A front side embossing method for reserving chip circuit pin

Abstract

The present application belongs to the field of nano-imprinting, and particularly relates to a front surface imprinting method for reserving chip circuit pin. The method changes the glass substrate and glue of an imprinting pattern stamp, directly imprints on the whole surface wafer of the chip, and opens the circuit pin of the chip through subsequent processes, so that the chip can be normally used after being cut.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of nanoimprint, and particularly relates to a front surface imprinting method for reserving chip circuit pin. BACKGROUND

[0002] Nanoimprint technology is a new micro-nano processing technology. Through photoresist assistance, micro-nano structures on a template are transferred to a material to be processed. The technology achieves ultra-high resolution through mechanical transfer and is an important processing means in the fields of microelectronics and materials.

[0003] In the prior art, there are two schemes for imprinting lenses on a chip wafer surface, one of which directly performs imprinting, and the other of which first imprints lenses on a glass substrate, then cuts into single dies, and then bonds the single lens with the chip after cutting. Both schemes cannot remove the cured glue on the circuit pin while keeping the overall module thickness low. SUMMARY

[0004] The application provides a front surface imprinting method for reserving chip circuit pins to solve the problem that the prior art is complex and difficult to reserve chip circuit pins.

[0005] To achieve the above purpose, the application provides the following technical solutions.

[0006] A front surface imprinting method for reserving chip circuit pins comprises the following steps.

[0007] Step 1: Perform a photoetching process on a transparent glass substrate to make a chip circuit pin protection pattern on the transparent glass substrate, and obtain a glass substrate with the chip circuit pin protection pattern.

[0008] Step 2: Perform imprinting pattern seal production on the glass substrate with the chip circuit pin protection pattern to obtain a glass substrate with a lens pattern.

[0009] Step 3: Apply glue on a chip wafer.

[0010] Step 4: Press the glass substrate with the lens pattern against the glue on the chip wafer to fill the glue into the pattern area and complete surface imprinting.

[0011] Step 5: Perform ultraviolet curing on the product after surface imprinting under a UV light source.

[0012] Step 6: Separate the glass substrate with the lens pattern from the imprinted lens, and the remaining part is a chip with a lens.

[0013] Step 7: Develop to obtain a chip with a reserved circuit pin.

[0014] Preferably, the photoetching process in the first step includes coating, exposure and development.

[0015] Preferably, the glue in the third step is HR3301 Optical RESIN solvent.

[0016] Preferably, in the fourth step, the glue on the chip wafer is imprinted to the target thickness during the face imprinting.

[0017] Preferably, in the fifth step, the part protected by the glass substrate with lens pattern is not exposed to the UV light source, and the glue does not completely polymerize. The part not protected by the glass substrate with lens pattern is exposed to the UV light source, and the glue forms a lens.

[0018] Preferably, in the seventh step, the development process is specifically as follows: the whole surface of the glue is covered with a liquid medicine, and then cleaned with pure water until the image appears.

[0019] Preferably, the liquid medicine is a tetramethylammonium hydroxide solution.

[0020] Preferably, the tetramethylammonium hydroxide solution has a mass concentration of 5%.

[0021] The present application has the following advantages:

[0022] The pattern of the chip circuit pin protection area is photoetched on the transparent glass substrate, and the glue that does not completely polymerize is removed through the development process, so that the product with reserved chip circuit pins can be obtained. BRIEF DESCRIPTION OF DRAWINGS

[0023] The drawings constituting a part of the specification of the present application are used to provide further understanding of the present application, and the schematic embodiments of the present application and the description thereof are used to explain the present application, and do not constitute improper limitation on the present application. In the drawings:

[0024] Figure 1 It is a flowchart of a face imprinting method for reserving chip circuit pins. DETAILED DESCRIPTION

[0025] The present application will be described in detail below with reference to the drawings and in combination with the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0026] The following detailed description is exemplary description, which is intended to provide further detailed description of the present application. Unless otherwise specified, all technical terms used in the present application have the same meanings as those generally understood by the general technical personnel in the field to which the present application belongs. The terms used in the present application are only used for describing the specific embodiments, and are not intended to limit the exemplary embodiments according to the present application.

[0027] Embodiment 1:

[0028] There are two solutions in the prior art for imprinting lenses on the surface of a chip wafer.

[0029] Solution one: directly imprinting on the chip wafer, which has the disadvantage that the PDA is also covered with the imprinting glue, and the cured glue on the PDA cannot be removed after the glue is UV cured, resulting in the chip being unable to be used.

[0030] Solution two: imprinting lenses on a glass substrate first, then cutting into single dies, and then bonding the single lens with the cut chip, which can ensure that the bonded chip can be normally used, but since the lens is imprinted on the glass substrate, the overall module thickness will be relatively thick.

[0031] Referring to Figure 1 The present application provides a front surface imprinting method for reserving chip circuit pin, specifically comprising:

[0032] Step one, photoetching: first, photoetching process (gluing, exposure, development) is performed on the transparent glass substrate of the imprinting pattern stamp to make the chip circuit pin protection pattern on the transparent glass substrate, as shown in the black part of the schematic diagram.

[0033] Step two, imprinting pattern stamp making: imprinting pattern stamp making is performed on the glass substrate with the protection pattern to form a glass substrate with a lens pattern;

[0034] Step three, dispensing: dispensing glue on the chip wafer; the glue is selected from the Mikes reagent, and the model is HR3303.

[0035] Step four, face type imprinting: using the transparent face type glass substrate with the pattern to press the glue downward, so that the glue fills the pattern area and is imprinted to the target glue thickness, and the face type imprinting is completed;

[0036] Step five, UV curing: the product after face type imprinting is subjected to ultraviolet curing under the UV light source, the part protected by the glass substrate with the lens pattern is not irradiated by the UV light source, and the glue does not completely polymerize. The UV light source can irradiate the place not protected by the glass substrate with the lens pattern, and the glue at this place is polymerized to form a lens;

[0037] Step six, demolding: separating the glass substrate with the lens pattern from the imprinted lens, and the remaining part is a chip with a lens.

[0038] Step seven, developing: the incomplete polymerization reaction glue is removed through developing process, namely using glue removing liquid, such as 5% mass concentration of tetramethylammonium hydroxide solution, spreads on the entire glue surface, soaks for a while, then uses pure water to clean, and the pattern is presented, so that the chip line pin is leaked out, and subsequent operation can be carried out.

[0039] In the operation, the tetramethylammonium hydroxide solution selected is Fuji CD-2060.

[0040] It is to be understood by those skilled in the art that the present application can be implemented by other embodiments without departing from the spirit or essential characteristics thereof. Therefore, the above disclosed embodiments are merely exemplary in all aspects and are not the only ones. All changes within the scope of the present application or within the equivalent scope of the present application are included in the present application.

Claims

1. A method for front-side imprinting of reserved chip circuit pins, characterized in that, Includes the following steps: Step 1: Perform photolithography on a transparent glass substrate to create the pin pattern of the protection chip circuitry on the transparent glass substrate, resulting in a glass substrate with the pin pattern of the protection chip circuitry. Step 2: Imprint a pattern stamp onto a glass substrate with a protective chip circuit pin pattern to obtain a glass substrate with a lens pattern. Step 3: Apply adhesive to the chip wafer; The adhesive is made with HR3301 Optical RESIN solvent; Step 4: Press the adhesive on the chip wafer with a glass substrate featuring a lens pattern, so that the adhesive fills the patterned area and completes the surface imprinting. Step 5: Curing the finished product under a UV light source; The parts protected by the glass substrate with the lens pattern were not exposed to the UV light source, and the adhesive did not fully polymerize; the parts not protected by the glass substrate with the lens pattern were exposed to the UV light source, and the adhesive formed a lens. Step 6: Separate the glass substrate with the lens pattern from the imprinted lens. The remaining part is the chip with the lens. Step 7: Development, to obtain the chip with reserved circuit pins.

2. The method for front-side imprinting of reserved chip circuit pins as described in claim 1, characterized in that, The photolithography process described in the first step includes coating, exposure, and development.

3. The method for front-side imprinting of reserved chip circuit pins as described in claim 1, characterized in that, In the fourth step, during the surface imprinting process, the adhesive on the chip wafer is imprinted to the target adhesive thickness.

4. The method for front-side imprinting of reserved chip circuit pins as described in claim 1, characterized in that, In the seventh step, the development process specifically involves covering the entire adhesive surface with the chemical solution, soaking it, and then rinsing it with pure water until the image appears.

5. The method for front-side imprinting of reserved chip circuit pins as described in claim 4, characterized in that, In step seven, the solution is a tetramethylammonium hydroxide solution.

6. The method for front-side imprinting of reserved chip circuit pins as described in claim 5, characterized in that, The tetramethylammonium hydroxide solution has a mass concentration of 5%.

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