Manager Duan, this is the newly machined circuit board, you see how. At this time, Zhao Xuewu, who was working in the dust-free workshop, came to Duan Yun with a circuit board that had just been made.

"Not bad. Duan Yun looked at the circuit board in his hand and said to Zhao Xuewu: "How is the quality of the products produced recently?"

"The laboratory has carried out extremely fatigue tests, the new products have been running for 5 days and 120 hours without failure, and other domestic products tested in the same period have been out of control of the motor speed and increased noise, so it seems that the quality of our new products is very good compared with similar domestic products. ”

During this time, the institute has been testing the operation of new products, including long playbacks, bump tests, fatigue resistance tests, and even hot and cold weather tests with refrigerators, freezers and electric stoves, all of which are carried out using the same test scheme they used to study military equipment.

There is no doubt that the durability of civilian products is definitely not as good as that of military products, and it is obviously too strict to test Duan Yun's new tape recorder with these strict standards.

Generally speaking, high-quality products mean high costs, and it is difficult for you to spend a dollar to use almost the same technology to manufacture a 10-dollar quality product, which is a very objective law, so Duan Yun's new products must find a balance in product quality and cost, which not only makes the price of the product advantageous, but also has no particularly obvious shortcomings in quality, which is what Duan Yun wants.

Therefore, although the testing of new products is very strict, in fact, when it really enters the production stage, the quality inspection standards will be lowered a lot, and it is only necessary to maintain the same or slightly higher level as similar domestic products, and then use the price advantage to occupy the market.

"Can the cost of our products go down a little further?" Duan Yun asked Zhao Xuewu.

"Manager Duan, the cost of our current products is already very low, because it adopts a single-motor drive mode, which is about 1/5 of the cost saving compared with peers, these days we have also made many improvements to the product, and the cost has been compressed to the limit, unless there are more advanced equipment and technology for process improvement, otherwise the room for decline is very small...... "Zhao Xuewu frowned slightly.

"This circuit board is still a bit ......" Looking at the finished PCd circuit board in his hand, Duan Yun pondered for a while and said, "Is there a way to make the circuits of this circuit board more closely connected?"

"At present, the design of this circuit board has been improved several times, if the electronic components are too close, on the one hand, it is easy to cause the temperature of the circuit board to be too high, and the heat dissipation problem between the electronic components is also difficult to solve, on the other hand, the soldering points of the circuit board are too many and too dense, and it is easy to accidentally short circuit, which will burn out ......the entire circuit board," Zhao Xuewu said with some embarrassment.

"Hmm. Duan Yun nodded lightly when he heard this.

Actually, he knows it. Zhao Xuewu raised these problems, at present, the new tape recorder circuit board has been very dense, in the design has indeed achieved the maximum optimization, the electronic components with large heat and less heat electronic components are arranged very scientifically and reasonably, the heat dissipation of the circuit board and the process difficulty have been fully considered, and the space for optimization and improvement is indeed very small.

Duan Yun was already very satisfied with the current circuit board design, but he was bent on developing a Walkman in the future, so he thought about the feasibility of making the components on the circuit board more dense.

"That's right, Master Zhao. Duan Yun seemed to suddenly remember something, and said to Zhao Xuewu: "Have you used double-sided and multi-sided PCB boards before?"

"Double-sided circuit boards have been used, and multilayer PCB circuit boards cannot be produced in China at present, but if there are really double-sided boards, our tape recorder circuit boards can be optimized again. Zhao Xuewu said.

Zhao Xuewu is no stranger to double-sided circuit boards, and when he was in Taiyuan Institute of Mechanical Engineering, he often used this kind of circuit board printed with double-sided metallized holes.

In fact, in the mid-50s, New China began the development of single-sided printed boards, first used in semiconductor radios, in the mid-60s, self-reliance developed China's foil-clad substrate, so that copper foil etching has become the leading process of PCB production in China, at present, most of the manufacturers of PCB circuit boards in Shenzhen are still using this process, which is polluting and low-yielding.

In the mid-to-late 60s, the country has been able to produce double-sided metal chemical printed PCB circuit boards in small quantities, and began to develop multi-layer boards in a few units, and in the 70s, the graphic electroplating etching process was promoted in China, but due to various interferences, the special materials and special equipment for printed circuits did not keep up in time, and the entire production technology level lagged behind the advanced level of foreign countries, and in the 80s, this gap has been very large.

In fact, Duan Yun can also buy double-sided circuit boards in Shenzhen, but the current output of this kind of circuit board is very small, basically only sharing joint ventures and state-owned factories, private enterprises have no purchase channels, even if they can buy, the price is much higher than single-sided circuit boards, and it is not cost-effective to use it to make products.

"Then Master Zhao, how much do you know about the manufacturing process of double-sided PCb circuit boards?" Duan Yun asked.

"I only know his production principle, but if you want to mass-produce this kind of double-sided circuit board, you need some equipment, and at present, only some large factories in our country have ......" Zhao Xuewu replied, and then asked repeatedly: "Manager Duan, you don't want to produce this kind of circuit board yourself, right?"

"Have this idea......" Duan Yun said after thinking for a while.

"Then you can only buy equipment from other electronics factories, but whether you can buy it is not necessarily, the electronics factory that can produce this kind of double-sided panel is definitely not a small factory, even if you pay more money, people may not be willing to sell it to you." Zhao Xuewu said.

"Yes, it is really difficult to buy ready-made equipment, and the investment in making double-sided multi-layer circuit boards is high, the pollution is large, and it also requires a lot of industrial land, so it is really not cost-effective for us to produce it ourselves......" Duan Yun said with a sigh.

Duan Yun actually has the heart to produce his own circuit boards, but in addition to the funds and purchase of equipment channels, there are land restrictions, although Duan Yun from the Shenzhen Municipal Government this year to 60 acres of industrial land, but this industrial land has built two large factories, mainly for the production of new tape recorder main parts and assembly work, there is no more place for the production of circuit boards, and the production of circuit boards is very polluting, the need for sedimentation tanks, sewage treatment facilities, this is a very large investment, once the circuit board factory is established, the entire plant environment will deteriorate rapidly......