The announcement of Kaiyuan infringement at an international conference is a rare event, but like so many incredible black swan events this year, it happened. Kaiyuan Communication and Jiweiwang want to interpret him as the suppression of the United States and the infighting of domestic manufacturers, but the key question is, is Dr. Ruby accusing the infringement of Kaiyuan? As a technical authority in the filter industry, did he lie? It’s a simple either-or question, if he’s not lying, who’s lying?
After the incident, Kaiyuan Communications first questioned that the meeting was irregular and violated the rules. However, this conference is an industry gathering of top scientists in the filter industry. All the participants are scientists, including domestic scientists. Do you need someone to educate them about the rules? They did not exclude China. Instead, they deliberately held the meeting in China. The meeting cited a large number of Chinese literature, and also emphasized the achievements and contributions of Chinese scholars in filter research. This meeting was not held to attack a company.
Filter companies all over the world are competitors, but their respective scientists are sitting together to discuss how to improve filter technology. They each have original technologies and respect each other. Isn’t this worth our thinking? Kaiyuan Communication should ask itself: “Kaiyuan’s independent innovation ability is so strong, why did these scientists not invite Kaiyuan?”. There are obviously a large number of domestic scientists in the meeting.
In response to this incident, Jiwei.com defended Kaiyuan Communications, saying that Dr. Ruby’s opening map came from a third-party company, and that Kaiyuan did not infringe Broadcom’s patent, and the evidence was the legal opinion issued by AllBright Law Firm. Excuse me, is Dr. Ruby the inventor of FBAR technology and an industry leader? Does the source of the cover image affect Broadcom’s judgment on infringement or non-infringement? Wouldn’t the judgment of the FBAR inventor be more direct? After so many detours, why not directly answer the simplest question, is the product that Dr. Ruby accused of infringing from Kaiyuan Communication?
Whether it is Kaiyuan, or Jiwei.com, which represents Kaiyuan, with so many explanations, can the inventor of FBAR technology be changed, and is it an ironclad fact that the industry leader has declared Kaiyuan communication infringement? Instead of doing PR every day, it is better to immerse yourself in original technology, so that everyone can’t pick out the problem.
When we talk about this, we hate that iron cannot become steel, and we are distressed why some practitioners do not first develop their own original technologies and truly gain the respect of scientists around the world, but spend a lot of money and energy on public relations and statements. Next, we will analyze the technology bit by bit, explain what Broadcom’s FBAR technology patent is, and why Kaiyuan Communication’s infringement will cause Broadcom’s attention.
Broadcom’s FBAR technology, which has several key features: cavity, resonator stack, resonator shape, wafer-level packaging, resonator edge structure, piezoelectric materials, and more. The processing methods between these features are closely linked to form the final product. Because of the complexity of its structure and the particularity of processing technology, MEMS products have only their own unique set of technological processes and structural characteristics. And these are closely linked to the company’s technological evolution IP assets. Broadcom’s FBAR has gone through less than 30 years of research and development, and about 383 key patents have been accumulated during this series of evolution. The most intensive filing and grant period of these patents was between 2003 and 2015. During this period, the performance of its FBAR products improved sharply and the sales of products increased rapidly. The consensus of industry insiders is that for competing products whose products contain most of their key features, its patent infringement is certain, and 100% infringement of its patents will definitely be blocked by Broadcom.
The author has searched the relevant patents of Broadcom, in order to understand the origin of the relevant disputes more clearly. The following are the core patents selected by the author, and we will briefly discuss them.
Figure 1 is from patent US9219464B2 (valid for 2030-01-19). This picture represents the typical structure of Broadcom’s FBAR product device, which can help illustrate the four key structural features of Broadcom’s FBAR product, and Broadcom’s core patents are also arranged around it.
Figure 1: Comparison of edge structure and patent map of Broadcom FBAR device
Part (1): The lower cavity structure of the FBAR device and related manufacturing processes, the lower cavity is located in the substrate, and Broadcom calls it “Swimming Pool”.
Part (2): The composite lower electrode layer, including the Seed Layer (seed layer) and the layered structure of the lower electrode, is a key patent of Broadcom and is the key to ensuring the acquisition of piezoelectric films with excellent quality.
Part (3): The air gap and raised structure on the edge of the upper electrode (Broadcom calls it “Air Frame”), this structure is the key structure of Broadcom’s FBAR resonator with high Q filter and high performance, the electrode and piezoelectric There are air gaps between the layers, and the edge of the electrode has many steps and protrusions, and the technical characteristics are very obvious. In response to this structure, Broadcom’s patent protection covers a series of variant derivative structures, and the scope of protection is very wide. The industry needs to pay special attention to the risk of infringement.
Part (4): The air bridge structure between the upper electrode and the piezoelectric layer (Broadcom calls it “Air Bridge”), this structure is one of the guarantees for the superior performance of Broadcom’s FBAR devices. There are companies that have not copied other structures of Broadcom’s FBAR devices and dare not use this structure.
Figure 2 comes from the patent US8232845B2 (valid for 2030-11-02), which represents another typical structure of Broadcom FBAR products and devices, namely its Wafer Level Package (WLP, Wafer Level Package) structure, which Broadcom calls “Micro-Cap” , Using Au-Au bonding, the grooved Silicon Cap wafer realizes WLP with air cavity. This structure is the key to the high reliability and stability of Broadcom’s FBAR products, and is one of its core patented technologies.
Part (5): used to seal the FBAR structure and form the Cap Wafer of the WLP die. These include TSVs, as well as Gaskets (gasket structures) for bonding and electrical connections.
Next, we will compare the slicing diagram of Kaiyuan Communication’s products with the slicing diagram of Broadcom’s FBAR products and Broadcom’s patent structure, so as to judge whether Kaiyuan Communication’s products infringe Broadcom’s patents.
First, let’s look at the part of Broadcom’s device structure (1), the part of the lower cavity structure. As shown in Figure 3, the slicing of Kaiyuan Communication’s FBAR product shows that the lower cavity structure of the product is highly consistent with the slicing structure of Broadcom’s FBAR product. Broadcom’s FBAR lower cavity is placed in the substrate and the lower electrode extends to the empty space The structural characteristics outside the cavity are all seen in the products of Kaiyuan Communication. In fact, the etched boundary bevel morphology of the lower electrode of Kaiyuan Communication products and the structural details of the slope morphology of the corresponding piezoelectric layer are similar to those of Broadcom. , Kaiyuan Communication’s FBAR products obviously copied Broadcom’s products. Broadcom has a series of patents to protect its lower cavity structure and manufacturing process. The FBAR structure features defined by the claims of these patents are reflected in Broadcom’s FBAR slices. There is no doubt that Kaiyuan Communication’s products are infringing Broadcom’s patents. .
Let’s look at the device structure part of Broadcom (2), the stacked structure of the AlN Seed Layer (seed layer), the lower electrode and the piezoelectric layer. One of Broadcom’s FBAR core patent systems is the FBAR electrode and piezoelectric laminate structure including AlN Seed Layer and the corresponding manufacturing method. This patented technology is the key technology to ensure high-quality piezoelectric thin films. As shown in Figure 4, taking Broadcom’s patent US9608589B2 (valid for 2033-06-14) as an example, the patent claims define the stack structure numbered ① to ⑥. Comparing the slices of Kaiyuan Communication’s FBAR products, it can be seen that the stacking of Kaiyuan Communication products The layer structure is exactly the same as that of Broadcom’s patent, and it is also highly consistent with the structure presented by Broadcom’s products.
Let’s look at the device structure part (3) of Broadcom, the air gap and raised structure at the edge of the upper electrode (Broadcom calls it “Air Frame”). One of the keys to the high Q value and high performance of Broadcom’s FBAR products is that the device structure has an air gap microstructure at the edge of the electrode. Broadcom has a series of related patents, and it has invented various types of electrode edge air gaps and Frame structures. Patent Protection. As shown in Figure 5, taking patent US8384497B2 (valid for 2031-06-27) as an example, one of the air gap structures is that the passivation layer (300) extends beyond the upper electrode (12) to form cantilever beam structures (301 and 302) , and air gaps (61 and 62) are formed between the passivation layer and the piezoelectric layer (2). Observing the FBAR product slice of Kaiyuan Communication, it can be seen that there is also an air gap structure on the edge of the upper electrode, and this structure is completely consistent with the structure defined by the Broadcom patent. There is no doubt that the FBAR product structure of Kaiyuan Communication is infringing the Broadcom patent.
Finally, look at Broadcom’s device structure part (5), wafer-level packaging structure, “Micro-Cap”. A typical structure of Broadcom’s FBAR product device is its wafer-level packaging (WLP) structure, which Broadcom calls “Micro-Cap”. The silicon cover wafer with grooves realizes WLP with air cavity through Au-Au bonding. Structure, this structure is one of the key core technologies for the high reliability of Broadcom’s FBAR products. As shown in Figure 6, the horizontal comparison between Kaiyuan Communication’s products and Broadcom’s products can be very easy to judge that they use the exact same WLP technology. The typical structural features of Kaiyuan Communication’s products fall into Broadcom’s patent US8232845B2 (valid for 2030-11-02) The scope of the patent claims is clearly infringing.
To sum up, it is easy to judge that Kaiyuan Communication’s products are infringing Broadcom’s patents. It is worth noting that the author also noticed the article “International Academic Symposium Triggers Local Filter Manufacturers to Lay Up” published by Jiwei.com, and mentioned that the patent US8232845B2 is about active circuits (or ASICs) and FBAR integrated packaging. Therefore, it does not constitute infringement. The author believes that this statement is very misleading. Carefully examine the claims of the patent US8232845B2 (especially the independent claim 1), it is very clear that the core claim of the patent is about the WLP structure, and this WLP structure can be used to integrate and package various types of chips. It is not that the understanding of the technology and the patent claims is not in place and unclear, then there is at least a suspicion of avoiding the important in the form of stealing the concept. The news about Kaiyuan’s products infringing Broadcom’s patents has been buzzing on the Internet, and many technical points are not easy to understand when it comes to FBAR, a complex MEMS device. The author hopes to give the majority of technology enthusiasts, especially semiconductor technicians and engineers a more in-depth technical analysis through this article, so that everyone can better understand what technology Broadcom accuses our domestic company of plagiarizing and infringing its FBAR patent. and product structure. The practice of using the legal opinions of domestic law firms to prove that there is no problem is to evade technical discussions and hide the bells and whistles. In any case, the author hopes that the domestic self-developed FBAR device companies can continue to develop their own way, accumulate technology, and face the competition of Broadcom as soon as possible without falling behind.
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