Method for reducing warping of substrate in construction process

Abstract

The invention discloses a method for reducing warping of a substrate in a packaging process. The method comprises the following steps of: bonding a crystal grain on the upper surface of the substrate; adhering a glue material to the lower surface of the substrate, wherein the glue material has a first curing temperature; applying a liquid encapsulation material around the crystal grains, wherein the liquid encapsulation material has a second curing temperature; heating the substrate, the adhesive material and the liquid packaging material to a heating temperature, wherein the heating temperature is not lower than the first curing temperature and the second curing temperature; and cooling the substrate, the adhesive material and the liquid packaging material to room temperature. When the substrate is cooled to room temperature, the liquid packaging material applies an upper surface shrinkage stress to the upper surface of the substrate, the adhesive material applies a lower surface shrinkage stress to the lower surface of the substrate, and the lower surface shrinkage stress is substantially equal to the upper surface shrinkage stress.

Description

Technical Field

[0001] The invention relates to a method for reducing the warping of a substrate during an assembly process. Background Art

[0002] In the conventional packaging process of integrated circuit chips, the die is first bonded to a substrate, and then the I / O contacts on the die are electrically connected to the corresponding metal pins on the lead frame by wire bonding. Next, the packaging material is coated on the surface of the die by a filling / dispensing process or a molding process (also called a molding process or a sealing process) to protect the die and isolate the die from the outside world.

[0003] However, when the die is bonded to a substrate (especially a substrate containing organic components), after the dispensing process or the molding process is completed, it is often found that the entire substrate warps (see Figure 8 , which will be described in detail later), thereby affecting or even being detrimental to subsequent procedures. Summary of the invention

[0004] In view of this, one embodiment of the present invention proposes a method for reducing the warping of a substrate during the assembly process. The method includes bonding a die to the upper surface of a substrate; bonding an adhesive to the lower surface of the substrate, and the adhesive has a first curing temperature; applying a liquid packaging material around the die, and the liquid packaging material has a second curing temperature; heating the substrate, the adhesive, and the liquid packaging material to a heating temperature, and the heating temperature is not lower than the first curing temperature and the second curing temperature; and cooling the substrate, the adhesive, and the liquid packaging material to room temperature. Wherein, when the liquid packaging material is cooled to room temperature, an upper surface shrinkage stress is applied to the upper surface of the substrate; when the adhesive is cooled to room temperature, a lower surface shrinkage stress is applied to the lower surface of the substrate; and the lower surface shrinkage stress is substantially equal to the upper surface shrinkage stress.

[0005] In addition, one embodiment of the present invention also proposes a method for reducing the warping of the substrate during the assembly process. The method includes bonding a die to the upper surface of the substrate; bonding a glue to the lower surface of the substrate, and the glue has a first curing temperature. Heating a sealing material to the sealing temperature, and applying the sealing material around the die, and the sealing material has a third curing temperature; heating the substrate, the glue and the sealing material to a heating temperature, and the heating temperature is not lower than the first curing temperature and the third curing temperature; and cooling the substrate, the glue and the sealing material to room temperature. Wherein, when the sealing material is cooled to room temperature, an upper surface shrinkage stress is applied to the upper surface of the substrate; when the glue is cooled to room temperature, a lower surface shrinkage stress is applied to the lower surface of the substrate; and the lower surface shrinkage stress is substantially equal to the upper surface shrinkage stress.

[0006] From the above solutions, it can be seen that the method of the present invention applies equal shrinkage stresses to the upper and lower surfaces of the substrate, so that the substrate can reduce (or even avoid) warping caused by the solidification shrinkage of the liquid packaging material on its upper surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1A It is a flow chart of a method for reducing warping of a substrate during an assembly process according to a first embodiment of the present invention;

[0008] Figure 1B A flow chart of a method for reducing warping of a substrate during an assembly process according to a second embodiment of the present invention;

[0009] Figure 2 It is a schematic diagram of a top view of a substrate and a die in a YZ plane according to an embodiment of the present invention;

[0010] Figure 3 For Figure 2 A schematic diagram of the structure of the substrate and the die in the XY plane;

[0011] Figure 4 For Figure 2 A schematic diagram of the structure of the substrate, die and adhesive material in the XY plane;

[0012] Figure 5 It is a schematic structural diagram of a substrate, a die and a glue material in an XY plane according to an embodiment of the present invention;

[0013] Figure 6 It is a schematic diagram of the structure of a packaging element (including a substrate, a die and a plastic material) in a bottom view on the YZ plane according to an embodiment of the present invention;

[0014] Fig. 7A It is a schematic diagram of the structure of a packaging element (including a substrate, a die and a plastic material) in a bottom view on the YZ plane according to an embodiment of the present invention;

[0015] Figure 7B It is a bottom view structural diagram of a second embodiment of a packaging element (including a substrate, a die and a plastic material) of an embodiment of the present invention in the YZ plane;

[0016] Figure 8 A schematic diagram of the warping structure and warping degree of a substrate and a die in an XY plane according to an embodiment of the present invention;

[0017] Fig. 9 A schematic diagram of the warping structure and warping degree of the adhesive material in the XY plane according to an embodiment of the present invention;

[0018] Fig. 10A A flow chart of a method for reducing warping of a substrate during an assembly process according to a third embodiment of the present invention;

[0019] Fig. 10B A flowchart of a method for reducing warping of a substrate during an assembly process according to a fourth embodiment of the present invention;

[0020] Fig.11 FIG. 1 is a schematic diagram of the structure of a substrate, a die and a glue material in an XY plane according to an embodiment of the present invention; wherein the reference numerals

[0021] 1: assembly components;

[0022] 10:Substrate;

[0023] 101: upper surface;

[0024] 102: lower surface;

[0025] 103: cutting path;

[0026] 11: grain;

[0027] 12: plastic material;

[0028] 13: Liquid packaging material;

[0029] 14: Sealing material;

[0030] L1: length;

[0031] L2: length;

[0032] S1: A method for reducing the warping of the substrate during the assembly process;

[0033] S11~S17: steps;

[0034] S2: A method for reducing the warping of the substrate during the assembly process;

[0035] S21-S27: steps;

[0036] T1: thickness;

[0037] T2: thickness;

[0038] W0: cutting path width;

[0039] W0': cutting track width;

[0040] W1: width;

[0041] W1': width;

[0042] X: X axis of the coordinate;

[0043] Y: Y axis of the coordinate;

[0044] Z: Z axis of the coordinate;

[0045] d0: warpage amount;

[0046] d1: warpage amount;

[0047] d2: Warping amount. DETAILED DESCRIPTION

[0048] In the following exemplary embodiments of the present invention, the terms “upper” and “lower” are merely used to illustrate the orientations shown in the drawings, but are not intended to limit the actual orientations.

[0049] The following describes an implementation of a method for reducing substrate warping during a dispensing process.

[0050] Please refer to Figure 1A , which is a flow chart of a method S1 for reducing the warping of the substrate 10 during the assembly process according to the first embodiment of the present invention. Figures 2 to 6 , steps S11 to S17 are described in detail as follows.

[0051] Step S11: Bonding a plurality of dies 11 to the upper surface 101 of the substrate 10, such as Figure 2 and Figure 3 As shown. The substrate 10 may be a BT (Bismaleimide Triazine) substrate, an ABF (Ajinomoto Build-up Film) substrate, or other substrates suitable for BGA (Ball Grid Array) assembly procedures. The bonding may be connected by an insulating adhesive or a conductive adhesive; the insulating adhesive may be, for example, epoxy resin, and the conductive adhesive may be, for example, conductive silver glue.

[0052] Step S12: Bonding the adhesive 12 to the lower surface 102 of the substrate 10 (eg Figure 4 and Figure 6 As shown in FIG. 1 , the adhesive material 12 has a first curing temperature. The adhesive material 12 can be made of various polymer materials and has a length L1 (as shown in FIG. 1 ). Figure 5 and Figure 6 As shown), width W1 (as Figure 6 As shown) and thickness T1 (as Figure 5 The material of the adhesive material 12 may be, for example, but not limited to, epoxy resin plus filler. The first curing temperature refers to the temperature at which the polymer material becomes toughened and hardened due to the cross-linking of the polymer chains. The cross-linking of the polymer chains may be induced by applying heat or ultraviolet light.

[0053] Step S13: Apply liquid packaging material 13 around the die 11 (such as Figure 5As shown), and the liquid encapsulation material 13 has a second curing temperature. The liquid encapsulation material 13 may be various liquid encapsulation agents (LES), and may be in liquid state at room temperature (about 25°C or a reasonable error range thereof, such as 22°C to 27°C) without the need to heat the liquid encapsulation material 13 separately. The liquid encapsulation material 13 may be, for example, but not limited to, epoxy resin plus filler. The surroundings of the above-mentioned grain 11 refer to the surroundings of the grain 11 located on the upper surface 101 of the substrate 10, and may further include the upper side and / or lower side of the grain 11 (i.e., between the grain 11 and the upper surface 101 of the substrate 10). The liquid encapsulation materials 13 around adjacent grains 11 may be connected to each other or not. For example, in Figure 5 In the embodiment, the liquid encapsulation material 13 is located around the die 10 and fills between adjacent die 10, and the liquid encapsulation material 13 is a thin film layer having a length L2 and a thickness T2. Therefore, when the liquid encapsulation material 13 is applied around the die 11 and after a subsequent curing step, the die 11 can be more firmly fixed on the upper surface 101 of the substrate 10 by the liquid encapsulation material 13. The definition of the second curing temperature can refer to the definition of the first curing temperature, and the second curing temperature can be higher, equal to or lower than the first curing temperature.

[0054] In some embodiments, the first curing temperature and the second curing temperature substantially refer to the lower limit of the first curing temperature interval and the lower limit of the second curing temperature interval. Therefore, in some embodiments, by heating to a temperature higher than the lower limit of the first curing temperature interval or higher than the lower limit of the second curing temperature interval (and located in the first curing temperature interval and the second curing temperature interval, respectively), the curing reaction of the glue 12 or the liquid encapsulating material 13 can be induced. In contrast, if the temperature is heated to a temperature higher than the upper limit of the first curing temperature interval or higher than the upper limit of the second curing temperature interval, the glue 12 or the liquid encapsulating material 13 will be cracked or excessive stress will be generated, which is not conducive to the curing of the glue 12 and the liquid encapsulating material 13.

[0055] For example, the material of the adhesive 12 is epoxy resin plus filler, and its first curing temperature is, for example, 120°C to 150°C; the material of the liquid packaging material 13 is epoxy resin plus filler, and its second curing temperature range is, for example, 120°C to 150°C.

[0056] Step S14: heating the substrate 10, the die 11, the glue 12 and the liquid packaging material 13 to a heating temperature, and the heating temperature is not lower than the first curing temperature of the glue 12 and the second curing temperature of the liquid packaging material 13. Since the heating temperature is set to be not lower than the first curing temperature (or the lower limit of the first curing temperature range) and the second curing temperature (or the lower limit of the second curing temperature range), the curing reaction of the glue 12 and the liquid packaging material 13 can be induced during the heating process. In some embodiments, step S14 is to further maintain the substrate 10, the die 11, the glue 12 and the liquid packaging material 13 at the heating temperature for a period of time to ensure that the curing reaction of the glue 12 and the liquid packaging material 13 can be fully induced.

[0057] Step S15: Cooling the substrate 10, the die 11, the glue 12 and the liquid packaging material 13 to room temperature. In some embodiments, the above-mentioned cooling process to room temperature must ensure that the liquid packaging material 13 and the glue 12 are still connected to the upper surface 101 and the lower surface 102 of the substrate 10 respectively. Based on this, when cooling to room temperature (or in the process of cooling to room temperature), the liquid packaging material 13 applies an upper surface shrinkage stress to the upper surface 101 of the substrate 10, and the glue 12 also applies a lower surface shrinkage stress to the lower surface 102 of the substrate 10, and the lower surface shrinkage stress is substantially equal to the upper surface shrinkage stress. Therefore, the shrinkage stresses on the upper surface 101 and the lower surface 102 of the substrate 10 are substantially equal to each other, so the substrate 10 will be able to reduce (or even avoid) the warping of the substrate 10 caused by the solidification shrinkage of the liquid packaging material 13 on its upper surface 101.

[0058] Thus, the method for reducing (or even avoiding) the warping of the substrate 10 during the dispensing process is described. A person with ordinary knowledge in the technical field of the present case should understand that the aforementioned method S1 for reducing the warping of the substrate 10 during the assembly process can be equivalently changed according to different process requirements, and can still solve the technical problem of reducing (or even avoiding) the warping of the substrate 10 during the dispensing process, and produce corresponding technical effects.

[0059] Further references Figure 8 and Fig. 9 ,in Figure 8 Schematic diagram of the warping structure and warping degree of the substrate 10 and the die 11 in the XY plane after being heated and cured. Fig. 9 FIG. 1 is a schematic diagram of the warping structure and warping degree of the adhesive material 12 in the XY plane after being heated and cured.

[0060] exist Figure 8In the embodiment, since the liquid encapsulating material 13 is a polymer material, during the heating and curing process, the liquid encapsulating material 13 will shrink and exert shrinkage stress (such as upper surface shrinkage stress) on the substrate 10 (such as the upper surface 101). The degree of warping of the liquid encapsulating material 13 can be measured by Figure 8 The warping amount d2 refers to the height difference between the highest point (such as the two ends) and the lowest point (such as the middle low point) of the liquid encapsulating material 13 on its upper surface.

[0061] In addition, since the substrate 10 contains organic components, the substrate 10 itself will shrink, thereby causing the substrate 10 to warp. In addition, the difference in coefficient of thermal expansion (CTE) between the liquid encapsulation material 13 and the substrate 10 will also cause the substrate 10 to warp. By summing up the warping effects caused by the above-mentioned various reasons, the total warping degree of the substrate 10 can be calculated as follows: Figure 8 The warpage amount d0 is represented by the warpage amount d0, which refers to the height difference between the highest point (such as the two ends) and the lowest point (such as the middle low point) of the substrate 10 on its upper surface 101.

[0062] like Fig. 9 As shown, in Figure 8 During the same heating and curing process, the adhesive material 12 will also shrink, thereby applying shrinkage stress to the substrate 10. The degree of warping of the adhesive material 12 can be measured by Fig. 9 The warpage d1 is represented by the warpage d1, which refers to the height difference between the lowest point (e.g., two ends) and the highest point (e.g., the middle height) of the adhesive 12 on its upper surface. In some embodiments, the warpage d1 of the adhesive 12 is substantially equal to or greater than the warpage d2 of the liquid encapsulating material 13.

[0063] In some embodiments, the warping amount d0 of the above-mentioned substrate 10 is substantially equal to 0; or, in some embodiments, the warping amount d0 of the above-mentioned substrate 10 is slightly greater than 0 (equivalent to the upper surface shrinkage stress of the liquid packaging material 13 on the upper surface 101 of the substrate 10 being slightly greater than the lower surface shrinkage stress) or slightly less than 0 (equivalent to the lower surface shrinkage stress of the glue 12 on the lower surface 102 of the substrate 10 being slightly less than the upper surface shrinkage stress).

[0064] In some embodiments, based on the warpage d1 of the glue 12 and the warpage d2 of the liquid encapsulation material 13, different parameter conditions can be further adjusted to obtain the warpage effect (i.e., the warpage d0) caused by different parameter conditions on the substrate 10. By collecting and arranging the warpage d1, d2 and each parameter condition and the corresponding warpage d0, the corresponding empirical relationship of the warpage can be obtained. In addition, in some embodiments, for a substrate 10 of the same specification (e.g., fixed size and material), the adjustable parameter conditions can be, for example, (but not limited to) at least one of the following: the material combination of the glue 12 and the liquid encapsulation material 13, the thickness (T1 or T2) combination, the length (L1 or L2) combination, the width (W1 or the width of the liquid encapsulation material 13) combination, the heating temperature, the area ratio of the glue 12 relative to the substrate 10, and the area ratio of the liquid encapsulation material 13 relative to the substrate 10. By adjusting one or more of the above-mentioned parameter conditions, the warping effect (i.e., the warping amount d0) caused to the substrate 10 can be obtained respectively. By adjusting these parameter conditions and the corresponding warping effect, the corresponding warping amount empirical relationship can be obtained. Further, by changing the substrate 10 to a substrate 10 of a different specification from the above-mentioned specification (for example, changing the size, or changing the material), and supplemented by the parameter combination of the above-mentioned various glue materials 12 and liquid packaging materials 13, more different specifications of substrates 10 and their corresponding warping amount empirical relationships can be obtained. Based on this, for a substrate 10 of a certain specification, according to the obtained warping amount empirical relationship of the substrate 10, the corresponding parameter conditions can be further known, and then it can be known which specifications of glue materials 12 and liquid packaging materials 13 should be selected, and which dispensing process conditions should be supplemented, so as to minimize (or even avoid) the warping of the substrate 10 during the dispensing process. The above-mentioned various combinations of parameters of glue materials 12 and liquid packaging materials 13 and the specifications of the substrate 10 can be adjusted according to various needs, and a more complete warping amount empirical relationship of the substrate 10 can be established.

[0065] Therefore, in some embodiments, after establishing the above-mentioned empirical relationship of the warping amount, the corresponding parameter conditions can be called up according to the specifications of the existing substrate 10, glue material 12 and liquid packaging material 13 to perform the dispensing process, which can also reduce (or even avoid) the warping of the substrate 10 during the dispensing process.

[0066] Please refer again Figure 1A After the step S15 is performed, the step S16 is further performed: removing the adhesive material 12. The above removal can be performed by applying various physical external forces (such as a tool and / or a fixture), or by physical and / or chemical actions (such as hydrolysis and / or pyrolysis). Based on this, in some embodiments, since the entire structure element 1 has been cooled to room temperature, removing the adhesive material 12 in this case will not affect the overall warping degree of the substrate 10, and the flatness of the substrate 10 can still be maintained.

[0067] In some embodiments, after or at the same time as step S16, step S17 is further performed: cutting the substrate 10. Figure 1A In the method S1 for reducing the warping of the substrate 10 during the assembly process, after removing the adhesive 12 , the substrate 10 is cut to separate the dies 11 from each other, thereby completing the singulation process.

[0068] Please refer to Figure 1B , which is a flow chart of a method S1 for reducing the warping of the substrate 10 during the assembly process according to the second embodiment of the present invention. Figure 1A , Figure 1B The main differences of the method S1 for reducing the warping of the substrate 10 during the assembly process are: Figure 1B Step S16 further combines Figure 1A In other words, in steps S16 and S17, Figure 1B In the embodiment shown, the method S1 for reducing the warping of the substrate 10 during the assembly process is to remove part or all of the adhesive 12 while cutting the substrate 10. Fig. 7A and Figure 7B , detailed description Figure 1B The step S16 is as follows; the implementation of the remaining steps can refer to the above description and will not be described in detail here.

[0069] Please refer to Fig. 7A and Figure 7B , which is a schematic diagram of the structure of the assembly element 1 (including the substrate 10, the die 11 and the adhesive 12) in the YZ plane when viewed from the bottom. Fig. 7A and Figure 7B In the embodiment, the substrate 10 also has a cutting path 103. The cutting path 103 refers to the route that the cutting tool or fixture is expected to pass through during the subsequent cutting process of the substrate 10. Therefore, the cutting path 103 can be a track or groove actually made on the substrate 10 (which can be the upper surface 101 and / or the lower surface 102), or it can be a virtual cutting route expected to be followed in the cutting process. Fig. 7A As shown, the scribe line 103 has a scribe line width W0 in the width direction (i.e., Z direction) of the substrate 10 and a scribe line width W0′ in the length direction (i.e., Y direction) of the substrate 10, and the scribe line width W0 and the scribe line width W0′ may be the same or different from each other. Figure 1B In step S12, the adhesive material 12 is bonded to the lower surface 102 of the substrate 10 and to a part or all of the scribe lines 103 (eg Figure 7B As shown in Figure 7BAs shown, the adhesive material 12 has an adhesive material width W1 in the width direction (i.e., Z direction) of the substrate 10 and an adhesive material width W1' in the length direction (i.e., Y direction) of the substrate 10, and the adhesive material width W1 and the adhesive material width W1' correspond to the cutting line width W0 and the cutting line width W0', respectively. That is, in some embodiments, the adhesive material width W1 and the adhesive material width W1' are substantially equal to or less than the cutting line width W0 and the cutting line width W0', respectively. Therefore, in Figure 1B In step S16, when the substrate 10 is cut along the cutting path 103, the adhesive material 12 is also removed. In addition, in some embodiments, when the width of the cutting tool is substantially greater than or equal to the adhesive material width W1 and the adhesive material width W1', Figure 1B In step S16, the substrate 10 is cut directly along the cutting lines 103, so that the adhesive material 12 corresponding to the cutting lines 103 can be removed at the same time.

[0070] The following further describes implementation aspects of the method for reducing substrate warping during the molding process.

[0071] Please refer to Fig. 10A , which is a flow chart of a method S2 for reducing the warping of the substrate 10 during the assembly process according to the third embodiment of the present invention. Fig.11 , steps S21 to S27 are described in detail as follows.

[0072] Step S21: Bonding a plurality of dies 11 to the upper surface 101 of the substrate 10 (eg Fig.11 As shown in FIG. 1 , step S21 is similar to step S11 , so the implementation of step S21 may refer to the description of the aforementioned step S11 , and will not be described in detail here.

[0073] Step S22: Bonding the adhesive 12 to the lower surface 102 of the substrate 10 (eg Fig.11 As shown), the adhesive material 12 has a first curing temperature. Since step S22 is similar to step S12, the implementation of step S22 can refer to the description of the aforementioned step S12, and will not be described in detail here.

[0074] Step S23: Heat the molding material 14 to the molding temperature, and apply the molding material 14 around the grain 11, and the molding material 14 has a third curing temperature. The above-mentioned molding material 14 can be various epoxy molding compounds (EMC). However, since the melting point (or glass transition temperature) of the molding material 14 is higher than the room temperature, the molding material 14 is solid at room temperature and needs to be heated by the molding equipment to exceed its melting point (or glass transition temperature) to have fluidity. That is, the above-mentioned molding temperature is at least higher than or equal to the melting point (or glass transition temperature) of the molding material 14. The material of the molding material 14 can be, for example, but not limited to, epoxy resin plus filler. The surrounding of the above-mentioned grain 11 refers to the surrounding of the grain 11 located on the upper surface 101 of the substrate 10, and may further include the upper side and / or lower side of the grain 11 (that is, between the grain 11 and the upper surface 101 of the substrate 10). For example, in Fig.11 , the encapsulation material 14 is located on the upper side of the die 11 and around it, so as to cover the die 11 in the encapsulation material 14. Therefore, when the encapsulation material 14 is applied around the die 11 and after the subsequent curing step, the die 11 can be more firmly fixed on the upper surface 101 of the substrate 10 through the encapsulation material 14, and the contacts of the active surface of the die 11 and the wiring between the die 11 and the epoxy resin plus filler of the substrate 10 can also be protected by the encapsulation material 14. The definition of the third curing temperature can refer to the definition of the first curing temperature, and the third curing temperature can be higher, equal to or lower than the first curing temperature.

[0075] For example, the material of the adhesive 12 is epoxy resin plus filler, and its first curing temperature is, for example, 120°C to 150°C; the material of the sealing material 14 is, for example, epoxy resin plus filler, and its third curing temperature range is, for example, 120°C to 150°C.

[0076] Step S24: heating the substrate 10, the die 11, the glue 12 and the sealing material 14 to a heating temperature, and the heating temperature is not lower than the first curing temperature and the third curing temperature. Since the heating temperature is set to be not lower than the first curing temperature (or the lower limit of the first curing temperature range) and the third curing temperature (or the lower limit of the third curing temperature range), the curing reaction of the glue 12 and the sealing material 14 can be induced during the heating process. In some embodiments, step S24 is to further maintain the substrate 10, the die 11, the glue 12 and the sealing material 14 at the heating temperature for a period of time to ensure that the curing reaction of the glue 12 and the sealing material 14 can be fully induced.

[0077] Step S25: Cool the substrate 10, the die 11, the glue 12 and the sealing material 14 to room temperature. In some embodiments, the above-mentioned cooling process to room temperature must ensure that the sealing material 14 and the glue 12 are still connected to the upper surface 101 and the lower surface 102 of the substrate 10 respectively. Based on this, when cooling to room temperature (or in the process of cooling to room temperature), the sealing material 14 applies an upper surface shrinkage stress to the upper surface 101 of the substrate 10, and the glue 12 also applies a lower surface shrinkage stress to the lower surface 102 of the substrate 10, and the lower surface shrinkage stress is substantially equal to the upper surface shrinkage stress. Therefore, the shrinkage stresses to which the upper surface 101 and the lower surface 102 of the substrate 10 are subjected are substantially equal to each other, so the substrate 10 will be able to reduce (or even avoid) the warping of the substrate 10 caused by the solidification shrinkage of the sealing material 14 on its upper surface 101.

[0078] So far, the method for reducing (or even avoiding) the warping of the substrate 10 during the molding process is described. A person with ordinary knowledge in the technical field of the present case should understand that the aforementioned method S2 for reducing the warping of the substrate 10 during the assembly process can be equivalently changed according to different process requirements, and can still solve the technical problem of reducing (or even avoiding) the warping of the substrate 10 during the molding process and produce corresponding technical effects.

[0079] Since the sealing material 14 is a polymer material, during the heating and curing process, the sealing material 14 will also shrink and exert shrinkage stress on the substrate 10. The degree of warping of the sealing material 14 can be referred to as Figure 8 In addition, as mentioned above, the substrate 10 itself will shrink and warp, so the difference in thermal expansion coefficient (CTE) between the encapsulation material 14 and the substrate 10 will also cause the substrate 10 to produce a warping effect caused by the sum of the above-mentioned various reasons, which can be explained by Figure 8 The warpage d0 is represented by the amount of warpage; the detailed definition can be found in the above description and will not be described in detail here. In addition, as mentioned above, during the heating and curing process, the adhesive material 12 will also shrink and produce the following Fig. 9 The warping (for example, the warping amount d1) can apply shrinkage stress to the substrate 10; the detailed definition can be found in the above description and will not be described in detail here.

[0080] In some embodiments, based on the warpage d1 of the glue 12 and the warpage d2 of the sealing material 14, different parameter conditions can be further adjusted to obtain the warpage effect (i.e., the warpage d0) caused by different parameter conditions on the substrate 10. By adjusting the warpage d1, d2 and each parameter condition and the corresponding warpage d0, the corresponding empirical relationship of the warpage can be obtained. In addition, in some embodiments, for a substrate 10 of the same specification (e.g., fixed size and material), the adjustable parameter conditions can be, for example, (but not limited to) at least one of the following: material combination, thickness combination, length combination, width combination, heating temperature, area ratio of the glue 12 to the substrate 10, and area ratio of the sealing material 14 to the substrate 10. The corresponding adjustment of one or more of the above parameter conditions can respectively obtain the final warpage effect (i.e., the warpage d0) caused to the substrate 10, and the corresponding empirical relationship of the warpage can be obtained by collecting and arranging these parameter conditions and the corresponding warpage effects. Further, by changing the substrate 10 to a substrate 10 of a different specification from the aforementioned specifications (e.g., changing the size, or changing the material), and supplemented by the parameter combinations of the various adhesives 12 and the sealing materials 14, more substrates 10 of different specifications and their corresponding empirical relationships of warpage can be obtained. Based on this, for a substrate 10 of a certain specification, according to the obtained empirical relationship of the warpage of the substrate 10, the corresponding parameter conditions can be further known, and then it can be known what specifications of adhesives 12 and sealing materials 14 should be selected, and what sealing process conditions should be supplemented, so as to minimize (or even avoid) the warpage of the substrate 10 during the sealing process. The parameter combinations of the various adhesives 12 and the sealing materials 14 and the specifications of the substrate 10 can be adjusted according to various needs, and a more complete empirical relationship of the warpage of the substrate 10 can be established.

[0081] In some embodiments, after establishing the above-mentioned empirical relationship of the warping amount, the corresponding parameter conditions can be called up according to the specifications of the existing substrate 10, glue material 12 and sealing material 14 to perform the sealing process, which can also reduce (or even avoid) the warping of the substrate 10 during the sealing process.

[0082] Please refer again Fig. 10A After the step S25 is implemented, the step S26 is further implemented: removing the glue 12. Since the step S26 is similar to the step S16, the implementation of the step S26 can refer to the description of the aforementioned step S16, and will not be described in detail here. Based on this, in some embodiments, since the entire substrate 10 has been cooled to room temperature, removing the glue 12 in this case will not affect the overall warping of the substrate 10, and the flatness of the substrate 10 can still be maintained.

[0083] In some embodiments, after or at the same time as step S26, step S27 is further performed to cut the substrate 10 to separate the dies 11. Since step S27 is similar to step S17, the implementation of step S27 can refer to the description of step S17, and will not be described in detail here.

[0084] Please refer to Fig. 10B , which is a flow chart of a method S2 for reducing the warping of the substrate 10 during the assembly process according to the fourth embodiment of the present invention. Fig. 10A , Fig. 10B The main differences of the method S2 for reducing the warping of the substrate 10 during the assembly process are: Fig. 10B Step S26 further combines Fig. 10A In other words, in steps S26 and S27, Fig. 10B In the embodiment shown, the method S2 for reducing the warping of the substrate 10 during the assembly process is to remove part or all of the adhesive 12 while cutting the substrate 10. Fig. 10B Step S26 is similar to Figure 1B Step S16, therefore Fig. 10B The implementation of step S26 can refer to the aforementioned Figure 1B The description of step S16 will not be described in detail here.

[0085] It should be noted that, in order to facilitate the description of the various steps of methods S1 and S2 for reducing the warping of the substrate during the assembly process, the size and warping amount of each element in the accompanying drawings should be understood as not being drawn completely according to the actual scale.

[0086] Although the present invention is disclosed as above with the aforementioned embodiments, it is not intended to limit the present invention. Any person skilled in the art may make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the patent protection scope of the present invention shall be subject to the scope of the patent application attached to this specification.

Claims

1. A method for reducing warping of a substrate during an assembly process, characterized in that: Include: Bonding a plurality of dies to an upper surface of a substrate; Bonding an adhesive material to a lower surface of the substrate, the adhesive material having a first curing temperature; Applying a liquid packaging material around the die, the liquid packaging material having a second curing temperature; Heating the substrate, the adhesive material, and the liquid packaging material to a heating temperature that is not lower than the first curing temperature and the second curing temperature; and Cooling the substrate, the adhesive and the liquid packaging material to room temperature; The liquid packaging material applies an upper surface shrinkage stress to the upper surface of the substrate when cooled to the room temperature, and the adhesive applies a lower surface shrinkage stress to the lower surface of the substrate when cooled to the room temperature, and the lower surface shrinkage stress is equal to the upper surface shrinkage stress.

2. The method according to claim 1, characterized in that After cooling the substrate, the adhesive and the liquid packaging material to the room temperature, the method further comprises: removing the adhesive.

3. The method according to claim 2, characterized in that The adhesive is removed by hydrolysis and / or pyrolysis.

4. The method according to claim 2, characterized in that: After removing the glue material, the method further includes: cutting the substrate to separate the dies from each other.

5. The method according to claim 1, characterized in that After cooling the substrate, the glue and the liquid packaging material to the room temperature, the method further comprises: cutting the substrate along a cutting path to separate the dies from each other.

6. The method according to claim 5, characterized in that The adhesive is bonded to the cutting path, the cutting path has a cutting path width, and the adhesive has an adhesive width, the cutting path width is equal to the adhesive width, so as to cut the substrate along the cutting path and remove the adhesive.

7. A method for reducing warping of a substrate during an assembly process, characterized in that: Include: Bonding a plurality of dies to an upper surface of a substrate; Bonding an adhesive material to a lower surface of the substrate, the adhesive material having a first curing temperature; Heating a sealing material to a sealing temperature and applying the sealing material around the die, wherein the sealing material has a third curing temperature; Heating the substrate, the adhesive material, and the sealing material to a heating temperature that is not lower than the first curing temperature and the third curing temperature; and Cooling the substrate, the adhesive and the sealing material to room temperature; The sealing material applies an upper surface shrinkage stress to the upper surface of the substrate when cooled to the room temperature, and the adhesive applies a lower surface shrinkage stress to the lower surface of the substrate when cooled to the room temperature, and the lower surface shrinkage stress is equal to the upper surface shrinkage stress.

8. The method according to claim 7, characterized in that After cooling the substrate, the glue and the sealing material to the room temperature, the method further comprises: removing the glue.

9. The method according to claim 8, characterized in that The adhesive is removed by hydrolysis and / or pyrolysis.

10. The method according to claim 8, characterized in that After removing the glue material, the method further includes: cutting the substrate to separate the dies from each other.

11. The method according to claim 7, characterized in that After cooling the substrate, the glue and the sealing material to the room temperature, the method further comprises: cutting the substrate along a cutting path to separate the dies from each other.

12. The method according to claim 11, characterized in that The adhesive is bonded to the cutting path, the cutting path has a cutting path width, and the adhesive has an adhesive width, the cutting path width is equal to the adhesive width, so as to cut the substrate along the cutting path and remove the adhesive.

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