TSV anti-radiation packaging structure and packaging method

Abstract

The invention provides a TSV anti-radiation packaging structure and packaging method, and the structure comprises a first rewiring layer which is disposed on the front surface of a wafer; a cavity is etched in the wafer; the chip is arranged in the inner cavity of the wafer; the second redistribution layer is arranged on the back surface of the wafer and is electrically connected with the chip; the radiation protection layer is arranged in the inner cavity and the back surface of the wafer and wraps the chip; and the TSV is arranged on the wafer in a penetrating manner and is connected with the first redistribution layer and the second redistribution layer. The anti-radiation material is used for protecting the chip, and can be applied to the fields of high-energy X-ray detection, gamma ray detection and the like, so that the protection performance of the chip is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a TSV radiation-resistant packaging structure and a packaging method. Background Art

[0002] In the current technology scenario, X-ray detectors are widely used in medical and industrial fields such as CT. Currently, the photon counter has the highest resolution. In the usual photon counter structure, there is an X-ray detector on the top and a processor chip on the bottom. The detector chip and the processing chip are manufactured using different processes and then stacked in three dimensions. The processor chip below is manufactured using a CMOS process. High-energy rays such as X-rays may damage the processor chip. High-energy rays can produce ionization effects in electronic components, resulting in varying degrees of damage to the device, such as oxide layer charge traps, increased leakage current and other defects.

[0003] Therefore, the processing chip in the detector module needs to be protected from high-energy X-rays coming from the direction of the detector to prevent module failure. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a TSV radiation-resistant packaging structure, which is characterized by comprising:

[0005] A first redistribution layer is disposed on the front side of the wafer;

[0006] a wafer having a cavity extending inwardly from the front surface;

[0007] A chip is disposed in the inner cavity of the wafer;

[0008] A second redistribution layer is disposed on the back side of the wafer and is electrically connected to the chip;

[0009] A radiation protection layer is disposed in the inner cavity of the wafer and on at least a portion of the surface of the back side of the wafer, wrapping the chip;

[0010] The TSV through hole is disposed through the wafer and is electrically connected to the first redistribution layer and the second redistribution layer.

[0011] In an embodiment of the present invention, the packaging structure further includes solder balls disposed on the first redistribution layer on the front side of the wafer for connecting to external structures.

[0012] In another embodiment of the present invention, the packaging structure further includes a detector, which is disposed on the back side of the wafer and is electrically connected to the second redistribution layer.

[0013] In another embodiment of the present invention, the radiation shielding layer is made of metal, polymer, aluminum-lead microcomposite material or lead-free polymeric material;

[0014] The metal material is one or more of lead and tungsten, and the lead-free polymer material is one or more of bismuth B, barium Ba, gadolinium Gd, tungsten W, antimony Sb, and tin Sn.

[0015] In another embodiment of the present invention, the chip is disposed in a cavity inside the wafer, and the cavity is filled with a dry film or a resin.

[0016] In another embodiment of the present invention, the chip is a single chip or a plurality of chips are integrated and packaged to form a chipset, and then assembled with a plurality of detectors.

[0017] In another embodiment of the present invention, the radiation protection layer forms a sealed space for accommodating the chip and isolating it from external radiation.

[0018] The present invention also provides a TSV radiation-resistant structure packaging method, which is characterized by comprising:

[0019] Step 1: Make TSV through holes on the wafer, then etch the cavity, and put anti-radiation material in the cavity to form a radiation protection layer;

[0020] Step 2: Embed the processor chip in the cavity and fill it with dry film or resin;

[0021] Step 3: fabricating a first redistribution layer on the front side of the wafer, the first redistribution layer being electrically connected to the TSV through-holes and the processor chip, and bonding the front side of the wafer to a first temporary carrier;

[0022] Step 4: Thinning the back side of the wafer to expose the TSV through-holes, and making a second redistribution layer, wherein the second redistribution layer is electrically connected to the TSV through-holes;

[0023] Step 5: Bond the back side of the wafer to the second temporary carrier, then debond the front side of the wafer from the first temporary carrier, and finally perform radiation protection treatment on the processor chip on the front side of the wafer to form a radiation protection layer;

[0024] Step 6: Remove the second temporary carrier and form solder balls on the front side of the wafer.

[0025] In one embodiment of the present invention, the radiation protection layer is a lead plate or other radiation-resistant materials.

[0026] In another embodiment of the present invention, the detector is further installed on the second redistribution layer on the back side of the wafer.

[0027] The present invention protects high-energy X-rays from the detector direction by placing the chip in a cavity with a radiation protection layer, and uses a material with radiation resistance to make the radiation protection layer, such as metal material (such as lead, tungsten) or other radiation-resistant materials (such as polymers, aluminum-lead micro-composite materials, such as a combination of lead-free polymer materials with multiple precious metals such as bismuth B, barium Ba, gadolinium Gd, tungsten W, antimony Sb, tin Sn, etc.). In this way, module failure is prevented. The present invention can be used in the fields of high-energy X-ray detection, gamma-ray detection, etc. to improve the protection performance of the chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of a TSV radiation-resistant packaging structure in one embodiment of the present invention is shown;

[0029] FIG. 2A to FIG. 2F A TSV radiation-resistant packaging structure packaging flow chart according to an embodiment of the present invention is shown;

[0030] Figure 3 A schematic diagram of a TSV radiation-resistant packaging structure group in an embodiment of the present invention is shown. Specific embodiments

[0031] In the following description, the present invention is described with reference to various embodiments. However, those skilled in the art will recognize that various embodiments may be implemented without one or more specific details or with other replacement and / or additional methods, materials or components. In other cases, well-known structures, materials or operations are not shown or described in detail to avoid obscuring the inventive point of the present invention. Similarly, for the purpose of explanation, specific quantities, materials and configurations are set forth to provide a comprehensive understanding of embodiments of the present invention. However, the present invention is not limited to these specific details.

[0032] In addition, it should be understood that the embodiments shown in the drawings are illustrative representations and are not necessarily drawn to the correct scale. In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than explicitly or implicitly indicating that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as expressing or implying relative importance. In this specification, reference to "one embodiment" or "the embodiment" means that a particular feature, structure or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present invention. The phrase "in one embodiment" appearing in various places in this specification does not necessarily refer to the same embodiment.

[0034] Figure 1 A schematic diagram of a TSV radiation-resistant packaging structure in an embodiment of the present invention is shown.

[0035] The present invention provides a TSV radiation-resistant packaging structure, which specifically includes: a first redistribution layer 403 , a wafer 4 , a chip 3 , a second redistribution layer 402 , a radiation protection layer 2 , and a TSV through hole 401 .

[0036] A cavity is formed by etching the wafer 4, and a radiation shielding layer 2 is formed in the cavity to accommodate the chip 3. The radiation shielding layer 2 is used to shield the chip 3 from radiation due to its radiation shielding property, thereby protecting the chip 3.

[0037] By forming a closed space with the radiation protection layer 2, the influence of external radiation on the chip 3 is blocked in turn, and at the same time, the chip 3 is electrically connected through the first redistribution layer 403, and then through the TSV through hole 401, the electrical connection between the first redistribution layer 403 and the second redistribution layer 402 on the front and back sides of the wafer 4 is achieved, completing the electrical connection of the entire packaging structure.

[0038] like Figure 1 As shown, in one embodiment of the present invention, a single chip package is used, and in another embodiment of the present invention, as shown Figure 3 As shown, multiple chips are integrated and packaged to form a chipset, which is then assembled with multiple detectors. The present invention does not specifically limit the number of chips.

[0039] Compared with the prior art, the present invention forms a radiation protection layer 2 through a radiation protection layer 2, that is, a cut lead plate, or a radiation-resistant polymer is spin-coated or sprayed to block the influence of external radiation. Compared with the existing photon technology device structure that directly places the detector above the processor chip, a radiation protection layer 2 that isolates radiation is added, which is used in high-energy X-ray detection, gamma-ray detection and other fields, thereby improving the protection performance of the chip 3.

[0040] Based on the above structure, the present invention provides a TSV radiation-resistant structure packaging method, comprising the following steps:

[0041] Step 1: Make TSV through holes on the wafer, then etch the cavity, and put anti-radiation material in the cavity to form a radiation protection layer;

[0042] Step 2: Embed the processor chip in the cavity and fill it with dry film or resin;

[0043] Step 3: Fabricate the first redistribution layer on the front side of the wafer, connect the TSV vias, and bond it to the first temporary carrier;

[0044] Step 4: Thin the back of the wafer to expose the TSV through-holes, and make a second redistribution layer to complete the electrical connection with the TSV through-holes;

[0045] Step 5: Bond the back side of the wafer to the second temporary carrier, debond the front side from the first temporary carrier, and perform radiation protection treatment on the front side of the wafer, such as photolithography, electroplating, etc. to form the required radiation protection layer; or adhere the required radiation protection layer; or form a protective layer on the front side, and then etch to form the required radiation protection layer;

[0046] Step 6: Disassemble the second temporary carrier, form solder balls on the front side, cut into single chips, and complete the package.

[0047] In step 1, if Figure 2A As shown, TSV holes are made on the surface of wafer 4 by photolithography and etching processes, and the diameter of the TSV holes ranges from 1um to 1000um and the depth ranges from 10um to 1000um. Then, copper is electroplated to fill the TSV holes with copper metal, and the copper is electroplated at a temperature of 200 degrees Celsius to 500 degrees Celsius to make the copper more dense, forming TSV through-holes 401. In some embodiments of the present invention, wafer 4 may include a variety of semiconductor materials, such as silicon, germanium, gallium arsenide, indium phosphide, etc. Alternatively, wafer 4 may also be made of electrically non-conductive materials, such as glass, plastic, or sapphire wafers.

[0048] Then, a groove is made by dry etching on the front side of the wafer 4. The groove can be a cubic shape, an inverted trapezoid, a cylinder or a hemisphere. In one embodiment of the present invention, a cubic groove is used, and its size range is between 10um and 10000um, where the size includes the length, width and height of a cubic shape, an inverted trapezoid or the diameter or height of a cylinder or a hemisphere.

[0049] Next, a radiation-resistant material, such as a cut metal material such as a lead plate, is placed in the cavity groove, or a radiation-resistant polymer is spin-coated or spray-coated to form a radiation protection layer 2. The radiation protection layer 2 covers the sidewalls and bottom surface of the cavity groove.

[0050] Step 2, such as Figure 2B As shown, the chip 3 is buried in the cavity, and the gap is filled with a dry film or resin.

[0051] Step 3, such as Figure 2CAs shown, the first redistribution layer 403 is made on the front of the wafer 4 by photolithography and electroplating processes, so that the copper pillars in the TSV through-hole 401 and the chip 3 can be electrically connected to the first redistribution layer 403; wherein the first redistribution layer 403 includes routing and bonding functions. Then the front of the wafer 4 is bonded to the first temporary carrier 102 through a temporary bonding film. The temporary bonding film is a thermoplastic or thermosetting organic material, or an inorganic material containing components such as Cu, Ni, Cr, Co, etc. The temporary bonding film can be debonded or removed by heating, mechanical, chemical, laser, freezing, etc. The first redistribution layer 403 is a structure composed of a metal layer and an insulating dielectric layer. The metal layer is used to form an electrical connection, and the insulating dielectric layer is used to isolate the conductive metal layer. In one embodiment of the present invention, the metal wiring layer can be prepared by physical vapor deposition (PVD), photolithography, electroplating and other processes, and the insulating dielectric layer can be prepared by photolithography and other methods.

[0052] Step 4, such as Figure 2D As shown, the back side of the wafer 4 is thinned, and the other end of the copper column is exposed through grinding, wet etching, and dry etching processes, and a second redistribution layer 402 and bonding metal are made on the back side of the wafer 4.

[0053] Step 5, such as Figure 2E As shown, the back side of the wafer 4 is bonded to the second temporary carrier 103, and then the front side is debonded from the first temporary carrier 102. The front side of the wafer 4 is subjected to radiation protection treatment to form a radiation protection layer 2, which forms an enclosed space with the radiation protection material in the cavity, thereby isolating the influence of external radiation.

[0054] Step 6, finally debonding the wafer 4 from the second temporary carrier 103, and forming solder balls 101 on the front side of the wafer 4 for external connection.

[0055] Finally, the detector is mounted on the second redistribution layer on the back of the wafer, and the bonded wafer is cut to complete the single module process. The detector is electrically connected to the second redistribution layer 402, and then electrically connected to the chip 3 through the TSV through hole 401.

[0056] Those skilled in the art will appreciate that the operations shown in the above method are not exhaustive, and other operations may also be performed before, after or between the operations shown. In addition, some of the operations may be performed simultaneously or in an order different from the above order.

[0057] The present invention protects high-energy X-rays from the direction of the detector by placing the chip in a cavity with a radiation protection layer. The radiation protection layer is made of a material with radiation resistance, such as a cut lead plate, or spin-coated or spray-coated radiation-resistant polymer (which can be photolithographically processed), so as to prevent module failure. The present invention can be used in the fields of high-energy X-ray detection, gamma-ray detection, etc. to improve the protection performance of the chip.

[0058] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A TSV radiation-resistant packaging structure, characterized in that: include: A first redistribution layer is disposed on the front side of the wafer; a wafer having a cavity extending inwardly from the front surface; A chip is disposed in the inner cavity of the wafer; A second redistribution layer is disposed on the back side of the wafer and is electrically connected to the chip; A radiation protection layer is disposed in the inner cavity of the wafer and on at least a portion of the surface of the back side of the wafer, wrapping the chip; The TSV through hole is disposed through the wafer and is electrically connected to the first redistribution layer and the second redistribution layer.

2. The TSV radiation-resistant packaging structure according to claim 1, characterized in that: The packaging structure also includes solder balls, which are arranged on the first redistribution layer on the front side of the wafer and are used for connecting to external structures.

3. The TSV radiation-resistant packaging structure according to claim 1, characterized in that: The packaging structure also includes a detector, which is arranged on the back side of the wafer and is electrically connected to the second redistribution layer.

4. The TSV radiation-resistant packaging structure according to claim 1, characterized in that: The radiation protection layer is made of metal, polymer, aluminum-lead microcomposite material or lead-free polymer material; The metal material is one or more of lead and tungsten, and the lead-free polymer material is one or more of bismuth B, barium Ba, gadolinium Gd, tungsten W, antimony Sb, and tin Sn.

5. The TSV radiation-resistant packaging structure according to claim 1, characterized in that: The chip is arranged in the inner cavity of the wafer, and the cavity is filled with dry film or resin.

6. The TSV radiation-resistant packaging structure according to claim 2, characterized in that: The chip is a single chip or a plurality of chips are integrated and packaged to form a chipset, and is assembled with a plurality of detectors.

7. The TSV radiation-resistant packaging structure according to claim 1, characterized in that: The radiation protection layer forms a sealed space for accommodating the chip and isolating it from external radiation.

8. A TSV radiation-resistant structure packaging method, characterized in that: include: Step 1: Make TSV through holes on the wafer, then etch the cavity, and put anti-radiation material in the cavity to form a radiation protection layer; Step 2: Embed the processor chip in the cavity and fill it with dry film or resin; Step 3: fabricating a first redistribution layer on the front side of the wafer, the first redistribution layer being electrically connected to the TSV through-holes and the processor chip, and temporarily bonding the front side of the wafer to a first temporary carrier; Step 4: Thinning the back side of the wafer to expose the TSV through-holes, and making a second redistribution layer, wherein the second redistribution layer is electrically connected to the TSV through-holes; Step 5: Bond the back side of the wafer to the second temporary carrier, then debond the front side of the wafer from the first temporary carrier, and finally perform radiation protection treatment on the processor chip on the front side of the wafer to form a radiation protection layer; Step 6: Remove the second temporary carrier and form solder balls on the front side of the wafer.

9. The TSV radiation-resistant structure packaging method according to claim 8, characterized in that: The radiation protection layer is made of metal, polymer, aluminum-lead micro-composite material, or lead-free polymer material; The metal material is one or more of lead and tungsten, and the lead-free polymer material is one or more of bismuth B, barium Ba, gadolinium Gd, tungsten W, antimony Sb, and tin Sn.

10. The TSV radiation-resistant structure packaging method according to claim 8, characterized in that: The method also includes mounting a detector on the second redistribution layer on the back side of the wafer.

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