generating the etching solutions by mixing more than one chemical substance of acetic acid(CH COOH), sulfuric acid(H SO ), nitric acid(HNO ), fuming sulfuric acid(H SO _F), fuming nitric acid(HNO _F), hydrofluoric acid(HF), hydrochloric acid(HCL), PAE(PoIy Alyene Ethers, AL Etchant, H PO :HN0 ), BOE(Buffered Oxide Etchants, HF:NH F), Poly Etchant(HNO :HF:CH COOH) and sodium hydroxide(NaOH) with a diluted solution.

[15] The method for eliminating the molding compounds of the semi-conductor and electronic devices of claim 12, wherein the fifth step comprises: a 5-2 step of chemically wet-etching the soluble wafer layers by injecting the etching solutions into the soluble wafer layers of the wafer; and a 5-3 step of washing the wafer with wash liquids after a certain time elapses; and wherein the 5-2 and 5-3 steps are repeatedly performed until the soluble wafer layers to be removed are perfectly eliminated.