1. **Causes and Solutions for PCB Film Deformation:**
**Causes:**
(1) Failure in temperature and humidity control
(2) Excessive temperature in the exposure machine
**Solutions:**
(1) Maintain the temperature at 22±2°C and relative humidity at 55%±5% RH.
(2) Use a cold light source or an aerator equipped with a cooling system, and ensure regular replacement of the backup film.
2. **Process for Correcting PCB Film Distortion:**
1. After mastering the operation of the digital programming instrument, first install the negative film and compare it with a drilled test board. Measure the length and width of the deformation. Based on the deformation values, adjust the hole positions by either lengthening or shortening them using the digital programming instrument. The modified test board, with adjusted hole positions, is then used to align with the deformed negative film. This method eliminates the need to cut the negative film, ensuring both the integrity and accuracy of the graphic design. This approach is referred to as the “hole position adjustment method.”
2. Considering the physical phenomenon that the negative film can change with environmental temperature and humidity, it is important to remove the negative film from its sealed bag before copying. Hang the film for 4-8 hours in the working environment to allow it to deform before the copying process. This pre-deformation helps prevent the copied film from becoming too small. This method is referred to as the “hanging method.”
3. For graphics that have simple lines, large line widths and spacing, or exhibit irregular deformations, you can cut the deformed section of the negative film to match the hole patterns on a drill test board and re-splice the film before copying. This technique is known as the “splicing method.”
4. When enlarging the hole on the PCB to a circuit chip without causing significant deformation to the pad, the minimum ring width technical requirements can still be met. This method is called the “pad overlap method.”
5. After scaling the graphics on the deformed negative film, re-map and create a new plate. This approach is called the “mapping method.”
6. The use of a camera to either enlarge or reduce the deformed graphic is known as the “photographic method.”
### Notes on Relevant Methods:
1. **Splicing Method**:
– **Applicable**: Negative films with low line density and uneven deformation across layers; especially useful for solder mask films and multi-layer board power layer films.
– **Not Applicable**: Negative films with high wire density or line widths and spacing smaller than 0.2mm.
– **Note**: When splicing, minimize damage to the wires and pads. Pay attention to the integrity of the connections when revising the design after splicing and copying.
2. **Hole Position Modification Method**:
– **Applicable**: When the deformation across all layers of the film is uniform. This method is also suitable for films with high line density.
– **Not Applicable**: When the film experiences uneven deformation, with particularly severe local distortions.
– **Note**: After using the programmer to adjust the hole positions, ensure that any out-of-tolerance hole positions are corrected.
3. **Hanging Method**:
– **Applicable**: For films that have not been deformed and are prevented from deforming after copying.
– **Not Applicable**: For already deformed films.
– **Note**: Hang the film in a ventilated, dark environment (safety conditions are acceptable) to avoid contamination. Ensure that the temperature and humidity of the hanging area match the working conditions.
4. **PCB Pad Overlap Method**:
– **Applicable**: When the graphic lines are not densely packed, and the line width and spacing are greater than 0.30mm.
– **Not Applicable**: For situations where there are strict aesthetic requirements for the appearance of the printed circuit board.
– **Note**: After overlapping and copying, the pad will appear elliptical. Additionally, the edge of the line and disk may exhibit halo effects and distortion.
5. **PCB Photography Method**:
– **Applicable**: When the deformation of the PCB film is consistent in both the length and width directions, and re-drilling the test board is inconvenient. This method requires the use of silver salt film.
– **Not Applicable**: When there is inconsistent deformation in the length and width directions.
– **Note**: Ensure accurate focus when taking pictures to prevent distortion of the lines. The negative film may suffer from greater loss, and typically, several iterations of adjustment are needed to achieve a satisfactory circuit pattern.
If you have any PCB manufacturing needs, please do not hesitate to contact me.Contact me
**Causes:**
(1) Failure in temperature and humidity control
(2) Excessive temperature in the exposure machine
**Solutions:**
(1) Maintain the temperature at 22±2°C and relative humidity at 55%±5% RH.
(2) Use a cold light source or an aerator equipped with a cooling system, and ensure regular replacement of the backup film.
2. **Process for Correcting PCB Film Distortion:**
1. After mastering the operation of the digital programming instrument, first install the negative film and compare it with a drilled test board. Measure the length and width of the deformation. Based on the deformation values, adjust the hole positions by either lengthening or shortening them using the digital programming instrument. The modified test board, with adjusted hole positions, is then used to align with the deformed negative film. This method eliminates the need to cut the negative film, ensuring both the integrity and accuracy of the graphic design. This approach is referred to as the “hole position adjustment method.”
2. Considering the physical phenomenon that the negative film can change with environmental temperature and humidity, it is important to remove the negative film from its sealed bag before copying. Hang the film for 4-8 hours in the working environment to allow it to deform before the copying process. This pre-deformation helps prevent the copied film from becoming too small. This method is referred to as the “hanging method.”
3. For graphics that have simple lines, large line widths and spacing, or exhibit irregular deformations, you can cut the deformed section of the negative film to match the hole patterns on a drill test board and re-splice the film before copying. This technique is known as the “splicing method.”
4. When enlarging the hole on the PCB to a circuit chip without causing significant deformation to the pad, the minimum ring width technical requirements can still be met. This method is called the “pad overlap method.”
5. After scaling the graphics on the deformed negative film, re-map and create a new plate. This approach is called the “mapping method.”
6. The use of a camera to either enlarge or reduce the deformed graphic is known as the “photographic method.”
### Notes on Relevant Methods:
1. **Splicing Method**:
– **Applicable**: Negative films with low line density and uneven deformation across layers; especially useful for solder mask films and multi-layer board power layer films.
– **Not Applicable**: Negative films with high wire density or line widths and spacing smaller than 0.2mm.
– **Note**: When splicing, minimize damage to the wires and pads. Pay attention to the integrity of the connections when revising the design after splicing and copying.
2. **Hole Position Modification Method**:
– **Applicable**: When the deformation across all layers of the film is uniform. This method is also suitable for films with high line density.
– **Not Applicable**: When the film experiences uneven deformation, with particularly severe local distortions.
– **Note**: After using the programmer to adjust the hole positions, ensure that any out-of-tolerance hole positions are corrected.
3. **Hanging Method**:
– **Applicable**: For films that have not been deformed and are prevented from deforming after copying.
– **Not Applicable**: For already deformed films.
– **Note**: Hang the film in a ventilated, dark environment (safety conditions are acceptable) to avoid contamination. Ensure that the temperature and humidity of the hanging area match the working conditions.
4. **PCB Pad Overlap Method**:
– **Applicable**: When the graphic lines are not densely packed, and the line width and spacing are greater than 0.30mm.
– **Not Applicable**: For situations where there are strict aesthetic requirements for the appearance of the printed circuit board.
– **Note**: After overlapping and copying, the pad will appear elliptical. Additionally, the edge of the line and disk may exhibit halo effects and distortion.
5. **PCB Photography Method**:
– **Applicable**: When the deformation of the PCB film is consistent in both the length and width directions, and re-drilling the test board is inconvenient. This method requires the use of silver salt film.
– **Not Applicable**: When there is inconsistent deformation in the length and width directions.
– **Note**: Ensure accurate focus when taking pictures to prevent distortion of the lines. The negative film may suffer from greater loss, and typically, several iterations of adjustment are needed to achieve a satisfactory circuit pattern.
If you have any PCB manufacturing needs, please do not hesitate to contact me.Contact me
