Device for chemically unsealing chip package

Abstract

The utility model provides a device for chemical unsealing of chip package, which comprises a carrier and a liquid storage tank, the carrier comprises a top plate, a bottom plate and a rotating shaft and is arranged in the liquid storage tank through the rotating shaft, a plurality of openings with different sizes are arranged on the top plate, and the longitudinal section of each opening is of an inverted trapezoidal structure. When the device provided by the utility model is used for chemical unsealing, mixed acid can be prevented from overflowing, the possibility that other parts of a packaging body are corroded is reduced, and the product yield is improved; besides, the interval time between the reaction step and the washing step is shortened, the sample can be prevented from being damaged due to over-etching, and the sample preparation efficiency can be improved; and finally, the device is suitable for packaging bodies with different sizes, and the chip can be accurately unpackaged.

Description

Technical Field

[0001] The utility model belongs to the technical field of semiconductor manufacturing, and in particular relates to a device for chemically opening a chip package. Background Art

[0002] In the field of plastic-encapsulated device reliability, many testing projects require opening the encapsulation layer of the plastic-encapsulated device to expose the internal chip, bonding wires, lead frame, and other information for subsequent testing and analysis. Common opening methods include laser opening and chemical opening. The laser opening method uses high-energy laser ablation. However, when opening the chip surface using this method, the high-energy laser will ablate the aluminum metal wiring on the chip surface, damaging the chip surface. The chemical opening method uses mixed acid to decompose the epoxy resin on the outside of the package into low-molecular compounds that are easily soluble in acetone, thereby exposing the chip. This method is convenient and inexpensive, but without a laser opening machine to thin the epoxy resin on the package surface, the mixed acid can easily overflow, causing corrosion to other parts of the package. Utility Model Content

[0003] In view of the shortcomings of the prior art described above, the present invention provides a device for chemically unsealing chip packages, comprising a carrier and a liquid reservoir. The carrier comprises a top plate, a bottom plate, and a rotating shaft, and is mounted in the liquid reservoir via the rotating shaft. The top plate has multiple openings of varying sizes, each with an inverted trapezoidal longitudinal cross-section. Using the device provided by the present invention for chemical unsealing can prevent mixed acid overflow, reduce the likelihood of corrosion to other parts of the package, and improve product yield. Furthermore, the time interval between the reaction step and the rinsing step is reduced, preventing damage to the sample caused by over-etching and improving sample preparation efficiency. Finally, the device is suitable for packages of varying sizes and can accurately unseal chips.

[0004] To achieve the above-mentioned and other related purposes, the present invention provides a device for chemically desealing a chip package, which is characterized by comprising:

[0005] A liquid storage tank for holding an organic solvent;

[0006] A carrier, comprising a top plate, a bottom plate, and a rotating shaft, wherein the top plate and the bottom plate form a receiving portion for placing a sample; the rotating shaft is disposed at both ends of the carrier and located between the top plate and the bottom plate, the carrier being mounted on the side wall of the liquid reservoir via the rotating shaft, and the rotating shaft being used to flip the carrier;

[0007] The top plate is provided with a plurality of openings of different sizes, the plurality of openings are evenly spaced and arranged in the length direction of the top plate, and the longitudinal cross-section of the openings is an inverted trapezoidal structure.

[0008] Optionally, the top plate and the bottom plate are connected via a connecting piece.

[0009] Optionally, a heating unit is fixedly mounted on a surface of the bottom plate facing the top plate, and on a surface parallel to the bottom plate, a coverage area of ​​the heating unit is larger than a coverage area of ​​the plurality of openings.

[0010] Optionally, the number of the openings is five, and the apertures of the five openings are 0.5 cm, 1 cm, 1.5 cm, 2 cm, and 2.5 cm, respectively.

[0011] Optionally, the spacing between adjacent openings is 3.5 cm to 4.5 cm.

[0012] Optionally, the top plate and the bottom plate are made of polytetrafluoroethylene material.

[0013] Optionally, an ultrasonic device is placed at the bottom of the liquid storage tank.

[0014] Optionally, a magnifying glass is also included for observing the surface morphology of the sample.

[0015] Optionally, a nitrogen gun is included to blow dry the sample.

[0016] The device for chemically desealing chip packages provided by the present invention has at least the following beneficial effects:

[0017] Using the device provided by the utility model for chemical unsealing can avoid overflow of mixed acid, reduce the possibility of corrosion of other parts of the package, and improve product yield; in addition, the interval time between the reaction step and the rinsing step is reduced, which can avoid damage to the sample due to over-etching and improve sample preparation efficiency; finally, the device is suitable for packages of different sizes and can accurately unseal the chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Shown is a schematic structural diagram of a device for chemical desealing of a chip package provided by an embodiment.

[0019] Figure 2 A top view of a top plate provided for an embodiment is shown.

[0020] Component number description

[0021] 1 fluid reservoir

[0022] 2 Top plate

[0023] 20 Opening

[0024] 3 bottom plate

[0025] 4 Rotation axis

[0026] 5 Connectors

[0027] 6 Heating unit

[0028] 7 Ultrasonic devices

[0029] 100 samples DETAILED DESCRIPTION

[0030] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0031] It should be noted that the illustrations provided in this embodiment only illustrate the basic concept of the present invention in a schematic manner. Although the illustrations only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation, the form, quantity, positional relationship and proportion of each component in actual implementation can be changed at will under the premise of realizing the technical solution of this party, and the component layout form may also be more complicated.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0033] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate relative importance or implicitly specify the quantity of the technical features indicated. Therefore, unless otherwise specified, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features; "plurality" means two or more. The term "comprising" and any variations thereof are intended to be non-exclusive inclusion, and one or more other features, integers, steps, operations, units, components, and / or combinations thereof may be present or added.

[0034] In addition, terms indicating orientation or positional relationships such as “center,” “lateral,” “up,” “down,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inside,” and “outside” are described based on the orientation or relative positional relationships shown in the accompanying drawings. They are merely simplified descriptions for the convenience of describing the present application, and do not indicate that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present application.

[0035] Furthermore, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly, and may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0036] The present application is described in detail below with reference to the accompanying drawings and optional embodiments. It should be noted that, under the premise of no conflict, the embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0037] Example

[0038] This embodiment provides a device for chemical decapsulation of chip packages, such as Figure 1 As shown, it includes a liquid storage tank 1 and a carrier, and the carrier includes a top plate 2, a bottom plate 3 and a rotating shaft 4.

[0039] like Figure 1 As shown, the top plate 2 and bottom plate 3 form a receiving portion for placing the sample 100, and the two are connected by a connector 5. In this embodiment, the connector 5 is a screw, and the top plate 2 and bottom plate 3 can be removably connected by the screw. As an example, the top plate 2 and bottom plate 3 are made of polytetrafluoroethylene. Polytetrafluoroethylene is inert to almost all chemicals, including strong acids, strong bases, and organic solvents. Therefore, using polytetrafluoroethylene to make the top plate 2 and bottom plate 3 can ensure that they are not corroded by mixed acids during the unpacking process.

[0040] like Figure 2 As shown, the top plate 2 has a plurality of openings 20 of different sizes, and the plurality of openings 20 are evenly spaced and arranged in the length direction of the top plate 2. Such a design enables the device to be suitable for packages of different sizes, thereby accurately unsealing the chip. Figure 1 As shown, the longitudinal cross-section of opening 20 is an inverted trapezoidal structure that is wide at the top and narrow at the bottom. During the unsealing process, the sample 100 is placed below opening 20, and the mixed acid is dripped onto the surface of the sample 100 through opening 20. Therefore, the inverted trapezoidal structure of opening 20 can reduce the risk of mixed acid overflow by utilizing surface tension. As an example, the number and size of openings 20 are designed based on the size of sample 100. In this embodiment, there are five openings 20, with maximum apertures of 0.5 cm, 1 cm, 1.5 cm, 2 cm, and 2.5 cm, respectively. The spacing between adjacent openings 20 is 3.5 cm to 4.5 cm, preferably 4 cm.

[0041] like Figure 1As shown, a heating unit 6 is fixedly mounted on the side of the bottom plate 3 facing the top plate 2 for heating the sample 100. During the unsealing process, the sample 100 is placed on the surface of the heating unit 6. Therefore, on the surface parallel to the bottom plate 3, the coverage area of ​​the heating unit 6 is larger than the coverage area of ​​the multiple openings 20.

[0042] like Figure 1 As shown, the rotating shaft 4 is provided at both ends of the carrier and is located between the top plate 2 and the bottom plate 3. The carrier is mounted on the side wall of the liquid storage tank 1 through the rotating shaft 4. The rotating shaft 4 is used to flip the carrier.

[0043] As an example, the liquid reservoir 1 is used to contain an organic solvent, and the liquid level of the organic solvent is flush with the rotating shaft 4, that is, half of the carrier is immersed in the organic solvent. In this embodiment, the organic solvent can be acetone or ethanol.

[0044] like Figure 1 As shown, an ultrasonic device 7 is placed at the bottom of the liquid storage tank 1. The ultrasonic device 7 can use high-frequency sound waves to generate tiny bubbles. The energy released when the bubbles burst can quickly peel off dirt and residues on the surface of the object, thereby cleaning the sample 100.

[0045] As an example, the device provided in this embodiment also includes a magnifying glass (not shown in the figure) and a nitrogen gun (not shown in the figure), both of which are arranged above the carrier. The magnifying glass is used to observe the surface morphology of the sample 100, and the nitrogen gun is used to blow dry the sample 100.

[0046] The operating method of the device for chemical desealing of chip packages provided in this embodiment is as follows:

[0047] First, place the sample 100 between the heating unit 6 and the top plate 2, referring to Figure 2 As shown, sample 100 is placed with its device pins facing outward, with the heat-conducting portion of the back of sample 100 in close contact with heating unit 6. Then, the connectors 5 at both ends of the carrier are tightened to ensure that the carrier, sample 100, and heating unit 6 are completely in close contact. As an example, by comparing the size of sample 100 with that of opening 20, sample 100 is placed under an opening 20 of appropriate size. Specifically, the epoxy resin material area of ​​sample 100 needs to be larger than that of opening 20 to ensure that the projection of opening 20 is completely located on the epoxy resin shell of sample 100.

[0048] Next, the heating unit 6 is turned on and the temperature of the heating unit 6 is stabilized to be above 120° C. The thermometer confirms that the upper surface temperature of the sample 100 is above 80° C.

[0049] Next, the mixed acid solution is slowly dripped into the opening 20 where the sample 100 is placed. Since the opening 20 has an inverted trapezoidal structure, while ensuring complete contact between the mixed acid solution and the sample 100, surface tension is utilized to prevent the mixed acid solution from overflowing, provided that the liquid level does not exceed the upper surface of the opening 20. In this embodiment, the mixed acid solution is a mixture of concentrated sulfuric acid and concentrated nitric acid.

[0050] Next, the reaction is observed through a magnifying glass. Once the droplet reacts with the epoxy resin, the carrier is immediately rotated 180°, with the top plate 2 immersed in the organic solvent. Ultrasonic device 7 is activated to clean low-molecular-weight polymer impurities from the surface of sample 100. This reduces the time between the reaction and rinse steps, preventing damage to the sample from over-etching and improving sample preparation efficiency. For example, the cleaning time is 10 to 60 seconds.

[0051] Finally, the carrier is flipped back to its original position by rotating shaft 4, so that the top plate 2 is located above the bottom plate 3. The surface of sample 100 is blown dry with a nitrogen gun, and the surface morphology of sample 100 is observed using a magnifying glass. As an example, if the chip is not yet exposed, repeat the above steps; if the chip is completely exposed, the experiment is terminated. If the chip is not completely exposed, the experiment can be continued by replacing the opening 20 with a different size.

[0052] As an example, when the size of the sample 100 is unknown and the thickness of the epoxy resin shell is not thinned in advance by laser, the chip can be slowly exposed through multiple steps of experiments by replacing the openings 20 with different sizes.

[0053] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed in the present invention are intended to be covered by the claims of the present invention.

Claims

1. A device for chemical desealing of chip packages, characterized in that: include: A liquid storage tank for holding an organic solvent; The carrier comprises a top plate, a bottom plate and a rotating shaft, wherein the top plate and the bottom plate form a receiving portion for placing a sample; The rotating shaft is provided at both ends of the carrier and is located between the top plate and the bottom plate. The carrier is mounted on the side wall of the liquid storage tank via the rotating shaft, and the rotating shaft is used to flip the carrier; The top plate is provided with a plurality of openings of different sizes, the plurality of openings are evenly spaced and arranged in the length direction of the top plate, and the longitudinal cross-section of the openings is an inverted trapezoidal structure.

2. The device for chemical desealing of chip packages according to claim 1, characterized in that: The top plate and the bottom plate are connected via a connecting piece.

3. The device for chemical desealing of chip packages according to claim 1, characterized in that: A heating unit is fixedly mounted on a surface of the bottom plate facing the top plate. On a surface parallel to the bottom plate, a coverage area of ​​the heating unit is larger than a coverage area of ​​the plurality of openings.

4. The device for chemically desealing a chip package according to claim 1, wherein: There are five openings, and the apertures of the five openings are 0.5 cm, 1 cm, 1.5 cm, 2 cm, and 2.5 cm respectively.

5. The device for chemical desealing of chip packages according to claim 1, wherein: The distance between adjacent openings is 3.5 cm to 4.5 cm.

6. The device for chemical desealing of chip packages according to claim 1, characterized in that: The top plate and the bottom plate are made of polytetrafluoroethylene material.

7. The device for chemical desealing of chip packages according to claim 1, characterized in that: An ultrasonic device is placed at the bottom of the liquid storage tank.

8. The device for chemical desealing of chip packages according to claim 1, characterized in that: A magnifying glass is also included for observing the surface morphology of the sample.

9. The device for chemical desealing of chip packages according to claim 1, wherein: A nitrogen gun is also included for blowing dry the samples.

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