CN107221509B

CN107221509B - Method for identifying position information of single product on QFN frame

Info

Publication number: CN107221509B
Application number: CN201710493427.3A
Authority: CN
Inventors: 王玲; 彭林源
Original assignee: Nanjing Microbonding Semiconductor Co ltd
Current assignee: Nanjing Microbonding Semiconductor Co ltd
Priority date: 2017-06-20
Filing date: 2017-06-20
Publication date: 2020-10-13
Anticipated expiration: 2037-06-20
Also published as: CN107221509A

Abstract

The invention discloses a method for identifying position information of a single product on a QFN frame, which comprises the following steps: arranging products on the QFN lead frame; etching an array matrix of points on a single product chip base; respectively acquiring the position information of a single product on the frame and the position information of an etching point matrix of a chip base of the single product, corresponding the two kinds of respectively acquired position information, and then canceling the etching point of the single product at the corresponding position of the chip base; and inspecting the array matrix of the chip base points of the single product to obtain an inspection result, namely obtaining the position of the single product on the QFN frame. The invention can realize the experiment of special product position requirements, mainly solves the use problems that a single product can not realize ID identification and can not meet the requirement of commonality or regularity in the production process, improves the traceability of the QFN product in the manufacturing process, has simple operation and low cost, and is worthy of popularization.

Description

Method for identifying position information of single product on QFN frame

Technical Field

The invention relates to the technical field of semiconductor QFN product packaging, in particular to a method for identifying position information of a single product on a QFN frame.

Background

QFN (quad flat no-lead package), one of the surface mount packages, square or rectangular, is now commonly referred to as LCC. QFN is a name prescribed by the japan electronics and mechanical industries. The four sides of the package are provided with electrode contacts, so that the mounting occupied area is small and the height is low. A large area of exposed bonding pads are disposed in the center of the bottom of the package for heat conduction, and electrically conductive bonding pads for electrical connection are disposed around the periphery of the package surrounding the large bonding pads. QFN packages provide excellent electrical performance because they do not have gull-wing leads as do conventional SOIC and TSOP packages, the electrical path between the inner leads and the pads is short, the self-inductance, and the wiring resistance within the package is low. In addition, it provides excellent heat dissipation through the exposed leadframe pad, which has a direct heat dissipation path for dissipating heat within the package. Heat sink pads are typically soldered directly to the circuit board and heat sink vias in the PCB help to spread excess power dissipation into the copper ground plate, thereby absorbing excess heat. QFN packages are small, lightweight, have excellent electrical and thermal properties, and are suitable for any application where size, weight, and performance are required. The QFN package has excellent thermal performance mainly because the package bottom has large area heat dissipation pads, and in order to effectively conduct heat from the chip to the PCB, the bottom of the PCB must be designed with corresponding heat dissipation pads and heat dissipation vias, and the heat dissipation pads provide reliable bonding areas and the vias provide heat dissipation paths. The size of the heat spreader pad is typically matched to at least the component exposed pad, however, the heat spreader pad size needs to be revised in consideration of various other factors, such as avoiding bridging with peripheral pads, etc. The position of a single QFN product on the frame before cutting is identified, the method can be used for identifying the ID of the single product, the use problem of the requirement of commonality or regularity in the production process is solved, and the traceability in the manufacturing process is improved. However, in practical applications, most of the mixed QFN products have no identification, and a few methods for identifying the position information of a single product on the QFN frame after mixing use the same pattern or adopt digital identification, so that the operation difficulty is high, the operation cost is high, and the identification efficiency is low. Therefore, a method for quickly and effectively identifying the position information of a single product on the QFN frame after mixing is lacked.

Disclosure of Invention

The purpose of the invention is as follows: in order to solve the problems in the prior art and identify the position of each single QFN product on the frame, the invention provides a method for identifying the position information of the single product on the QFN frame.

The technical scheme is as follows: a method of identifying positional information for a single product on a QFN frame comprising the steps of:

s1: arranging QFN products on a QFN lead frame, defining a single arrangement matrix for each QFN product, wherein the single arrangement matrixes of different QFN products on the same QFN lead frame are different;

s2: adding etching points on the chip base of a single QFN product to obtain an arrangement matrix of the etching points, wherein the arrangement matrix of the etching points corresponds to the single arrangement matrix of the single FNQ product in the step S1;

s3: respectively acquiring the position information of a single array matrix of the single QFN product on the lead frame in the step S1 and the position information of the array matrix of the point, which is additionally etched, of the single QFN product chip base in the step S2, and corresponding the two kinds of position information acquired respectively; then, eliminating the etching point of the single QFN product to be identified at the corresponding position of the chip base;

s4: and checking the array matrix of the points additionally etched on the chip base of the single QFN product, acquiring a checking result, acquiring the position information of the missing etching points in the array matrix of the points additionally etched on the chip base of the single QFN product, and corresponding the position information of the missing etching points to the position information of the single QFN product on the QFN frame to obtain the position of the single QFN product on the QFN frame.

Preferably, in the step S1, only one element in the entire matrix of the single arrangement matrix is an etching dot.

Preferably, in step S2, the method for increasing the etching point on the chip base of the single QFN product is one of dry etching or wet etching.

Preferably, the method for identifying the position information of the single product on the QFN frame can realize an experiment with special product position requirements.

Preferably, the QFN frame has N rows and M columns of single products, and the arrangement matrix is an N × M matrix.

Has the advantages that: the invention provides a method for identifying position information of a single product on a QFN frame, which adopts a method of adding an etching matrix on a chip base of the QFN product to achieve that all the single QFN products on the same frame have different identification points, the etching matrix arrangement of the chip base of the QFN product is the same as that of the QFN frame, and thus the position of each single QFN product on the frame is identified. The invention can realize an experiment with special product position requirements, so that a single QFN product can still find the position on a frame before cutting after mixing, the use problems that the single product cannot realize ID identification and cannot meet the requirement of commonality or regularity in the production process are mainly solved, and the traceability of the QFN product in the manufacturing process is improved.

Drawings

FIG. 1 is a single array matrix of QFN products on a QFN lead frame;

FIG. 2 is a matrix of dots of increased etching for a single QFN product die pad.

Detailed Description

The invention is further described with reference to the following figures and specific examples.

A method of identifying positional information for a single product on a QFN frame comprising the steps of:

s1: the QFN products on the QFN lead frame are arranged, a single arrangement matrix is defined for each QFN product, the single arrangement matrices of different QFN products on the same QFN lead frame are different, as shown in fig. 1, 5 rows and 8 columns of single products 2 are shared on the QFN lead frame 1, and one single product 2 corresponds to one single arrangement matrix. The permutation matrix is designed as a 5 × 8 matrix. Only one element in each matrix of the single arrangement matrix is an etching point, which facilitates subsequent inspection.

S2: adding etched points to the chip base of a single QFN product to obtain an array matrix of the etched points, where the array matrix of the etched points corresponds to the single array matrix of the single QFN product in step S1, and as shown in fig. 2, the etched points are added to the chip base of a first row and a first column of single QFN products 2 at the upper left corner of the QFN frame, and the etched points 3 are first row and first column elements of the array matrix;

The method for increasing the etching point in this embodiment is dry etching, and wet etching may also be used.

The method for identifying the position information of the single product on the QFN frame can realize an experiment with special product position requirements.

In the embodiment, the method for adding the etching matrix on the chip base of the QFN product is adopted to achieve the purpose that all single QFN products on the same QFN frame have different identification points, the etching matrix arrangement of the chip base of the QFN product is the same as the etching matrix arrangement of the frame, so that the position of each single QFN product on the frame is identified, the invention can realize an experiment with the requirement on the position of a special product, the single QFN product can still be found on the frame before cutting after mixing, the use problems that the single product cannot realize ID identification and cannot meet the requirement on commonality or regularity in the production process are mainly solved, the traceability of the QFN product in the manufacturing process is improved, compared with the traditional method, the operation is simple, the cost is low, the quick and accurate positioning of the QFN products in the manufacturing process can be realized, the position following of the QFN products is realized, is worthy of popularization.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.

Claims

1. A method of identifying positional information for a single product on a QFN frame, comprising the steps of:

s1: arranging QFN products on a QFN lead frame, defining a single arrangement matrix for each QFN product, wherein the single arrangement matrixes of different QFN products on the same QFN lead frame are different; only one element in the whole matrix of the single arrangement matrix is an etching point;

s2: adding etching points on the chip base of a single QFN product to obtain an arrangement matrix of the etching points, wherein the arrangement matrix of the etching points corresponds to the single arrangement matrix of the single FNQ product in the step S1; the method for increasing the etching point on the chip base of the single QFN product is one of dry etching or wet etching;

2. The method for identifying the position information of the single product on the QFN frame as claimed in claim 1, wherein the method for identifying the position information of the single product on the QFN frame can realize experiments with special product position requirements.

3. The method of claim 1, wherein the QFN frame has a total of N rows and M columns of the individual products, and the arrangement matrix is an N x M matrix.