LCD liquid crystal display module and assembly process control techniques

1 assembly process:
Assembly tool is a hammer and a wrench, they are used to twist the foot frame. Assembly sequence of operation is the first of all the tools and materials in order to put on the table. Secondly, according to the process of the shell card is positioned correctly on the table, such as assembly tooling, according to the requirements on the tooling, pay attention to the direction of the right to housing. The next screen protective film off LCD, with clean paper will clean the electrode, confirm the direction, according to the process card, installed in the casing pressure position alignment framework, zebra, the shell and the circuit board is fixed with a special assembly tools. Pay attention to the frame legs twisted into 450 angle, don't bite board and card disconnection, the frame and PCB plate in parallel with the foot. Finally, the assembled product, from the table down, with protective film, in the rotating disk. Attention to the screen and the screen, the board and the board, so as to avoid the scratch, product assembly to the inspection personnel detection, the unqualified assembly.

2 assembly method:
The purpose is to make each of the electrode assembly and a circuit board corresponding to the one one screen, complete with the electrical properties. But because the screen is not in direct contact with the circuit board, and the conductive rubber strip as the medium, so that the screen and the board can not through the visual correspondence, so that the corresponding electrode can not correspond with each other, resulting in dislocation. The electrode of each screen and circuit board assembly in the process of the corresponding connection is called para, in assembly, mainly through the screen and plate alignment, alignment of shells and plates, to achieve the corresponding with the screen plate assembly. Shell as medium, as the corresponding standard screen and the shell, the alignment in the great role is played. Alignment method of main edge alignment, alignment and positioning pinhole.

(1) the edge position:
A short edge alignment is based on the standard framework on the LCD screen and a circuit board electrode corresponding to the one one, in order to achieve the assembly position, edge alignment refers to alignment mode screen and shell. Since the edge alignment refers to alignment mode screen and the shell, then according to different situations in the screen and the shell of some position in their own way. According to the design requirements of shell, the shell on the basis of different there are many kinds of situations, such as a shell, a symmetric gap gap, shell side foot side direction, all of these can be used as reference in the shell side position, in the description can be called the opening edge and non edge to an opening position, smooth edge para. And the screen edge alignment only opening edge and edge of the seal two kinds, it is often referred to as the opening edge and non edge on the opening position, while the combined description, the combination of the two, such as: the screen edge of the seal at the opening edge of the shell, the edge of the seal in the non screen the opening of the shell side in shell side, the opening screen along the edge. On the basis of some screen alignment mode mentioned above and the matching method, combined with the circuit board and the shell, such as a shell or shell feet two feet as the alignment reference assembly shell. This completes the edge alignment for assembly on the assembly, this way is suitable for wide electrode module.

(2) the pinhole alignment:
The screen assembly and circuit board electrodes of a narrow, such as electrode width 0.35mm, 0.5mm module, on the way to a fine, and the circuit board assembly error of Jian Xiaoping in the relative between the electrodes, an increase in the rate of finished products, reduce consumption, so the method of using pinhole. Pinhole alignment is through careful calculation, in the shell hit the two position alignment benchmark as the screen hole. When assembling the outer edge of the sealing edge tangent screen or non sealing edge and two positioning holes in the shell, is placed in a circuit board, the two circuit board assembly hole of the circuit board, the positioning hole and the positioning shaft shell on Kong Tong. When the electrode and the screen on the line just one one corresponding electrode, so as to realize the assembly position.

(3) the middle position:
In addition to the pinhole side Para Para, there is a way called intermediate para para. In the design, the design into a symmetrical shell shell. On the long side shell as a benchmark, or with short edge notch as the base placed LCD screen, the screen in the middle part of the shell, the long side of the bisector of the shell screen long edge bisection line, placing a circuit board, the positioning projections coincide with the positioning hole and the shell side of circuit board with two the outside of the assembly hole or circuit board as the orientation and shell base, so as to realize the assembly position.

1 LCM assembling techniques:
In the long-term production practice, along with the increase of the number of assembly, the accumulation of experience, you can slowly master many skills assembly (assembly is to tell the assembly skill).

(1) to improve the rate of finished products:
In the module assembly, a finished product rate is an important parameter for evaluation of production efficiency and an assembly personnel technical level. There is a high rate of finished products, in order to improve production efficiency, ensure the completion time, reduce the necessary labor time, reduce labor costs. In addition also can ensure the reliability of the module.

(2) to reduce waste, reduce costs:
A module such as repeated assembly cost increases, the material is possible. If the screen scratch, scratch, shell paint, the main is to make the shell foot deformation, reduce the force should be, this is the module reliability. If the assembly skills, ensure the module yield, reduce the number of assembly, can make the screen and the shell to reduce cost.

(3) the elimination of contraposition difficulties caused by the unqualified raw materials:
In the production process, because the shell or circuit board failure, caused by difficult alignment is possible, but if there is a technique of counterpoint good, because some of the raw materials on the difficulties can be solved.

2 experience and principle:
Skills are the accumulation of experience in production, and then refine and produce technology. Assembly skill is from production in the past, is the accumulation of experience summary, it should have some experience, and experience not assemble principle is impossible to have a good skill. Assembling principle simply is to make the electrode and the circuit board LCD screen on the control electrode corresponding to the one one corresponding. Therefore, on the basis of experience, according to the principle, give full play to the assembly skills, promote production. On the difficult assembling techniques, resulting in overcoming the raw material is extremely useful. Because the raw materials such as shell, screen and a circuit board is not qualified, the alignment mode failure, can not be assembled according to the original program is the original process documents, that is to say that the assembly is blind. For contraposition difficulties caused by these reasons, mainly adopt two kinds of skills to be resolved, one is to look for the alignment reference; second is the visual alignment. A further advantage of the tooling counterpoint.

(1) to find alignment benchmark
Sometimes because of raw material, the provisions of the original process documentation or due to the accumulation of tolerance to the benchmark, alignment between the screen and the shell or shell and plate failure, which causes the need to re find the alignment benchmark production, realize the assembly location. Before the re search on reference to analysis of the causes of the failure of contraposition base so as to have a definite object in view, think of ways to solve, to achieve the smooth production. On the basis of failure is mainly caused by the shell, screen and a circuit board assembly of basic raw materials three.

On the basis of shell caused by the failure is the most common, mainly displays in: the shell of the long side is wide tolerances, has more than one electrode width, the edge position failure. Pinhole wrong place, can't carry out pinhole counterpoint. A long, so that the screen has a certain angle, so that the electrode dislocation. The long side of the shell is too long, resulting in increased positive tolerance, because the electrode width screen and plate is fixed, then if the edge alignment, so that the screen electrode to produce more than design too much displacement. When the displacement of more than one electrode, such as assembly according to the edge position, will inevitably lead to the screen and a plate electrode dislocation, resulting in the failure of the assembly. This is played by redefining the benchmark. Assembly on two benchmark, one is on screen and the shell; on the another is shell and the circuit board. The shell and the circuit board on the benchmark for edge alignment is often in the shell feet for the benchmark, then still using edge alignment, the screen and the shell side stick; but change the alignment reference shell and the circuit board, then the shell toe according to the experiment to determine.

If the alignment difficulty is caused by the pinhole to shell, the shell on standard screen and failure, para basal needs with the edge position as corresponding changes in the shell and the circuit board, the circuit board and the shell is no longer the pinhole is the same axis, and the circuit board is relative to the shell's tolerance for the positive direction, do the same moves, to fill the gap between the electrodes of tolerance, in order to achieve alignment.
The new benchmark for alignment is to practice, in the actual assembly for tolerance, sometimes too large, and the electrode spacing is small, the benchmark for alignment is very difficult, there are some experienced people to make full use of assembling principle to overcome error, assembly, this is the visual alignment.

(4) visual alignment:
The principle is to make the electrode assembly and a circuit board LCD screen on the control electrode corresponding to the one one corresponding, this is assembling principle is the basis of visual alignment. The corresponding relationship between the screen and the circuit board is determined, the screen into the shell, and then the circuit board in the shell side of the shell side and close with electrode, the electrode and the electrode on the circuit board screen across the shell one one corresponding, view