Method for improving internal stress deformation of chip

Abstract

The invention discloses a method for improving internal stress deformation of a chip, which comprises the following steps of: sealing the chip between two opposite substrates by adopting UV (Ultraviolet) glue, then placing the two substrates with the chip in a water tank filled with deionized water of an ultrasonic generating device, and then controlling the ultrasonic generating device to switch between a first frequency and a second frequency, the time is the first time length, then the ultrasonic generating device is controlled to switch between the third frequency and the fourth frequency, the time is the second time length, finally, the two substrates with the chips are taken out, and the UV glue is irradiated by ultraviolet light to enable the UV glue to lose viscosity, so that the chips and the two substrates are separated, and in this way, under the two times of ultrasonic treatment, the two substrates are separated from each other. The ultrasonic waves with different frequencies repeatedly impact and vibrate the chip in water, so that the internal stress of the chip is improved, the bending degree of the chip is reduced, the condition of deformation caused by the internal stress is improved, and the chip is not subjected to a mechanical and physical processing process, so that the chip is not damaged.

Description

Technical Field

[0001] The present invention relates to the technical field of chips, and in particular to a method for improving stress deformation within a chip. Background Art

[0002] Traditional chips are processed in a collective manner. During the processing, the chip is deformed due to internal stress. This deformation will act on each chip, causing different damages to the chip. At present, the method to improve this deformation is usually through grinding and heat treatment. However, grinding will cause the chip material to be thinned, resulting in unnecessary over-processing; and in heat treatment, although the deformation is alleviated, it cannot be improved further, so the above two methods are not effective. Summary of the invention

[0003] In view of the deficiencies in the prior art, an embodiment of the present invention provides a method for improving stress deformation in a chip, comprising:

[0004] The chip is sealed between two opposing substrates using UV glue;

[0005] Placing the two substrates with chips in a water tank of an ultrasonic generator; wherein the water tank is filled with deionized water;

[0006] Control the ultrasonic generating device to switch between a first frequency and a second frequency for a first duration; wherein the first frequency is lower than the second frequency;

[0007] Controlling the ultrasonic generating device to switch between a third frequency and a fourth frequency for a second duration; wherein the third frequency is greater than or equal to the second frequency, the third frequency is lower than the fourth frequency, and the second duration is greater than the first duration;

[0008] The two substrates with the chips are taken out, and the UV glue is irradiated with ultraviolet light to separate the chip and the two substrates.

[0009] As a preferred solution, the first frequency is 25.5 KHz, the second frequency is 49.5 KHz, and the first duration is 20 minutes.

[0010] As a preferred solution, the third frequency is 49.5 KHz, the fourth frequency is 97.5 KHz, and the second duration is 30-40 minutes.

[0011] As a preferred solution, at least one of the two substrates has a receiving groove, and the depth of the receiving groove is greater than or equal to the height of the chip; then the chip is sealed between the two opposite substrates using UV glue, specifically including:

[0012] placing the chip between two opposing substrates and accommodating the chip in an accommodating groove of the substrates;

[0013] The gap between the two opposing substrates is sealed with UV glue.

[0014] As a preferred solution, before the chip is sealed between two opposite substrates using UV glue, the method further includes:

[0015] The surface of the chip is covered with an antistatic film.

[0016] As a preferred solution, the resistivity of the antistatic film is 106Ω / sq to 108Ω / sq.

[0017] As a preferred solution, controlling the ultrasonic generating device to switch between the first frequency and the second frequency specifically includes:

[0018] Control the ultrasonic generator to operate at a first frequency for a first period of time;

[0019] Controlling the ultrasonic generator to operate at a second frequency for a second period of time;

[0020] Update the first time period and the second time period, and return to the step of controlling the ultrasonic generating device to operate at the first frequency for the first time period until the operating duration of the ultrasonic generating device is greater than or equal to the first duration.

[0021] As a preferred solution, the updating of the first time period and the second time period specifically includes:

[0022] Determine a first update coefficient corresponding to the current update number based on a preconfigured mapping relationship between the first update coefficient and the update number;

[0023] The first time period is updated by the following formula: 1k '=t 1k +a k ; where t 1k ' represents the first time period after the kth update; t 1k represents the first time period before the kth update; a k represents the first update coefficient at the kth update;

[0024] Determine a second update coefficient corresponding to the current update number based on a preconfigured mapping relationship between the second update coefficient and the update number;

[0025] The second time period is updated by the following formula: 2k '=t 2k +b k ; where t 2k' represents the second time period after the kth update; t 2k represents the second time period before the kth update; b k represents the second update coefficient at the kth update.

[0026] As a preferred solution, controlling the ultrasonic generating device to switch between the third frequency and the fourth frequency specifically includes:

[0027] Controlling the ultrasonic generating device to operate at a third frequency for a third time period;

[0028] Controlling the ultrasonic generating device to operate at a fourth frequency for a fourth time period;

[0029] Update the third time period and the fourth time period, and return to the step of controlling the ultrasonic generating device to operate at the third frequency for the third time period until the operating time length of the ultrasonic generating device is greater than or equal to the second time length.

[0030] As a preferred solution, the updating of the third time period and the fourth time period specifically includes:

[0031] Determine a third update coefficient corresponding to the current update number based on a preconfigured mapping relationship between the third update coefficient and the update number;

[0032] The third time period is updated by the following formula: 3k '=t 3k +c k ; where t 3k ' represents the third time period after the kth update; t 3k represents the third time period before the kth update; c k represents the third update coefficient at the kth update;

[0033] Determine a fourth update coefficient corresponding to the current update number based on a preconfigured mapping relationship between a fourth update coefficient and the update number;

[0034] The fourth time period is updated by the following formula: 4k '=t 4k +d k ; where t 4k ' represents the fourth time period after the kth update; t 4k represents the fourth time period before the kth update; b k represents the fourth update coefficient at the kth update.

[0035] Compared with the prior art, the beneficial effect of the embodiment of the present invention is that: the embodiment of the present invention provides a method for improving stress and deformation in a chip, wherein a chip is sealed between two opposite substrates using UV glue, and then the two substrates with the chip are placed in a water tank filled with deionized water in an ultrasonic generator, and then the ultrasonic generator is controlled to switch between a first frequency and a second frequency for a first duration, wherein the first frequency is lower than the second frequency, and then the ultrasonic generator is controlled to switch between a third frequency and a fourth frequency for a second duration, wherein the third frequency is greater than or equal to the second frequency, the third frequency is lower than the fourth frequency, and the second duration is greater than the first duration, and finally, the two substrates with the chip are taken out, and UV glue is irradiated with ultraviolet light to make the UV glue lose viscosity, thereby separating the chip and the two substrates, so that under two ultrasonic treatments, ultrasonic waves of different frequencies repeatedly impact and vibrate the chip in the water to improve the stress in the chip, reduce the curvature of the chip, and improve the deformation caused by internal stress, and the chip itself does not undergo mechanical and physical processing, so it will not be damaged. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a flow chart of a method for improving stress deformation in a chip in an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] See also Figure 1 As shown, it is a schematic flow chart of a method for improving stress deformation within a chip in an embodiment of the present invention.

[0039] The method for improving stress deformation in a chip according to an embodiment of the present invention includes:

[0040] Step S101, using UV glue to seal the chip between two opposite substrates;

[0041] Step S102, placing the two substrates with chips in a water tank of an ultrasonic generator; wherein the water tank is filled with deionized water;

[0042] Step S103, controlling the ultrasonic generating device to switch between a first frequency and a second frequency for a first duration; wherein the first frequency is lower than the second frequency;

[0043] Step S104, controlling the ultrasonic generating device to switch between the third frequency and the fourth frequency for a second duration; wherein the third frequency is greater than or equal to the second frequency, the third frequency is lower than the fourth frequency, and the second duration is greater than the first duration;

[0044] Step S105 , taking out the two substrates with the chips, and irradiating the UV glue with ultraviolet light to separate the chip and the two substrates.

[0045] In an embodiment of the present invention, UV glue is used to seal the chip between two relative substrates, and then the two substrates with the chips are placed in a water tank filled with deionized water of an ultrasonic generator. Next, the ultrasonic generator is controlled to switch between a first frequency and a second frequency for a first duration, wherein the first frequency is lower than the second frequency. The ultrasonic generator is then controlled to switch between a third frequency and a fourth frequency for a second duration, wherein the third frequency is greater than or equal to the second frequency, the third frequency is lower than the fourth frequency, and the second duration is greater than the first duration. Finally, the two substrates with the chips are taken out, and the UV glue is irradiated with ultraviolet light to make the UV glue lose viscosity, thereby separating the chip and the two substrates. In this way, under two ultrasonic treatments, ultrasonic waves of different frequencies repeatedly impact and vibrate the chip in the water to improve the internal stress of the chip, reduce the curvature of the chip, and improve the deformation caused by internal stress. In addition, the chip itself does not undergo mechanical and physical processing, so it will not be damaged.

[0046] In the embodiment of the present invention, in the step S103, the first frequency is 25.5 KHz, the second frequency is 49.5 KHz, and the first duration is 20 minutes.

[0047] In the specific implementation, two ultrasonic treatments were carried out. In the first ultrasonic treatment, the ultrasonic generator was turned on to switch between the two sound fields of 25.5KHz and 49.5KHz, so that the deionized water was subjected to the oscillation of two different sound fields, thereby causing the chip in the water to be impacted and vibrated. The time was 20 minutes.

[0048] In an embodiment of the present invention, in step S104, the third frequency is 49.5KHz, the fourth frequency is 97.5KHz, and the second duration is 30-40 minutes, for example, 30 minutes, 31 minutes, 32 minutes, 33 minutes, 34 minutes, 35 minutes, 36 minutes, 37 minutes, 38 minutes, 39 minutes, 40 minutes, etc. Of course, the second duration can also be set to other values ​​according to actual use requirements, and no further details are given here. In a specific implementation, in the second ultrasonic treatment, the ultrasonic generator is turned on to switch between the two sound fields of 49.5KHz and 97.5KHz, so that the deionized water is again subjected to the vibration of two different sound fields, so that the chip in the water is again subjected to the impact vibration, and the time is 30-40 minutes.

[0049] In the first ultrasonic treatment, a relatively low frequency is used first, and in the second ultrasonic treatment, a higher frequency is used than the first ultrasonic treatment, so that the stress inside the chip is gradually affected, which is conducive to the stable change of the stress inside the chip.

[0050] In an optional embodiment, at least one of the two substrates has a receiving groove, and the depth of the receiving groove is greater than or equal to the height of the chip; then the step S101 of "using UV glue to seal the chip between the two opposite substrates" specifically includes:

[0051] placing the chip between two opposing substrates and accommodating the chip in an accommodating groove of the substrates;

[0052] The gap between the two opposing substrates is sealed with UV glue.

[0053] In this embodiment, at least one of the two substrates has a receiving groove, i.e., a groove, and the depth of the receiving groove is greater than or equal to the height of the chip. By placing the chip in the receiving groove, the chip can be firmly fixed between the two opposite substrates and will not fall off. In addition, UV glue is used to seal the gap between the two opposite substrates, so that when the chip is subsequently placed in water for ultrasonic treatment, the chip can be sealed and protected, thereby preventing water from entering the chip.

[0054] In an optional implementation, before the step S101 of "sealing the chip between two opposite substrates using UV glue", the method further includes:

[0055] The surface of the chip is covered with an antistatic film. The surface of the chip is wrapped with an antistatic film, which can not only prevent static shock, but also prevent scratches during operation. Specifically, the resistivity of the antistatic film is 106Ω / sq to 108Ω / sq.

[0056] In a specific implementation, if conventional grinding and heat treatment are used to treat chip stress, the curvature caused by chip stress is usually greater than 15 μm, while the curvature of the chip treated by the method provided in the embodiment of the present invention is between 1-3 μm, which effectively reduces the curvature of the chip and thus meets production requirements.

[0057] In an optional implementation, controlling the ultrasonic wave generating device to switch between the first frequency and the second frequency specifically includes:

[0058] Control the ultrasonic generator to operate at a first frequency for a first period of time;

[0059] Controlling the ultrasonic generator to operate at a second frequency for a second period of time;

[0060] Update the first time period and the second time period, and return to the step of controlling the ultrasonic generating device to operate at the first frequency for the first time period until the operating duration of the ultrasonic generating device is greater than or equal to the first duration.

[0061] In this embodiment, the ultrasonic generating device is first controlled to work at a first frequency for a first time period, and then the ultrasonic generating device is controlled to work at a second frequency for a second time period, and then the first time period and the second time period are updated, and the above operation is repeated. In this way, as the ultrasonic oscillation action time changes, the oscillation switching time of the ultrasonic wave on the chip in the water is controlled to change accordingly, so as to change the degree of impact on the chip multiple times, which is beneficial to adapt to the internal stress changes of the chip, and then it is beneficial to reduce the curvature of the chip and improve the deformation caused by internal stress; in addition, by updating the first time period and the second time period multiple times, the impact change degree is updated slowly multiple times, thereby further ensuring that no damage is caused to the chip, thereby playing a role in protecting the chip.

[0062] Exemplarily, the updating the first time period and the second time period specifically includes:

[0063] Determine a first update coefficient corresponding to the current update number based on a preconfigured mapping relationship between the first update coefficient and the update number;

[0064] The first time period is updated by the following formula: 1k '=t 1k +a k ; where t 1k ' represents the first time period after the kth update; t 1k represents the first time period before the kth update; a k represents the first update coefficient at the kth update;

[0065] Determine a second update coefficient corresponding to the current update number based on a preconfigured mapping relationship between the second update coefficient and the update number;

[0066] The second time period is updated by the following formula: 2k '=t 2k +b k ; where t 2k ' represents the second time period after the kth update; t 2k represents the second time period before the kth update; b k represents the second update coefficient at the kth update.

[0067] In the specific implementation, considering that the impact on the chip changes to different degrees each time it is updated, the first update coefficient and the second update coefficient are set, and the mapping relationship between the first update coefficient and the number of updates and the mapping relationship between the second update coefficient and the number of updates are pre-configured. In specific applications, for example, the above mapping relationship can be set in the form of a table. In actual use, the first update coefficient and the second update coefficient are determined by looking up the table, so that the first update coefficient can be quickly obtained each time the first time period is updated, and the second update coefficient can be quickly obtained each time the second time period is updated. In addition, as the number of updates increases each time, the first time period and the second time period are slowly extended to gradually change the impact of the ultrasonic wave on the chip in the water, so that the internal stress of the chip slowly tends to stabilize, thereby further ensuring that no damage is caused to the chip, and playing a role in protecting the chip.

[0068] In an optional implementation, controlling the ultrasonic wave generating device to switch between the third frequency and the fourth frequency specifically includes:

[0069] Controlling the ultrasonic generating device to operate at a third frequency for a third time period;

[0070] Controlling the ultrasonic generating device to operate at a fourth frequency for a fourth time period;

[0071] Update the third time period and the fourth time period, and return to the step of controlling the ultrasonic generating device to operate at the third frequency for the third time period until the operating time length of the ultrasonic generating device is greater than or equal to the second time length.

[0072] In this embodiment, the ultrasonic generating device is first controlled to operate at a third frequency for a third time period, and then the ultrasonic generating device is controlled to operate at a fourth frequency for a fourth time period, and then the third time period and the fourth time period are updated, and the above operation is repeated. In this way, as the ultrasonic oscillation action time changes, the oscillation switching time of the ultrasonic wave on the chip in the water is controlled to change accordingly, so as to change the degree of impact on the chip multiple times, which is beneficial to adapt to the internal stress changes of the chip, and then it is beneficial to reduce the curvature of the chip and improve the deformation caused by internal stress; in addition, by updating the third time period and the fourth time period multiple times and slowly updating the degree of impact change multiple times, it is further ensured that the chip is not damaged, thereby playing a role in protecting the chip.

[0073] Exemplarily, the updating the third time period and the fourth time period specifically includes:

[0074] Determine a third update coefficient corresponding to the current update number based on a preconfigured mapping relationship between the third update coefficient and the update number;

[0075] The third time period is updated by the following formula: 3k '=t 3k +c k ; where t 3k ' represents the third time period after the kth update; t 3k represents the third time period before the kth update; c k represents the third update coefficient at the kth update;

[0076] Determine a fourth update coefficient corresponding to the current update number based on a preconfigured mapping relationship between a fourth update coefficient and the update number;

[0077] The fourth time period is updated by the following formula: 4k '=t 4k +d k ; where t 4k ' represents the fourth time period after the kth update; t 4k represents the fourth time period before the kth update; b k represents the fourth update coefficient at the kth update.

[0078] In the specific implementation, considering that the impact on the chip changes to different degrees each time it is updated, the third update coefficient and the fourth update coefficient are set, and the mapping relationship between the third update coefficient and the number of updates and the mapping relationship between the fourth update coefficient and the number of updates are pre-configured. In specific applications, for example, the above mapping relationship can be set in the form of a table, and the third update coefficient and the fourth update coefficient are determined by looking up the table in actual use, so that the third update coefficient can be quickly obtained each time the third time period is updated, and the fourth update coefficient can be quickly obtained each time the fourth time period is updated. In addition, as the number of updates increases each time, the third time period and the third time period are slowly extended to gradually change the impact of the ultrasonic wave on the chip in the water, so that the internal stress of the chip slowly tends to be stable, thereby further ensuring that no damage is caused to the chip, and playing a role in protecting the chip.

[0079] Compared with the prior art, the beneficial effect of the embodiment of the present invention is that: the embodiment of the present invention provides a method for improving stress and deformation in a chip, wherein a chip is sealed between two opposite substrates using UV glue, and then the two substrates with the chip are placed in a water tank filled with deionized water in an ultrasonic generator, and then the ultrasonic generator is controlled to switch between a first frequency and a second frequency for a first duration, wherein the first frequency is lower than the second frequency, and then the ultrasonic generator is controlled to switch between a third frequency and a fourth frequency for a second duration, wherein the third frequency is greater than or equal to the second frequency, the third frequency is lower than the fourth frequency, and the second duration is greater than the first duration, and finally, the two substrates with the chip are taken out, and UV glue is irradiated with ultraviolet light to make the UV glue lose viscosity, thereby separating the chip and the two substrates, so that under two ultrasonic treatments, ultrasonic waves of different frequencies repeatedly impact and vibrate the chip in the water to improve the stress in the chip, reduce the curvature of the chip, and improve the deformation caused by internal stress, and the chip itself does not undergo mechanical and physical processing, so it will not be damaged.

[0080] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A method for improving stress deformation in a chip, characterized in that: include: The chip is sealed between two opposing substrates using UV glue; Placing the two substrates with chips in a water tank of an ultrasonic generator; wherein the water tank is filled with deionized water; Control the ultrasonic generating device to switch between a first frequency and a second frequency for a first duration; wherein the first frequency is lower than the second frequency; Controlling the ultrasonic generating device to switch between a third frequency and a fourth frequency for a second duration; wherein the third frequency is greater than or equal to the second frequency, the third frequency is lower than the fourth frequency, and the second duration is greater than the first duration; The two substrates with the chips are taken out, and the UV glue is irradiated with ultraviolet light to separate the chip and the two substrates.

2. The method for improving stress deformation in a chip according to claim 1, characterized in that: The first frequency is 25.5 KHz, the second frequency is 49.5 KHz, and the first duration is 20 minutes.

3. The method for improving stress deformation in a chip according to claim 2, characterized in that: The third frequency is 49.5 KHz, the fourth frequency is 97.5 KHz, and the second duration is 30-40 minutes.

4. The method for improving stress deformation in a chip according to claim 1, characterized in that: At least one of the two substrates has a receiving groove, and the depth of the receiving groove is greater than or equal to the height of the chip; the chip is sealed between the two opposite substrates using UV glue, specifically including: placing the chip between two opposing substrates and accommodating the chip in an accommodating groove of the substrates; The gap between the two opposing substrates is sealed with UV glue.

5. The method for improving stress deformation in a chip according to claim 1, characterized in that: Before the chip is sealed between two opposite substrates using UV glue, the method further includes: The surface of the chip is covered with an antistatic film.

6. The method for improving stress deformation in a chip according to claim 5, characterized in that: The resistivity of the antistatic film is 106Ω / sq to 108Ω / sq.

7. The method for improving stress deformation in a chip according to any one of claims 1 to 6, characterized in that: The controlling the ultrasonic generating device to switch between the first frequency and the second frequency specifically includes: Control the ultrasonic generator to operate at a first frequency for a first period of time; Controlling the ultrasonic generator to operate at a second frequency for a second period of time; Update the first time period and the second time period, and return to the step of controlling the ultrasonic generating device to operate at the first frequency for the first time period until the operating duration of the ultrasonic generating device is greater than or equal to the first duration.

8. The method for improving stress deformation in a chip according to claim 7, characterized in that: The updating of the first time period and the second time period specifically includes: Determine a first update coefficient corresponding to the current update number based on a preconfigured mapping relationship between the first update coefficient and the update number; The first time period is updated by the following formula: 1k '=t 1k +a k ; where t 1k ' represents the first time period after the kth update; t 1k represents the first time period before the kth update; a k represents the first update coefficient at the kth update; Determine a second update coefficient corresponding to the current update number based on a preconfigured mapping relationship between the second update coefficient and the update number; The second time period is updated by the following formula: 2k '=t 2k +b k ; where t 2k ' represents the second time period after the kth update; t 2k represents the second time period before the kth update; b k represents the second update coefficient at the kth update.

9. The method for improving stress deformation in a chip according to any one of claims 1 to 6, characterized in that: The controlling the ultrasonic generating device to switch between the third frequency and the fourth frequency specifically includes: Controlling the ultrasonic generating device to operate at a third frequency for a third time period; Controlling the ultrasonic generating device to operate at a fourth frequency for a fourth time period; Update the third time period and the fourth time period, and return to the step of controlling the ultrasonic generating device to operate at the third frequency for the third time period until the operating time length of the ultrasonic generating device is greater than or equal to the second time length.

10. The method for improving stress deformation in a chip according to claim 9, characterized in that: The updating of the third time period and the fourth time period specifically includes: Determine a third update coefficient corresponding to the current update number based on a preconfigured mapping relationship between the third update coefficient and the update number; The third time period is updated by the following formula: 3k '=t 3k +c k ; where t 3k ' represents the third time period after the kth update; t 3k represents the third time period before the kth update; c k represents the third update coefficient at the kth update; Determine a fourth update coefficient corresponding to the current update number based on a preconfigured mapping relationship between a fourth update coefficient and the update number; The fourth time period is updated by the following formula: 4k '=t 4k +d k ; where t 4k ' represents the fourth time period after the kth update; t 4k represents the fourth time period before the kth update; b k represents the fourth update coefficient at the kth update.

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