A light emitting diode chip die bonding apparatus and a die bonding method thereof

Abstract

This invention relates to the field of chip die bonding technology, and discloses a die bonding device and method for light-emitting diode (LED) chips. The method includes: S1: Identifying the phosphor type code of the chip to be die bonded and extracting the corresponding color gamut value and coefficient of thermal expansion; S2: Calculating the target adhesive layer thickness and the height of the first adhesive layer after dispensing; S3: Calculating the first die bonding pressure based on the target adhesive layer thickness and the height of the first adhesive layer, and correcting the first die bonding pressure to obtain a second die bonding pressure; S4: After applying the second die bonding pressure and completing the chip bonding, measuring the height of the second adhesive layer, selecting target curing curve parameters, calculating the first curing temperature based on the color gamut value, and correcting it to obtain the second curing temperature; S5: Performing heating according to the second curing temperature and the target curing curve parameters, and calculating the curing rate. When the curing rate reaches a preset threshold, heating is terminated. This invention solves the technical problems of halved lifespan of high color gamut products and insufficient low-current driving capability caused by traditional fixed-parameter die bonding processes.

Description

Technical Field

[0001] This invention relates to the field of chip die bonding technology, and in particular to a die bonding device and method for light-emitting diode chips. Background Technology

[0002] Die bonding of light-emitting diode (LED) chips is a core process in LED packaging manufacturing, and the quality of the conductive adhesive layer directly affects the electrical performance and lifespan of the chip. As display technology continues to demand higher color gamut coverage, LED products are gradually shifting from traditional silicate and yttrium aluminum garnet phosphor systems to nitride and fluoride high color gamut phosphor systems, increasing the color gamut value from NTSC 65% to over 95%.

[0003] However, existing die-bonding equipment uses uniform dispensing amount, die-bonding pressure, and curing temperature parameters, which cannot adapt to the different requirements of different color gamut phosphors for adhesive layer thickness and contact resistance. This results in high color gamut KSF fluoride phosphor products having a lifespan that is only half that of traditional products due to excessively high contact resistance and concentrated thermal stress during the die-bonding process. Furthermore, the voltage drop is too large under low current driving conditions of 0.2mA, leading to reduced luminous efficiency. Summary of the Invention

[0004] The main objective of this invention is to provide a die bonding device and method for light-emitting diode chips. This invention solves the technical problems of halved lifespan of high color gamut products and insufficient low current driving capability caused by traditional fixed-parameter die bonding processes.

[0005] To achieve the above objectives, the present invention provides a method for die bonding of a light-emitting diode chip, comprising the following steps: S1: Identify the phosphor type code of the chip to be die bonded and extract the corresponding color gamut value and coefficient of thermal expansion; S2: Calculate the target adhesive layer thickness and the height of the first adhesive layer after dispensing based on the color gamut value; S3: Calculate the first die-bonding pressure based on the target adhesive layer thickness and the first adhesive layer height, and correct the first die-bonding pressure based on the thermal expansion coefficient to obtain the second die-bonding pressure; S4: After applying the second die-bonding pressure to complete the patch application, measure the height of the second adhesive layer, select the target curing curve parameters according to the height of the second adhesive layer, calculate the first curing temperature according to the color gamut value, and correct it to obtain the second curing temperature; S5: Perform heating according to the second curing temperature and the target curing curve parameters and calculate the curing rate. When the curing rate reaches the preset threshold, terminate the heating.

[0006] Optionally, in a first implementation of the first aspect of the present invention, step S1 includes: S11: Scan the identification information on the substrate of the chip to be die-bonded, and read the phosphor type code corresponding to the chip to be die-bonded; S12: Match the phosphor type code with the silicate phosphor type, yttrium aluminum garnet phosphor type, nitride phosphor type and fluoride phosphor type stored in the preset database to determine the target phosphor type corresponding to the chip to be bonded; S13: Extract the color gamut value and thermal expansion coefficient corresponding to the target phosphor type from the preset database.

[0007] Optionally, in a second implementation of the first aspect of the present invention, step S2 includes: S21: Subtract the first product of the color gamut value and the preset resistance coefficient from the preset reference resistance value to obtain the maximum permissible contact resistance; S22: Obtain the resistivity of the conductive adhesive and the contact area of ​​the chip to be bonded; S23: Divide the second product of the maximum permissible contact resistance and the contact area by the resistivity of the conductive adhesive to obtain the target adhesive layer thickness; S24: Calculate the amount of adhesive applied based on the target adhesive layer thickness and calculate the height of the first adhesive layer after application.

[0008] Optionally, in a third implementation of the first aspect of the present invention, step S21 includes: S211: Multiply the color gamut value by the preset resistance coefficient to obtain a first product, and use the first product as the resistance adjustment amount; S212: Subtract the resistance adjustment amount from the preset reference resistance value to obtain the maximum allowable contact resistance.

[0009] Optionally, in a fourth implementation of the first aspect of the present invention, step S24 includes: S241: Calculate the adhesive layer volume based on the target adhesive layer thickness and the chip edge length of the chip to be bonded, and multiply the adhesive layer volume by the conductive adhesive density to obtain the dispensing amount; S242: Calculate the height of the first adhesive layer formed by the natural diffusion of conductive adhesive on the substrate surface after dispensing, based on the amount of adhesive dispensed and the chip side length.

[0010] Optionally, in a fifth implementation of the first aspect of the present invention, step S3 includes: S31: Calculate the thickness ratio of the target adhesive layer thickness to the height of the first adhesive layer and take the natural logarithm to obtain the logarithmic result. Divide the negative value of the logarithmic result by the preset adhesive layer compression coefficient to obtain the first solidification pressure. S32: Calculate the difference between the coefficient of thermal expansion and the reference coefficient of thermal expansion, and divide the difference by the reference coefficient of thermal expansion to obtain the thermal expansion deviation ratio; S33: Multiply the first die-bonding pressure by the thermal expansion deviation ratio to obtain the second die-bonding pressure.

[0011] Optionally, in a sixth implementation of the first aspect of the present invention, step S4 includes: S41: After applying the second die-bonding pressure to complete the patch application, measure the height of the second adhesive layer and compare the height of the second adhesive layer with a preset thickness threshold. When the height of the second adhesive layer is less than or equal to the preset thickness threshold, select the target curing curve parameter as the fast curing curve parameter. When the height of the second adhesive layer is greater than the preset thickness threshold, select the target curing curve parameter as the slow curing curve parameter. S42: The first curing temperature is obtained by multiplying the temperature difference between the preset temperature reference value and the color gamut value by the preset temperature coefficient, and the main curing temperature in the target curing curve parameters is compared with the first curing temperature and the second curing temperature is selected.

[0012] Optionally, in a seventh implementation of the first aspect of the present invention, step S42 includes: S421: Subtract the color gamut value from the preset temperature reference value to obtain the temperature difference value, multiply the temperature difference value by the preset temperature coefficient to obtain the temperature adjustment amount, and add the temperature adjustment amount to the preset reference temperature value to obtain the first curing temperature. S422: Compare the main curing temperature in the target curing curve parameters with the first curing temperature, and take the smaller value as the second curing temperature.

[0013] Optionally, in an eighth implementation of the first aspect of the present invention, step S5 includes: S51: The temperature is increased from room temperature to the second curing temperature according to the heating rate in the target curing curve parameters. The current adhesive layer resistance value is measured at preset time intervals. The current adhesive layer resistance value is subtracted from the initial adhesive layer resistance value and then divided by the initial adhesive layer resistance value to obtain the curing rate. S52: Determine whether the curing rate has reached the preset curing rate threshold. When the curing rate reaches the preset curing rate threshold, terminate heating and cool down to room temperature at a preset cooling rate.

[0014] The present invention also provides a die bonding apparatus for light-emitting diode chips, comprising: The identification module is used to identify the phosphor type code of the chip to be die bonded and extract the corresponding color gamut value and coefficient of thermal expansion. The height calculation module is used to calculate the target adhesive layer thickness and the height of the first adhesive layer after dispensing based on the color gamut value. The pressure calculation module is used to calculate the first die-bonding pressure based on the target adhesive layer thickness and the first adhesive layer height, and to correct the first die-bonding pressure based on the thermal expansion coefficient to obtain the second die-bonding pressure. The selection module is used to measure the height of the second adhesive layer after applying the second die-bonding pressure to complete the patch application, select the target curing curve parameters according to the height of the second adhesive layer, calculate the first curing temperature according to the color gamut value, and correct it to obtain the second curing temperature. The heating module is used to perform heating according to the second curing temperature and the target curing curve parameters and calculate the curing rate. When the curing rate reaches a preset threshold, the heating is terminated.

[0015] In summary, this invention establishes a quantitative calculation relationship between the phosphor gamut value and the parameters of the three-stage die-bonding process. In the first stage, the maximum allowable contact resistance is calculated based on the gamut value, and the target adhesive layer thickness is derived in reverse, ensuring that the voltage drop of products with different gamuts meets design requirements under low-current driving conditions. In the second stage, the initial die-bonding pressure is calculated using an adhesive layer compression model and corrected based on the phosphor's thermal expansion coefficient, reserving space for thermal stress release to avoid interface cracking. In the third stage, fast or slow curing curve parameters are selected based on the actual adhesive layer thickness, and the curing endpoint temperature is corrected based on the gamut value, reducing the risk of thermal damage to high-gamut phosphors. This invention solves the technical problems of halved lifespan and insufficient low-current driving capability of high-gamut products caused by traditional fixed-parameter die-bonding processes, keeping the contact resistance variation coefficient of products with different gamut types within a reasonable range, maintaining stable thermal resistance, and ensuring consistent curing degree. Through precise matching of phosphor type and process parameters, the consistency of electrical and optical performance of LED products with different gamuts in mass production is ensured. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the die bonding method for a light-emitting diode chip in one embodiment of the present invention; Figure 2 This is a comparison diagram of the contact resistance of products with different color gamut types in one embodiment of the present invention; Figure 3 This is a schematic diagram of the curing temperature curve in one embodiment of the present invention; Figure 4 This is a schematic diagram of the adhesive layer resistance decay curve in one embodiment of the present invention; Figure 5 This is a block diagram of a die bonding device for a light-emitting diode chip according to one embodiment of the present invention.

[0017] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0019] Reference Figure 1 This embodiment provides a die bonding method for a light-emitting diode chip, including the following steps: S1: Identify the phosphor type code of the chip to be die bonded and extract the corresponding color gamut value and coefficient of thermal expansion; The system utilizes hardware modules capable of automatically identifying chip substrate markings, such as QR code scanners or RFID readers, to non-contactly read the markings printed or embedded on the substrate after the chip is loaded onto the die-bonding equipment. It then extracts the phosphor type code from the markings. The equipment compares this phosphor type code with records of four phosphor types in a pre-set database. This database contains four standard phosphor types: silicate, yttrium aluminum garnet, nitride, and fluoride. Each type has a pre-set unique coding rule and physical property parameter fields. Upon successful comparison, the target phosphor type for the chip to be die-bonded is determined. Based on this target phosphor type, the corresponding color gamut value and coefficient of thermal expansion are retrieved from the database. The color gamut value represents the phosphor's color coverage under the NTSC standard, while the coefficient of thermal expansion characterizes the material's sensitivity to dimensional changes in a thermal environment.

[0020] Figure 2 This chart compares the contact resistance of products with different color gamut types. The horizontal axis represents the four phosphor types (silicate phosphor, yttrium aluminum garnet phosphor, nitride phosphor, and fluoride phosphor), and the vertical axis represents the contact resistance value (in ohms). Each group contains two bars: the lined bars represent the fixed-parameter die-bonding method (using a uniform dispensing amount of 0.08mg, die-bonding pressure of 15N, and curing temperature of 150℃), and the black-filled bars represent the color gamut adaptive parameter control method (dynamically adjusting the dispensing amount, die-bonding pressure, and curing temperature according to the phosphor color gamut type). The error bars at the top of the bars represent the standard deviation range of the contact resistance, reflecting the batch consistency level. The black dashed line above each group is the maximum allowable contact resistance threshold calculated based on low current drive requirements for that color gamut type. As shown in the figure, the contact resistance of the high color gamut product of fluoride phosphor reaches 2.10±0.45Ω under the fixed parameter crystal bonding method (exceeding the threshold of 1.69Ω), while the color gamut adaptive three-stage parameter control method reduces it to 1.68±0.09Ω (meeting the standard), and the error range of all products is reduced. This invention significantly improves batch consistency while ensuring that the contact resistance meets the standard.

[0021] Figure 3The graph shows the curing temperature curve, with the horizontal axis representing curing time (min) and the vertical axis representing temperature (°C). The solid line represents the slow curing curve of the fluoride phosphor (heating rate 1.5°C / min, main curing temperature 138.5°C), and the dashed line represents the fast curing curve of the silicate phosphor (heating rate 3°C / min, main curing temperature 160°C), reflecting the feature of this invention that selects curing parameters according to the differences in phosphor color gamut and adhesive layer thickness.

[0022] Figure 4 The graph shows the decay curve of the adhesive layer resistance, with the horizontal axis representing curing time (min) and the vertical axis representing adhesive layer resistance (Ω). The solid and dashed lines represent the exponential decay of the resistance of the fluoride phosphor and silicate phosphor products over time, respectively. The black dots mark the termination point when the curing rate reaches 95%. The resistance of the KSF product drops to 27Ω after 85 minutes, and the resistance of the silicate phosphor product drops to 30Ω after 50 minutes. The vertical black dashed line indicates the curing termination point, demonstrating the adaptive control feature of this invention that dynamically determines the curing endpoint by real-time monitoring of the resistance value.

[0023] S2: Calculate the target adhesive layer thickness and the height of the first adhesive layer after dispensing based on the color gamut value; Specifically, a functional mapping relationship is established between the maximum allowable contact resistance and the phosphor gamut value. A set of resistance calculation parameters is preset, including a reference resistance value and a resistivity. For example, the maximum contact resistance expression derived under the conditions of a reference voltage of 3.0V, a current of 0.2mA, and a contact voltage drop not exceeding 5% of the forward voltage drop is set as "reference resistance minus the product of the gamut value and the resistivity". That is, the maximum allowable contact resistance value for this type of phosphor chip is calculated by subtracting the product of the gamut value and the preset resistivity (e.g., 0.015) from the preset reference resistance value (e.g., 3.0Ω). The resistivity parameters of the conductive adhesive stored internally in the device (e.g., 2×10⁻⁶) are then called. -4 (Ω·cm), and combined with the effective contact area of ​​the chip body in the bonding area (e.g., 1mm × 1mm, which is 0.01cm). 2 The adhesive layer thickness H = R × A / ρ is obtained by transforming the resistance formula R = ρ × L / A, where L represents the conductive path length (i.e., adhesive layer thickness), R is the maximum contact resistance, ρ is the resistivity of the conductive adhesive, and A is the contact area. The target adhesive layer thickness is calculated by dividing the product of the maximum contact resistance and the contact area by the resistivity of the conductive adhesive. This target thickness reflects the chip's tolerance range for contact resistance under low current drive and provides a constraint boundary for dispensing control. Based on the target thickness and the chip's bottom surface dimension D (i.e., the side length of the chip's bottom surface), the volume is calculated using the formula V = π·(D / 2). 2• H calculates the required volume of conductive adhesive and converts it into a mass value based on the density of the conductive adhesive to achieve quantitative control of the dispensing amount. Considering the minimum resolution of the dispensing equipment, an up-rounding operation is performed to obtain the actual dispensing amount, and the height of the first adhesive layer formed by the natural expansion of the adhesive on the substrate surface after dispensing is calculated. Based on the hemispherical volume model, its geometric height is calculated in reverse, thereby completing the coupled estimation of dispensing thickness and initial adhesive height.

[0024] S3: Calculate the first die bonding pressure based on the target adhesive layer thickness and the first adhesive layer height, and correct the first die bonding pressure based on the coefficient of thermal expansion to obtain the second die bonding pressure; It should be noted that, based on the target adhesive layer thickness H and the first adhesive layer height H1, the thickness compression ratio is calculated. H is divided by H1 to obtain the compression ratio, and then the natural logarithm of the compression ratio is taken to form the logarithmic result ln(H / H1). Since H is less than H1, the logarithmic result is negative. The absolute value of this negative value is divided by the preset adhesive layer compression coefficient k, where k is an empirically set positive parameter in reciprocal units of Newtons (N). -1 The first solidification pressure P1 is obtained by multiplying the first solidification pressure P1 by the reference thermal expansion coefficient α0. The difference Δα = α - α0 is calculated, and the difference is divided by the reference thermal expansion coefficient α0 to obtain the thermal expansion deviation ratio ε = Δα / α0. The thermal expansion deviation ratio measures the relative difference between the thermal expansion response of the target phosphor material and the reference material. To introduce a pre-stress relief mechanism during the solidification stage, the first solidification pressure P1 is multiplied by the thermal expansion deviation ratio ε, and then multiplied by an adjustment factor, such as 0.5, to form the corrected pressure drop ΔP = P1 × ε × 0.5. Subtracting ΔP from P1 yields the second solidification pressure P2, i.e., P2 = P1 × (1 - 0.5 × ε). The modified second die bonding pressure P2 is written into the die bonding controller to drive the chip placement action.

[0025] S4: After applying the second die-bonding pressure to complete the patch application, measure the height of the second adhesive layer, select the target curing curve parameters based on the height of the second adhesive layer, calculate the first curing temperature based on the color gamut value, and correct it to obtain the second curing temperature; Specifically, after the second die-bonding pressure bonding operation is completed, the actual forming thickness of the conductive adhesive layer after pressing is measured in real time using a laser displacement sensor, i.e., the second adhesive layer height H2. The second adhesive layer height value is compared with a preset thickness threshold H0, where H0 reflects the critical level of the adhesive layer's sensitivity to internal and external temperature gradients during thermal curing. For high-viscosity, high-color-gamut phosphor products, it is set at around 7.0 μm. When the judgment result shows that H2 is less than or equal to H0, the chip structure is considered to have a high tolerance for thermal stress. Therefore, the rapid curing curve parameters are selected as the target curing curve, including a faster heating rate v1, a higher main curing temperature T1, and a shorter holding time t1. When H2 is greater than H0, it indicates that the adhesive layer is too thick, which is prone to uneven temperature distribution and thermal stress concentration during heating. Therefore, the slow curing curve parameter group is switched as the target curing scheme, characterized by a lower heating rate v2, a milder main curing temperature T2, and a longer holding time t2, in order to reduce the accumulation of internal stress in the thick adhesive layer. The correction calculation for the first curing temperature is based on the fluorescent pink threshold N, using the formula T3 = T_ref + k × (N_ref) N), where T_ref is the preset curing temperature reference value (e.g., 140℃), N_ref is the color gamut reference value (e.g., 80), and k is the temperature adjustment coefficient (e.g., 0.2). By multiplying the color gamut deviation by the coefficient and then weighting it with the reference temperature, the first curing temperature T3 is obtained. The first curing temperature reflects the difference in curing temperature tolerance of different phosphor types in terms of thermosensitivity. Comparing the main curing temperatures T1 or T2 with T3 in the current target curing curve parameters, the smaller value between the two is selected as the final second curing temperature T_final used for heating, i.e., T_final = min(T1, T3) or T_final = min(T2, T3).

[0026] S5: Perform heating according to the second curing temperature and target curing curve parameters and calculate the curing rate. When the curing rate reaches the preset threshold, terminate heating.

[0027] Specifically, the temperature control process is initiated based on the target curing curve parameters, and the temperature is linearly increased from the initial room temperature at a rate v defined in the curve parameters until the second curing temperature T_final is reached. During the temperature rise and subsequent heat preservation process, the resistance value R(t) of the conductive adhesive layer is collected at preset time intervals t (e.g., every 5 minutes) using an integrated impedance test probe. Simultaneously, the initial resistance value R0 is recorded at t=0 minutes, which is located in the high-resistance range where the silver particles are not yet fully conductive in the semi-cured state. Based on the curing rate calculation formula η(t) = [R0 - R(t)] / R0, the current resistance value is subtracted from the initial resistance value and then divided by the initial resistance value to obtain the current curing rate η(t). The curing rate reflects the degree of conductive path formation of the silver filler particles in the conductive adhesive, thus indirectly quantifying the progress of the curing process. As the temperature gradually rises and the holding time continues, the curing rate η(t) gradually increases. The current curing rate is continuously compared with a preset curing rate threshold (e.g., 0.95). When η(t) is determined to be greater than or equal to the preset curing rate threshold, the adhesive layer is considered to have met the set cross-linking molding quality requirements. At this point, the heating operation is terminated, and the system switches to cooling mode to stabilize the encapsulation structure. During the cooling phase, a fixed cooling rate (e.g., 0.5℃ / min) is used to control the temperature to smoothly drop from T_final to room temperature. Parameters such as the final curing rate η_final, the termination time t_stop, and the final resistance R_final are continuously recorded and written into the quality traceability database.

[0028] In one example, step S1 includes: S11: Scan the identification information on the substrate of the chip to be die bonded and read the phosphor type code corresponding to the chip to be die bonded; S12: Match the phosphor type code with the silicate phosphor type, yttrium aluminum garnet phosphor type, nitride phosphor type and fluoride phosphor type stored in the preset database to determine the target phosphor type corresponding to the chip to be bonded; S13: Extract the color gamut value and thermal expansion coefficient corresponding to the target phosphor type from the preset database.

[0029] In this example, an image recognition module or an RFID module is deployed at the loading or positioning station of the die bonding equipment. The image recognition module is used to parse two-dimensional visual identifiers such as QR codes and DataMatrix, while the RFID module is used to read RFID tag information embedded in the chip substrate or wafer carrier. The extracted information includes a set of phosphor type codes written by the upstream process system. The phosphor type code serves as the primary key index between the chip batch and its physical characteristics, with a predefined unified data format and field structure. After the recognition operation is completed, the read phosphor type code is written to an internal registered variable. The type matching logic is then initiated, comparing the read phosphor type code with a set of standard phosphor types built into the equipment control system or an independent process database. The set of standard phosphor types includes four typical representative phosphor types: silicate phosphor, yttrium aluminum garnet phosphor, nitride phosphor, and fluoride phosphor. Each type has a unique pre-defined code identifier field in the database for the matching operation. A hash search or index matching mechanism is used to find a record of the type that matches the current code, thereby identifying it as the target phosphor type and locking the data row corresponding to that record. After the matching operation is completed, two parameters are extracted from the record. The first is the color gamut value, expressed as a percentage of NTSC color gamut coverage, for example, 67.5% for silicate, 70.0% for yttrium aluminum garnet, 76.0% for nitride, and 87.5% for fluoride, which reflects the color saturation of the phosphor's emission. The second is the coefficient of thermal expansion, expressed as a linear scaling factor per Kelvin (e.g., ×10⁻⁶). -6 The coefficient of thermal expansion (C / K) is used to characterize the sensitivity of a material to dimensional changes under heating conditions; for example, the coefficient of thermal expansion of fluoride phosphors is 8.7 × 10⁻⁶. -6 / K, while nitrides are only 3.1×10 -6 / K. The color gamut value and thermal expansion coefficient are assigned to the color gamut value variable N and thermal expansion coefficient variable α in the control register, respectively, and then transmitted to the die bonding parameter calculation module via the bus interface.

[0030] In one example, step S2 includes: S21: Subtract the first product of the color gamut value and the preset resistance coefficient from the preset reference resistance value to obtain the maximum allowable contact resistance; S22: Obtain the resistivity of the conductive adhesive and the contact area of ​​the chip to be bonded; S23: Divide the second product of the maximum permissible contact resistance and the contact area by the resistivity of the conductive adhesive to obtain the target adhesive layer thickness; S24: Calculate the amount of adhesive applied based on the target adhesive layer thickness and calculate the height of the first adhesive layer after application.

[0031] In this example, based on the phosphor gamut value N and a preset resistance parameter model, the maximum permissible contact resistance R_max corresponding to the current phosphor type is calculated by subtracting the product of the gamut value N and the resistivity coefficient K1 from the reference resistance value R0. That is, R_max = R0. K1×N. The calculation formula is based on the tolerance constraints of LED chips on contact resistance under low current drive (e.g., 0.2mA) and limited voltage drop range (e.g., not exceeding 5% of the forward voltage drop). Essentially, it transforms the characteristic that higher color gamut phosphor products correspond to lower luminous efficiency into more stringent requirements for electrical contact loss. The resistivity ρ of the currently used conductive adhesive is extracted from the database or die-bonding material parameter table, where ρ represents the impedance of the conductive adhesive to current per unit length and unit cross-sectional area, in Ω·cm. Simultaneously, the contact area A between the bottom of the chip and the substrate is obtained based on the chip process drawings or data provided by the identification module; for example, a typical 1mm×1mm chip corresponds to A=0.01cm. 2 According to the modified form of the resistance formula R = ρ × L / A, L = R × A / ρ, the target adhesive layer thickness H_target is calculated by multiplying the maximum allowable contact resistance R_max by the contact area A and then dividing by the resistivity ρ of the conductive adhesive. H_target actually represents the maximum allowable conductive path length determined by the physical properties of the conductive adhesive, while ensuring the constraint of R_max. Using the target thickness H_target as the boundary of the adhesive space, and combining it with the chip bottom diameter D, the volume of the adhesive is calculated according to the formula V = π·(D / 2). 2 The theoretical dispensing volume V is calculated using H_target. Multiplying the theoretical dispensing volume by the conductive adhesive density yields the corresponding mass, i.e., the required dispensing amount m. Since actual dispensing devices have a minimum dispensing unit (e.g., 0.005 mg), m is rounded up and converted to a standardized dispensing command value. The initial adhesive layer height H1, naturally formed after dispensing, is derived based on the dispensing volume and chip diffusion model. This initial adhesive layer height is calculated using an approximate hemispherical expansion model, specifically using the hemispherical volume formula V = (2 / 3)·π·r. 2 Given the volume and diffusion radius r = D / 2 in H1, solve for H1 to obtain the geometric thickness of the colloid in the unpressurized state after dispensing.

[0032] The process includes a dynamic compensation step for the initial pressure value after dispensing amount correction, following steps S24 and S3: S25: Based on the dispensing amount and chip edge length corrected by rounding up in step S241, the actual adhesive layer volume corresponding to the corrected dispensing amount is calculated in reverse. The actual adhesive layer volume is divided by the chip contact area to obtain the corrected first adhesive layer height. S26: The thickness deviation between the corrected first adhesive layer height and the target adhesive layer thickness in step S23 is calculated, and it is determined whether the thickness deviation is greater than a preset deviation threshold. S27: When the thickness deviation is greater than the preset deviation threshold, the target adhesive layer thickness is divided by the corrected first adhesive layer height to obtain the corrected thickness ratio. The natural logarithm of the corrected thickness ratio is taken to obtain the corrected logarithm value. The negative value of the corrected logarithm value is divided by the preset adhesive layer compression coefficient to obtain the compensated die bonding pressure. S28: The pressure deviation between the compensated die bonding pressure and the reference die bonding pressure is calculated. The pressure deviation value is multiplied by the preset pressure compensation coefficient to obtain the initial pressure compensation amount. The initial pressure compensation amount is transferred to step S31 as the correction reference for the first die bonding pressure.

[0033] In one example, step S21 includes: S211: Multiply the color gamut value by the preset resistance coefficient to obtain the first product, and use the first product as the resistance adjustment amount; S212: Subtract the resistance adjustment amount from the preset reference resistance value to obtain the maximum allowable contact resistance.

[0034] In this example, based on the color gamut value N in the process parameter register, the color gamut value is expressed as a percentage under the NTSC standard, reflecting the luminous color coverage capability of the phosphor material used in the current chip, and also indirectly characterizing its luminous efficiency and thermal sensitivity. A preset resistance coefficient K is retrieved. This preset resistance coefficient is a scaling factor obtained from an empirical model or large-scale regression analysis, used to convert the color gamut value into a corresponding resistance adjustment. Phosphor materials with higher color gamuts are associated with lower luminous efficiency and stricter electrical contact energy consumption constraints, thus requiring smaller tolerances in resistance control. Multiplying the color gamut value N by the resistance coefficient K yields the first product ΔR, i.e., ΔR = K × N. This product is the resistance adjustment, used to dynamically correct the reference resistance value. A preset reference resistance value R0 is retrieved from the parameter register. This preset reference resistance value is the upper limit derived from the maximum total voltage drop that the chip can withstand under a low current drive condition of 0.2mA, for example, 3.0Ω is taken as a typical value. Subtracting the resistance adjustment ΔR from the reference resistance value R0, i.e., R_max = R0, gives R_max = R0. ΔR yields the maximum permissible contact resistance R_max for the current color gamut type.

[0035] The process includes a contact resistance dynamic threshold compensation step based on luminous efficiency differences before step S21: S201: Extract the luminous efficiency value corresponding to the target phosphor type from a preset database, and calculate the efficiency deviation ratio between the luminous efficiency value and the reference luminous efficiency value; S202: Calculate the input power of the chip during operation based on the preset low current drive current value and the chip forward voltage drop, and multiply the input power by the efficiency deviation ratio to obtain the power loss compensation amount; S203: Calculate the resistance compensation value corresponding to the power loss based on the power loss compensation amount and the low current drive current value, and determine whether the efficiency deviation ratio is less than zero; S204: When the efficiency deviation ratio is less than zero, confirm... S205: When the target phosphor type is determined to be low-efficiency type, the product of the resistance compensation value and the first compensation weight coefficient is subtracted from the preset resistivity to obtain the corrected resistivity; S206: When the efficiency deviation ratio is greater than or equal to zero, the target phosphor type is determined to be high-efficiency type. The product of the resistance compensation value and the second compensation weight coefficient is subtracted from the preset resistivity to obtain the corrected resistivity, wherein the value range of the first compensation weight coefficient is 0.15 to 0.25, and the value range of the second compensation weight coefficient is 0.05 to 0.10; S207: The corrected resistivity is used to replace the preset resistivity in step S21 for subsequent calculation of the maximum allowable contact resistance.

[0036] In one example, step S24 includes: S241: Calculate the adhesive layer volume based on the target adhesive layer thickness and the chip edge length of the chip to be bonded, and multiply the adhesive layer volume by the conductive adhesive density to obtain the dispensing amount; S242: Calculate the height of the first adhesive layer formed by the natural diffusion of conductive adhesive on the substrate surface after dispensing, based on the amount of adhesive dispensed and the chip edge length.

[0037] In this example, the target adhesive layer thickness H is a parameter derived by combining the resistivity of the conductive adhesive and the chip contact area, under the constraint of satisfying the maximum allowable contact resistance. This parameter is used to determine the length of the vertical conduction path of the conductive adhesive within the chip electrode region. The side length D of the chip to be bonded is read; the side length is on the order of 1.0 mm, which is 0.1 cm. It is assumed that the distribution area of ​​the conductive adhesive is consistent with the bottom surface area of ​​the chip; that is, the adhesive coverage area model is constructed with the chip side length as a reference. The geometric calculation formula based on the adhesive layer volume is V = π·(D / 2). 2 ·H, substituting half the chip side length D as the adhesive layer radius into the calculation, and combining this with the target adhesive layer thickness H, calculate the theoretical adhesive layer volume V after dispensing. Then, call the density parameter ρ_m corresponding to the conductive adhesive from the materials database, in grams per cubic centimeter (g / cm³). 3The volume V of the obtained adhesive layer is multiplied by the density ρ_m to calculate the required dispensing mass m = V × ρ_m, which is the actual dispensing amount. The mass value m is rounded up to the nearest controllable unit of measurement and converted into a dispensing control command that the equipment can recognize. The initial height H1 of the first adhesive layer formed under the natural diffusion state of the conductive adhesive without pressure is estimated in reverse. The initial height of the first adhesive layer is limited by factors such as dispensing volume, chip area, and adhesive surface tension, and is approximated using a hemispherical diffusion model. The hemispherical volume formula V = (2 / 3)·π·r 2 Based on H1, given the volume V and radius r = D / 2, derive H1 = (3·V) / (2·π·r) in reverse. 2 Substitute the calculated volume into the equation and combine it with the specific value of the chip side length D to obtain the geometric height H1 of the adhesive layer in its natural state.

[0038] In one example, step S3 includes: S31: Calculate the thickness ratio of the target adhesive layer thickness to the height of the first adhesive layer and take the natural logarithm to obtain the logarithmic result. Divide the negative value of the logarithmic result by the preset adhesive layer compression coefficient to obtain the first solidification pressure. S32: Calculate the difference between the coefficient of thermal expansion and the reference coefficient of thermal expansion, and divide the difference by the reference coefficient of thermal expansion to obtain the thermal expansion deviation ratio; S33: Multiply the first solidification pressure by the thermal expansion deviation ratio to obtain the second solidification pressure.

[0039] In this example, the target thickness H is calculated as a ratio to the first adhesive layer height H1, yielding the thickness compression ratio H / H1. The natural logarithm of this ratio, ln(H / H1), is then taken. Since H is less than H1, this logarithmic value is negative; its absolute value is then calculated. A preset adhesive layer compression coefficient k is then used. This coefficient is an empirical parameter obtained through experimental fitting based on the thickness variation behavior of the conductive adhesive material under quasi-static compression conditions, and its unit is N. -1 This describes the relative thickness shrinkage rate of the adhesive layer under unit pressure. Dividing the absolute value of the logarithmic result by the compressibility factor k, the basic die-bonding pressure P1 required to complete the shrinkage from H1 to H under conditions without thermal compensation correction is calculated, i.e., P1 = -ln(H / H1) / k. The basic die-bonding pressure value is the minimum loading strength required to achieve the target thickness under ideal conditions. Based on the phosphor's thermal expansion coefficient α, it is compared with the reference thermal expansion coefficient α0 of the standard material; the difference between the two is Δα = α α0 characterizes the strain deviation capability of the phosphor material used relative to the reference value during temperature changes. Dividing the difference Δα by the reference coefficient α0 yields the thermal expansion deviation ratio ε = Δα / α0. The thermal expansion deviation ratio reflects the uncertainty intensity of the potential dimensional change of the adhesive layer under thermal load. By multiplying the first die-bonding pressure P1 by the thermal expansion deviation ratio ε, and then by an adjustable scaling factor (such as 0.5), a compensation term ΔP is constructed, i.e., ΔP = P1 × ε × 0.5. The compensation term is used to deduct a portion of the pressure from the original calculation to reserve space for deformation of the adhesive layer during thermal expansion. Subtracting the compensation amount ΔP from the first die-bonding pressure P1 yields the second die-bonding pressure P2, i.e., P2 = P1 × (1 0.5 × ε). The corrected pressure value P2 is written into the die bonding execution module to drive the actual bonding operation.

[0040] The step between steps S32 and S33 includes a nonlinear mapping step based on the pressure correction coefficient of the phosphor's thermal sensitivity: S321: Extract the thermal sensitivity temperature threshold corresponding to the target phosphor type from a preset database, and calculate the temperature sensitivity deviation between the thermal sensitivity temperature threshold and the reference thermal sensitivity temperature; S322: Determine whether the thermal expansion deviation ratio is greater than a first preset deviation threshold. When the thermal expansion deviation ratio is greater than the first preset deviation threshold, determine that the target phosphor type is a high thermal expansion type. When the thermal expansion deviation ratio is less than or equal to the first preset deviation threshold, determine that the target phosphor type is a low thermal expansion type; S323: When the target phosphor type is a high thermal expansion type... When the target phosphor is of low thermal expansion type, the product of thermal expansion deviation ratio and first nonlinear compensation coefficient is subtracted from the first reference correction coefficient, and then the product of temperature sensitivity deviation and second nonlinear compensation coefficient is subtracted to obtain the high thermal expansion pressure correction coefficient; S324: When the target phosphor is of low thermal expansion type, the product of thermal expansion deviation ratio and third nonlinear compensation coefficient is subtracted from the second reference correction coefficient to obtain the low thermal expansion pressure correction coefficient; S325: The first solidification pressure is multiplied by the corresponding pressure correction coefficient to obtain the second solidification pressure, wherein the value range of the high thermal expansion pressure correction coefficient is 0.60 to 0.75, and the value range of the low thermal expansion pressure correction coefficient is 0.85 to 0.95.

[0041] In one example, step S4 includes: S41: After applying the second die-bonding pressure to complete the patch application, measure the height of the second adhesive layer and compare it with the preset thickness threshold. When the height of the second adhesive layer is less than or equal to the preset thickness threshold, select the target curing curve parameter as the fast curing curve parameter. When the height of the second adhesive layer is greater than the preset thickness threshold, select the target curing curve parameter as the slow curing curve parameter. S42: The first curing temperature is obtained by multiplying the temperature difference between the preset temperature reference value and the color gamut value by the preset temperature coefficient, and then comparing the main curing temperature in the target curing curve parameters with the first curing temperature and selecting the second curing temperature.

[0042] In this example, after the second die-bonding pressure bonding operation is completed, the forming thickness of the conductive adhesive layer in its current state is measured non-contactly using a laser displacement sensor module. This measurement obtains the height H2 of the second adhesive layer after bonding. The height of the second adhesive layer reflects the final geometric thickness formed by the shrinkage of the conductive adhesive from its naturally diffused state to its compressed state under the action of die-bonding pressure P2. After the measurement, the height value H2 is compared with a pre-set thickness threshold in the control system. This thickness threshold is used to classify the thermal stress resistance of the conductive adhesive layer during the curing process; for example, it is empirically set to approximately 7.0 μm. If the result is that H2 is less than or equal to the thickness threshold, it indicates that the chip has a thin adhesive layer, a short thermal path, and a small temperature gradient, which can tolerate a faster heating rate and a higher master curing temperature. Therefore, the target curing curve parameters are set to a fast curing curve scheme, which includes a higher heating rate (e.g., 3.0℃ / min), a higher master curing temperature (e.g., 160℃), and a shorter holding time (e.g., 40min) to improve die bonding efficiency. If H2 is greater than the thickness threshold, it is determined that the adhesive layer is a thick adhesive layer structure, which is prone to uneven internal and external thermal expansion during high-temperature rapid heating, thereby causing interface stress accumulation and the risk of curing layer delamination. Therefore, the target curing curve parameters are switched to a slow curing curve scheme, using a lower heating rate (e.g., 1.5℃ / min), a lower master curing temperature (e.g., 145℃), and a longer holding time (e.g., 60min) to achieve the slow distribution of thermal stress and the steady-state formation of the conductive network. After selecting the curve scheme, the main curing temperature adjustment requirement caused by the color gamut parameter in terms of thermosensitive temperature control is calculated by calling the phosphor pink gamut value N stored in the die bonding parameter register. A preset reference temperature value T_ref (e.g., 140℃) and a reference color gamut value N_ref (e.g., 80℃) are set, and the difference ΔN between N_ref and the current color gamut value N is calculated as ΔN = N_ref. Multiply N by the temperature adjustment coefficient k (e.g., 0.2), and then add it to T_ref to obtain the first curing temperature T1, i.e., T1 = T_ref + k × (N_ref) N) Dynamic compensation is achieved by using phosphors with higher color gamut and stronger thermal sensitivity to correspond to lower temperature tolerance. The first curing temperature T1 is compared with the preset main curing temperature T2 in the target curing curve parameters, and the smaller value of the two is selected as the second curing temperature T_final for temperature control execution, in order to prevent problems such as conductive path failure and surface cracks caused by phosphor pyrolysis or rapid cross-linking of colloids.

[0043] The process of selecting the target curing curve parameters in step S41 includes a multi-parameter weighted coupling decision step: S411: Calculate the thickness deviation between the second adhesive layer height and the preset thickness threshold, and divide the thickness deviation by the preset thickness threshold to obtain a normalized thickness deviation coefficient; S412: Extract the heat-sensitive temperature threshold corresponding to the target phosphor type from the preset database, and calculate the temperature sensitivity coefficient between the heat-sensitive temperature threshold and the reference heat-sensitive temperature; S413: Calculate the pressure deviation between the second die-bonding pressure and the reference die-bonding pressure, and divide the pressure deviation by the reference die-bonding pressure to obtain a normalized pressure deviation coefficient; S414: Multiply the normalized thickness deviation coefficient by the first weighting coefficient, add the second weighting coefficient multiplied by the temperature sensitivity coefficient, and add the third weighting coefficient multiplied by the... Normalize the pressure deviation coefficient to obtain the comprehensive score value of the curing curve, where the first weight coefficient is 0.50, the second weight coefficient is 0.35, and the third weight coefficient is 0.15; S415: Determine the relationship between the comprehensive score value of the curing curve and the preset score threshold. When the comprehensive score value of the curing curve is greater than the preset score threshold, select the slow curing curve parameter; when the comprehensive score value of the curing curve is less than or equal to the preset score threshold, select the fast curing curve parameter; S416: Fine-tune the heating rate in the selected curing curve parameter according to the comprehensive score value of the curing curve. Multiply the reference heating rate by the heating rate adjustment coefficient to obtain the final heating rate, where the heating rate adjustment coefficient is equal to 1 minus the product of the comprehensive score value of the curing curve and the preset adjustment sensitivity coefficient.

[0044] In one example, step S42 includes: S421: Subtract the color gamut value from the preset temperature reference value to obtain the temperature difference value. Multiply the temperature difference value by the preset temperature coefficient to obtain the temperature adjustment amount. Add the temperature adjustment amount to the preset reference temperature value to obtain the first curing temperature. S422: Compare the main curing temperature and the first curing temperature in the target curing curve parameters, and take the smaller value as the second curing temperature.

[0045] In this example, based on the identified phosphor gamut value N, and retrieving the preset temperature reference value N0 and temperature adjustment coefficient k, the gamut deviation calculation logic is executed. Specifically, the current gamut value N is subtracted from the preset temperature reference value N0 to obtain the gamut temperature difference ΔN. This difference reflects the degree of deviation between the current phosphor material and the reference material in terms of luminous color gamut, indicating their difference in temperature sensitivity. The gamut temperature difference ΔN is multiplied by the preset temperature coefficient k to calculate the temperature adjustment amount ΔT, which is used to dynamically correct the master curing temperature setting to match the higher requirements of high-gamut phosphors for thermally sensitive boundaries. The preset reference curing temperature T0 is retrieved and set to 140℃. The temperature reference value T0 is added to the temperature adjustment amount ΔT to calculate the first curing temperature T1, where T1 = T0 + k × (N0) N), the first curing temperature represents the thermal compatibility target temperature calculated based on color gamut differences, used to ensure the curing uniformity and structural integrity of the conductive adhesive under different phosphor conditions. Based on the target curing curve parameter set, the defined master curing temperature T2 is extracted, and T2 is compared with the first curing temperature T1. The smaller value between the two is selected as the second curing temperature T_final for actual thermal control execution, i.e., T_final = min(T1, T2).

[0046] In this embodiment, after step S4 and before step S5, a segmented impedance monitoring and pressure application step for adhesive layer shrinkage compensation during curing is also included: S401: After the chip is mounted in step S4 and before the curing heating is started, the initial contact impedance between the chip and the substrate is measured using an impedance test probe and recorded as the reference contact impedance; S402: The curing heating program is started, and the temperature is increased from room temperature according to the heating rate in the target curing curve parameters. During the heating process, the current contact impedance is measured every first preset time interval, and the current contact impedance and the corresponding current temperature value are recorded; S403: The resistance of the current contact impedance relative to the reference contact impedance is calculated. The impedance change rate is used to determine the trend of the impedance change rate. When the impedance change rate is negative for three consecutive measurements, the adhesive layer is determined to be in the thermal expansion stage. When the impedance change rate changes from negative to positive for three consecutive measurements, the adhesive layer is determined to be changing from expansion to shrinkage. S404: Record the moment when the impedance change rate changes from negative to positive as the starting moment of adhesive layer shrinkage. Record the temperature value corresponding to this moment as the shrinkage initiation temperature. Extract the theoretical shrinkage initiation temperature corresponding to the target phosphor type from the preset database and calculate the temperature deviation between the shrinkage initiation temperature and the theoretical shrinkage initiation temperature. S405: Calculate the theoretical curing shrinkage amount based on the height of the second adhesive layer and multiply the second adhesive layer height by... The theoretical curing shrinkage is obtained using a preset adhesive layer shrinkage rate. The preset adhesive layer shrinkage rate is 0.08 when the second adhesive layer height is less than or equal to 7 micrometers, and 0.12 when the second adhesive layer height is greater than 7 micrometers. S406: Calculate the additional pressure based on the theoretical curing shrinkage and temperature deviation. Divide the theoretical curing shrinkage by the preset pressure-thickness response coefficient to obtain the baseline additional pressure. When the absolute value of the temperature deviation is greater than the preset temperature deviation threshold, multiply the baseline additional pressure by the temperature deviation correction coefficient to obtain the additional pressure. The temperature deviation correction coefficient is equal to 1 plus the temperature deviation divided by the theoretical shrinkage initiation temperature. S40 7: At the moment when the adhesive layer shrinks, apply additional pressure to the chip through the pressure actuator, and maintain the additional pressure until the curing temperature reaches the second curing temperature. During the additional pressure process, continue to monitor the current contact impedance at the second preset time interval; S408: Calculate the deviation between the current contact impedance after the additional pressure and the target contact resistance calculated based on the color gamut value in step S2. When the absolute value of the deviation is less than the preset contact resistance deviation threshold, confirm that the additional pressure is effective, and continue to execute the curing procedure in step S5. When the absolute value of the deviation is greater than or equal to the preset contact resistance deviation threshold, finely adjust the additional pressure according to the positive or negative direction of the deviation value.

[0047] In one example, step S5 includes: S51: Heat from room temperature to the second curing temperature according to the heating rate in the target curing curve parameters. Measure the current adhesive layer resistance value at preset intervals. Subtract the current adhesive layer resistance value from the initial adhesive layer resistance value and then divide by the initial adhesive layer resistance value to obtain the curing rate. S52: Determine whether the curing rate has reached the preset curing rate threshold. When the curing rate reaches the preset curing rate threshold, stop heating and cool down to room temperature at the preset cooling rate.

[0048] In this example, the temperature control program is initiated, and the temperature is gradually increased linearly from a room temperature starting value (e.g., 25°C) at a rate v defined in the curing curve parameters until the set second curing temperature T_final is reached. During the heating and holding process, the configured resistance acquisition module applies a low-amplitude detection current to the conductive adhesive layer at fixed time intervals t (e.g., 5 minutes) and measures its instantaneous resistance value R(t). Simultaneously, at t=0 minutes, the initial resistance value R0 is recorded. R0 represents the high resistance range of the adhesive layer in the semi-cured state, characterizing the structural feature of the conductive channels not yet formed. The measured R(t) and R0 are compared periodically, and the curing rate calculation formula η(t) = [R0] is called. The curing rate is calculated at each sampling time point using the formula R(t) / R0. This formula is based on the physical law that silver filler particles in the conductive adhesive gradually form a conductive network under the influence of a thermal field, leading to a decrease in overall resistance. This reflects the real-time evolution of the curing process. As curing time progresses, R(t) gradually decreases, while η(t) gradually increases. The system continuously monitors whether η(t) reaches a preset curing rate threshold (e.g., 95%). When η(t) ≥ the curing rate threshold is detected at a certain moment, the heating is immediately terminated, the heat source output is stopped, and the cooling process is initiated. During the cooling phase, a preset cooling rate (e.g., 0.5℃ / min) is used to control the temperature to gradually decrease until it returns to room temperature, ensuring a stable temperature gradient within the cured structure to avoid thermal shock or adhesive layer cracking caused by rapid cooling. Simultaneously, the curing termination time, the last measured resistance value, and the final curing rate are recorded and written into the die bonding traceability database for production quality statistics and packaging performance verification.

[0049] The process of step S51 also includes a step of predicting the degree of curing based on the resistance decay rate and dynamically adjusting the temperature: S511: Within the first three preset time intervals after the curing heating starts, record the current adhesive layer resistance value three times, and mark them as the first resistance value, the second resistance value, and the third resistance value, respectively; S512: Subtract the second resistance value from the first resistance value to obtain the first resistance decrease, subtract the third resistance value from the second resistance value to obtain the second resistance decrease, and divide the second resistance decrease by the first resistance decrease to obtain the resistance decay acceleration ratio; S513: Calculate the current curing progress based on the initial adhesive layer resistance value and the third resistance value, subtract the current curing progress from the preset curing rate threshold to obtain the remaining curing progress, and calculate the remaining curing progress based on the second resistance decrease and the resistance decay acceleration ratio. S514: Establish a resistance decay rate model, divide the remaining curing progress by the average decay rate of the resistance decay rate model to obtain the predicted remaining curing time; S515: Compare the predicted remaining curing time with the preset heat preservation time in the target curing curve parameters. When the predicted remaining curing time is greater than the preset heat preservation time and the deviation exceeds the first time threshold, decrease the second curing temperature by the first temperature adjustment amount. When the predicted remaining curing time is less than the preset heat preservation time and the deviation exceeds the second time threshold, increase the second curing temperature by the second temperature adjustment amount; S516: Continue to perform curing heating according to the adjusted second curing temperature, and update the resistance decay rate model and the predicted remaining curing time every preset time until the curing rate reaches the preset curing rate threshold.

[0050] In this embodiment, the execution process of steps S2 to S5 also includes a full-process parameter deviation accumulation tracking and linkage compensation step: S101: After step S23 is executed, the calculated target adhesive layer thickness is recorded as the first target parameter. After step S242 is executed, the actual first adhesive layer height is measured as the first actual parameter, and the first stage deviation between the first actual parameter and the first target parameter is calculated; S102: It is determined whether the absolute value of the first stage deviation is greater than the first preset deviation threshold. When the absolute value of the first stage deviation is greater than the first preset deviation threshold, the first stage deviation compensation coefficient is calculated. The first stage deviation compensation coefficient is obtained by adding 1 to the first stage deviation and dividing by the first target parameter; S103: When step S31 is executed, the calculation result of the first die-bonding pressure is corrected by the first stage deviation compensation coefficient. Specifically, the first die-bonding pressure calculated in step S31 is multiplied by the first stage deviation compensation coefficient to obtain the first die-bonding pressure after deviation compensation; S104: After step S33 is executed, the calculated second die-bonding pressure is recorded as the second target parameter. When the first die-bonding pressure is applied... After die bonding is completed, the actual bonding pressure is measured by a pressure sensor as the second actual parameter, and the second-stage deviation between the second actual parameter and the second target parameter is calculated; S105: Determine whether the absolute value of the second-stage deviation is greater than the second preset deviation threshold. When the absolute value of the second-stage deviation is greater than the second preset deviation threshold, calculate the second-stage deviation compensation coefficient. Use the weighted sum of the first-stage deviation and the second-stage deviation as the cumulative deviation, where the weight of the first-stage deviation is 0.40 and the weight of the second-stage deviation is 0.60; S106: Compensate and correct the first curing temperature in step S42 according to the cumulative deviation. When the cumulative deviation is positive, it indicates that the actual parameter is greater than the target parameter, and the first curing temperature is reduced by the first temperature compensation amount. When the cumulative deviation is negative, it indicates that the actual parameter is less than the target parameter, and the first curing temperature is increased by the second temperature compensation amount. The first temperature compensation amount is equal to the absolute value of the cumulative deviation multiplied by the first temperature compensation coefficient, and the second temperature compensation amount is equal to the absolute value of the cumulative deviation multiplied by the second temperature compensation coefficient.

[0051] Reference Figure 5 This embodiment provides a die bonding device for light-emitting diode chips, including: Identification module 1 is used to identify the phosphor type code of the chip to be die bonded and extract the corresponding color gamut value and coefficient of thermal expansion; Height calculation module 2 is used to calculate the target adhesive layer thickness and the height of the first adhesive layer after dispensing based on the color gamut value; The pressure calculation module 3 is used to calculate the first die bonding pressure based on the target adhesive layer thickness and the first adhesive layer height, and to correct the first die bonding pressure based on the coefficient of thermal expansion to obtain the second die bonding pressure. Select module 4 to measure the height of the second adhesive layer after applying the second die-bonding pressure to complete the patch application, select the target curing curve parameters based on the height of the second adhesive layer, calculate the first curing temperature based on the color gamut value and correct it to obtain the second curing temperature; Heating module 5 is used to perform heating according to the second curing temperature and target curing curve parameters and calculate the curing rate. When the curing rate reaches the preset threshold, heating is terminated.

[0052] In this embodiment, the specific implementation of each unit in the above device embodiment is described in the above method embodiment, and will not be repeated here.

[0053] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, apparatus, article, or method that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, apparatus, article, or method. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, apparatus, article, or method that includes that element.

[0054] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for die bonding of a light emitting diode chip, characterized by, include: S1: Identify the phosphor type code of the chip to be die bonded and extract the corresponding color gamut value and coefficient of thermal expansion; S2: Calculate the target adhesive layer thickness and the height of the first adhesive layer after dispensing based on the color gamut value; S3: Calculate the first die-bonding pressure based on the target adhesive layer thickness and the first adhesive layer height, and correct the first die-bonding pressure based on the thermal expansion coefficient to obtain the second die-bonding pressure; S4: After applying the second die-bonding pressure to complete the patch application, measure the height of the second adhesive layer, select the target curing curve parameters according to the height of the second adhesive layer, calculate the first curing temperature according to the color gamut value, and correct it to obtain the second curing temperature; S5: Perform heating according to the second curing temperature and the target curing curve parameters and calculate the curing rate. When the curing rate reaches the preset threshold, terminate the heating.

2. The method of claim 1, wherein the adhesive is applied to the LED chip by a dispensing method. Step S1 includes: S11: Scan the identification information on the substrate of the chip to be die-bonded, and read the phosphor type code corresponding to the chip to be die-bonded; S12: Match the phosphor type code with the silicate phosphor type, yttrium aluminum garnet phosphor type, nitride phosphor type and fluoride phosphor type stored in the preset database to determine the target phosphor type corresponding to the chip to be bonded; S13: Extract the color gamut value and thermal expansion coefficient corresponding to the target phosphor type from the preset database.

3. The LED chip die bonding method according to claim 1, wherein Step S2 includes: S21: Subtract the first product of the color gamut value and the preset resistance coefficient from the preset reference resistance value to obtain the maximum permissible contact resistance; S22: Obtain the resistivity of the conductive adhesive and the contact area of ​​the chip to be bonded; S23: Divide the second product of the maximum permissible contact resistance and the contact area by the resistivity of the conductive adhesive to obtain the target adhesive layer thickness; S24: Calculate the amount of adhesive applied based on the target adhesive layer thickness and calculate the height of the first adhesive layer after application.

4. The method of claim 3, wherein the adhesive is applied to the LED chip by dispensing the adhesive onto the LED chip. Step S21 includes: S211: Multiply the color gamut value by the preset resistance coefficient to obtain a first product, and use the first product as the resistance adjustment amount; S212: Subtract the resistance adjustment amount from the preset reference resistance value to obtain the maximum allowable contact resistance.

5. The method of claim 4, wherein the adhesive is applied to the LED chip by dispensing the adhesive onto the LED chip. Step S24 includes: S241: Calculate the adhesive layer volume based on the target adhesive layer thickness and the chip edge length of the chip to be bonded, and multiply the adhesive layer volume by the conductive adhesive density to obtain the dispensing amount; S242: Calculate the height of the first adhesive layer formed by the natural diffusion of conductive adhesive on the substrate surface after dispensing, based on the amount of adhesive dispensed and the chip side length.

6. The die bonding method for a light-emitting diode chip according to claim 1, characterized in that, Step S3 includes: S31: Calculate the thickness ratio of the target adhesive layer thickness to the height of the first adhesive layer and take the natural logarithm to obtain the logarithmic result. Divide the negative value of the logarithmic result by the preset adhesive layer compression coefficient to obtain the first solidification pressure. S32: Calculate the difference between the coefficient of thermal expansion and the reference coefficient of thermal expansion, and divide the difference by the reference coefficient of thermal expansion to obtain the thermal expansion deviation ratio; S33: Multiply the first die-bonding pressure by the thermal expansion deviation ratio to obtain the second die-bonding pressure.

7. The die bonding method for a light-emitting diode chip according to claim 1, characterized in that, Step S4 includes: S41: After applying the second die-bonding pressure to complete the patch application, measure the height of the second adhesive layer and compare the height of the second adhesive layer with a preset thickness threshold. When the height of the second adhesive layer is less than or equal to the preset thickness threshold, select the target curing curve parameter as the fast curing curve parameter. When the height of the second adhesive layer is greater than the preset thickness threshold, select the target curing curve parameter as the slow curing curve parameter. S42: The first curing temperature is obtained by multiplying the temperature difference between the preset temperature reference value and the color gamut value by the preset temperature coefficient, and the main curing temperature in the target curing curve parameters is compared with the first curing temperature and the second curing temperature is selected.

8. The die bonding method for a light-emitting diode chip according to claim 7, characterized in that, Step S42 includes: S421: Subtract the color gamut value from the preset temperature reference value to obtain the temperature difference value, multiply the temperature difference value by the preset temperature coefficient to obtain the temperature adjustment amount, and add the temperature adjustment amount to the preset reference temperature value to obtain the first curing temperature. S422: Compare the main curing temperature in the target curing curve parameters with the first curing temperature, and take the smaller value as the second curing temperature.

9. The die bonding method for a light-emitting diode chip according to claim 1, characterized in that, Step S5 includes: S51: The temperature is increased from room temperature to the second curing temperature according to the heating rate in the target curing curve parameters. The current adhesive layer resistance value is measured at preset time intervals. The current adhesive layer resistance value is subtracted from the initial adhesive layer resistance value and then divided by the initial adhesive layer resistance value to obtain the curing rate. S52: Determine whether the curing rate has reached the preset curing rate threshold. When the curing rate reaches the preset curing rate threshold, terminate heating and cool down to room temperature at a preset cooling rate.

10. A die bonding device for light-emitting diode chips, characterized in that, The steps for implementing the die bonding method for a light-emitting diode chip according to any one of claims 1 to 9 include: The identification module is used to identify the phosphor type code of the chip to be die bonded and extract the corresponding color gamut value and coefficient of thermal expansion. The height calculation module is used to calculate the target adhesive layer thickness and the height of the first adhesive layer after dispensing based on the color gamut value. The pressure calculation module is used to calculate the first die-bonding pressure based on the target adhesive layer thickness and the first adhesive layer height, and to correct the first die-bonding pressure based on the thermal expansion coefficient to obtain the second die-bonding pressure. The selection module is used to measure the height of the second adhesive layer after applying the second die-bonding pressure to complete the patch application, select the target curing curve parameters according to the height of the second adhesive layer, calculate the first curing temperature according to the color gamut value, and correct it to obtain the second curing temperature. The heating module is used to perform heating according to the second curing temperature and the target curing curve parameters and calculate the curing rate. When the curing rate reaches a preset threshold, the heating is terminated.

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