Self-adaptive fitting mass production test method for chip power supply trimming module

Abstract

The invention provides a self-adaptive fitting mass production test method for a chip power supply trimming module. The method comprises the following steps: S1, providing a tested power supply chip; s2, verifying a relationship between a power module trimming code value and a power output value of the tested chip; s3, calculating a power supply module trimming step length of the tested chip by using a self-adaptive fitting method formula; s4, converting the trimming step length into a binary trimming code value through an algorithm; and S5, after the trimming code value is burnt into the chip to be trimmed, verification is carried out, and trimming is completed. The method solves the problem of yield loss caused by insufficient trimming precision of the mass production test of the power supply module, reduces the test time, and saves the test cost.

Description

Technical Field

[0001] The invention relates to the field of integrated circuit mass production testing, and in particular to an adaptive fitting and adjustment testing method for a chip power module. Background Art

[0002] Affected by the integrated circuit manufacturing process, the output of the power module inside the chip will have a certain degree of deviation. These deviations need to be calibrated through the trimming test items of ATE (Automatic Test Equipment) to optimize the output accuracy of the power supply and improve the yield of the chip. Due to the increase in the trimming modules inside the chip, the trimming test items occupy more and more test time, and the test cost is also increasing. Current research mostly uses sacrificing trimming accuracy to reduce test time, which is difficult to balance test time and test accuracy. Although the single test time is reduced, the impact of test accuracy on yield is ignored. At the same time, the reduction in test accuracy also affects the performance of the chip. Summary of the invention

[0003] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an adaptive fitting mass production test method for chip power trimming modules, which solves the yield loss caused by insufficient trimming accuracy in mass production testing of power modules, while reducing test time and saving test costs. The specific technical solution is as follows:

[0004] An adaptive fitting mass production test method for a chip power trimming module comprises the following steps:

[0005] S1. Provide a power chip to be tested;

[0006] S2, verifying the relationship between the power module adjustment code value and the power output value of the power chip under test, and finally obtaining the adjustment direction factor direction and the adjustment code value corresponding to the maximum power output value;

[0007] S3, using an adaptive fitting method formula to calculate the trimStep of the power module of the chip under test;

[0008] S4, converting the trimming step length trimStep into a binary trimming code value through an algorithm;

[0009] S5, burning one of the binary adjustment code values ​​output in step S4 into the chip for post-adjustment verification and completing the adjustment.

[0010] Preferably, the chip in step S1 contains a voltage or current related module (power module), and the module needs to be tested and adjusted in mass production to ensure the accuracy of power output.

[0011] Preferably, the adaptive fitting mass production test method for a chip power trimming module, step S2 specifically includes the following steps:

[0012] S21, configuring the initial values ​​of the adjustment code values ​​corresponding to different power modules of the chip;

[0013] If the bit is 4, first configure 0000 to the trim register, and the power module reads the power output value corresponding to the trim code value of 0000 at this time;

[0014] Wherein, a trimming register, a power trimming module and a power module are connected in sequence;

[0015] S22, repeat step S21 to sequentially configure 15 trimming code values ​​from 0001 to 1111 to the trimming register, and read out the corresponding power output value;

[0016] S23, confirm the adjustment direction factor, whether the relationship curve between the adjustment code value and the corresponding output is positively correlated or negatively correlated, and obtain the adjustment code value corresponding to the maximum power output value of 2 m-1 -1.

[0017] Among them, the power output value is displayed by the power module.

[0018] Preferably, the relationship curve obtained in step S23 is a linear relationship.

[0019] Preferably, the adaptive fitting formula of step S3 needs to be configured with the initial value of the power adjustment module with bit m and the adjustment code value 2 m-1 -1, the output values ​​are V(0) and V(2 m-1 -1), so as to use the formula to calculate the adjustment step length step of the single code value of the test item;

[0020]

[0021] Assume that the target adjustment value is Vtarget, borrow the adjustment direction factor direction, and then use the formula

[0022]

[0023] The number of steps between the target value and the initial value can be calculated, which is the trimming step length trimStep.

[0024] Preferably, when the relationship curve between the adjustment code value and the corresponding output is positively correlated, the direction in the formula is directly substituted with 1; when the relationship curve between the adjustment code value and the corresponding output is positively correlated, the direction is directly substituted with -1.

[0025] Preferably, step calculation is performed for each chip so that it can adaptively fit the curve of the current chip and achieve the best adjustment accuracy.

[0026] Preferably, step S3 only needs to configure the register once, and the adjustment code value is 2 m-1 The output value of -1 can be used to calculate the step, which greatly reduces the test time.

[0027] In the prior art, in addition to configuring the adjustment code value 0, all adjustment codes need to be traversed.

[0028] Preferably, the test time of a single trimming test item is independent of the m value and will not increase with the increase of m, but is only related to the configuration timing of the chip itself.

[0029] Preferably, when the trimming step is converted into a binary trimming code value by an algorithm in step S4, the interval of trimStep needs to be determined manually or by software, and the decimal trimming code value trimStepfinal is first calculated by a formula, and finally the decimal is converted into a binary trimming code value.

[0030]

[0031] Preferably, step S5 burns the calculated binary trimming code value into the chip, performs accuracy verification after trimming, and completes the trimming.

[0032] Compared with the prior art, the present invention has the following advantages:

[0033] During mass production testing of the power module, adaptive fitting is performed for each chip to find the optimal adjustment code with high adjustment accuracy.

[0034] For modules with different bit positions, the test time of the adaptive fitting method is the same and will not increase with the increase of bit positions, which greatly reduces the test time and test cost.

[0035] For chips with multiple power modules, during the mass production test development process, there is no need to develop test cases for each module separately, which simplifies the test procedure and shortens the development cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A flowchart of the steps for implementing an adaptive fitting mass production test method for a chip power trimming module according to the present invention;

[0037] Figure 2 A positive correlation diagram between the trimming code and the power output value of the adaptive fitting mass production test method of the chip power trimming module according to the present invention;

[0038] Figure 3This is a negative correlation diagram between the adjustment code and the power output value;

[0039] Figure 4 The figure is a flow chart of the adaptive fitting algorithm of the chip power module according to the present invention. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Reference Figure 1-4 , an adaptive fitting mass production test method for a chip power trimming module, comprising the following steps:

[0042] S1. Provide a power chip to be tested;

[0043] S2. Verify the relationship between the power module adjustment code value and the power output value of the tested power chip;

[0044] S3, using the adaptive fitting method formula to calculate the power module adjustment step size of the chip under test;

[0045] S4, converting the adjustment step length into a binary adjustment code value through an algorithm;

[0046] S5, burning the trimming code value into the chip for trimming and verification, and completing the trimming.

[0047] 1) Provide a power chip to be tested.

[0048] The target output value of one of the power modules of the chip under test is a 1.2V bandgap reference voltage with an accuracy requirement of ±5mV and a 4-bit trimming design.

[0049] 2) Confirm the relationship between the power output value of the power module of the chip under test and the adjustment code value.

[0050] Configure the trim code value of the chip power module. When the bit is 4, first configure 0000 to the trim register, read out the power output value corresponding to the trim code value of 0000 at this time, and record it.

[0051] Furthermore, 15 trimming code values ​​from 0001 to 1111 are sequentially configured to the trimming register, and the corresponding power supply output values ​​are read out and recorded.

[0052] Based on the above adjustment code value and power output value, draw Figure 2 .

[0053] Further integration Figure 2 As shown, the horizontal axis is the decimal adjustment code value, and the vertical axis is the corresponding output reference voltage value. The adjustment direction factor, the adjustment code value and the corresponding output are positively correlated.

[0054] 3) Use the adaptive fitting method formula to calculate the power module adjustment step size of the chip under test;

[0055] Combination Figure 3 Algorithm flow,Furthermore, using the adaptive fitting formula requires configuring the bit,m,in combination with the power module, with m taking 4 and 5 respectively.

[0056] In this embodiment, the value of m is 4.

[0057] The initial value 0 and the adjustment code value 2 of the power adjustment module m-1 The output values ​​corresponding to -1 are V(0) and V(2 m-1 -1), so as to further calculate the adjustment step length step of the single code value of the test item by using the formula.

[0058]

[0059] It is known from the prior art that the adjustment step length is the slope difference between two adjacent code values.

[0060] In this embodiment, the adjustment step length is the slope difference between the adjustment code value corresponding to the maximum power output value and the initial voltage value.

[0061] Vtarget is substituted with 1.2 (when m is 4) and 2.006 (when m is 5) respectively, and the trimming direction factor direction is borrowed. Then the formula can be used to calculate the number of steps between the target value and the initial value, which is the trimming step length trimStep.

[0062]

[0063] like Figure 2 As shown, when the relationship curve between the adjustment code value and the corresponding output when m=4 is positively correlated, direction is directly substituted into 1.

[0064] like Figure 2 As shown, when the correlation is positive, the corresponding adjustment code value when the power output value is the maximum is 2 m-1 -1, which is 7.

[0065] like Figure 3 As shown, when the correlation is negative, the corresponding adjustment code value when the power output value is the maximum is -2 m-1 , that is -8.

[0066] In a preferred embodiment, the step calculation is performed for each chip so that the chip can adaptively fit the curve of the current chip and achieve the best adjustment accuracy.

[0067] In a preferred embodiment, step S3 only needs to configure the register once, and the adjustment code is 2 m -1 The output value of -1 can be used to calculate the step, which greatly reduces the test time.

[0068] The test time of a single trim test item (power module) has nothing to do with the m value and will not increase with the increase of m. It is only related to the configuration timing of the chip itself.

[0069] 4) The adjustment step size is converted into a binary adjustment code value, i.e., the optimal adjustment code value, through an algorithm.

[0070] After calculating trimStep, further use the following formula to calculate trimStepfinal, which is the decimal trim code value, and finally needs to be converted into binary before being burned into the register.

[0071]

[0072] In the decimal trim code value trimStepfinal, the first two piecewise functions have endpoint values ​​2 m-1 -1, by Figure 2 , combined with formula (1) and (2) to obtain.

[0073] The basis of the last two piecewise functions is: Figure 3 , combining formulas (1) and (2), we get its endpoint value -2 m-1 . Figure 3 In the example, the current is the output value of the current module measured by the traversal adjustment code.

[0074] The power module includes a voltage module and a current module.

[0075] Finally, according to the calculated trimStep, the corresponding binary trim code value is burned into the trim register, and the post-trim verification is performed and completed.

[0076] Specifically, performing and completing post-adjustment verification includes the following steps:

[0077] 2 m-1 The binary trim code corresponding to -1 is burned into the trim register. If the voltage value displayed by the power module is 1.2V, it meets the requirements.

[0078] The beneficial effect of the technical solution of the present invention is that during mass production testing of the power module, adaptive fitting is performed for each chip to find the optimal adjustment code with high adjustment accuracy;

[0079] For modules with different bit positions, the test time of the adaptive fitting method is the same and will not increase with the increase of bit positions, which greatly reduces the test time and test cost.

[0080] For chips with multiple power modules, during the mass production test development process, there is no need to develop test cases for each module separately, which simplifies the test procedure and shortens the development cycle.

[0081] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. An adaptive fitting mass production test method for a chip power trimming module, characterized in that: The following steps are involved: S1. Provide a power chip to be tested; S2, verifying the relationship between the adjustment code value and the power output value of the power module of the tested power chip, and finally finding the adjustment direction factor direction and the adjustment code value corresponding to the maximum power output value; S3, calculating the trimming step length trimStep of the power module of the power chip under test based on the trimming direction factor direction and the trimming code value corresponding to the maximum power output value; S4, converting the trimming step length trimStep into a binary trimming code value; S5, burning one of the binary adjustment code values ​​output in step S4 into a chip for adjustment.

2. The adaptive fitting mass production test method for a chip power trimming module as claimed in claim 1, characterized in that: The chip in step S1 contains voltage or current related modules, and the modules need to be tested and adjusted in mass production to ensure the accuracy of power output.

3. The adaptive fitting mass production test method for a chip power trimming module as claimed in claim 1, characterized in that: Step S2 specifically includes the following steps: S21, configuring the initial values ​​of the adjustment code values ​​corresponding to different power modules of the chip; If the bit is 4, first configure 0000 to the trim register, and the power module reads the power output value corresponding to the trim code value of 0000 at this time; S22, repeat step S21 to sequentially configure 15 trimming code values ​​from 0001 to 1111 to the trimming register, and read the corresponding power output value from the power module; S23, according to whether the relationship curve between the adjustment code value and the corresponding output is positively correlated or negatively correlated, confirm the adjustment direction factor, and obtain the adjustment code value corresponding to the maximum power output value of 2 m-1 -1.

4. The adaptive fitting mass production test method for a chip power trimming module as claimed in claim 3, characterized in that: The relationship curve obtained in step S23 is a linear relationship.

5. The adaptive fitting mass production test method for a chip power trimming module as claimed in claim 3, characterized in that: Step S3 specifically includes the following steps: Where step is the adjustment step size of a single adjustment code value of the power module; V(0) - the initial value 0 of the power trim module with bit position m, and the corresponding power output value; V(2 m-1 -1)-The adjustment code value of the power adjustment module with bit position m is 2 m-1 -1, the corresponding power output value; Vtarget-target adjustment value; trimStep - the trim step of the power module; round - rounding function.

6. The adaptive fitting mass production test method for a chip power trimming module as claimed in claim 5, characterized in that: When the relationship curve between the adjustment code value and the corresponding output is positively correlated, direction is 1; when the relationship curve between the adjustment code value and the corresponding output is negatively correlated, direction is -1.

7. An adaptive fitting mass production test method for a chip power trimming module as described in claim 1, characterized in that formulas (1) and (2) are calculated for each chip to adaptively fit the trimming curve of the current chip so that the trimming accuracy can reach the optimal level.

8. The adaptive fitting mass production test method for a chip power trimming module as claimed in claim 5, characterized in that: In addition to the initial value of the adjustment code value, a adjustment code value 2 that needs to be configured is used in step S3 m-1 -1, you can get the step.

9. The adaptive fitting mass production test method for a chip power trimming module as claimed in claim 1, wherein when the trimming step is converted into a binary trimming code value by an algorithm in step S4, it is necessary to determine the interval of trimStep, then calculate the decimal trimming code value trimStepfinal, and finally convert the decimal trimming code value into a binary trimming code value; The decimal adjustment code value obtained in step S4 is:

10. The adaptive fitting mass production test method for a chip power trimming module as claimed in claim 1, wherein step S5 burns one of the binary trimming code values ​​outputted from step S4 into the chip, performs a post-trim accuracy verification and completes the trimming.

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