The main parameters of the hot press equipment are: temperature, time, pressure, control these three elements, the welding product will be stable. The products welded by the hot press are generally: PCB / FPC / FFC are connected to each other with solder to achieve the function. For welding products, it is very important to set the above parameters accurately. A good solder joint probably allows the solder to adequately weld two surfaces, and the occurrence of molten tin on the surfaces of two parts. Only the above parameters can be effectively cooperated to produce good products. FPC is composed of two layers of polyimide and copper platinum. The operating temperature scale of FPC is 130 to 200 degrees. It can taste the welding temperature of 300 degrees for a short time. Because PCB and FPC will bring heat dissipation effect to the indenter during welding (FPC and PCB will absorb heat. When the indenter is pressed down, the condensate of the welding material and the air around the indenter will cause the indenter to dissipate heat. In addition, the FPC thickness is between 0.02 and 0.12, so a loss of 50 to 80 degrees may occur when the welding surface is reached. Therefore, the temperature of the loss should be added when the temperature is set (the melting point of the solder plus the loss temperature). Parameter value and its setting scale: I. Setting of heating speed gear. There are 8 gears for heating speed (1st to 8th). The 1st heating is the fastest, and the 8th heating is the slowest. Its setting is related to the width of the indenter. The narrow head (10mm) is slower. Warming gear (6, 7, 8 gear), wide head such as 80mm) Use fast warming gear (1, 2, 3 gear). 2. Temperature and time setting: The temperature setting is divided into three sections: preheating, welding, and cooling. 1, the first stage of preheating temperature setting: the solder point of the pad reaches the state of melting. The set value is about the melting temperature of tin. Lead-free is about 230 degrees. Lead is about 180 degrees. The time is set at 2 to 4 seconds. The advantages of the preheat setting are: 1) It takes about a few seconds for the indenter temperature to rise to the soldering temperature (including the set time to adhere to the temperature). During this time, the flux is activated and the oxide layer is removed to improve the molten tin. Preheating is generally used for oversized products. There is much heat dissipation, or when a weak substrate (such as ceramic) is applied, the heating is controlled in a more controlled manner to avoid cracking. 2) When the second stage is heated, the tin activity of the pad is better, and it can be moved back and forth smoothly. Otherwise, when the second stage is heated, the indenter suddenly rises to the melting temperature of the tin, causing the solder on the pad tin. When the solder is under pressure, it suddenly melts, and the temperature at both ends of the pad is low, making the tin unable to move back and forth, causing the left and right to move and short circuit. 2, the second stage of heating temperature setting: FPC and PCB are completely integrated into one, its setting value depends on the raw materials being soldered. In general: with lead is about 230 to 320 degrees. For lead-free is 280 to About 350 degrees. Due to different products, the size of the indenter is different, resulting in different heat dissipation speed. Set the temperature according to the amount of heat dissipation. Note: When the electrolytically deposited copper of FPC is below 0.03mm, the two stages of temperature should not be set too high. It may be at the temperature where the tin is completely melted. If the temperature is too high, the temperature passed to the soldering surface through FPC will also be too high As a result, tin has a very strong activity. Simple short-circuits and tin beads are formed. And the product will change color due to high temperature. Setting the temperature too low can cause snowflake short circuits. The following is a reference value: The temperature setting scale of the first stage of lead-free products: 230 to 280: the temperature setting scale of the second stage: 280 to 350 degrees. The temperature setting scale for the first stage of lead products: 200 to 230: the temperature setting scale for the second stage: 230 to 320 degrees. 3, the third stage cooling temperature setting. The setting is to allow the two welding surfaces to cool sufficiently to condense. To avoid the indenter rising after the product is welded after the product is welded, the FPC will rise with the indenter at this moment, forming a desoldering. Setting the cooling temperature too low will reduce the production power, and its temperature can be set at about 180 degrees. Three. Pressure setting
[Pulse hot press operation description!]
Views: 213 Times of release: 2017-12-2 17:26:53
The general setting scale is: 0.08 to 0.14MP. Below this setting scale, it may cause the cylinder to rise and fall slowly, or the welding may be weak and weak. If the pressure is too high, it is easy to cause short-circuiting of the tin beads, which may damage the FPC and PCB.
Dongguan Hangchen Automation Equipment Technology Co., Ltd. specializes in production; sales: pulse heat press, FPC pulse heat press, pulse pressure welder, FPC heat pressure welding, heat pressure welding machine, Hotbar welding machine, etc. Sales Hotline: 13580899052