Packaging method and packaging structure of tube core

Abstract

The invention discloses a packaging method and a packaging structure of tube cores. The packaging method comprises the following steps: arranging a plurality of tube cores on a first surface of a packaging substrate; forming pins of a plurality of tube cores on the second surface of the packaging substrate; performing first plastic packaging on the first surface and the second surface of the packaging substrate, wherein a first plastic packaging material covers the plurality of tube cores and fills gaps among the pins of the plurality of tube cores; cutting scribing channel areas among the plurality of tube cores for the first time from the second surface of the packaging substrate to form grooves with a first width; and filling a second plastic package material in the groove, performing second cutting on the scribing channel area among the plurality of tube cores to form a gap with a second width, the second width being smaller than the first width, and the second plastic package material covering the side surface of the pin. According to the packaging method and the packaging structure of the tube core, through two times of plastic packaging and two times of cutting, the pins on the cut side surface of the packaging structure are wrapped by the plastic packaging material, so that the problem of copper migration on the side surface of the packaging structure is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor packaging, and in particular to a packaging method and packaging structure of a tube core. Background Art

[0002] With the high integration, high performance and high speed of the die, the requirements for semiconductor packaging technology are getting higher and higher, and miniaturization and large-scale production have become the development trend of semiconductor packaging. After the package is cut (package saw) of the traditional mass-produced QFN package or LGA package, the frame copper will be exposed on the side, such as Figure 1 As shown, during subsequent applications, under high temperature and high humidity conditions, copper migration will occur between adjacent pins with different functions on the side surface, resulting in leakage failure, affecting service life and reliability.

[0003] Currently, the main approach to reducing the risk is to increase the pin pitch, but this approach will increase the size of the package structure and cannot completely solve the copper migration problem. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a packaging method and packaging structure of a tube core, through two plastic packaging and two cutting, so that the copper pins on the side of the packaging structure after cutting are wrapped by plastic packaging material, thereby avoiding the problem of copper migration on the side of the packaging structure.

[0005] According to one aspect of the present invention, a method for packaging tube cores is provided, comprising: arranging a plurality of tube cores on a first surface of a packaging substrate, wherein the plurality of tube cores include a scribe line area between the plurality of tube cores; forming pins of the plurality of tube cores on a second surface of the packaging substrate; performing a first plastic encapsulation on the first surface and the second surface of the packaging substrate, wherein a first plastic encapsulation material of the first plastic encapsulation covers the plurality of tube cores and fills the gaps between the pins of the plurality of tube cores; performing a first cutting on the scribe line area between the plurality of tube cores from the second surface of the packaging substrate to form a groove of a first width, wherein the groove separates the pins of the plurality of tube cores from each other; filling the groove with a second plastic encapsulation material, and performing a second cutting on the scribe line area between the plurality of tube cores to form a gap of a second width, thereby forming a plurality of independent packaging structures, wherein the second width is smaller than the first width, so that the second plastic encapsulation material covers the side surfaces of the pins.

[0006] Optionally, a laser knife is used to cut the scribe line area, and the energy of the laser knife during the first cutting is greater than the energy of the laser knife during the second cutting, so that the second width is smaller than the first width.

[0007] Optionally, a physical knife is used to cut the scribe line area, and the width of the physical knife during the first cutting is greater than the width of the physical knife during the second cutting, so that the second width is smaller than the first width.

[0008] Optionally, the first width is less than or equal to a width of the scribe line area.

[0009] Optionally, the center lines of the knives used in the first cutting and the second cutting coincide.

[0010] Optionally, in the step of forming pins of a plurality of tube cores on the second surface of the packaging substrate, the pins cross the scribe line area, and two tube cores adjacent to the scribe line area are electrically connected.

[0011] Optionally, in the step of performing a first cutting on the dicing street area between the plurality of tube cores from the second surface of the packaging substrate to form a groove of a first width, the depth of the groove is greater than the thickness of the pin so that the pin crossing the dicing street area is divided into two parts.

[0012] Optionally, after the second surface of the packaging substrate is first plastic-sealed, the surface of the first plastic-sealing material is flush with the surface of the lead.

[0013] According to another aspect of the present invention, there is provided a packaging structure, which is formed by the above-mentioned packaging method and includes: a packaging substrate, a tube core located on a first surface of the packaging substrate, a plurality of pins located on a second surface of the packaging substrate, and a plastic encapsulation material wrapping the packaging substrate, the tube core, and the plurality of pins, wherein the side surfaces of the pins are wrapped by the plastic encapsulation material.

[0014] The tube core packaging method and packaging structure provided by the present invention are suitable for batch packaging of tube cores. After the first plastic packaging is completed, a first cutting is performed in a scribe line area of ​​the plastic packaging body to form a groove of a first width to cut off the pins in the packaging structure, and then a second plastic packaging material is filled in the groove to perform a second plastic packaging, and then a second cutting is performed in the scribe line area to form a gap of a second width, the second width is smaller than the first width, and the center line of the second cutting coincides with the center line of the groove, so that the side of the packaging structure after the second cutting is the plastic packaging material, that is, the pins on the side of the packaging structure after cutting are wrapped by the plastic packaging material, thereby avoiding the copper migration problem on the side of the packaging structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0016] Figure 1A schematic diagram of the three-dimensional structure of an independent packaging structure after cutting in batch packaging according to the prior art is shown;

[0017] Figure 2 A schematic diagram of the three-dimensional structure of an independent packaging structure after cutting in batch packaging according to an embodiment of the present invention is shown;

[0018] Figure 3 A flow chart of a method for packaging a die according to an embodiment of the present invention is shown;

[0019] Figure 4a to Figure 4h Schematic cross-sectional views and bottom views of various stages in a method for packaging a die according to an embodiment of the present invention are shown. DETAILED DESCRIPTION

[0020] Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, the same elements are represented by the same or similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale.

[0021] The specific implementation of the present invention is further described in detail below in conjunction with the drawings and examples.

[0022] Figure 2 A schematic diagram of the three-dimensional structure of an independent packaging structure after cutting in batch packaging according to an embodiment of the present invention is shown.

[0023] refer to Figure 2 The packaging structure 200 of the present application includes: a die ( Figure 2 Not shown), packaging substrate ( Figure 2 ), a plurality of array-arranged pins 202, pads 103, and a molding material 101. The die is fixed on the first surface A of the packaging substrate via conduction, and the packaging substrate provides support for the die; a plurality of pins 202 are arranged on the second surface B of the packaging substrate, and are arranged into a desired wiring pattern of the die, and the pins and the die are electrically connected via the packaging substrate, thereby serving as a lead-out structure of the die; the pads 103 are located on the second surface B of the packaging substrate, and serve as heat dissipation pads for the die; the molding material 101 wraps the packaging substrate and the die, and a portion of the surfaces of the plurality of pins 202 and the pads 103 are also wrapped by the molding material, and only one side of the surface of the pins 202 and the pads 103 away from the packaging substrate is exposed.

[0024] In this embodiment, a plurality of pins 202 are exposed on the second surface of the packaging structure 200 on a side surface away from the second surface of the packaging substrate, and on the second surface of the packaging structure 200, adjacent pins 202 are separated by molding material, while other surfaces of the pins 202, especially the side surfaces, are wrapped by molding material 101, so that the pins 202 can only be electrically connected to other structures through the second surface, and leakage failure of the packaging structure 200 caused by copper migration will not occur on the side surface.

[0025] Furthermore, in this embodiment, the pins 202 on the second surface of the package structure 200 are arranged in a quadrilateral, and the number of the pins 202 on each side of the quadrilateral may be the same or different.

[0026] Figure 3 A flow chart of a method for packaging a die according to an embodiment of the present invention is shown; Figure 4a to Figure 4h The cross-sectional schematic diagram and bottom view of each stage in the packaging method of the tube core according to the embodiment of the present invention are shown. Figure 3 and Figure 4a to Figure 4h The packaging method of the tube core of the present application is described in detail.

[0027] Step S301: a plurality of tube cores are arranged on a first surface of a packaging substrate, and a dicing road area is included between the plurality of tube cores.

[0028] In this step, since the packaging is performed in batches, a plurality of tube dies 105 are arranged on the first surface of the packaging substrate 104, and there are scribe line areas (such as Figure 4a ), so as to facilitate the subsequent steps of dividing it into multiple independent packaging structures 200, such as Figure 4a In this embodiment, a plurality of dies 105 are disposed on a first surface of a package substrate 104 , for example in an array.

[0029] Furthermore, it also includes: electrically connecting the plurality of tube cores 105 to the first surface of the package substrate 104. Specifically, the tube core 105 can be adhered to the first surface of the package substrate 104 by an adhesive, and the electrical connection with the package substrate 104 is achieved through a wire or a circuit layer. It can be understood that the specific implementation method of step S301 in this embodiment can be understood with reference to the prior art, and will not be described in detail herein.

[0030] In this embodiment, Figure 4a In the batch packaging process shown in , for example, a plurality of tube cores 105 are arrayed on a packaging substrate 104. In other batch packaging embodiments, for example, one tube core 105 may correspond to one packaging substrate 104. Those skilled in the art may make corresponding selections as needed, and this application does not limit this.

[0031] Optionally, in this embodiment, the package substrate 104 may be a single-layer board, or a combined structure including, for example, a dielectric layer, a circuit layer, a pad, etc. In addition, the package substrate 104 may also be a lead frame commonly used in the art or other commonly used structures having the same function as the package substrate 104. In this embodiment, the structure and manufacturing method of the package substrate 104 are not closely related to the technical problem to be solved by the present invention, so they can be understood with reference to the prior art and will not be described in detail herein. It should be understood that when the package substrate 104 is a combined structure, the first surface and the second surface of the package substrate 104 described herein correspond to the corresponding surfaces of the entire package substrate 104.

[0032] Step S302: forming pins of a plurality of dies on the second surface of the packaging substrate.

[0033] In this step, the method for forming the pins 102 on the second surface of the package substrate 104 specifically includes: forming a patterned metal layer on the second surface of the package substrate 104 by a deposition method such as chemical plating, chemical vapor deposition, or physical vapor deposition, such as Figure 4b The metal layer is formed of a material such as aluminum, copper, gold or silver, and copper is used as an example for description in this application.

[0034] Further, for example, a pad 103 is formed on the second surface of the package substrate 104 corresponding to the central area of ​​the tube core 105 (for example, refer to Figure 2 , Figure 4b The solder pad 103 is surrounded by the pin 102 but is not electrically connected to the pin 102 . The solder pad 103 serves as a heat dissipation structure for the die 105 .

[0035] It should be noted that, in this embodiment, when the patterned metal layer is deposited, the shape, quantity, size and position adopted are all set according to the position of the tube core 105, so that the pins 102 on the adjacent sides of the adjacent tube core 105 are connected, that is, the pins 102 on the adjacent sides of the adjacent tube core 105 pass through the scribe line area between the adjacent tube cores 105 and are connected. Figure 4d shown.

[0036] Furthermore, the present invention also includes providing a plurality of vias and / or metal pillars at corresponding positions of the package substrate 104 , and realizing electrical connection between the plurality of package pins 104 and corresponding lead ends of the corresponding tube core 105 through the vias and / or metal pillars.

[0037] Step S303: performing a first plastic packaging on the first surface and the second surface of the packaging substrate, wherein a first plastic packaging material of the first plastic packaging covers the plurality of tube cores and fills the gaps between the pins of the plurality of tube cores.

[0038] In this step, the tube die 105 and the pins 102 on the packaging substrate 104 can be packaged by the first plastic packaging material 101, such as Figure 4c and Figure 4d Optionally, the first molding material 101 is made of a material having insulating properties and strong bonding strength, such as epoxy resin.

[0039] In this embodiment, after the first molding material 101 has molded the tube core 105, the tube core 105 is wrapped by the molding material 101, so that the tube core is not affected by the external environment, such as moisture, dust, chemicals, etc., thereby improving the stability and reliability of the tube core 105. At the same time, after the pins 102 are molded by the first molding material 101, the gaps between adjacent pins are filled with the first molding material, and the second surface of the first molding material 101 is substantially flush with the second surface of the pin 102, or slightly lower than the second surface of the pin 102, so that the second surface of the pin 102 is exposed, but the other surfaces are wrapped by the first molding material 101, and the exposed second surface of the pin 102 is used to realize the electrical connection between the package structure and other structures, such as a circuit board or a PCB board.

[0040] Further, refer to Figure 4d , wherein, on the second surface of the package structure, the dotted line frame is, for example, a corresponding setting area of ​​the tube core 105, and the area between adjacent dotted line frames is, for example, a scribe line area, which separates the corresponding area arrays of multiple tube cores 105. At the same time, between adjacent tube cores, a pin 102 crosses the scribe line area to realize electrical connection with two tube cores.

[0041] Step S304: performing a first cutting on the dicing street area between the plurality of tube dies from the second surface of the package substrate to form a groove of a first width, wherein the groove separates the pins of the plurality of tube dies from each other.

[0042] In this step, a wide blade is used to perform a first cut on the scribe lanes between the plurality of dies from the second surface of the structure to form grooves 106 of a first width. During this cutting process, the cutting depth is, for example, greater than the thickness of the lead 102, that is, this cutting step only cuts off the lead 102 in the scribe lane area, such as Figure 4e shown.

[0043] In this embodiment, the broad knife cutting in this step can be physical knife cutting, laser knife cutting, or any other cutting method.

[0044] Further, in this embodiment, in the first cutting of this step, the depth of the groove 106 is not less than the thickness of the pin 102. To ensure that the pin 102 is cut off, the groove 106 may extend into the packaging substrate 104, but the groove 106 will not penetrate the packaging structure.

[0045] In this embodiment, the pins 102 located on the second surface of the package substrate 104 after cutting become pins 202 , for example. The pins 202 are only electrically connected to the corresponding tube core 105 , but not to the pins 202 of the adjacent tube core 105 .

[0046] Step S305: filling the groove with a second molding material, and performing a second cutting on the dicing lane area between the plurality of dies to form a gap of a second width, thereby forming a plurality of independent packaging structures.

[0047] In this step, the second molding material 101' is filled in the groove 106 to make the second surface of the package structure flush, and the side surface of the cut pin 202 exposed in the groove 106 is again wrapped by the second molding material 101', leaving only the second surface of the pin 202 exposed. Figure 4f and Figure 4g shown.

[0048] Furthermore, a narrow knife is used to perform a second cutting on the dicing lanes between the plurality of tube cores 105 to form a second width gap penetrating the package structure, wherein the second width is smaller than the first width, so as to obtain a plurality of independent package structures in which the side surfaces of the pins 202 are wrapped by the second plastic encapsulation material 101', such as Figure 4h shown.

[0049] In this embodiment, the two cuts may be physical knife cutting or laser knife cutting, or any other cutting method. In one embodiment, for example, a laser knife is used to cut the scribe line area, and the energy of the laser knife during the first cut is greater than the energy of the laser knife during the second cut, so that the second width is smaller than the first width. In another embodiment, a physical knife is used to cut the scribe line area, and the width of the physical knife during the first cut is greater than the width of the physical knife during the second cut, so that the second width is smaller than the first width.

[0050] In this embodiment, the second width is smaller than the first width, that is, the width of the narrow blade is smaller than the width of the wide blade in step S304, and during cutting, the width direction of the dicing road (i.e. Figure 4f The center line of the wide blade coincides with the center line of the scribe line, and the center line of the narrow blade coincides with the center line of the scribe line, so that after the narrow blade cuts, part of the plastic encapsulation material 101' filled in the groove is still located on the side surface of the pin 202, and the side surface of the pin 202 is not exposed, so that in each independent packaging structure, the side surface of the pin 202 will not have copper migration problems.

[0051] Specifically, the center lines of the knives used in the first cutting and the second cutting coincide with each other, so that in the independent packaging structure formed after the second cutting, the thickness of the side of the pin 202 wrapped by the second plastic packaging material 101' is basically the same, avoiding the risk of exposing the pin on one side due to the second cutting being biased to one side due to the center lines not coinciding.

[0052] In addition, technicians in this field can set the difference between the first width and the second width to be no less than a preset value to ensure that the side of the pin is well wrapped by the plastic packaging material after the second cutting. Specifically, technicians in this field can set the preset value according to the different plastic packaging materials and the situation of the knife used during cutting.

[0053] The tube core packaging method and packaging structure provided by the present invention are suitable for batch packaging of tube cores. After the first plastic packaging is completed, a wide knife is used to perform a first cutting in a scribe line area of ​​a plastic packaging body to form a groove of a first width, so as to cut off the pins in the packaging structure. Then, a second plastic packaging material is filled in the groove to perform a second plastic packaging. Then, a second cutting is performed in the scribe line area to form a gap of a second width. The second width is smaller than the first width, and the center line of the second cutting coincides with the center line of the groove, so that the side of the packaging structure after the second cutting is the plastic packaging material, that is, the pins on the side of the packaging structure after cutting are wrapped by the plastic packaging material, thereby avoiding the copper migration problem on the side of the packaging structure.

[0054] According to the embodiments of the present invention as described above, these embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and the modified use based on the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for packaging a tube die, comprising: A plurality of tube cores are arranged on the first surface of the packaging substrate, and a dicing road area is included between the plurality of tube cores; forming a plurality of die pins on the second surface of the packaging substrate; Performing a first plastic encapsulation on the first surface and the second surface of the packaging substrate, wherein a first plastic encapsulation material of the first plastic encapsulation covers the plurality of tube cores and fills the gaps between the pins of the plurality of tube cores; Performing a first cutting on the dicing street area between the plurality of tube dies from the second surface of the packaging substrate to form a groove of a first width, wherein the groove separates the pins of the plurality of tube dies from each other; A second molding material is filled in the groove, and the dicing area between the plurality of dies is cut for a second time to form a gap of a second width, thereby forming a plurality of independent packaging structures. The second width is smaller than the first width, so that the second plastic encapsulation material covers the side surface of the pin.

2. The packaging method according to claim 1, wherein: The scribe line area is cut using a laser knife, and the energy of the laser knife during the first cutting is greater than the energy of the laser knife during the second cutting, so that the second width is smaller than the first width.

3. The packaging method according to claim 1, wherein: The scribe line area is cut using a physical knife, and the width of the physical knife during the first cutting is greater than the width of the physical knife during the second cutting, so that the second width is smaller than the first width.

4. The packaging method according to claim 1, wherein: The first width is smaller than or equal to a width of the scribe line region.

5. The packaging method according to claim 2 or 3, wherein: The center lines of the knives used during the first and second cuts coincide.

6. The packaging method according to claim 1, wherein: In the step of forming pins of a plurality of tube dies on the second surface of the packaging substrate, the pins cross the scribe line area, and two tube dies adjacent to the scribe line area are electrically connected.

7. The packaging method according to claim 6, wherein: In the step of performing a first cutting on the dicing street area between the plurality of tube cores from the second surface of the packaging substrate to form a groove of a first width, the depth of the groove is greater than the thickness of the pin so that the pin crossing the dicing street area is divided into two parts.

8. The packaging method according to claim 1, wherein: After the second surface of the packaging substrate is firstly plastic-sealed, the surface of the first plastic-sealing material is flush with the surface of the lead.

9. A packaging structure, formed by the packaging method according to any one of claims 1 to 8, comprising: A packaging substrate, a tube core located on the first surface of the packaging substrate, a plurality of pins located on the second surface of the packaging substrate, and a plastic packaging material wrapping the packaging substrate, the tube core, and the plurality of pins, wherein the side surfaces of the pins are wrapped by the plastic packaging material.

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