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CN-121985858-A - Chip bonding calibration method and device

CN121985858ACN 121985858 ACN121985858 ACN 121985858ACN-121985858-A

Abstract

The invention relates to the field of semiconductor processing, and discloses a chip bonding calibration method and device, comprising the steps of providing calibration equipment, wherein the calibration equipment comprises a first lens, a second lens and a turnover mechanism, a substrate and a chip are respectively arranged below the first lens and the second lens, and the turnover mechanism is used for turning the chip to the substrate; the method comprises the steps of obtaining global reference coordinates of a substrate and a chip through a first lens and a second lens, controlling a turnover mechanism to turn over and attach the chip to the substrate based on the global reference coordinates to obtain deviation data of the chip, carrying out translation compensation processing on the second lens according to the deviation data, carrying out residual deviation verification on the compensated second lens position to obtain a calibration confirmation result, and effectively eliminating attaching deviation caused by mechanical motion errors, repeated positioning precision limitation and pose change in the turnover process through obtaining the deviation data after attaching and carrying out translation compensation processing on the second lens, so that final alignment precision of the chip and the substrate is improved.

Inventors

  • CHEN XING
  • CHEN DANFENG

Assignees

  • 深圳市鸿芯微组科技有限公司

Dates

Publication Date
20260505
Application Date
20260408

Claims (10)

  1. 1. A method of chip bonding calibration, comprising: Providing calibration equipment, wherein the calibration equipment comprises a first lens, a second lens and a turnover mechanism, a substrate and a chip are respectively arranged below the first lens and the second lens, and the turnover mechanism is used for turning the chip to the substrate; Acquiring global reference coordinates of a substrate and a chip through a first lens and a second lens, and controlling a turnover mechanism to turn and attach the chip to the substrate based on the global reference coordinates to acquire deviation data of the chip; and carrying out translation compensation processing on the second lens according to the deviation data, and carrying out residual deviation verification on the compensated second lens position to obtain a calibration confirmation result.
  2. 2. The method of claim 1, wherein the surface of the substrate and the surface of the chip are provided with alignment marks; The step of obtaining global reference coordinates of the substrate and the chip through the first lens and the second lens comprises the following steps: Collecting alignment mark images of a substrate and a chip respectively through a first lens and a second lens, centering the alignment mark of the first lens and the substrate in sequence according to the alignment mark images, and centering the alignment mark of the second lens and the chip; Acquiring a central pixel coordinate of a substrate alignment mark based on the centered first lens to obtain a substrate reference coordinate; Acquiring a central pixel coordinate of a chip alignment mark based on the centered second lens, and establishing a mapping relation between the acquired initial chip coordinate and a reference coordinate to acquire a coordinate transformation parameter between the lenses; and carrying out initial chip coordinate conversion processing according to the coordinate conversion parameters, and confirming the relative relation between the obtained chip reference coordinates and the substrate reference coordinates to obtain global reference coordinates.
  3. 3. The method for calibrating a die bonding according to claim 1, wherein the step of controlling the flip mechanism to flip and attach the die to the substrate based on the global reference coordinates to obtain the deviation data of the die comprises: the turnover mechanism is controlled to turn the chip 180 degrees around a preset turnover axis to form a chip posture to be attached; According to the global reference coordinates and the gesture of the chip to be attached, the flip mechanism is controlled to temporarily attach the chip to the substrate in an alignment mode, and a composite mark image is obtained; And carrying out coordinate difference processing on the composite marker image, and synthesizing deviation data of the obtained pixel level deviation vector and the global reference coordinate to obtain deviation data of a chip.
  4. 4. The method of claim 1, wherein the step of performing a translational compensation process on the second lens according to the deviation data comprises: Performing physical quantity conversion on the deviation data, and obtaining a lens compensation vector by reversely moving the obtained actual physical displacement on a water plane; Performing closed-loop translational control on a driving mechanism of the second lens according to the lens compensation vector to obtain the actual compensated lens position; Repeatedly reading a position sequence of the actual compensated lens position, and carrying out consistency comparison on the position sequence and a lens compensation vector to obtain a compensation quantity verification result; And carrying out threshold judgment on the compensation quantity verification result and a preset compensation threshold value, re-executing to acquire deviation data of the chip if the compensation quantity verification result exceeds the preset compensation threshold value, and obtaining an effective compensated second lens position if the compensation quantity verification result exceeds the preset compensation threshold value.
  5. 5. The method for chip bonding calibration according to claim 2, wherein the step of verifying the residual deviation of the compensated second lens position to obtain a calibration confirmation result comprises: based on the compensated second lens position, controlling the turnover mechanism to repeatedly turn over and attach the chip to the substrate to obtain a verification composite image; extracting the characteristics of the verification composite image, and respectively carrying out residual pixel deviation calculation on the central pixel coordinates of the alignment marks of the substrate and the chip to obtain a residual deviation vector; Performing physical quantity conversion on the residual deviation vector according to the current optical parameters of the first lens, and performing numerical comparison on the converted physical residual displacement and a preset residual deviation to obtain a deviation judging result; And obtaining the current coordinate of the compensated second lens position, carrying out consistency verification on the current coordinate and the global reference coordinate, and obtaining a calibration confirmation result when the verification result and the deviation judgment result are qualified.
  6. 6. The method for chip bonding calibration according to claim 1, wherein after the step of verifying the residual deviation of the compensated second lens position to obtain the calibration confirmation result, further comprising: Converting the calibration equipment into a production state, centering alignment marks of a production substrate and a production chip on the first lens and the second lens respectively, and controlling a turnover mechanism to turn over and attach the production chip to the production substrate to obtain a bonding completed chip; Detecting alignment deviation of the bonded chips on line, and judging drift trend of the production batch according to the obtained actual bonding deviation vector to obtain a drift trend judging result of the current batch; Repeatedly collecting deviation data for the verification chips randomly selected from the current batch according to the drift trend judging result to obtain a current compensation vector; And comparing the current compensation vector with the compensated second lens position to obtain an updated compensated second lens position.
  7. 7. Chip bonding calibration equipment, characterized in that the chip bonding calibration equipment adopts the chip bonding calibration method according to any one of claims 1 to 6, and comprises a first lens (1), a second lens (2) and a turnover mechanism (3), wherein a first platform assembly (4) is arranged below the first lens (1), a second platform assembly (5) is arranged below the second lens (2), the first platform assembly (4) and the second platform assembly (5) are respectively used for placing a substrate and a chip, the turnover mechanism (3) is arranged between the first platform assembly (4) and the second platform assembly (5), and the turnover mechanism (3) is connected with the second platform assembly (5); The turnover mechanism (3) is used for turning the second platform assembly (5) 180 degrees around a preset turnover axis to the position above the first platform assembly (4) so as to bond the chip to the substrate.
  8. 8. The chip bonding calibration device according to claim 7, further comprising a base (6), wherein the base (6) is connected with a supporting plate (7), two adjusting components (8) distributed in an array are arranged on one side of the supporting plate (7), the two adjusting components (8) are respectively connected with a first lens (1) and a second lens (2), and the first lens (1) and the second lens (2) have the same structure; The adjusting assembly (8) comprises a first adjusting seat (81) and a first adjusting rod (82) which are distributed along a first direction, the first adjusting seat (81) is connected with a second adjusting seat (83) in an L shape in a sliding manner, the first adjusting rod (82) is rotationally connected with the first adjusting seat (81), and the first adjusting rod (82) is in threaded connection with the second adjusting seat (83); The second adjusting seat (83) is rotationally connected with second adjusting rods (84) distributed along a second direction, one side of the second adjusting seat (83) is slidably connected with a sliding block (85), the second adjusting rods (84) are in threaded connection with the sliding block (85), and the sliding block (85) is fixedly connected with the first lens (1) or the second lens (2).
  9. 9. The chip bonding calibration device according to claim 7, wherein the first platform assembly (4) and the second platform assembly (5) have the same structure, the first platform assembly (4) comprises a flat seat (41), a plurality of first flat plates (42) are stacked on the flat seat (41), and an air floating plate (43) and a surface plate (44) are sequentially arranged on the upper end face of the first flat plates (42); the panel (44) is provided with a plurality of fixed air holes (441) distributed in a circumferential array, the air floating plate (43) is provided with cross-shaped distribution air holes (431) corresponding to the fixed air holes (441), and the bottom end of the distribution air holes (431) is provided with connecting air holes (45) penetrating through the first flat plate (42) and the flat plate seat (41); a plurality of parallel air floatation grooves (432) are formed in the bottom end of the air floatation plate (43), a plurality of air floatation channels (46) corresponding to the air floatation grooves (432) are formed in the flat plate seat (41) and the first flat plate (42), and the air floatation channels (46) are distributed in an array mode.
  10. 10. The chip bonding calibration device according to claim 7, wherein the turnover mechanism (3) comprises a turnover seat (31) arranged on the upper end surface of the base (6), the upper end surface of the turnover seat (31) is provided with a transmission assembly (32), and the movable end of the transmission assembly (32) is connected with the second platform assembly (5); The transmission assembly (32) comprises sliding rails (33) distributed along a first direction, the sliding rails (33) are connected with racks (34) in a sliding mode, one side of each sliding rail (33) is provided with an air cylinder (35), the driving end of each air cylinder (35) is fixedly connected with each rack (34), each rack (34) is meshed with a gear (36), each gear (36) is fixedly connected with the corresponding second platform assembly (5) through a transmission shaft (37), a bearing seat (38) for supporting the corresponding transmission shaft (37) is arranged on the upper end face of each overturning seat (31), the bearing seat (38) is connected with the corresponding transmission shaft (37) in a rotating mode, and each bearing seat (38) is provided with a limiting structure for limiting the corresponding transmission shaft (37) to move axially.

Description

Chip bonding calibration method and device Technical Field The invention relates to the field of semiconductor processing, in particular to a chip bonding calibration method and device. Background In the field of chip bonding, as semiconductor devices rapidly progress toward high density, high performance and miniaturization, flip chip bonding technology has become one of the core processes in advanced packaging. The technology realizes shorter electric interconnection paths, lower parasitic parameters and higher I/O density by directly bonding the bumps on the chip with the corresponding bonding pads of the substrate, and is widely applied to high-requirement scenes such as high-bandwidth memories, CMOS image sensors, 3D stacked devices, heterogeneous integration and the like. In order to ensure bonding reliability and electrical performance, accurate alignment and calibration in the bonding process are key links for determining yield and product consistency, and an optical vision system is generally adopted in industry to combine with a precision mechanical motion platform to complete relative position calibration of a chip and a substrate. The existing chip bonding calibration method mainly adopts an upper optical system and a lower optical system to collect images of a chip and a substrate before the chip is turned over so as to identify respective targets and calculate relative deviation, and further control a chip mounting device to finish the turning over and bonding of the chip, however, the chip is easily influenced by mechanical motion errors, repeated positioning precision limitation of the chip mounting device and tiny pose change caused by turning over actions in the turning over process, so that the deviation of the chip relative to the substrate after actual bonding often exceeds an expected range, the deviation is particularly remarkable in the application of fine-pitch salient points (such as the pitch is smaller than 50 mu m) or large-size chips, and the tiny rotation or translation errors can cause dislocation or non-contact of the salient points, so that open circuit, bridging or potential reliability hazards are caused, and the whole precision stability and the production yield of the bonding process are seriously restricted. Therefore, it is necessary to provide a method and a device for calibrating chip bonding, so as to solve the problem that the deviation of the chip bonding device is easy to exceed the expected range. Disclosure of Invention The invention mainly aims to provide a chip bonding calibration method and device, and aims to solve the technical problems in the background technology. The invention adopts the following technical scheme: A chip bonding calibration method and device comprises the following steps: Providing calibration equipment, wherein the calibration equipment comprises a first lens, a second lens and a turnover mechanism, a substrate and a chip are respectively arranged below the first lens and the second lens, and the turnover mechanism is used for turning the chip to the substrate; Acquiring global reference coordinates of a substrate and a chip through a first lens and a second lens, and controlling a turnover mechanism to turn and attach the chip to the substrate based on the global reference coordinates to acquire deviation data of the chip; and carrying out translation compensation processing on the second lens according to the deviation data, and carrying out residual deviation verification on the compensated second lens position to obtain a calibration confirmation result. Further, the surface of the substrate and the surface of the chip are provided with alignment marks; The step of obtaining global reference coordinates of the substrate and the chip through the first lens and the second lens comprises the following steps: Collecting alignment mark images of a substrate and a chip respectively through a first lens and a second lens, centering the alignment mark of the first lens and the substrate in sequence according to the alignment mark images, and centering the alignment mark of the second lens and the chip; Acquiring a central pixel coordinate of a substrate alignment mark based on the centered first lens to obtain a substrate reference coordinate; Acquiring a central pixel coordinate of a chip alignment mark based on the centered second lens, and establishing a mapping relation between the acquired initial chip coordinate and a reference coordinate to acquire a coordinate transformation parameter between the lenses; and carrying out initial chip coordinate conversion processing according to the coordinate conversion parameters, and confirming the relative relation between the obtained chip reference coordinates and the substrate reference coordinates to obtain global reference coordinates. Further, the step of controlling the turnover mechanism to turn over and attach the chip to the substrate based on the global reference coordinate to obta